Module: Rbzlib

Defined in:
lib/pr/rbzlib.rb,
lib/pr/rbzlib/posf.rb,
lib/pr/rbzlib/bytef.rb,
lib/pr/rbzlib/bytef_arr.rb,
lib/pr/rbzlib/bytef_str.rb

Overview

rbrzlib – pure ruby version of ‘zlib’ general purpose compression library

version 1.2.3, July 18th, 2005

Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler

This software is provided 'as-is', without any express or implied
warranty.  In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not
   claim that you wrote the original software. If you use this software
   in a product, an acknowledgment in the product documentation would be
   appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.

Jean-loup Gailly        Mark Adler
[email protected]          [email protected]

The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
(zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).

Ruby translation
Copyright (C) 2009 by Park Heesob [email protected]

Defined Under Namespace

Classes: Bytef, Bytef_arr, Bytef_str, Code, Config, Ct_data, Deflate_state, Gz_header, Gz_stream, Inflate_state, Posf, Static_tree_desc, Tree_desc, Z_stream

Constant Summary collapse

MAX_MEM_LEVEL = 
9
DEF_MEM_LEVEL = 
8
MAX_WBITS = 
15
DEF_WBITS = 
MAX_WBITS
Z_NO_FLUSH = 
0
Z_PARTIAL_FLUSH = 
1
Z_SYNC_FLUSH = 
2
Z_FULL_FLUSH = 
3
Z_FINISH = 
4
Z_BLOCK = 
5
Z_OK = 
0
Z_STREAM_END = 
1
Z_NEED_DICT = 
2
Z_ERRNO = 
-1
Z_STREAM_ERROR = 
-2
Z_DATA_ERROR = 
-3
Z_MEM_ERROR = 
-4
Z_BUF_ERROR = 
-5
Z_VERSION_ERROR = 
-6
Z_NO_COMPRESSION = 
0
Z_BEST_SPEED = 
1
Z_BEST_COMPRESSION = 
9
Z_DEFAULT_COMPRESSION = 
-1
Z_FILTERED = 
1
Z_HUFFMAN_ONLY = 
2
Z_RLE = 
3
Z_FIXED = 
4
Z_DEFAULT_STRATEGY = 
0
Z_BINARY = 
0
Z_ASCII = 
1
Z_TEXT = 
1
Z_UNKNOWN = 
2
Z_DEFLATED = 
8
STORED_BLOCK = 
0
STATIC_TREES = 
1
DYN_TREES = 
2
MIN_MATCH = 
3
MAX_MATCH = 
258
PRESET_DICT = 
0x20
ZLIB_VERSION = 
'1.2.3'
Z_errbase = 
Z_NEED_DICT
BASE = 
65521
NMAX = 
5552
OS_CODE = 
0
SEEK_SET = 
0
SEEK_CUR = 
1
SEEK_END = 
2
Z_EOF = 
-1
Z_BUFSIZE = 
16384
ASCII_FLAG = 
0x01
HEAD_CRC = 
0x02
EXTRA_FIELD = 
0x04
ORIG_NAME = 
0x08
COMMENT_ = 
0x10
RESERVED = 
0xE0
ZNIL = 
0
TOO_FAR = 
4096
MIN_LOOKAHEAD = 
(MAX_MATCH + MIN_MATCH + 1)
EQUAL = 
0
LENGTH_CODES = 
29
LITERALS = 
256
L_CODES = 
(LITERALS + 1 + LENGTH_CODES)
D_CODES = 
30
BL_CODES = 
19
HEAP_SIZE = 
(2 * L_CODES + 1)
MAX_BITS = 
15
INIT_STATE = 
42
EXTRA_STATE = 
69
NAME_STATE = 
73
COMMENT_STATE = 
91
HCRC_STATE = 
103
BUSY_STATE = 
113
FINISH_STATE = 
666
DIST_CODE_LEN = 
512
MAX_BL_BITS = 
7
END_BLOCK = 
256
REP_3_6 = 
16
REPZ_3_10 = 
17
REPZ_11_138 = 
18
Buf_size = 
(8 * 2 * 1)
SMALLEST = 
1
ENOUGH = 
2048
MAXD = 
592
MAXBITS = 
15
' inflate 1.2.3 Copyright 1995-2005 Mark Adler '
@@z_errmsg = 
[
  'need dictionary',
  'stream end',
  '',
  'file error',
  'stream error',
  'data error',
  'insufficient memory',
  'buffer error',
  'incompatible version',
  ''
]
@@z_verbose = 
1
@@crc_table = 
[
  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
  0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
  0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
  0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
  0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
  0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
  0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
  0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
  0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
  0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
  0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
  0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
  0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
  0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
  0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
  0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
  0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
  0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
  0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
  0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
  0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
  0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
  0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
  0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
  0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
  0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
  0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
  0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
  0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
  0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
  0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
  0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
  0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
  0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
  0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
  0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
  0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
  0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
  0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
  0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
  0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
  0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
  0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
  0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
  0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
  0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
  0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
  0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
  0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
  0x2d02ef8d
]
@@gz_magic = 
"\x1F\x8B"
@@configuration_table = 
[
[0,  0,   0,   0,    :deflate_stored],
[4,  4,   8,   4,    :deflate_fast],
[4,  5,   16,  8,    :deflate_fast],
[4,  6,   32,  32,   :deflate_fast],
 [4,  4,   16,  16,   :deflate_slow],
[8,  16,  32,  32,   :deflate_slow],
[8,  16,  128, 128,  :deflate_slow],
[8,  32,  128, 256,  :deflate_slow],
[32, 128, 258, 1024, :deflate_slow],
[32, 258, 258, 4096, :deflate_slow]].map{|i|Config.new(*i)}
@@static_ltree = 
[
[ 12,  8], [140,  8], [ 76,  8],
[204,  8], [ 44,  8], [172,  8],
[108,  8], [236,  8], [ 28,  8],
[156,  8], [ 92,  8], [220,  8],
[ 60,  8], [188,  8], [124,  8],
[252,  8], [  2,  8], [130,  8],
[ 66,  8], [194,  8], [ 34,  8],
[162,  8], [ 98,  8], [226,  8],
[ 18,  8], [146,  8], [ 82,  8],
[210,  8], [ 50,  8], [178,  8],
[114,  8], [242,  8], [ 10,  8],
[138,  8], [ 74,  8], [202,  8],
[ 42,  8], [170,  8], [106,  8],
[234,  8], [ 26,  8], [154,  8],
[ 90,  8], [218,  8], [ 58,  8],
[186,  8], [122,  8], [250,  8],
[  6,  8], [134,  8], [ 70,  8],
[198,  8], [ 38,  8], [166,  8],
[102,  8], [230,  8], [ 22,  8],
[150,  8], [ 86,  8], [214,  8],
[ 54,  8], [182,  8], [118,  8],
[246,  8], [ 14,  8], [142,  8],
[ 78,  8], [206,  8], [ 46,  8],
[174,  8], [110,  8], [238,  8],
[ 30,  8], [158,  8], [ 94,  8],
[222,  8], [ 62,  8], [190,  8],
[126,  8], [254,  8], [  1,  8],
[129,  8], [ 65,  8], [193,  8],
[ 33,  8], [161,  8], [ 97,  8],
[225,  8], [ 17,  8], [145,  8],
[ 81,  8], [209,  8], [ 49,  8],
[177,  8], [113,  8], [241,  8],
[  9,  8], [137,  8], [ 73,  8],
[201,  8], [ 41,  8], [169,  8],
[105,  8], [233,  8], [ 25,  8],
[153,  8], [ 89,  8], [217,  8],
[ 57,  8], [185,  8], [121,  8],
[249,  8], [  5,  8], [133,  8],
[ 69,  8], [197,  8], [ 37,  8],
[165,  8], [101,  8], [229,  8],
[ 21,  8], [149,  8], [ 85,  8],
[213,  8], [ 53,  8], [181,  8],
[117,  8], [245,  8], [ 13,  8],
[141,  8], [ 77,  8], [205,  8],
[ 45,  8], [173,  8], [109,  8],
[237,  8], [ 29,  8], [157,  8],
[ 93,  8], [221,  8], [ 61,  8],
[189,  8], [125,  8], [253,  8],
[ 19,  9], [275,  9], [147,  9],
[403,  9], [ 83,  9], [339,  9],
[211,  9], [467,  9], [ 51,  9],
[307,  9], [179,  9], [435,  9],
[115,  9], [371,  9], [243,  9],
[499,  9], [ 11,  9], [267,  9],
[139,  9], [395,  9], [ 75,  9],
[331,  9], [203,  9], [459,  9],
[ 43,  9], [299,  9], [171,  9],
[427,  9], [107,  9], [363,  9],
[235,  9], [491,  9], [ 27,  9],
[283,  9], [155,  9], [411,  9],
[ 91,  9], [347,  9], [219,  9],
[475,  9], [ 59,  9], [315,  9],
[187,  9], [443,  9], [123,  9],
[379,  9], [251,  9], [507,  9],
[  7,  9], [263,  9], [135,  9],
[391,  9], [ 71,  9], [327,  9],
[199,  9], [455,  9], [ 39,  9],
[295,  9], [167,  9], [423,  9],
[103,  9], [359,  9], [231,  9],
[487,  9], [ 23,  9], [279,  9],
[151,  9], [407,  9], [ 87,  9],
[343,  9], [215,  9], [471,  9],
[ 55,  9], [311,  9], [183,  9],
[439,  9], [119,  9], [375,  9],
[247,  9], [503,  9], [ 15,  9],
[271,  9], [143,  9], [399,  9],
[ 79,  9], [335,  9], [207,  9],
[463,  9], [ 47,  9], [303,  9],
[175,  9], [431,  9], [111,  9],
[367,  9], [239,  9], [495,  9],
[ 31,  9], [287,  9], [159,  9],
[415,  9], [ 95,  9], [351,  9],
[223,  9], [479,  9], [ 63,  9],
[319,  9], [191,  9], [447,  9],
[127,  9], [383,  9], [255,  9],
[511,  9], [  0,  7], [ 64,  7],
[ 32,  7], [ 96,  7], [ 16,  7],
[ 80,  7], [ 48,  7], [112,  7],
[  8,  7], [ 72,  7], [ 40,  7],
[104,  7], [ 24,  7], [ 88,  7],
[ 56,  7], [120,  7], [  4,  7],
[ 68,  7], [ 36,  7], [100,  7],
[ 20,  7], [ 84,  7], [ 52,  7],
[116,  7], [  3,  8], [131,  8],
[ 67,  8], [195,  8], [ 35,  8],
[163,  8], [ 99,  8], [227,  8]
].map{|i| Ct_data.new(*i)}
@@static_dtree = 
[
[ 0, 5], [16, 5], [ 8, 5],
[24, 5], [ 4, 5], [20, 5],
[12, 5], [28, 5], [ 2, 5],
[18, 5], [10, 5], [26, 5],
[ 6, 5], [22, 5], [14, 5],
[30, 5], [ 1, 5], [17, 5],
[ 9, 5], [25, 5], [ 5, 5],
[21, 5], [13, 5], [29, 5],
[ 3, 5], [19, 5], [11, 5],
[27, 5], [ 7, 5], [23, 5]
].map{|i| Ct_data.new(*i)}
@@_dist_code = 
[
 0,  1,  2,  3,  4,  4,  5,  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  8,
 8,  8,  8,  8,  9,  9,  9,  9,  9,  9,  9,  9, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  0,  0, 16, 17,
18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29]
@@_length_code = 
[
 0,  1,  2,  3,  4,  5,  6,  7,  8,  8,  9,  9, 10, 10, 11, 11, 12, 12, 12, 12,
13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28]
@@base_length = 
[
0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
64, 80, 96, 112, 128, 160, 192, 224, 0]
@@base_dist = 
[
   0,     1,     2,     3,     4,     6,     8,    12,    16,    24,
  32,    48,    64,    96,   128,   192,   256,   384,   512,   768,
1024,  1536,  2048,  3072,  4096,  6144,  8192, 12288, 16384, 24576]
@@extra_lbits = 
[0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0]
@@extra_dbits = 
[0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13]
@@extra_blbits = 
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7]
@@bl_order = 
[16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15]
@@static_l_desc = 
Static_tree_desc.new(@@static_ltree, @@extra_lbits, LITERALS + 1, L_CODES, MAX_BITS)
@@static_d_desc = 
Static_tree_desc.new(@@static_dtree, @@extra_dbits, 0, D_CODES, MAX_BITS)
@@static_bl_desc = 
Static_tree_desc.new(nil, @@extra_blbits, 0, BL_CODES, MAX_BL_BITS)

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

._tr_align(s) ⇒ Object

Send one empty static block to give enough lookahead for inflate. This takes 10 bits, of which 7 may remain in the bit buffer. The current inflate code requires 9 bits of lookahead. If the last two codes for the previous block (real code plus EOB) were coded on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode the last real code. In this case we send two empty static blocks instead of one. (There are no problems if the previous block is stored or fixed.) To simplify the code, we assume the worst case of last real code encoded on one bit only.



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# File 'lib/pr/rbzlib.rb', line 3096

def _tr_align(s)
  send_bits(s, STATIC_TREES << 1, 3)
  send_bits(s, @@static_ltree[END_BLOCK].fc, @@static_ltree[END_BLOCK].dl)

  bi_flush(s)
  if 1 + s.last_eob_len + 10 - s.bi_valid < 9
    send_bits(s, STATIC_TREES << 1, 3)
    send_bits(s, @@static_ltree[END_BLOCK].fc, @@static_ltree[END_BLOCK].dl)
    bi_flush(s)
  end
  s.last_eob_len = 7
end

._tr_flush_block(s, buf, stored_len, eof) ⇒ Object

Determine the best encoding for the current block: dynamic trees, static

trees or store, and output the encoded block to the zip file.



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# File 'lib/pr/rbzlib.rb', line 3162

def _tr_flush_block(s, buf, stored_len, eof)
  max_blindex = 0
  if s.level > 0
    if stored_len > 0 && s.strm.data_type == Z_UNKNOWN
      set_data_type(s)
    end

    build_tree(s, s.l_desc)

    build_tree(s, s.d_desc)
    max_blindex = build_bl_tree(s)

    opt_lenb = (s.opt_len + 3 + 7) >> 3
    static_lenb = (s.static_len + 3 + 7) >> 3
    if static_lenb <= opt_lenb
      opt_lenb = static_lenb
    end
  else
    static_lenb = stored_len + 5
    opt_lenb = static_lenb
  end
  if (stored_len + 4 <= opt_lenb) && buf
    _tr_stored_block(s, buf, stored_len, eof)
  elsif s.strategy == Z_FIXED || static_lenb == opt_lenb
    send_bits(s, (STATIC_TREES << 1) + (eof ? 1 : 0), 3)
    compress_block(s, @@static_ltree, @@static_dtree)
  else
    send_bits(s, (DYN_TREES << 1) + (eof ? 1 : 0), 3)
    send_all_trees(s, s.l_desc.max_code + 1, s.d_desc.max_code + 1,
                   max_blindex + 1)
    compress_block(s, s.dyn_ltree, s.dyn_dtree)
  end

  init_block(s)

  bi_windup(s) if eof
end

._tr_init(s) ⇒ Object

Initialize the tree data structures for a new zlib stream.



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# File 'lib/pr/rbzlib.rb', line 2683

def _tr_init(s)
  s.l_desc = Tree_desc.new
  s.l_desc.dyn_tree = s.dyn_ltree
  s.l_desc.stat_desc = @@static_l_desc
  s.d_desc = Tree_desc.new
  s.d_desc.dyn_tree = s.dyn_dtree
  s.d_desc.stat_desc = @@static_d_desc
  s.bl_desc = Tree_desc.new
  s.bl_desc.dyn_tree = s.bl_tree
  s.bl_desc.stat_desc = @@static_bl_desc

  s.bi_buf = 0
  s.bi_valid = 0
  s.last_eob_len = 8

  init_block(s)
end

._tr_stored_block(s, buf, stored_len, eof) ⇒ Object

Send a stored block



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# File 'lib/pr/rbzlib.rb', line 3062

def _tr_stored_block(s, buf, stored_len, eof)
  send_bits(s, (STORED_BLOCK << 1) + (eof ? 1 : 0), 3)

  copy_block(s, buf, stored_len, true)
end

._tr_tally(s, dist, lc) ⇒ Object

Save the match info and tally the frequency counts. Return true if

the current block must be flushed.



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# File 'lib/pr/rbzlib.rb', line 3202

def _tr_tally(s, dist, lc)
  s.d_buf[s.last_lit] = dist
  s.l_buf[s.last_lit] = lc
  s.last_lit += 1
  if dist == 0
    s.dyn_ltree[lc].fc += 1
  else
    s.matches += 1
    dist -= 1

    code = (dist < 256) ? @@_dist_code[dist] : @@_dist_code[256 + (dist >> 7)]
    s.dyn_ltree[@@_length_code[lc] + LITERALS + 1].fc += 1
    s.dyn_dtree[code].fc += 1
  end

  (s.last_lit == s.lit_bufsize - 1)
end

.adler32(adler, buf, len = 0) ⇒ Object

Compute the Adler-32 checksum of a data stream



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# File 'lib/pr/rbzlib.rb', line 157

def adler32(adler, buf, len = 0)
  return 1 if buf.nil?

  len = buf.length if len == 0
  sum2 = (adler >> 16) & 0xFFFF
  adler &= 0xffff

  if len == 1
    adler += buf[0].ord

    if adler >= BASE
      adler -= BASE
    end

    sum2 += adler

    if sum2 >= BASE
      sum2 -= BASE
    end

    return adler | (sum2 << 16)
  end

  if len < 16
    i = 0

    while len > 0
      len -= 1
      adler += buf[i].ord
      i += 1
      sum2 += adler
    end

    if adler >= BASE
      adler -= BASE
    end

    sum2 %= BASE

    return adler | (sum2 << 16)
  end

  i = 0

  while len >= NMAX
    len -= NMAX
    n = NMAX / 16

    loop do
      for j in 0 .. 15
        adler += buf[i + j].ord
        sum2 += adler
      end
      i += 16
      n -= 1
      break if n == 0
    end
    adler %= BASE
    sum2 %= BASE
  end

  if len != 0
    while len >= 16
      len -= 16
      for j in 0 .. 15
        adler += buf[i + j].ord
        sum2 += adler
      end
      i += 16
    end
    while len != 0
      len -= 1
      adler += buf[i].ord
      i += 1
      sum2 += adler
    end
    adler %= BASE
    sum2 %= BASE
  end

  adler | (sum2 << 16)
end

.bi_flush(s) ⇒ Object

Flush the bit buffer, keeping at most 7 bits in it.



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# File 'lib/pr/rbzlib.rb', line 3069

def bi_flush(s)
  if s.bi_valid == 16
    s.pending_buf[s.pending] = (s.bi_buf & 0xff)
    s.pending += 1
    s.pending_buf[s.pending] = (s.bi_buf >> 8)
    s.pending += 1

    s.bi_buf = 0
    s.bi_valid = 0
  elsif s.bi_valid >= 8
    s.pending_buf[s.pending] = s.bi_buf
    s.pending += 1

    s.bi_buf >>= 8
    s.bi_valid -= 8
  end
end

.bi_reverse(code, len) ⇒ Object

Reverse the first len bits of a code, using straightforward code (a faster method would use a table) IN assertion: 1 <= len <= 15



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# File 'lib/pr/rbzlib.rb', line 2628

def bi_reverse(code, len)
  res = 0
  loop do
    res |= (code & 1)
    code >>= 1
    res <<= 1
    len -= 1
    break if len <= 0
  end
  res >> 1
end

.bi_windup(s) ⇒ Object

Flush the bit buffer and align the output on a byte boundary



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# File 'lib/pr/rbzlib.rb', line 3022

def bi_windup(s)
  if s.bi_valid > 8
    s.pending_buf[s.pending] = s.bi_buf & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = s.bi_buf >> 8
    s.pending += 1
  elsif s.bi_valid > 0
    s.pending_buf[s.pending] = s.bi_buf
    s.pending += 1
  end
  s.bi_buf = 0
  s.bi_valid = 0
end

.BITS(n) ⇒ Object

Return the low n bits of the bit accumulator (n < 16)



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# File 'lib/pr/rbzlib.rb', line 4090

def BITS(n)
  (@@hold & ((1 << (n)) - 1))
end

.build_bl_tree(s) ⇒ Object

Construct the Huffman tree for the bit lengths and return the index in bl_order of the last bit length code to send.



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# File 'lib/pr/rbzlib.rb', line 2989

def build_bl_tree(s)
  scan_tree(s, s.dyn_ltree, s.l_desc.max_code)
  scan_tree(s, s.dyn_dtree, s.d_desc.max_code)

  build_tree(s, s.bl_desc)

  max_blindex = 0
  (BL_CODES - 1).downto(3) do |i|
    max_blindex = i
    break if s.bl_tree[@@bl_order[i]].dl != 0
  end
  s.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4

  max_blindex
end

.build_tree(s, desc) ⇒ Object

Construct one Huffman tree and assigns the code bit strings and lengths. Update the total bit length for the current block. IN assertion: the field freq is set for all tree elements. OUT assertions: the fields len and code are set to the optimal bit length

and corresponding code. The length opt_len is updated; static_len is
also updated if stree is not null. The field max_code is set.



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# File 'lib/pr/rbzlib.rb', line 2806

def build_tree(s, desc)
  tree = desc.dyn_tree
  stree = desc.stat_desc.static_tree
  elems = desc.stat_desc.elems
  max_code = -1

  s.heap_len = 0
  s.heap_max = HEAP_SIZE

  for n in 0 ... elems
    if tree[n].fc != 0
      max_code = n
      s.heap_len += 1
      s.heap[s.heap_len] = n
      s.depth[n] = 0
    else
      tree[n].dl = 0
    end
  end

  while s.heap_len < 2
    s.heap_len += 1
    if max_code < 2
      max_code += 1
      s.heap[s.heap_len] = max_code
      node = max_code
    else
      s.heap[s.heap_len] = 0
      node = 0
    end
    tree[node].fc = 1
    s.depth[node] = 0
    s.opt_len -= 1
    if stree
      s.static_len -= stree[node].dl
    end
  end
  desc.max_code = max_code

  (s.heap_len / 2).downto(1) do |nheap|
    pqdownheap(s, tree, nheap)
  end

  node = elems
  loop do
    n = s.heap[SMALLEST]
    s.heap[SMALLEST] = s.heap[s.heap_len]
    s.heap_len -= 1
    pqdownheap(s, tree, SMALLEST)

    m = s.heap[SMALLEST]

    s.heap_max -= 1
    s.heap[s.heap_max] = n
    s.heap_max -= 1
    s.heap[s.heap_max] = m
    tree[node].fc = tree[n].fc + tree[m].fc
    if s.depth[n] >= s.depth[m]
      s.depth[node] = s.depth[n] + 1
    else
      s.depth[node] = s.depth[m] + 1
    end
    tree[m].dl = node
    tree[n].dl = node

    s.heap[SMALLEST] = node
    node += 1
    pqdownheap(s, tree, SMALLEST)
    break if s.heap_len < 2
  end

  s.heap_max -= 1
  s.heap[s.heap_max] = s.heap[SMALLEST]

  gen_bitlen(s, desc)

  gen_codes(tree, max_code, s.bl_count)
end

.BYTEBITS ⇒ Object

Remove zero to seven bits as needed to go to a byte boundary



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# File 'lib/pr/rbzlib.rb', line 4101

def BYTEBITS
  @@hold >>= @@bits & 7
  @@bits -= @@bits & 7
end

.check_header(s) ⇒ Object

Check the gzip header of a gz_stream opened for reading. Set the stream mode to transparent if the gzip magic header is not present; set s->err to Z_DATA_ERROR if the magic header is present but the rest of the header is incorrect.

IN assertion: the stream s has already been created sucessfully;

s->stream.avail_in is zero for the first time, but may be non-zero
for concatenated .gz files.



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# File 'lib/pr/rbzlib.rb', line 572

def check_header(s)
  len = s.stream.avail_in

  if len < 2
    if len != 0
      s.inbuf[0] = s.stream.next_in[0]
    end

    begin
      buf = s.file.read(Z_BUFSIZE >> len)
      if buf
        s.inbuf[len, buf.length] = buf
        len = buf.length
      else
        len = 0
      end
    rescue
      len = 0
      s.z_err = Z_ERRNO
    end

    s.stream.avail_in += len
    s.stream.next_in = Bytef.new(s.inbuf)

    if s.stream.avail_in < 2
      s.transparent = !s.stream.avail_in == 0
      return
    end
  end

  if s.stream.next_in[0] != @@gz_magic[0].ord ||
    s.stream.next_in[1] != @@gz_magic[1].ord
  then
    s.transparent = true
    return
  end

  s.stream.avail_in -= 2
  s.stream.next_in += 2

  method = get_byte(s)
  flags = get_byte(s)

  if (method != Z_DEFLATED) || (flags & RESERVED) != 0
    s.z_err = Z_DATA_ERROR
    return
  end

  for len in 0 .. 5
    get_byte(s)
  end

  if (flags & EXTRA_FIELD) != 0
    len = get_byte(s)
    len += ((get_byte(s)) << 8)
    while len != 0 || (get_byte(s) != Z_EOF)
      len -= 1
    end
  end

  if (flags & ORIG_NAME) != 0
    loop do
      c = get_byte(s)
      break if c == 0 || (c == Z_EOF)
    end
  end

  if (flags & COMMENT_) != 0
    loop do
      c = get_byte(s)
      break if c == 0 || (c == Z_EOF)
    end
  end

  if (flags & HEAD_CRC) != 0
    get_byte(s)
    get_byte(s)
  end

  s.z_err = s.z_eof ? Z_DATA_ERROR : Z_OK
end

.check_match(s, start, match, length) ⇒ Object

Check that the match at match_start is indeed a match.



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# File 'lib/pr/rbzlib.rb', line 2064

def check_match(s, start, match, length)
end

.compress(dest, destLen, source, sourceLen) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 3260

def compress(dest, destLen, source, sourceLen)
  compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION)
end

.compress2(dest, destLen, source, sourceLen, level) ⇒ Object

Compresses the source buffer into the destination buffer. The level parameter has the same meaning as in deflateInit. sourceLen is the byte length of the source buffer. Upon entry, destLen is the total size of the destination buffer, which must be at least 0.1% larger than sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.

compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough

memory, Z_BUF_ERROR if there was not enough room in the output buffer, Z_STREAM_ERROR if the level parameter is invalid.



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# File 'lib/pr/rbzlib.rb', line 3229

def compress2(dest, destLen, source, sourceLen, level)
  stream = Z_stream.new
  stream.next_in = Bytef.new(source)
  stream.avail_in = sourceLen
  stream.next_out = Bytef.new(dest)
  stream.avail_out = destLen
  if stream.avail_out != destLen
    return [Z_BUF_ERROR, destLen]
  end

  err = deflateInit(stream, level)
  if err != Z_OK
    return [err, destLen]
  end

  err = deflate(stream, Z_FINISH)
  if err != Z_STREAM_END
    deflateEnd(stream)
    if err == Z_OK
      return [Z_BUF_ERROR, destLen]
    else
      return [err, destLen]
    end
  end
  destLen = stream.total_out

  err = deflateEnd(stream)
  [err, destLen]
end

.compress_block(s, ltree, dtree) ⇒ Object

Send the block data compressed using the given Huffman trees



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# File 'lib/pr/rbzlib.rb', line 3126

def compress_block(s, ltree, dtree)
  lx = 0
  if s.last_lit != 0
    loop do
      dist = s.d_buf[lx]
      lc = s.l_buf[lx]
      lx += 1
      if dist == 0
        send_bits(s, ltree[lc].fc, ltree[lc].dl)
      else
        code = @@_length_code[lc]
        send_bits(s, ltree[code + LITERALS + 1].fc, ltree[code + LITERALS + 1].dl)
        extra = @@extra_lbits[code]
        if extra != 0
          lc -= @@base_length[code]
          send_bits(s, lc, extra)
        end
        dist -= 1
        code = (dist < 256) ? @@_dist_code[dist] : @@_dist_code[256 + (dist >> 7)]

        send_bits(s, dtree[code].fc, dtree[code].dl)
        extra = @@extra_dbits[code]
        if extra != 0
          dist -= @@base_dist[code]
          send_bits(s, dist, extra)
        end
      end
      break if lx >= s.last_lit
    end
  end
  send_bits(s, ltree[END_BLOCK].fc, ltree[END_BLOCK].dl)
  s.last_eob_len = ltree[END_BLOCK].dl
end

.copy_block(s, buf, len, header) ⇒ Object

Copy a stored block, storing first the length and its one’s complement if requested.



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# File 'lib/pr/rbzlib.rb', line 3038

def copy_block(s, buf, len, header)
  bi_windup(s)
  s.last_eob_len = 8

  if header
    s.pending_buf[s.pending] = len & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = len >> 8
    s.pending += 1
    s.pending_buf[s.pending] = ((~len) & 0xff)
    s.pending += 1
    s.pending_buf[s.pending] = ((~len) >> 8) & 0xff
    s.pending += 1
  end
  i = 0
  while len != 0
    len -= 1
    s.pending_buf[s.pending] = buf[i].ord
    i += 1
    s.pending += 1
  end
end

.CRC2(check, word) ⇒ Object

compute crc



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# File 'lib/pr/rbzlib.rb', line 4027

def CRC2(check, word)
  hbuf = 0.chr * 2
  hbuf[0] = (word & 0xff).chr
  hbuf[1] = ((word >> 8) & 0xff).chr
  crc32(check, hbuf)
end

.crc32(crc, buf, len = 0) ⇒ Object

Compute the CRC-32 of a data stream.



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# File 'lib/pr/rbzlib.rb', line 303

def crc32(crc, buf, len = 0)
  return 0 if buf.nil?
  len = buf.length if len == 0
  crc = crc ^ 0xffffffff
  i = 0

  while len >= 8
    8.times do
      crc = @@crc_table[(crc ^ buf[i].ord) & 0xff] ^ (crc >> 8)
      i += 1
    end
    len -= 8
  end

  if len != 0
    len.times do
      crc = @@crc_table[(crc ^ buf[i].ord) & 0xff] ^ (crc >> 8)
      i += 1
    end
  end

  crc ^ 0xffffffff
end

.CRC4(check, word) ⇒ Object

compute crc



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# File 'lib/pr/rbzlib.rb', line 4035

def CRC4(check, word)
  hbuf = 0.chr * 4
  hbuf[0] = (word & 0xff).chr
  hbuf[1] = ((word >> 8) & 0xff).chr
  hbuf[2] = ((word >> 16) & 0xff).chr
  hbuf[3] = ((word >> 24) & 0xff).chr
  crc32(check, hbuf)
end

.deflate(strm, flush) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1507

def deflate(strm, flush)
  if strm.state.nil? || (flush > Z_FINISH) || (flush < 0)
    return Z_STREAM_ERROR
  end
  s = strm.state

  if strm.next_out.nil? ||
     (strm.next_in.nil? && strm.avail_in != 0) ||
     ((s.status == FINISH_STATE) && (flush != Z_FINISH))
    strm.msg = @@z_errmsg[Z_errbase - Z_STREAM_ERROR]
    return Z_STREAM_ERROR
  end

  if strm.avail_out == 0
    strm.msg = @@z_errmsg[Z_errbase - Z_BUF_ERROR]
    return Z_BUF_ERROR
  end

  s.strm = strm
  old_flush = s.last_flush
  s.last_flush = flush

  if s.status == INIT_STATE
    if s.wrap == 2
      strm.adler = crc32(0, nil)
      s.pending_buf[s.pending] = 31
      s.pending += 1
      s.pending_buf[s.pending] = 139
      s.pending += 1
      s.pending_buf[s.pending] = 8
      s.pending += 1
      if s.gzhead.nil?
        s.pending_buf[s.pending] = 0
        s.pending += 1
        s.pending_buf[s.pending] = 0
        s.pending += 1
        s.pending_buf[s.pending] = 0
        s.pending += 1
        s.pending_buf[s.pending] = 0
        s.pending += 1
        s.pending_buf[s.pending] = 0
        s.pending += 1
        s.pending_buf[s.pending] = (s.level == 9) ? 2 :
          (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2 ?
                           4 : 0)
        s.pending += 1
      else
        c = (s.gzhead.text ? 1 : 0) +
                          (s.gzhead.hcrc ? 2 : 0) +
                          (s.gzhead.extra.nil? ? 0 : 4) +
                          (s.gzhead.name.nil? ? 0 : 8) +
                          (s.gzhead.comment.nil? ? 0 : 16)
        s.pending_buf[s.pending] = c
        s.pending += 1
        c = s.gzhead.time & 0xff
        s.pending_buf[s.pending] = c
        s.pending += 1
        c = (s.gzhead.time >> 8) & 0xff
        s.pending_buf[s.pending] = c
        s.pending += 1
        c = (s.gzhead.time >> 16) & 0xff
        s.pending_buf[s.pending] = c
        s.pending += 1
        c = (s.gzhead.time >> 24) & 0xff
        s.pending_buf[s.pending] = c
        s.pending += 1
        c = s.level == 9 ? 2 :
                          (s.strategy >= Z_HUFFMAN_ONLY || s.level < 2 ?
                           4 : 0)
        s.pending_buf[s.pending] = c
        s.pending += 1
        c = s.gzhead.os & 0xff
        s.pending_buf[s.pending] = c
        s.pending += 1
        if s.gzhead.extra
          c = s.gzhead.extra_len & 0xff
          s.pending_buf[s.pending] = c
          s.pending += 1
          c = (s.gzhead.extra_len >> 8) & 0xff
          s.pending_buf[s.pending] = c
          s.pending += 1
        end
        if s.gzhead.hcrc
          strm.adler = crc32(strm.adler, s.pending_buf.buffer, s.pending)
          s.gzindex = 0
          s.status = EXTRA_STATE
        end
      end
    else
      header = (Z_DEFLATED + ((s.w_bits - 8) << 4)) << 8

      if s.strategy >= Z_HUFFMAN_ONLY || s.level < 2
        level_flags = 0
      elsif s.level < 6
        level_flags = 1
      elsif s.level == 6
        level_flags = 2
      else
        level_flags = 3
      end
      header |= (level_flags << 6)
      if s.strstart != 0
        header |= PRESET_DICT
      end
      header += 31 - (header % 31)

      s.status = BUSY_STATE
      putShortMSB(s, header)

      if s.strstart != 0
        putShortMSB(s, (strm.adler >> 16))
        putShortMSB(s, (strm.adler & 0xffff))
      end
      strm.adler = adler32(0, nil)
    end
  end

  if s.status == EXTRA_STATE
    if s.gzhead.extra
      beg = s.pending

      while s.gzindex < (s.gzhead.extra_len & 0xffff)
        if s.pending == s.pending_buf_size
          if s.gzhead.hcrc && s.pending > beg
            strm.adler = crc32(strm.adler, s.pending_buf.buffer[beg, s.pending - beg])
          end
          flush_pending(strm)
          beg = s.pending
          break if s.pending == s.pending_buf_size
        end
        s.pending_buf[s.pending] = s.gzhead.extra[s.gzindex]
        s.pending += 1
        s.gzindex += 1
      end
      if s.gzhead.hcrc && s.pending > beg
        strm.adler = crc32(strm.adler, s.pending_buf[beg, s.pending - beg])
      end
      if s.gzindex == s.gzhead.extra_len
        s.gzindex = 0
        s.status = NAME_STATE
      end
    else
      s.status = NAME_STATE
    end
  end
  if s.status == NAME_STATE
    if s.gzhead.name
      beg = s.pending
      loop do
        if s.pending == s.pending_buf_size
          if s.gzhead.hcrc && s.pending > beg
            strm.adler = crc32(strm.adler, s.pending_buf.buffer[beg, s.pending - beg])
          end
          flush_pending(strm)
          beg = s.pending
          if s.pending == s.pending_buf_size
            val = 1
            break
          end
        end
        val = s.gzhead.name[s.gzindex]
        s.gzindex += 1
        s.pending_buf[s.pending] = val
        s.pending += 1
        break if val == 0
      end
      if s.gzhead.hcrc && s.pending > beg
        strm.adler = crc32(strm.adler, s.pending_buf.buffer[beg, s.pending - beg])
      end
      if val == 0
        s.gzindex = 0
        s.status = COMMENT_STATE
      end
    else
      s.status = COMMENT_STATE
    end
  end
  if s.status == COMMENT_STATE
    if s.gzhead.comment
      beg = s.pending
      loop do
        if s.pending == s.pending_buf_size
          if s.gzhead.hcrc && s.pending > beg
            strm.adler = crc32(strm.adler, s.pending_buf.buffer[beg, s.pending - beg])
          end
          flush_pending(strm)
          beg = s.pending
          if s.pending == s.pending_buf_size
            val = 1
            break
          end
        end
        val = s.gzhead.comment[s.gzindex]
        s.gzindex += 1
        s.pending_buf[s.pending] = val
        s.pending += 1
        break if val == 0
      end
      if s.gzhead.hcrc && s.pending > beg
        strm.adler = crc32(strm.adler, s.pending_buf.buffer[beg, s.pending - beg])
      end
      if val == 0
        s.status = HCRC_STATE
      end
    else
      s.status = HCRC_STATE
    end
  end
  if s.status == HCRC_STATE
    if s.gzhead.hcrc
      if s.pending + 2 > s.pending_buf_size
        flush_pending(strm)
      end
      if s.pending + 2 <= s.pending_buf_size
        s.pending_buf[s.pending] = strm.adler & 0xff
        s.pending += 1
        s.pending_buf[s.pending] = (strm.adler >> 8) & 0xff
        s.pending += 1
        strm.adler = crc32(0, nil)
        s.status = BUSY_STATE
      end
    else
      s.status = BUSY_STATE
    end
  end
  if s.pending != 0
    flush_pending(strm)
    if strm.avail_out == 0
      s.last_flush = -1
      return Z_OK
    end
  elsif strm.avail_in == 0 && (flush <= old_flush) && (flush != Z_FINISH)
    strm.msg = @@z_errmsg[Z_errbase - Z_BUF_ERROR]
    return Z_BUF_ERROR
  end
  if (s.status == FINISH_STATE) && strm.avail_in != 0
    strm.msg = @@z_errmsg[Z_errbase - Z_BUF_ERROR]
    return Z_BUF_ERROR
  end

  if strm.avail_in != 0 || s.lookahead != 0 || ((flush != Z_NO_FLUSH) && (s.status != FINISH_STATE))
    bstate = send(@@configuration_table[s.level].func, s, flush)
    if (bstate == :finish_started) || (bstate == :finish_done)
      s.status = FINISH_STATE
    end
    if (bstate == :need_more) || (bstate == :finish_started)
      if strm.avail_out == 0
        s.last_flush = -1
      end
      return Z_OK
    end
    if bstate == :block_done
      if flush == Z_PARTIAL_FLUSH
        _tr_align(s)
      else
        _tr_stored_block(s, nil, 0, false)

        if flush == Z_FULL_FLUSH
          s.head = Array.new(s.hash_size, 0)
          s.head[s.hash_size - 1] = ZNIL
        end
      end
      flush_pending(strm)
      if strm.avail_out == 0
        s.last_flush = -1
        return Z_OK
      end

    end
  end
  if flush != Z_FINISH
    return Z_OK
  end

  if s.wrap <= 0
    return Z_STREAM_END
  end

  if s.wrap == 2
    s.pending_buf[s.pending] = strm.adler & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = (strm.adler >> 8) & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = (strm.adler >> 16) & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = (strm.adler >> 24) & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = strm.total_in & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = (strm.total_in >> 8) & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = (strm.total_in >> 16) & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = (strm.total_in >> 24) & 0xff
    s.pending += 1
  else
    putShortMSB(s, (strm.adler >> 16))
    putShortMSB(s, (strm.adler & 0xffff))
  end
  flush_pending(strm)

  s.wrap = -s.wrap if s.wrap > 0
  s.pending != 0 ? Z_OK : Z_STREAM_END
end

.deflate_fast(s, flush) ⇒ Object

Compress as much as possible from the input stream, return the current block state. This function does not perform lazy evaluation of matches and inserts new strings in the dictionary only for unmatched strings or for short matches. It is used only for the fast compression options.



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# File 'lib/pr/rbzlib.rb', line 2214

def deflate_fast(s, flush)
  hash_head = ZNIL
  loop do

    if s.lookahead < MIN_LOOKAHEAD
      fill_window(s)
      if (s.lookahead < MIN_LOOKAHEAD) && (flush == Z_NO_FLUSH)
        return :need_more
      end

      break if s.lookahead == 0
    end

    if s.lookahead >= MIN_MATCH
      hash_head = INSERT_STRING(s, s.strstart, hash_head)
    end

    if (hash_head != ZNIL) &&
     (s.strstart - hash_head <= (s.w_size - MIN_LOOKAHEAD))
      if s.strategy != Z_HUFFMAN_ONLY && s.strategy != Z_RLE
        s.match_length = longest_match(s, hash_head)
      elsif s.strategy == Z_RLE && s.srstart - hash_end == 1
        s.match_length = longest_match_fast(s, hash_head)
      end
    end
    if s.match_length >= MIN_MATCH
      bflush = _tr_tally(s, s.strstart - s.match_start,
                      s.match_length - MIN_MATCH)

      s.lookahead -= s.match_length
      if (s.match_length <= s.max_lazy_match) && (s.lookahead >= MIN_MATCH)
        s.match_length -= 1
        loop do
          s.strstart += 1
          hash_head = INSERT_STRING(s, s.strstart, hash_head)
          s.match_length -= 1
          break if s.match_length == 0
        end
        s.strstart += 1
      else
        s.strstart += s.match_length
        s.match_length = 0
        s.ins_h = s.window[s.strstart].ord
        s.ins_h = (( s.ins_h << s.hash_shift) ^
                   s.window[s.strstart + 1].ord) & s.hash_mask
      end
    else
      bflush = _tr_tally(s, 0, s.window[s.strstart].ord)

      s.lookahead -= 1
      s.strstart += 1
    end
    if bflush
      FLUSH_BLOCK_ONLY(s, false)
      if s.strm.avail_out == 0
        return :need_more
      end
    end
  end
  FLUSH_BLOCK_ONLY(s, flush == Z_FINISH)
  if s.strm.avail_out == 0
    if flush == Z_FINISH
      return :finish_started
    else
      return :need_more
    end
  end

  if flush == Z_FINISH
    :finish_done
  else
    :block_done
  end
end

.deflate_slow(s, flush) ⇒ Object

Same as above, but achieves better compression. We use a lazy evaluation for matches: a match is finally adopted only if there is no better match at the next window position.



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# File 'lib/pr/rbzlib.rb', line 2292

def deflate_slow(s, flush)
  hash_head = ZNIL

  loop do
    if s.lookahead < MIN_LOOKAHEAD
      fill_window(s)
      if (s.lookahead < MIN_LOOKAHEAD) && (flush == Z_NO_FLUSH)
        return :need_more
      end

      break if s.lookahead == 0
    end

    if s.lookahead >= MIN_MATCH
      hash_head = INSERT_STRING(s, s.strstart, hash_head)
    end

    s.prev_length = s.match_length
    s.prev_match = s.match_start
    s.match_length = MIN_MATCH - 1

    if (hash_head != ZNIL) && (s.prev_length < s.max_lazy_match) &&
     (s.strstart - hash_head <= (s.w_size - MIN_LOOKAHEAD))

      if s.strategy != Z_HUFFMAN_ONLY && s.strategy != Z_RLE
        s.match_length = longest_match(s, hash_head)
      elsif s.strategy == Z_RLE && s.strstart - hash_head == 1
        s.match_length = longest_match_fast(s, hash_head)
      end

      if (s.match_length <= 5) && ((s.strategy == Z_FILTERED) ||
           ((s.match_length == MIN_MATCH) &&
            (s.strstart - s.match_start > TOO_FAR)))
        s.match_length = MIN_MATCH - 1
      end
    end
    if (s.prev_length >= MIN_MATCH) && (s.match_length <= s.prev_length)
      max_insert = s.strstart + s.lookahead - MIN_MATCH

      bflush = _tr_tally(s, s.strstart - 1 - s.prev_match,
                        s.prev_length - MIN_MATCH)
      s.lookahead -= s.prev_length - 1
      s.prev_length -= 2
      loop do
        s.strstart += 1
        if s.strstart <= max_insert
          hash_head = INSERT_STRING(s, s.strstart, hash_head)
        end
        s.prev_length -= 1
        break if s.prev_length == 0
      end
      s.match_available = false
      s.match_length = MIN_MATCH - 1
      s.strstart += 1
      if bflush
        FLUSH_BLOCK_ONLY(s, false)
        if s.strm.avail_out == 0
          return :need_more
        end
      end
    elsif s.match_available
      bflush = _tr_tally(s, 0, s.window[s.strstart - 1].ord)
      if bflush
        FLUSH_BLOCK_ONLY(s, false)
      end
      s.strstart += 1
      s.lookahead -= 1
      if s.strm.avail_out == 0
        return :need_more
      end
    else
      s.match_available = true
      s.strstart += 1
      s.lookahead -= 1
    end
  end
  if s.match_available
    _tr_tally(s, 0, s.window[s.strstart - 1].ord)
    s.match_available = false
  end
  FLUSH_BLOCK_ONLY(s, flush == Z_FINISH)
  if s.strm.avail_out == 0
    if flush == Z_FINISH
      return :finish_started
    else
      return :need_more
    end
  end
  if flush == Z_FINISH
    :finish_done
  else
    :block_done
  end
end

.deflate_stored(s, flush) ⇒ Object

Copy without compression as much as possible from the input stream, return the current block state. This function does not insert new strings in the dictionary since uncompressible data is probably not useful. This function is used only for the level=0 compression option. NOTE: this function should be optimized to avoid extra copying from window to pending_buf.



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# File 'lib/pr/rbzlib.rb', line 2156

def deflate_stored(s, flush)
  max_block_size = 0xffff
  if max_block_size > s.pending_buf_size - 5
    max_block_size = s.pending_buf_size - 5
  end

  loop do
    if s.lookahead <= 1
      fill_window(s)
      if s.lookahead == 0 && (flush == Z_NO_FLUSH)
        return :need_more
      end

      break if s.lookahead == 0
    end
    s.strstart += s.lookahead
    s.lookahead = 0

    max_start = s.block_start + max_block_size
    if s.strstart == 0 || ((s.strstart) >= max_start)
      s.lookahead = (s.strstart - max_start)
      s.strstart = (max_start)
      FLUSH_BLOCK_ONLY(s, false)
      if s.strm.avail_out == 0
        return :need_more
      end
    end

    if s.strstart - s.block_start >=
        s.w_size - MIN_LOOKAHEAD
      FLUSH_BLOCK_ONLY(s, false)
      if s.strm.avail_out == 0
        return :need_more
      end
    end
  end

  FLUSH_BLOCK_ONLY(s, flush == Z_FINISH)
  if s.strm.avail_out == 0
    if flush == Z_FINISH
      return :finish_started
    else
      return :need_more
    end
  end

  if flush == Z_FINISH
    :finish_done
  else
    :block_done
  end
end

.deflateBound(strm, sourceLen) ⇒ Object

For the default windowBits of 15 and memLevel of 8, this function returns a close to exact, as well as small, upper bound on the compressed size. They are coded as constants here for a reason–if the #define’s are changed, then this function needs to be changed as well. The return value for 15 and 8 only works for those exact settings.

For any setting other than those defaults for windowBits and memLevel, the value returned is a conservative worst case for the maximum expansion resulting from using fixed blocks instead of stored blocks, which deflate can emit on compressed data for some combinations of the parameters.

This function could be more sophisticated to provide closer upper bounds for every combination of windowBits and memLevel, as well as wrap. But even the conservative upper bound of about 14% expansion does not seem onerous for output buffer allocation.



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# File 'lib/pr/rbzlib.rb', line 1458

def deflateBound(strm, sourceLen)
  destLen = sourceLen +
            ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 11

  if strm.nil? || strm.state.nil?
    return destLen
  end

  s = strm.state
  if s.w_bits != 15 || s.hash_bits != 8 + 7
    return destLen
  end

  compressBound(sourceLen)
end

.deflateCopy(dest, source) ⇒ Object

Copy the source state to the destination state. To simplify the source, this is not supported for 16-bit MSDOS (which doesn’t have enough memory anyway to duplicate compression states).



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# File 'lib/pr/rbzlib.rb', line 1841

def deflateCopy(dest, source)
  if source.nil? || dest.nil? || source.state.nil?
    return Z_STREAM_ERROR
  end
  ss = source.state
  dest = source.dup

  ds = Deflate_state.new
  dest.state = ds
  ds = ss.dup
  ds.strm = dest

  ds.window = ss.window.dup
  ds.prev = ss.prev.dup
  ds.head = ss.head.dup
  ds.pending_buf = ss.pending_buf.dup
  ds.pending_buf.buffer = ss.pending_buf.buffer.dup

  ds.pending_out = Bytef.new(ds.pending_buf, ss.pending_out.offset)
  ds.d_buf = Posf.new(ds.pending_buf, ds.lit_bufsize)
  ds.l_buf = Bytef.new(ds.pending_buf, (1 + 2) * ds.lit_bufsize)

  ds.l_desc.dyn_tree = ds.dyn_ltree
  ds.d_desc.dyn_tree = ds.dyn_dtree
  ds.bl_desc.dyn_tree = ds.bl_tree

  Z_OK
end

.deflateEnd(strm) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1813

def deflateEnd(strm)
  if strm.nil? || strm.state.nil?
    return Z_STREAM_ERROR
  end

  s = strm.state
  status = s.status
  if status != INIT_STATE &&
      status != EXTRA_STATE &&
      status != NAME_STATE &&
      status != COMMENT_STATE &&
      status != HCRC_STATE &&
      status != BUSY_STATE &&
      status != FINISH_STATE
    return Z_STREAM_ERROR
  end
  strm.state = nil

  if status == BUSY_STATE
    Z_DATA_ERROR
  else
    Z_OK
  end
end

.deflateInit(strm, level) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1309

def deflateInit(strm, level)
  deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS,
       DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, ZLIB_VERSION, strm.size)
end

.deflateInit2(strm, level, method, windowBits, memLevel, strategy) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1295

def deflateInit2(strm, level, method, windowBits, memLevel, strategy)
  deflateInit2_(strm, level, method, windowBits,
                 memLevel, strategy, ZLIB_VERSION, strm.size)
end

.deflateInit2_(strm, level, method, windowBits, memLevel, strategy, version, stream_size) ⇒ Object

Initialize the hash table (avoiding 64K overflow for 16 bit systems). prev[] will be initialized on the fly.



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# File 'lib/pr/rbzlib.rb', line 1223

def deflateInit2_(strm, level, method, windowBits, memLevel, strategy, version, stream_size)
  wrap = 1
  my_version = ZLIB_VERSION

  if (version == '') || (version[1] != my_version[1]) || (stream_size != Z_stream.new.size)
    return Z_VERSION_ERROR
  end

  strm.msg = ''
  if level == Z_DEFAULT_COMPRESSION
    level = 6
  end
  if windowBits < 0
    wrap = 0
    windowBits = -windowBits
  elsif windowBits > 15
    wrap = 2
    windowBits -= 16
  end
  if (memLevel < 1) || (memLevel > MAX_MEM_LEVEL) || (method != Z_DEFLATED) ||
         (windowBits < 8) || (windowBits > 15) || (level < 0) || (level > 9) ||
         (strategy < 0) || (strategy > Z_FIXED)
    return Z_STREAM_ERROR
  end

  windowBits = 9 if windowBits == 8
  s = Deflate_state.new
  s.dyn_ltree = Array.new(HEAP_SIZE).map{ Ct_data.new() }
  s.dyn_dtree = Array.new(2 * D_CODES + 1).map{ Ct_data.new() }
  s.bl_tree = Array.new(2 * BL_CODES + 1).map{ Ct_data.new() }
  s.bl_count = Array.new(MAX_BITS + 1, 0)
  s.heap = Array.new(2 * L_CODES + 1, 0)
  s.depth = Array.new(2 * L_CODES + 1, 0)
  strm.state = s
  s.strm = strm

  s.wrap = wrap
  s.gzhead = nil
  s.w_bits = windowBits
  s.w_size = 1 << s.w_bits
  s.w_mask = s.w_size - 1

  s.hash_bits = memLevel + 7
  s.hash_size = 1 << s.hash_bits
  s.hash_mask = s.hash_size - 1
  s.hash_shift = ((s.hash_bits + MIN_MATCH - 1) / MIN_MATCH)

  s.window = 0.chr * (s.w_size * 2)
  s.prev   = Array.new(s.w_size, 0)
  s.head   = Array.new(s.hash_size, 0)

  s.lit_bufsize = 1 << (memLevel + 6)

  overlay = 0.chr * (s.lit_bufsize * (2 + 2))
  s.pending_buf = Bytef.new(overlay)
  s.pending_buf_size = s.lit_bufsize * (2 + 2)

  if s.window.nil? || s.prev.nil? || s.head.nil? || s.pending_buf.nil?
    s.status = FINISH_STATE
    strm.msg = @@z_errmsg[Z_errbase - Z_MEM_ERROR]
    deflateEnd(strm)
    return Z_MEM_ERROR
  end
  s.d_buf = Posf.new(overlay, s.lit_bufsize)
  s.l_buf = Bytef.new(overlay, (1 + 2) * s.lit_bufsize)

  s.level = level
  s.strategy = strategy
  s.method = method
  deflateReset(strm)
end

.deflateInit_(strm, level, version, stream_size) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1300

def deflateInit_(strm, level, version, stream_size)
  if strm.nil?
    Z_STREAM_ERROR
  else
    deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS,
                 DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, version, stream_size)
  end
end

.deflateParams(strm, level, strategy) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1400

def deflateParams(strm, level, strategy)
  err = Z_OK
  if strm.state.nil?
    return Z_STREAM_ERROR
  end

  s = strm.state

  if level == Z_DEFAULT_COMPRESSION
    level = 6
  end
  if (level < 0) || (level > 9) || (strategy < 0) || (strategy > Z_HUFFMAN_ONLY)
    return Z_STREAM_ERROR
  end
  func = @@configuration_table[s.level].func

  if (func != @@configuration_table[level].func) && strm.total_in != 0
    err = deflate(strm, Z_PARTIAL_FLUSH)
  end
  if s.level != level
    s.level = level
    s.max_lazy_match   = @@configuration_table[level].max_lazy
    s.good_match       = @@configuration_table[level].good_length
    s.nice_match       = @@configuration_table[level].nice_length
    s.max_chain_length = @@configuration_table[level].max_chain
  end
  s.strategy = strategy
  err
end

.deflatePrime(strm, bits, value) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1390

def deflatePrime(strm, bits, value)
  if strm.nil? || strm.state.nil?
    return Z_STREAM_ERROR
  end
  strm.state.bi_valid = bits
  strm.state.bi_buf = (value & ((1 << bits) - 1))
  Z_OK
end

.deflateReset(strm) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1352

def deflateReset(strm)
  if strm.nil? || strm.state.nil?
    return Z_STREAM_ERROR
  end

  strm.total_out = 0
  strm.total_in = 0
  strm.msg = ''
  strm.data_type = Z_UNKNOWN

  s = strm.state
  s.pending = 0
  s.pending_out = Bytef.new(s.pending_buf)

  if s.wrap < 0
    s.wrap = -s.wrap
  end
  s.status = s.wrap != 0 ? INIT_STATE : BUSY_STATE
  strm.adler = (s.wrap == 2) ? crc32(0, nil) : adler32(0, nil)
  s.last_flush = Z_NO_FLUSH

  _tr_init(s)
  lm_init(s)

  Z_OK
end

.deflateSetDictionary(strm, dictionary, dictLength) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1315

def deflateSetDictionary(strm, dictionary, dictLength)
  length = dictLength
  offset = 0
  hash_head = 0

  if strm.nil? || strm.state.nil? || dictionary.nil? || strm.state.wrap == 2 ||
         (strm.state.wrap == 1 && strm.state.status != INIT_STATE)
    return Z_STREAM_ERROR
  end

  s = strm.state
  strm.adler = adler32(strm.adler, dictionary, dictLength) if s.wrap != 0
  if length < MIN_MATCH
    return Z_OK
  end
  _MAX_DIST = (s.w_size - MIN_LOOKAHEAD)
  if length > _MAX_DIST
    length = _MAX_DIST

    offset += dictLength - length
  end

  s.window[0, length] = dictionary[offset, length]
  s.strstart = length
  s.block_start = length

  s.ins_h = s.window[0].ord

  s.ins_h = ((s.ins_h << s.hash_shift) ^ (s.window[1].ord)) & s.hash_mask

  for n in 0 .. (length - MIN_MATCH)
    hash_head = INSERT_STRING(s, n, hash_head)
  end
  Z_OK
end

.deflateSetHeader(strm, head) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1380

def deflateSetHeader(strm, head)
  if strm.nil? || strm.state.nil?
    return Z_STREAM_ERROR
  end
  return Z_STREAM_ERROR if strm.state.wrap != 2
  strm.state.gzhead = head
  Z_OK
end

.deflateTune(strm, good_length, max_lazy, nice_length, max_chain) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 1431

def deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
  if strm.nil? || strm.state.nil?
    return Z_STREAM_ERROR
  end
  s = strm.state
  s.good_match = good_length
  s.max_lazy_match = max_lazy
  s.nice_match = nice_length
  s.max_chain_length = max_chain
  Z_OK
end

.destroy(s) ⇒ Object

Cleanup then free the given gz_stream. Return a zlib error code.



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# File 'lib/pr/rbzlib.rb', line 655

def destroy(s)
  err = Z_OK
  return Z_STREAM_ERROR if s.nil?

  if s.stream.state
    if s.mode == 'w'
      err = deflateEnd(s.stream)
    elsif s.mode == 'r'
      err = inflateEnd(s.stream)
    end
  end

  begin
    s.file.close if s.file
    s.file = nil
  rescue
    err = Z_ERRNO
  end

  if s.z_err < 0
    err = s.z_err
  end

  err
end

.do_flush(file, flush) ⇒ Object

Flushes all pending output into the compressed file. The parameter flush is as in the deflate() function.



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# File 'lib/pr/rbzlib.rb', line 913

def do_flush(file, flush)
  done = false
  s = file

  if s.nil? || (s.mode != 'w')
    return Z_STREAM_ERROR
  end

  s.stream.avail_in = 0

  loop do
    len = Z_BUFSIZE - s.stream.avail_out

    if len != 0
      written = s.file.write(s.outbuf[0, len])
      if written != len
        s.z_err = Z_ERRNO
        return Z_ERRNO
      end
      s.stream.next_out = Bytef.new(s.outbuf)
      s.stream.avail_out = Z_BUFSIZE
    end

    break if done
    s.out += s.stream.avail_out
    s.z_err = deflate(s.stream, flush)
    s.out -= s.stream.avail_out

    if len == 0 && (s.z_err == Z_BUF_ERROR)
      s.z_err = Z_OK
    end

    done = s.stream.avail_out != 0 || (s.z_err == Z_STREAM_END)
    break if (s.z_err != Z_OK) && (s.z_err != Z_STREAM_END)

  end

  if (s.z_err == Z_STREAM_END)
    Z_OK
  else
    s.z_err
  end
end

.DROPBITS(n) ⇒ Object

Remove n bits from the bit accumulator



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# File 'lib/pr/rbzlib.rb', line 4095

def DROPBITS(n)
  @@hold >>= n
  @@bits -= n
end

.fill_window(s) ⇒ Object

Fill the window when the lookahead becomes insufficient. Updates strstart and lookahead.

IN assertion: lookahead < MIN_LOOKAHEAD OUT assertions: strstart <= window_size-MIN_LOOKAHEAD

At least one byte has been read, or avail_in == 0; reads are
performed for at least two bytes (required for the zip translate_eol
option -- not supported here).



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# File 'lib/pr/rbzlib.rb', line 2075

def fill_window(s)
  wsize = s.w_size
  loop do
    more = s.window_size - s.lookahead - s.strstart

    if more == 0 && s.strstart == 0 && s.lookahead == 0
      more = wsize
    elsif more == (-1)
      more -= 1
    end
    if s.strstart >= wsize + (wsize - MIN_LOOKAHEAD)
      s.window[0, wsize] = s.window[wsize, wsize]
      s.match_start -= wsize
      s.strstart -= wsize
      s.block_start -= wsize


      n = s.hash_size
      ap = n
      loop do
        ap -= 1
        m = s.head[ap]
        if m >= wsize
          s.head[ap] = m - wsize
        else
          s.head[ap] = ZNIL
        end
        n -= 1
        break if n == 0
      end

      n = wsize
      ap = n
      loop do
        ap -= 1
        m = s.prev[ap]
        if m >= wsize
          s.prev[ap] = (m - wsize)
        else
          s.prev[ap] = ZNIL
        end
        n -= 1
        break if n == 0
      end
      more += wsize
    end
    return if s.strm.avail_in == 0

    n = read_buf(s.strm, s.window, (s.strstart + s.lookahead), more)
    s.lookahead += n

    if s.lookahead >= MIN_MATCH
      s.ins_h = s.window[s.strstart].ord
      s.ins_h = ((s.ins_h << s.hash_shift) ^ s.window[s.strstart + 1].ord) & s.hash_mask
    end
    break if (s.lookahead >= MIN_LOOKAHEAD) || s.strm.avail_in == 0
  end
end

.fixedtables(state) ⇒ Object

Return state with length and distance decoding tables and index sizes set to fixed code decoding. Normally this returns fixed tables from inffixed.h. If BUILDFIXED is defined, then instead this routine builds the tables the first time it’s called, and returns those tables the first time and thereafter. This reduces the size of the code by about 2K bytes, in exchange for a little execution time. However, BUILDFIXED should not be used for threaded applications, since the rewriting of the tables and virgin may not be thread-safe.



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# File 'lib/pr/rbzlib.rb', line 3878

def fixedtables(state)

  lenfix = [
      [96, 7, 0], [0, 8, 80], [0, 8, 16], [20, 8, 115], [18, 7, 31], [0, 8, 112], [0, 8, 48],
      [0, 9, 192], [16, 7, 10], [0, 8, 96], [0, 8, 32], [0, 9, 160], [0, 8, 0], [0, 8, 128],
      [0, 8, 64], [0, 9, 224], [16, 7, 6], [0, 8, 88], [0, 8, 24], [0, 9, 144], [19, 7, 59],
      [0, 8, 120], [0, 8, 56], [0, 9, 208], [17, 7, 17], [0, 8, 104], [0, 8, 40], [0, 9, 176],
      [0, 8, 8], [0, 8, 136], [0, 8, 72], [0, 9, 240], [16, 7, 4], [0, 8, 84], [0, 8, 20],
      [21, 8, 227], [19, 7, 43], [0, 8, 116], [0, 8, 52], [0, 9, 200], [17, 7, 13], [0, 8, 100],
      [0, 8, 36], [0, 9, 168], [0, 8, 4], [0, 8, 132], [0, 8, 68], [0, 9, 232], [16, 7, 8],
      [0, 8, 92], [0, 8, 28], [0, 9, 152], [20, 7, 83], [0, 8, 124], [0, 8, 60], [0, 9, 216],
      [18, 7, 23], [0, 8, 108], [0, 8, 44], [0, 9, 184], [0, 8, 12], [0, 8, 140], [0, 8, 76],
      [0, 9, 248], [16, 7, 3], [0, 8, 82], [0, 8, 18], [21, 8, 163], [19, 7, 35], [0, 8, 114],
      [0, 8, 50], [0, 9, 196], [17, 7, 11], [0, 8, 98], [0, 8, 34], [0, 9, 164], [0, 8, 2],
      [0, 8, 130], [0, 8, 66], [0, 9, 228], [16, 7, 7], [0, 8, 90], [0, 8, 26], [0, 9, 148],
      [20, 7, 67], [0, 8, 122], [0, 8, 58], [0, 9, 212], [18, 7, 19], [0, 8, 106], [0, 8, 42],
      [0, 9, 180], [0, 8, 10], [0, 8, 138], [0, 8, 74], [0, 9, 244], [16, 7, 5], [0, 8, 86],
      [0, 8, 22], [64, 8, 0], [19, 7, 51], [0, 8, 118], [0, 8, 54], [0, 9, 204], [17, 7, 15],
      [0, 8, 102], [0, 8, 38], [0, 9, 172], [0, 8, 6], [0, 8, 134], [0, 8, 70], [0, 9, 236],
      [16, 7, 9], [0, 8, 94], [0, 8, 30], [0, 9, 156], [20, 7, 99], [0, 8, 126], [0, 8, 62],
      [0, 9, 220], [18, 7, 27], [0, 8, 110], [0, 8, 46], [0, 9, 188], [0, 8, 14], [0, 8, 142],
      [0, 8, 78], [0, 9, 252], [96, 7, 0], [0, 8, 81], [0, 8, 17], [21, 8, 131], [18, 7, 31],
      [0, 8, 113], [0, 8, 49], [0, 9, 194], [16, 7, 10], [0, 8, 97], [0, 8, 33], [0, 9, 162],
      [0, 8, 1], [0, 8, 129], [0, 8, 65], [0, 9, 226], [16, 7, 6], [0, 8, 89], [0, 8, 25],
      [0, 9, 146], [19, 7, 59], [0, 8, 121], [0, 8, 57], [0, 9, 210], [17, 7, 17], [0, 8, 105],
      [0, 8, 41], [0, 9, 178], [0, 8, 9], [0, 8, 137], [0, 8, 73], [0, 9, 242], [16, 7, 4],
      [0, 8, 85], [0, 8, 21], [16, 8, 258], [19, 7, 43], [0, 8, 117], [0, 8, 53], [0, 9, 202],
      [17, 7, 13], [0, 8, 101], [0, 8, 37], [0, 9, 170], [0, 8, 5], [0, 8, 133], [0, 8, 69],
      [0, 9, 234], [16, 7, 8], [0, 8, 93], [0, 8, 29], [0, 9, 154], [20, 7, 83], [0, 8, 125],
      [0, 8, 61], [0, 9, 218], [18, 7, 23], [0, 8, 109], [0, 8, 45], [0, 9, 186], [0, 8, 13],
      [0, 8, 141], [0, 8, 77], [0, 9, 250], [16, 7, 3], [0, 8, 83], [0, 8, 19], [21, 8, 195],
      [19, 7, 35], [0, 8, 115], [0, 8, 51], [0, 9, 198], [17, 7, 11], [0, 8, 99], [0, 8, 35],
      [0, 9, 166], [0, 8, 3], [0, 8, 131], [0, 8, 67], [0, 9, 230], [16, 7, 7], [0, 8, 91],
      [0, 8, 27], [0, 9, 150], [20, 7, 67], [0, 8, 123], [0, 8, 59], [0, 9, 214], [18, 7, 19],
      [0, 8, 107], [0, 8, 43], [0, 9, 182], [0, 8, 11], [0, 8, 139], [0, 8, 75], [0, 9, 246],
      [16, 7, 5], [0, 8, 87], [0, 8, 23], [64, 8, 0], [19, 7, 51], [0, 8, 119], [0, 8, 55],
      [0, 9, 206], [17, 7, 15], [0, 8, 103], [0, 8, 39], [0, 9, 174], [0, 8, 7], [0, 8, 135],
      [0, 8, 71], [0, 9, 238], [16, 7, 9], [0, 8, 95], [0, 8, 31], [0, 9, 158], [20, 7, 99],
      [0, 8, 127], [0, 8, 63], [0, 9, 222], [18, 7, 27], [0, 8, 111], [0, 8, 47], [0, 9, 190],
      [0, 8, 15], [0, 8, 143], [0, 8, 79], [0, 9, 254], [96, 7, 0], [0, 8, 80], [0, 8, 16],
      [20, 8, 115], [18, 7, 31], [0, 8, 112], [0, 8, 48], [0, 9, 193], [16, 7, 10], [0, 8, 96],
      [0, 8, 32], [0, 9, 161], [0, 8, 0], [0, 8, 128], [0, 8, 64], [0, 9, 225], [16, 7, 6],
      [0, 8, 88], [0, 8, 24], [0, 9, 145], [19, 7, 59], [0, 8, 120], [0, 8, 56], [0, 9, 209],
      [17, 7, 17], [0, 8, 104], [0, 8, 40], [0, 9, 177], [0, 8, 8], [0, 8, 136], [0, 8, 72],
      [0, 9, 241], [16, 7, 4], [0, 8, 84], [0, 8, 20], [21, 8, 227], [19, 7, 43], [0, 8, 116],
      [0, 8, 52], [0, 9, 201], [17, 7, 13], [0, 8, 100], [0, 8, 36], [0, 9, 169], [0, 8, 4],
      [0, 8, 132], [0, 8, 68], [0, 9, 233], [16, 7, 8], [0, 8, 92], [0, 8, 28], [0, 9, 153],
      [20, 7, 83], [0, 8, 124], [0, 8, 60], [0, 9, 217], [18, 7, 23], [0, 8, 108], [0, 8, 44],
      [0, 9, 185], [0, 8, 12], [0, 8, 140], [0, 8, 76], [0, 9, 249], [16, 7, 3], [0, 8, 82],
      [0, 8, 18], [21, 8, 163], [19, 7, 35], [0, 8, 114], [0, 8, 50], [0, 9, 197], [17, 7, 11],
      [0, 8, 98], [0, 8, 34], [0, 9, 165], [0, 8, 2], [0, 8, 130], [0, 8, 66], [0, 9, 229],
      [16, 7, 7], [0, 8, 90], [0, 8, 26], [0, 9, 149], [20, 7, 67], [0, 8, 122], [0, 8, 58],
      [0, 9, 213], [18, 7, 19], [0, 8, 106], [0, 8, 42], [0, 9, 181], [0, 8, 10], [0, 8, 138],
      [0, 8, 74], [0, 9, 245], [16, 7, 5], [0, 8, 86], [0, 8, 22], [64, 8, 0], [19, 7, 51],
      [0, 8, 118], [0, 8, 54], [0, 9, 205], [17, 7, 15], [0, 8, 102], [0, 8, 38], [0, 9, 173],
      [0, 8, 6], [0, 8, 134], [0, 8, 70], [0, 9, 237], [16, 7, 9], [0, 8, 94], [0, 8, 30],
      [0, 9, 157], [20, 7, 99], [0, 8, 126], [0, 8, 62], [0, 9, 221], [18, 7, 27], [0, 8, 110],
      [0, 8, 46], [0, 9, 189], [0, 8, 14], [0, 8, 142], [0, 8, 78], [0, 9, 253], [96, 7, 0],
      [0, 8, 81], [0, 8, 17], [21, 8, 131], [18, 7, 31], [0, 8, 113], [0, 8, 49], [0, 9, 195],
      [16, 7, 10], [0, 8, 97], [0, 8, 33], [0, 9, 163], [0, 8, 1], [0, 8, 129], [0, 8, 65],
      [0, 9, 227], [16, 7, 6], [0, 8, 89], [0, 8, 25], [0, 9, 147], [19, 7, 59], [0, 8, 121],
      [0, 8, 57], [0, 9, 211], [17, 7, 17], [0, 8, 105], [0, 8, 41], [0, 9, 179], [0, 8, 9],
      [0, 8, 137], [0, 8, 73], [0, 9, 243], [16, 7, 4], [0, 8, 85], [0, 8, 21], [16, 8, 258],
      [19, 7, 43], [0, 8, 117], [0, 8, 53], [0, 9, 203], [17, 7, 13], [0, 8, 101], [0, 8, 37],
      [0, 9, 171], [0, 8, 5], [0, 8, 133], [0, 8, 69], [0, 9, 235], [16, 7, 8], [0, 8, 93],
      [0, 8, 29], [0, 9, 155], [20, 7, 83], [0, 8, 125], [0, 8, 61], [0, 9, 219], [18, 7, 23],
      [0, 8, 109], [0, 8, 45], [0, 9, 187], [0, 8, 13], [0, 8, 141], [0, 8, 77], [0, 9, 251],
      [16, 7, 3], [0, 8, 83], [0, 8, 19], [21, 8, 195], [19, 7, 35], [0, 8, 115], [0, 8, 51],
      [0, 9, 199], [17, 7, 11], [0, 8, 99], [0, 8, 35], [0, 9, 167], [0, 8, 3], [0, 8, 131],
      [0, 8, 67], [0, 9, 231], [16, 7, 7], [0, 8, 91], [0, 8, 27], [0, 9, 151], [20, 7, 67],
      [0, 8, 123], [0, 8, 59], [0, 9, 215], [18, 7, 19], [0, 8, 107], [0, 8, 43], [0, 9, 183],
      [0, 8, 11], [0, 8, 139], [0, 8, 75], [0, 9, 247], [16, 7, 5], [0, 8, 87], [0, 8, 23],
      [64, 8, 0], [19, 7, 51], [0, 8, 119], [0, 8, 55], [0, 9, 207], [17, 7, 15], [0, 8, 103],
      [0, 8, 39], [0, 9, 175], [0, 8, 7], [0, 8, 135], [0, 8, 71], [0, 9, 239], [16, 7, 9],
      [0, 8, 95], [0, 8, 31], [0, 9, 159], [20, 7, 99], [0, 8, 127], [0, 8, 63], [0, 9, 223],
      [18, 7, 27], [0, 8, 111], [0, 8, 47], [0, 9, 191], [0, 8, 15], [0, 8, 143], [0, 8, 79],
      [0, 9, 255]].map{|i|Code.new(*i)}

  distfix = [
      [16, 5, 1], [23, 5, 257], [19, 5, 17], [27, 5, 4097], [17, 5, 5], [25, 5, 1025],
      [21, 5, 65], [29, 5, 16385], [16, 5, 3], [24, 5, 513], [20, 5, 33], [28, 5, 8193],
      [18, 5, 9], [26, 5, 2049], [22, 5, 129], [64, 5, 0], [16, 5, 2], [23, 5, 385],
      [19, 5, 25], [27, 5, 6145], [17, 5, 7], [25, 5, 1537], [21, 5, 97], [29, 5, 24577],
      [16, 5, 4], [24, 5, 769], [20, 5, 49], [28, 5, 12289], [18, 5, 13], [26, 5, 3073],
      [22, 5, 193], [64, 5, 0]].map{|i|Code.new(*i)}
  state.lencode = Bytef.new(lenfix)
  state.lenbits = 9
  state.distcode = Bytef.new(distfix)
  state.distbits = 5
end

.FLUSH_BLOCK_ONLY(s, eof) ⇒ Object

Flush the current block, with given end-of-file flag. IN assertion: strstart is set to the end of the current match.



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# File 'lib/pr/rbzlib.rb', line 2136

def FLUSH_BLOCK_ONLY(s, eof)
  if s.block_start >= (0)
    _tr_flush_block(s, s.window[(s.block_start)..-1],
                  (s.strstart - s.block_start), eof)
  else
    _tr_flush_block(s, nil,
                  (s.strstart - s.block_start), eof)
  end

  s.block_start = s.strstart
  flush_pending(s.strm)
end

.flush_pending(strm) ⇒ Object

Flush as much pending output as possible. All deflate() output goes through this function so some applications may wish to modify it to avoid allocating a large strm->next_out buffer and copying into it. (See also read_buf()).



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# File 'lib/pr/rbzlib.rb', line 1488

def flush_pending(strm)
  s = strm.state
  len = s.pending
  if len > strm.avail_out
    len = strm.avail_out
  end
  return if len == 0
  strm.next_out.buffer[strm.next_out.offset, len] = s.pending_out.current[0, len]
  strm.next_out += len
  s.pending_out += len
  strm.total_out += len
  strm.avail_out -= len
  s.pending -= len
  if s.pending == 0
    s.pending_out = Bytef.new(strm.state.pending_buf)
  end
end

.gen_bitlen(s, desc) ⇒ Object

Compute the optimal bit lengths for a tree and update the total bit length for the current block. IN assertion: the fields freq and dad are set, heap and

above are the tree nodes sorted by increasing frequency.

OUT assertions: the field len is set to the optimal bit length, the

array bl_count contains the frequencies for each bit length.
The length opt_len is updated; static_len is also updated if stree is
not null.



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# File 'lib/pr/rbzlib.rb', line 2735

def gen_bitlen(s, desc)
  tree = desc.dyn_tree
  max_code = desc.max_code
  stree = desc.stat_desc.static_tree
  extra = desc.stat_desc.extra_bits
  base = desc.stat_desc.extra_base
  max_length = desc.stat_desc.max_length
  overflow = 0

  for bits in 0 .. MAX_BITS
    s.bl_count[bits] = 0
  end

  tree[s.heap[s.heap_max]].dl = 0

  for h in s.heap_max + 1 ... HEAP_SIZE
    n = s.heap[h]
    bits = tree[tree[n].dl].dl + 1
    if bits > max_length
      bits = max_length
      overflow += 1
    end
    tree[n].dl = bits

    next if n > max_code

    s.bl_count[bits] += 1
    xbits = 0
    xbits = extra[n - base] if n >= base
    f = tree[n].fc
    s.opt_len += f * (bits + xbits)
    if stree
      s.static_len += f * (stree[n].dl + xbits)
    end
  end

  return if overflow == 0

  loop do
    bits = max_length - 1
    bits -= 1 while s.bl_count[bits] == 0
    s.bl_count[bits] -= 1
    s.bl_count[bits + 1] += 2
    s.bl_count[max_length] -= 1

    overflow -= 2
    break if overflow <= 0
  end

  h = HEAP_SIZE
  max_length.downto(1) do |nbits|
    n = s.bl_count[nbits]
    while n != 0
      h -= 1
      m = s.heap[h]
      next if m > max_code
      if tree[m].dl != nbits
        s.opt_len += (nbits - tree[m].dl) * tree[m].fc
        tree[m].dl = nbits
      end
      n -= 1
    end
  end
end

.gen_codes(tree, max_code, bl_count) ⇒ Object

Generate the codes for a given tree and bit counts (which need not be optimal). IN assertion: the array bl_count contains the bit length statistics for the given tree and the field len is set for all tree elements. OUT assertion: the field code is set for all tree elements of non

zero code length.



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# File 'lib/pr/rbzlib.rb', line 2646

def gen_codes(tree, max_code, bl_count)
  next_code = Array.new(MAX_BITS + 1, 0)
  code = 0
  for bits in 1 .. MAX_BITS
    code = ((code + bl_count[bits - 1]) << 1)
    next_code[bits] = code
  end

  for n in 0..max_code
    len = tree[n].dl
    next if len == 0
    tree[n].fc = bi_reverse(next_code[len], len)
    next_code[len] += 1
  end
end

.get_byte(s) ⇒ Object

Read a byte from a gz_stream; update next_in and avail_in. Return EOF for end of file. IN assertion: the stream s has been sucessfully opened for reading.



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# File 'lib/pr/rbzlib.rb', line 522

def get_byte(s)
  return Z_EOF if s.z_eof

  if s.stream.avail_in == 0
    begin
      s.inbuf = s.file.read(Z_BUFSIZE)
      s.stream.avail_in = s.inbuf.length if s.inbuf
    rescue
      s.inbuf = nil
      s.z_err = Z_ERRNO
    end

    if s.inbuf.nil?
      s.z_eof = true
      return Z_EOF
    end
    s.stream.next_in = Bytef.new(s.inbuf)
  end

  s.stream.avail_in -= 1
  _get_byte = s.stream.next_in.get
  s.stream.next_in += 1

  _get_byte
end

.get_crc_table ⇒ Object

Tables of CRC-32s of all single-byte values, made by make_crc_table().



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# File 'lib/pr/rbzlib.rb', line 297

def get_crc_table
  @@crc_table
end

.getLong(s) ⇒ Object

Reads a long in LSB order from the given gz_stream. Sets z_err in case of error.



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# File 'lib/pr/rbzlib.rb', line 550

def getLong(s)
  x = 0.chr * 4
  x[0] = get_byte(s).chr
  x[1] = get_byte(s).chr
  x[2] = get_byte(s).chr
  c = get_byte(s)
  x[3] = c.chr

  s.z_err = Z_DATA_ERROR if c == Z_EOF

  x.unpack('v').first
end

.gz_open(path, mode, fd) ⇒ Object

Opens a gzip (.gz) file for reading or writing. The mode parameter is as in fopen (“rb” or “wb”). The file is given either by file descriptor or path name (if fd == -1).

gz_open returns NULL if the file could not be opened or if there was insufficient memory to allocate the (de)compression state; errno can be checked to distinguish the two cases (if errno is zero, the zlib error is Z_MEM_ERROR).



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# File 'lib/pr/rbzlib.rb', line 372

def gz_open(path, mode, fd)
  return nil if path.nil? || mode.nil?

  s = Gz_stream.new
  s.stream = Z_stream.new

  level = Z_DEFAULT_COMPRESSION
  strategy = Z_DEFAULT_STRATEGY

  s.stream.next_in = nil
  s.stream.next_out = nil
  s.stream.avail_in = 0
  s.stream.avail_out = 0
  s.stream.msg = ''

  s.file = nil
  s.z_err = Z_OK
  s.z_eof = false
  s.inbuf = nil
  s.outbuf = nil
  s.in = 0
  s.out = 0
  s.back = Z_EOF
  s.crc = crc32(0, nil)
  s.msg = ''
  s.transparent = false
  s.path = path.dup
  s.mode = nil

  fmode = ''

  mode.each_byte do |c|
    s.mode = 'r' if c == ?r.ord
    s.mode = 'w' if c == ?w.ord || c == ?a.ord

    if c >= ?0.ord && c <= ?9.ord
      level = c - ?0.ord
    elsif c == ?f.ord
      strategy = Z_FILTERED
    elsif c == ?h.ord
      strategy = Z_HUFFMAN_ONLY
    elsif c == ?R.ord
      strategy = Z_RLE
    else
      fmode += c.chr
    end
  end

  if s.mode.nil?
    destroy(s)
    return nil
  end

  if s.mode == 'w'
    err = deflateInit2(
      s.stream,
      level,
      Z_DEFLATED,
      -MAX_WBITS,
      DEF_MEM_LEVEL,
      strategy
    )

    s.outbuf = 0.chr * Z_BUFSIZE
    s.stream.next_out = Bytef.new(s.outbuf)

    if err != Z_OK || s.outbuf.nil?
      destroy(s)
      return nil
    end
  else
    s.inbuf = 0.chr * Z_BUFSIZE
    s.stream.next_in = Bytef.new(s.inbuf)

    err = inflateInit2_(s.stream, -MAX_WBITS, ZLIB_VERSION, s.stream.size)

    if err != Z_OK || s.inbuf.nil?
      destroy(s)
      return nil
    end
  end

  s.stream.avail_out = Z_BUFSIZE

  s.file = fd < 0 ? File.new(path, fmode) : IO.new(fd, fmode)

  if s.mode == 'w'
    gzheader = 0.chr * 10
    gzheader[0] = @@gz_magic[0]
    gzheader[1] = @@gz_magic[1]
    gzheader[2] = Z_DEFLATED.chr
    gzheader[3] = 0.chr
    gzheader[4] = 0.chr
    gzheader[5] = 0.chr
    gzheader[6] = 0.chr
    gzheader[7] = 0.chr
    gzheader[8] = 0.chr
    gzheader[9] = OS_CODE.chr
    s.file.write(gzheader)
    s.start = 10
  else
    check_header(s)
    s.start = s.file.pos - s.stream.avail_in
  end

  s
end

.gzclearerr(file) ⇒ Object

Clear the error and end-of-file flags, and do the same for the real file.



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# File 'lib/pr/rbzlib.rb', line 1176

def gzclearerr(file)
  s = file
  return if s.nil?
  s.z_err = Z_OK if s.z_err != Z_STREAM_END
  s.z_eof = false

end

.gzclose(file) ⇒ Object

Flushes all pending output if necessary, closes the compressed file and deallocates all the (de)compression state.



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# File 'lib/pr/rbzlib.rb', line 1123

def gzclose(file)
  s = file

  if s.nil?
    return Z_STREAM_ERROR
  end

  if s.mode == 'w'
    err = do_flush(file, Z_FINISH)
    if err != Z_OK
      return destroy(file)
    end

    putLong(s.file, s.crc)
    putLong(s.file, s.in & 0xffffffff)
  end

  destroy(file)
end

.gzdirect(file) ⇒ Object

Returns 1 if reading and doing so transparently, otherwise zero.



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# File 'lib/pr/rbzlib.rb', line 1104

def gzdirect(file)
  s = file

  return false if s.nil? || s.mode != 'r'
  s.transparent
end

.gzdopen(fd, mode) ⇒ Object

Associate a gzFile with the file descriptor fd. fd is not dup’ed here to mimic the behavio(u)r of fdopen.



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# File 'lib/pr/rbzlib.rb', line 489

def gzdopen(fd, mode)
  return nil if fd < 0
  name = "<fd:#{fd}"
  gz_open(name, mode, fd)
end

.gzeof(file) ⇒ Object

Returns 1 when EOF has previously been detected reading the given input stream, otherwise zero.



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# File 'lib/pr/rbzlib.rb', line 1095

def gzeof(file)
  s = file

  return false if s.nil? || (s.mode != 'r')
  return s.z_eof if s.z_eof
  s.z_err == Z_STREAM_END
end

.gzerror(file, errnum) ⇒ Object

Returns the error message for the last error which occurred on the given compressed file. errnum is set to zlib error number. If an error occurred in the file system and not in the compression library, errnum is set to Z_ERRNO and the application may consult errno



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# File 'lib/pr/rbzlib.rb', line 1147

def gzerror(file, errnum)
  s = file

  if s.nil?
    errnum = Z_STREAM_ERROR
    return zError(errnum)
  end

  errnum = s.z_err

  if errnum == Z_OK
    return zError(Z_OK)
  end

  m = s.stream.msg

  if errnum == Z_ERRNO
    m = ''
  end

  if m == ''
    m = zError(s.z_err)
  end

  s.msg = s.path + ': ' + m
  s.msg
end

.gzflush(file, flush) ⇒ Object

Flush output file.



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# File 'lib/pr/rbzlib.rb', line 958

def gzflush(file, flush)
  s = file
  err = do_flush(file, flush)

  if err != 0
    return err
  end

  if s.z_err == Z_STREAM_END
    Z_OK
  else
    s.z_err
  end
end

.gzgetc(file) ⇒ Object

Reads one byte from the compressed file. gzgetc returns this byte or -1 in case of end of file or error.



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# File 'lib/pr/rbzlib.rb', line 805

def gzgetc(file)
  c = 0.chr
  if gzread(file, c, 1) == 1
    c
  else
    -1
  end
end

.gzgets(file, buf, len) ⇒ Object

Reads bytes from the compressed file until len-1 characters are read, or a newline character is read and transferred to buf, or an end-of-file condition is encountered. The string is then terminated with a null character.

Returns buf, or Z_NULL in case of error.



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# File 'lib/pr/rbzlib.rb', line 834

def gzgets(file, buf, len)
  return nil if buf.nil? || (len <= 0)

  i = 0
  gzchar = 0.chr

  loop do
    len -= 1
    bytes = gzread(file, gzchar, 1)
    buf[i] = gzchar[0]
    i += 1
    break if len == 0 || (bytes != 1) || (gzchar == 13.chr)
  end

  buf[i..-1] = ''
  buf.chomp!(0.chr)

  if i == 0 && (len > 0)
    nil
  else
    buf
  end
end

.gzopen(path, mode) ⇒ Object

Opens a gzip (.gz) file for reading or writing.



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# File 'lib/pr/rbzlib.rb', line 482

def gzopen(path, mode)
  gz_open(path, mode, -1)
end

.gzputc(file, c) ⇒ Object

Writes c, converted to an unsigned char, into the compressed file. gzputc returns the value that was written, or -1 in case of error.



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# File 'lib/pr/rbzlib.rb', line 896

def gzputc(file, c)
  if gzwrite(file, c, 1) == 1
    c
  else
    -1
  end
end

.gzputs(file, s) ⇒ Object

Writes the given null-terminated string to the compressed file, excluding the terminating null character.

gzputs returns the number of characters written, or -1 in case of error.



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# File 'lib/pr/rbzlib.rb', line 907

def gzputs(file, s)
  gzwrite(file, s, s.length)
end

.gzread(file, buf, len) ⇒ Object

Reads the given number of uncompressed bytes from the compressed file. gzread returns the number of bytes actually read (0 for end of file).



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# File 'lib/pr/rbzlib.rb', line 683

def gzread(file, buf, len)
  s = file
  start = Bytef.new(buf)

  if s.nil? || s.mode != 'r'
    return Z_STREAM_ERROR
  end

  return -1 if (s.z_err == Z_DATA_ERROR) || (s.z_err == Z_ERRNO)
  return 0 if s.z_err == Z_STREAM_END

  next_out = Bytef.new(buf)
  s.stream.next_out = Bytef.new(buf)
  s.stream.avail_out = len

  if s.stream.avail_out != 0 && s.back != Z_EOF
    next_out.set(s.back)
    next_out += 1
    s.stream.next_out += 1
    s.stream.avail_out -= 1
    s.back = Z_EOF
    s.out += 1
    start += 1

    if s.last
      s.z_err = Z_STREAM_END
      return 1
    end
  end

  while s.stream.avail_out != 0
    if s.transparent
      n = s.stream.avail_in

      if n > s.stream.avail_out
        n = s.stream.avail_out
      end

      if n > 0
        s.stream.next_out.buffer[s.stream.next_out.offset, n] = s.stream.next_in.current[0, n]
        next_out += n
        s.stream.next_out.offset = next_out.offset
        s.stream.next_in += n
        s.stream.avail_out -= n
        s.stream.avail_in -= n
      end

      if s.stream.avail_out > 0
        buff = s.file.read(s.stream.avail_out)
        if buff
          next_out.buffer[next_out.offset, buff.length] = buff
          s.stream.avail_out -= buff.length
        end
      end

      len -= s.stream.avail_out
      s.in += len
      s.out += len

      if len == 0
        s.z_eof = true
      end

      return len
    end

    if s.stream.avail_in == 0 && !s.z_eof
      begin
        buf = s.file.read(Z_BUFSIZE)
        if buf
          s.inbuf[0, buf.length] = buf
          s.stream.avail_in = buf.length
        else
          s.stream.avail_in = 0
        end
      rescue
        s.z_err = Z_ERRNO
      end

      if s.stream.avail_in == 0
        s.z_eof = true
        break if s.z_err == Z_ERRNO
      end
      s.stream.next_in = Bytef.new(s.inbuf)
    end

    s.in += s.stream.avail_in
    s.out += s.stream.avail_out
    s.z_err = inflate(s.stream, Z_NO_FLUSH)
    s.in -= s.stream.avail_in
    s.out -= s.stream.avail_out

    if s.z_err == Z_STREAM_END
      s.crc = crc32(s.crc, start.current, s.stream.next_out.offset - start.offset)
      start = s.stream.next_out.dup
      if getLong(s) != s.crc
        s.z_err = Z_DATA_ERROR
      else
        getLong(s)
        check_header(s)
        if s.z_err == Z_OK
          inflateReset(s.stream)
          s.crc = crc32(0, nil)
        end
      end
    end

    break if s.z_err != Z_OK || s.z_eof
  end

  s.crc = crc32(s.crc, start.current, s.stream.next_out.offset - start.offset)

  if len == s.stream.avail_out && (s.z_err == Z_DATA_ERROR || s.z_err == Z_ERRNO)
    return -1
  end

  len - s.stream.avail_out
end

.gzrewind(file) ⇒ Object

Rewinds input file.



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# File 'lib/pr/rbzlib.rb', line 974

def gzrewind(file)
  s = file

  if s.nil? || (s.mode != 'r')
    return -1
  end

  s.z_err = Z_OK
  s.z_eof = false
  s.stream.avail_in = 0
  s.stream.next_in = Bytef.new(s.inbuf)
  s.crc = crc32(0, nil)
  if !s.transparent
    inflateReset(s.stream)
  end
  s.in = 0
  s.out = 0
  s.file.seek(s.start, SEEK_SET)
end

.gzseek(file, offset, whence) ⇒ Object

Sets the starting position for the next gzread or gzwrite on the given compressed file. The offset represents a number of bytes in the

gzseek returns the resulting offset location as measured in bytes from

the beginning of the uncompressed stream, or -1 in case of error.

SEEK_END is not implemented, returns error.
In this version of the library, gzseek can be extremely slow.



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# File 'lib/pr/rbzlib.rb', line 1000

def gzseek(file, offset, whence)
  s = file

  if s.nil? || (whence == SEEK_END) || (s.z_err == Z_ERRNO) ||
         (s.z_err == Z_DATA_ERROR)
    return(-1)
  end

  if s.mode == 'w'
    if whence == SEEK_SET
      offset -= s.in
    end
    if offset < 0
      return(-1)
    end

    if s.inbuf.nil?
      s.inbuf = 0.chr * Z_BUFSIZE
    end

    while offset > 0
      size = Z_BUFSIZE
      if offset < Z_BUFSIZE
        size = offset
      end

      size = gzwrite(file, s.inbuf, size)
      if size == 0
        return(-1)
      end

      offset -= size
    end

    return(s.in)
  end

  if whence == SEEK_CUR
    offset += s.out
  end
  if offset < 0
    return(-1)
  end

  if s.transparent
    s.back = Z_EOF
    s.stream.avail_in = 0
    s.stream.next_in = Bytef.new(s.inbuf)
    s.file.seek(offset, SEEK_SET)

    s.in = offset
    s.out = offset
    return offset
  end

  if offset >= s.out
    offset -= s.out
  elsif gzrewind(file) < 0
    return(-1)
  end

  if offset != 0 && s.outbuf.nil?
    s.outbuf = 0.chr * Z_BUFSIZE
  end
  if offset != 0 && s.back != Z_EOF
    s.back = Z_EOF
    s.out += 1
    offset -= 1
    s.z_err = Z_STREAM_END if s.last
  end
  while offset > 0
    size = Z_BUFSIZE
    if offset < Z_BUFSIZE
      size = offset
    end
    size = gzread(file, s.outbuf, size)

    if size <= 0
      return(-1)
    end
    offset -= size
  end

  s.out
end

.gzsetparams(file, level, strategy) ⇒ Object

Update the compression level and strategy



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# File 'lib/pr/rbzlib.rb', line 497

def gzsetparams(file, level, strategy)
  s = file

  if s.nil? || s.mode != 'w'
    return Z_STREAM_ERROR
  end

  if s.stream.avail_out == 0
    s.stream.next_out = Bytef.new(s.outbuf)
    written = s.file.write(s.outbuf)

    if written != Z_BUFSIZE
      s.z_err = Z_ERRNO
    end

    s.stream.avail_out = Z_BUFSIZE
  end

  deflateParams(s.stream, level, strategy)
end

.gztell(file) ⇒ Object

Returns the starting position for the next gzread or gzwrite on the given compressed file. This position represents a number of bytes in the uncompressed data stream.



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# File 'lib/pr/rbzlib.rb', line 1089

def gztell(file)
  gzseek(file, 0, SEEK_CUR)
end

.gzungetc(c, file) ⇒ Object

Push one byte back onto the stream.



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# File 'lib/pr/rbzlib.rb', line 816

def gzungetc(c, file)
  s = file
  return Z_EOF if s.nil? || s.mode != 'r' || c == Z_EOF || s.back != Z_EOF
  s.back = c
  s.out -= 1
  s.last = (s.z_err == Z_STREAM_END)
  s.z_err = Z_OK if s.last
  s.z_eof = false
  c
end

.gzwrite(file, buf, len) ⇒ Object

Writes the given number of uncompressed bytes into the compressed file. gzwrite returns the number of bytes actually written (0 in case of error).



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# File 'lib/pr/rbzlib.rb', line 860

def gzwrite(file, buf, len)
  s = file
  if s.nil? || (s.mode != 'w')
    return Z_STREAM_ERROR
  end

  s.stream.next_in = Bytef.new(buf)
  s.stream.avail_in = len
  while s.stream.avail_in != 0
    if s.stream.avail_out == 0
      s.stream.next_out = Bytef.new(s.outbuf)
      written = s.file.write(s.outbuf)
      if written != Z_BUFSIZE
        s.z_err = Z_ERRNO
        break
      end
      s.stream.avail_out = Z_BUFSIZE
    end

    prev_avail_in = s.stream.avail_in
    s.z_err = deflate(s.stream, Z_NO_FLUSH)
    # Track how many input bytes were consumed
    consumed = prev_avail_in - s.stream.avail_in
    s.in += consumed

    break if s.z_err != Z_OK
  end

  # Calculate CRC only on the actually processed data
  processed_len = len - s.stream.avail_in
  s.crc = crc32(s.crc, buf, processed_len)
  processed_len
end

.inflate(strm, flush) ⇒ Object

inflate() uses a state machine to process as much input data and generate as much output data as possible before returning. The state machine is structured roughly as follows:

for (;;) switch (state) {
...
case STATEn:
    if (not enough input data or output space to make progress)
        return;
    ... make progress ...
    state = STATEm;
    break;
...
}

so when inflate() is called again, the same case is attempted again, and if the appropriate resources are provided, the machine proceeds to the next state. The NEEDBITS() macro is usually the way the state evaluates whether it can proceed or should return. NEEDBITS() does the return if the requested bits are not available. The typical use of the BITS macros is:

NEEDBITS(n);
... do something with BITS(n) ...
DROPBITS(n);

where NEEDBITS(n) either returns from inflate() if there isn’t enough input left to load n bits into the accumulator, or it continues. BITS(n) gives the low n bits in the accumulator. When done, DROPBITS(n) drops the low n bits off the accumulator. INITBITS() clears the accumulator and sets the number of available bits to zero. BYTEBITS() discards just enough bits to put the accumulator on a byte boundary. After BYTEBITS() and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.

NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return if there is no input available. The decoding of variable length codes uses PULLBYTE() directly in order to pull just enough bytes to decode the next code, and no more.

Some states loop until they get enough input, making sure that enough state information is maintained to continue the loop where it left off if NEEDBITS() returns in the loop. For example, want, need, and keep would all have to actually be part of the saved state in case NEEDBITS() returns:

case STATEw:
    while (want < need) {
        NEEDBITS(n);
        keep[want++] = BITS(n);
        DROPBITS(n);
    }
    state = STATEx;
case STATEx:

As shown above, if the next state is also the next case, then the break is omitted.

A state may also return if there is not enough output space available to complete that state. Those states are copying stored data, writing a literal byte, and copying a matching string.

When returning, a “goto inf_leave” is used to update the total counters, update the check value, and determine whether any progress has been made during that inflate() call in order to return the proper return code. Progress is defined as a change in either strm->avail_in or strm->avail_out. When there is a window, goto inf_leave will update the window with the last output written. If a goto inf_leave occurs in the middle of decompression and there is no window currently, goto inf_leave will create one and copy output to the window for the next call of inflate().

In this implementation, the flush parameter of inflate() only affects the return code (per zlib.h). inflate() always writes as much as possible to strm->next_out, given the space available and the provided input–the effect documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers the allocation of and copying into a sliding window until necessary, which provides the effect documented in zlib.h for Z_FINISH when the entire input stream available. So the only thing the flush parameter actually does is: when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it will return Z_BUF_ERROR if it has not reached the end of the stream.



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# File 'lib/pr/rbzlib.rb', line 4191

def inflate(strm, flush)
  order = [
      16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15]

  if strm.nil? || strm.state.nil? || strm.next_out.nil? ||
      (strm.next_in.nil? && strm.avail_in != 0)
    return Z_STREAM_ERROR
  end

  state = strm.state
  state.mode = TYPEDO  if state.mode == TYPE
  LOAD(strm, state)
  _in = @@have
  out = @@left
  ret = Z_OK

  catch :inf_leave do
    loop do
      if state.mode == HEAD
        if state.wrap == 0
          state.mode = TYPEDO
          next
        end
        NEEDBITS(16)
        if (state.wrap & 2) != 0 && @@hold == 0x8b1f
          state.check = crc32(0, nil)
          state.check = CRC2(state.check, @@hold)
          INITBITS()
          state.mode = FLAGS
          next
        end
        state.flags = 0
        if state.head
          state.head.done = -1
        end
        if ((state.wrap & 1) == 0 ||
            ((BITS(8) << 8) + (@@hold >> 8)) % 31) != 0
          strm.msg = 'incorrect header check'
          state.mode = BAD
          next
        end
        if BITS(4) != Z_DEFLATED
          strm.msg = 'unknown compression method'
          state.mode = BAD
          next
        end
        DROPBITS(4)
        len = BITS(4) + 8
        if len > state.wbits
          strm.msg = 'invalid window size'
          state.mode = BAD
          next
        end
        state.dmax = 1 << len
        strm.adler = state.check = adler32(0, nil)
        state.mode = (@@hold & 0x200) != 0 ? DICTID : TYPE
        INITBITS()
      end
      if state.mode == FLAGS
        NEEDBITS(16)
        state.flags = (@@hold)
        if (state.flags & 0xff) != Z_DEFLATED
          strm.msg = 'unknown compression method'
          state.mode = BAD
          next
        end
        if (state.flags & 0xe000) != 0
          strm.msg = 'unknown header flags set'
          state.mode = BAD
          next
        end
        if state.head
          state.head.text = ((@@hold >> 8) & 1)
        end
        state.check = CRC2(state.check, @@hold) if (state.flags & 0x0200) != 0
        INITBITS()
        state.mode = TIME
      end
      if state.mode == TIME
        NEEDBITS(32)
        if state.head
          state.head.time = @@hold
        end
        state.check = CRC4(state.check, @@hold) if (state.flags & 0x0200) != 0
        INITBITS()
        state.mode = OS
      end
      if state.mode == OS
        NEEDBITS(16)
        if state.head
          state.head.xflags = (@@hold & 0xff)
          state.head.os = (@@hold >> 8)
        end
        state.check = CRC2(state.check, @@hold) if (state.flags & 0x0200) != 0
        INITBITS()
        state.mode = EXLEN
      end
      if state.mode == EXLEN
        if (state.flags & 0x0400) != 0
          NEEDBITS(16)
          state.length = @@hold
          if state.head
            state.head.extra_len = @@hold
          end
          state.check = CRC2(state.check, @@hold) if (state.flags & 0x0200) != 0
          INITBITS()
        elsif state.head
          state.head.extra = nil
        end
        state.mode = EXTRA
      end
      if state.mode == EXTRA
        if (state.flags & 0x0400) != 0
          copy = state.length
          copy = @@have if copy > @@have
          if copy != 0
            if state.head && state.head.extra
              len = state.head.extra_len - state.length
              l = len + copy > state.head.extra_max ?
                      state.head.extra_max - len : copy
              state.head.extra[len, l] = @@next.current[0, l]
            end
            if (state.flags & 0x0200) != 0
              state.check = crc32(state.check, @@next.current, copy)
            end
            @@have -= copy
            @@next += copy
            state.length -= copy
          end
          throw :inf_leave if state.length != 0
        end
        state.length = 0
        state.mode = NAME
      end
      if state.mode == NAME
        if (state.flags & 0x0800) != 0
          throw :inf_leave if @@have == 0
          copy = 0
          loop do
            len = (@@next[copy])
            copy += 1
            if state.head && state.head.name &&
                    state.length < state.head.name_max
              state.head.name[state.length] = len
              state.length += 1
            end
            break unless len != 0 && copy < @@have
          end
          if (state.flags & 0x0200) != 0
            state.check = crc32(state.check, @@next.current, copy)
          end
          @@have -= copy
          @@next += copy
          throw :inf_leave if len != 0
        elsif state.head
          state.head.name = nil
        end
        state.length = 0
        state.mode = COMMENT
      end
      if state.mode == COMMENT
        if (state.flags & 0x1000) != 0
          throw :inf_leave if @@have == 0
          copy = 0
          loop do
            len = (@@next[copy])
            copy += 1
            if state.head && state.head.comment &&
                    state.length < state.head.comm_max
              state.head.comment[state.length] = len
              state.length += 1
            end
            break unless len != 0 && copy < have
          end
          if (state.flags & 0x0200) != 0
            state.check = crc32(state.check, @@next.current, copy)
          end
          @@have -= copy
          @@next += copy
          throw :inf_leave if len != 0
        elsif state.head
          state.head.comment = nil
        end
        state.mode = HCRC
      end
      if state.mode == HCRC
        if (state.flags & 0x0200) != 0
          NEEDBITS(16)
          if @@hold != (state.check & 0xffff)
            strm.msg = 'header crc mismatch'
            state.mode = BAD
            next
          end
          INITBITS()
        end
        if state.head
          state.head.hcrc = ((state.flags >> 9) & 1)
          state.head.done = 1
        end
        strm.adler = state.check = crc32(0, nil)
        state.mode = TYPE
      end
      if state.mode == DICTID
        NEEDBITS(32)
        strm.adler = state.check = REVERSE(@@hold)
        INITBITS()
        state.mode = DICT
      end
      if state.mode == DICT
        if state.havedict == 0
          RESTORE(strm, state)
          return Z_NEED_DICT
        end
        strm.adler = state.check = adler32(0, nil)
        state.mode = TYPE
      end
      if state.mode == TYPE
        throw :inf_leave if flush == Z_BLOCK
      end
      if [TYPE, TYPEDO].include?(state.mode)
        if state.last != 0
          BYTEBITS()
          state.mode = CHECK
          next
        end
        NEEDBITS(3)
        state.last = BITS(1)
        DROPBITS(1)
        case BITS(2)
        when 0
          state.mode = STORED
        when 1
          fixedtables(state)
          state.mode = LEN
        when 2
          state.mode = TABLE
        when 3
          strm.msg = 'invalid block type'
          state.mode = BAD
        end
        DROPBITS(2)
      end
      if state.mode == STORED
        BYTEBITS()
        NEEDBITS(32)
        if (@@hold & 0xffff) != ((@@hold >> 16) ^ 0xffff)
          strm.msg = 'invalid stored block lengths'
          state.mode = BAD
          next
        end
        state.length = @@hold & 0xffff
        INITBITS()
        state.mode = COPY
      end
      if state.mode == COPY
        copy = state.length
        if copy != 0
          copy = @@have if copy > @@have
          copy = @@left if copy > @@left
          throw :inf_leave if copy == 0
          @@put.buffer[@@put.offset, copy] = @@next.current[0, copy]
          @@have -= copy
          @@next += copy
          @@left -= copy
          @@put += copy
          state.length -= copy
          next
        end
        state.mode = TYPE
      end
      if state.mode == TABLE
        NEEDBITS(14)
        state.nlen = BITS(5) + 257
        DROPBITS(5)
        state.ndist = BITS(5) + 1
        DROPBITS(5)
        state.ncode = BITS(4) + 4
        DROPBITS(4)
        if state.nlen > 286 || state.ndist > 30
          strm.msg = 'too many length or distance symbols'
          state.mode = BAD
          next
        end
        state.have = 0
        state.mode = LENLENS
      end
      if state.mode == LENLENS
        while state.have < state.ncode
          NEEDBITS(3)
          state.lens[order[state.have]] = BITS(3)
          state.have += 1
          DROPBITS(3)
        end
        while state.have < 19
          state.lens[order[state.have]] = 0
          state.have += 1
        end
        state.next = Bytef.new(state.codes)
        state.lencode = Bytef.new(state.codes)
        state.lenbits = 7
        ret, state.lenbits, state.next.offset = inflate_table(CODES, state.lens, 19, state.codes,
          state.next.offset, state.lenbits, state.work)

        if ret != 0
          strm.msg = 'invalid code lengths set'
          state.mode = BAD
          next
        end
        state.have = 0
        state.mode = CODELENS
      end
      if state.mode == CODELENS
        while state.have < state.nlen + state.ndist
          this = nil
          loop do
            this = state.lencode[BITS(state.lenbits)]
            break if (this.bits) <= @@bits
            PULLBYTE()
          end
          if this.val < 16
            NEEDBITS(this.bits)
            DROPBITS(this.bits)
            state.lens[state.have] = this.val
            state.have += 1
          else
            if this.val == 16
              NEEDBITS(this.bits + 2)
              DROPBITS(this.bits)
              if state.have == 0
                strm.msg = 'invalid bit length repeat'
                state.mode = BAD
                break
              end
              len = state.lens[state.have - 1]
              copy = 3 + BITS(2)
              DROPBITS(2)
            elsif this.val == 17
              NEEDBITS(this.bits + 3)
              DROPBITS(this.bits)
              len = 0
              copy = 3 + BITS(3)
              DROPBITS(3)
            else
              NEEDBITS(this.bits + 7)
              DROPBITS(this.bits)
              len = 0
              copy = 11 + BITS(7)
              DROPBITS(7)
            end
            if state.have + copy > state.nlen + state.ndist
              strm.msg = 'invalid bit length repeat'
              state.mode = BAD
              break
            end
            while copy != 0
              copy -= 1
              state.lens[state.have] = len
              state.have += 1
            end
          end
        end

        next if state.mode == BAD

        state.next = Bytef.new(state.codes)
        state.lencode = Bytef.new(state.codes)
        state.lenbits = 9
        ret, state.lenbits, state.next.offset = inflate_table(LENS, state.lens, state.nlen,
          state.codes, state.next.offset, state.lenbits, state.work)
        if ret != 0
          strm.msg = 'invalid literal/lengths set'
          state.mode = BAD
          next
        end
        state.distcode = Bytef.new(state.codes, state.next.offset)
        state.distbits = 6
        ret, state.distbits, state.next.offset = inflate_table(DISTS, state.lens + state.nlen, state.ndist,
                        state.codes, state.next.offset, state.distbits, state.work)
        if ret != 0
          strm.msg = 'invalid distances set'
          state.mode = BAD
          next
        end
        state.mode = LEN
      end
      if state.mode == LEN
        if @@have >= 6 && @@left >= 258
          RESTORE(strm, state)
          inflate_fast(strm, out)
          LOAD(strm, state)
          next
        end
        this = nil
        loop do
          this = state.lencode[BITS(state.lenbits)]
          break if (this.bits) <= @@bits
          PULLBYTE()
        end
        if this.op != 0 && (this.op & 0xf0) == 0
          last = this
          loop do
            this = state.lencode[last.val +
                    (BITS(last.bits + last.op) >> last.bits)]
            break if (last.bits + this.bits) <= @@bits
            PULLBYTE()
          end
          DROPBITS(last.bits)
        end
        DROPBITS(this.bits)
        state.length = this.val
        if this.op == 0
          state.mode = LIT
          next
        end
        if (this.op & 32) != 0
          state.mode = TYPE
          next
        end
        if (this.op & 64) != 0
          strm.msg = 'invalid literal/length code'
          state.mode = BAD
          next
        end
        state.extra = (this.op) & 15
        state.mode = LENEXT
      end
      if state.mode == LENEXT
        if state.extra != 0
          NEEDBITS(state.extra)
          state.length += BITS(state.extra)
          DROPBITS(state.extra)
        end
        state.mode = DIST
      end
      if state.mode == DIST
        loop do
          this = state.distcode[BITS(state.distbits)]
          break if (this.bits) <= @@bits
          PULLBYTE()
        end
        if (this.op & 0xf0) == 0
          last = this
          loop do
            this = state.distcode[last.val +
                    (BITS(last.bits + last.op) >> last.bits)]
            break if (last.bits + this.bits) <= @@bits
            PULLBYTE()
          end
          DROPBITS(last.bits)
        end
        DROPBITS(this.bits)
        if (this.op & 64) != 0
          strm.msg = 'invalid distance code'
          state.mode = BAD
          next
        end
        state.offset = this.val
        state.extra = (this.op) & 15
        state.mode = DISTEXT
      end
      if state.mode == DISTEXT
        if state.extra != 0
          NEEDBITS(state.extra)
          state.offset += BITS(state.extra)
          DROPBITS(state.extra)
        end
        if state.offset > state.whave + out - @@left
          strm.msg = 'invalid distance too far back'
          state.mode = BAD
          next
        end
        state.mode = MATCH
      end
      if state.mode == MATCH
        throw :inf_leave if @@left == 0
        copy = out - @@left
        if state.offset > copy
          copy = state.offset - copy
          if copy > state.write
            copy -= state.write
            from = Bytef.new(state.window, state.wsize - copy)
          else
            from = Bytef.new(state.window, state.write - copy)
          end
          copy = state.length if copy > state.length
        else
          from = Bytef.new(@@put, @@put.offset - state.offset)
          copy = state.length
        end
        copy = @@left if copy > @@left
        @@left -= copy
        state.length -= copy
        loop do
          @@put.set(from.get)
          @@put += 1
          from += 1
          copy -= 1
          break if copy == 0
        end
        state.mode = LEN if state.length == 0
      end
      if state.mode == LIT
        throw :inf_leave if @@left == 0
        @@put.set(state.length)
        @@put += 1
        @@left -= 1
        state.mode = LEN
      end
      if state.mode == CHECK
        if state.wrap != 0
          NEEDBITS(32)
          out -= @@left
          strm.total_out += out
          state.total += out
          if out != 0
            strm.adler = state.check =
                UPDATE(state, state.check, @@put.buffer[@@put.offset - out, out])
          end
          out = @@left
          if (state.flags != 0 ? @@hold : REVERSE(@@hold)) != state.check
            strm.msg = 'incorrect data check'
            state.mode = BAD
            next
          end
          INITBITS()
        end
        state.mode = LENGTH
      end
      if state.mode == LENGTH
        if state.wrap != 0 && state.flags != 0
          NEEDBITS(32)
          if @@hold != (state.total & 0xffffffff)
            strm.msg = 'incorrect length check'
            state.mode = BAD
            next
          end
          INITBITS()
        end
        state.mode = DONE
      end
      if state.mode == DONE
        ret = Z_STREAM_END
        throw :inf_leave
      end
      if state.mode == BAD
        ret = Z_DATA_ERROR
        throw :inf_leave
      elsif state.mode == MEM
        return Z_MEM_ERROR
      elsif state.mode == SYNC
        return Z_STREAM_ERROR
      end
    end
  end

  RESTORE(strm, state)

  if state.wsize != 0 || (state.mode < CHECK && out != strm.avail_out)
    if updatewindow(strm, out)
      state.mode = MEM
      return Z_MEM_ERROR
    end
  end

  _in -= strm.avail_in
  out -= strm.avail_out
  strm.total_in += _in
  strm.total_out += out
  state.total += out

  if state.wrap != 0 && out != 0
    strm.adler = state.check =
        UPDATE(state, state.check, strm.next_out.buffer[strm.next_out.offset - out, out])
  end
  strm.data_type = state.bits + (state.last != 0 ? 64 : 0) +
                    (state.mode == TYPE ? 128 : 0)
  if ((_in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK
    ret = Z_BUF_ERROR
  end
  ret
end

.inflate_fast(strm, start) ⇒ Object

Decode literal, length, and distance codes and write out the resulting literal and match bytes until either not enough input or output is available, an end-of-block is encountered, or a data error is encountered. When large enough input and output buffers are supplied to inflate(), for example, a 16K input buffer and a 64K output buffer, more than 95% of the inflate execution time is spent in this routine.

Entry assumptions:

state->mode == LEN
strm->avail_in >= 6
strm->avail_out >= 258
start >= strm->avail_out
state->bits < 8

On return, state->mode is one of:

LEN -- ran out of enough output space or enough available input
TYPE -- reached end of block code, inflate() to interpret next block
BAD -- error in block data

Notes:

- The maximum input bits used by a length/distance pair is 15 bits for the
  length code, 5 bits for the length extra, 15 bits for the distance code,
  and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
  Therefore if strm->avail_in >= 6, then there is enough input to avoid
  checking for available input while decoding.

- The maximum bytes that a single length/distance pair can output is 258
  bytes, which is the maximum length that can be coded.  inflate_fast()
  requires strm->avail_out >= 258 for each loop to avoid checking for
  output space.



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# File 'lib/pr/rbzlib.rb', line 3514

def inflate_fast(strm, start)
  state = strm.state
  _in = Bytef.new(strm.next_in, strm.next_in.offset - 1)
  last = Bytef.new(_in, _in.offset + (strm.avail_in - 5))
  out = Bytef.new(strm.next_out, strm.next_out.offset - 1)
  beg = Bytef.new(out, out.offset - (start - strm.avail_out))
  _end = Bytef.new(out, out.offset + (strm.avail_out - 257))
  wsize = state.wsize
  whave = state.whave
  write = state.write
  window = state.window
  hold = state.hold
  bits = state.bits
  lcode = state.lencode
  dcode = state.distcode
  lmask = (1 << state.lenbits) - 1
  dmask = (1 << state.distbits) - 1
  status = nil
  this = nil

  op = -1
  len = -1

  loop do
    if status.nil?
      if bits < 15
        _in += 1
        hold += _in.get << bits
        bits += 8
        _in += 1
        hold += _in.get << bits
        bits += 8
      end
      this = lcode[hold & lmask]
      status = :dolen if status.nil?
    end
    if status == :dolen
      op = this.bits
      hold >>= op
      bits -= op
      op = this.op
    end
    if op == 0
      out += 1
      out.set(this.val)
    elsif (op & 16) != 0 || status == :dodist
      if status != :dodist && (op & 16) != 0
        len = this.val
        op &= 15
        if op != 0
          if bits < op
            _in += 1
            hold += _in.get << bits
            bits += 8
          end
          len += hold & ((1 << op) - 1)
          hold >>= op
          bits -= op
        end
        if bits < 15
          _in += 1
          hold += _in.get << bits
          bits += 8
          _in += 1
          hold += _in.get << bits
          bits += 8
        end
        this = dcode[hold & dmask]
      end
      op = this.bits
      hold >>= op
      bits -= op
      op = this.op
      if (op & 16) != 0
        dist = this.val
        op &= 15
        if bits < op
          _in += 1
          hold += _in.get << bits
          bits += 8
          if bits < op
            _in += 1
            hold += _in.get << bits
            bits += 8
          end
        end
        dist += hold & ((1 << op) - 1)
        hold >>= op
        bits -= op
        op = (out.offset - beg.offset)
        if dist > op
          op = dist - op
          if op > whave
            strm.msg = 'invalid distance too far back'
            state.mode = BAD
            break
          end
          from = Bytef.new(window, -1)
          if write == 0
            from += wsize - op
            if op < len
              len -= op
              loop do
                out += 1
                from += 1
                out.set(from.get)
                op -= 1
                break if op == 0
              end
              from = Bytef.new(out, out.offset - dist)
            end
          elsif write < op
            from += wsize + write - op
            op -= write
            if op < len
              len -= op
              loop do
                out += 1
                from += 1
                out.set(from.get)
                op -= 1
                break if op == 0
              end
              from = Bytef.new(window, -1)
              if write < len
                op = write
                len -= op
                loop do
                  out += 1
                  from += 1
                  out.set(from.get)
                  op -= 1
                  break if op == 0
                end
                from = Bytef.new(out, out.offset - dist)
              end
            end
          else
            from += write - op
            if op < len
              len -= op
              loop do
                out += 1
                from += 1
                out.set(from.get)
                op -= 1
                break if op == 0
              end
              from = Bytef.new(out, out.offset - dist)
            end
          end
          while len > 2
            out += 1
            from += 1
            out.set(from.get)
            out += 1
            from += 1
            out.set(from.get)
            out += 1
            from += 1
            out.set(from.get)
            len -= 3
          end
          if len != 0
            out += 1
            from += 1
            out.set(from.get)
            if len > 1
              out += 1
              from += 1
              out.set(from.get)
            end
          end
        else
          from = Bytef.new(out, out.offset - dist)
          loop do
            out += 1
            from += 1
            out.set(from.get)
            out += 1
            from += 1
            out.set(from.get)
            out += 1
            from += 1
            out.set(from.get)
            len -= 3
            break if len <= 2
          end
          if len != 0
            out += 1
            from += 1
            out.set(from.get)
            if len > 1
              out += 1
              from += 1
              out.set(from.get)
            end
          end
        end
      elsif (op & 64) == 0
        this = dcode[this.val + (hold & ((1 << op) - 1))]
        status = :dodist
        redo
      else
        strm.msg = 'invalid distance code'
        state.mode = BAD
        break
      end
    elsif (op & 64) == 0
      this = lcode[this.val + (hold & ((1 << op) - 1))]
      status = :dolen
      redo
    elsif (op & 32) != 0
      state.mode = TYPE
      break
    else
      strm.msg = 'invalid literal/length code'
      state.mode = BAD
      break
    end
    status = nil
    break unless _in.offset < last.offset && out.offset < _end.offset
  end
  len = bits >> 3
  _in -= len
  bits -= len << 3
  hold &= (1 << bits) - 1
  strm.next_in.offset = _in.offset + 1
  strm.next_out.offset = out.offset + 1
  strm.avail_in = (_in.offset < last.offset ? 5 + (last.offset - _in.offset) : 5 - (_in.offset - last.offset))
  strm.avail_out = (out.offset < _end.offset ?
                               257 + (_end.offset - out.offset) : 257 - (out.offset - _end.offset))
  state.hold = hold
  state.bits = bits
  nil
end

.inflate_table(type, lens, codes, table, offset, bits, work) ⇒ Object

Build a set of tables to decode the provided canonical Huffman code. The code lengths are lens. The result starts at *table, whose indices are 0..2^bits-1. work is a writable array of at least lens shorts, which is used as a work area. type is the type of code to be generated, CODES, LENS, or DISTS. On return, zero is success, -1 is an invalid code, and +1 means that ENOUGH isn’t enough. table on return points to the next available entry’s address. bits is the requested root table index bits, and on return it is the actual root table index bits. It will differ if the request is greater than the longest code or if it is less than the shortest code.



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# File 'lib/pr/rbzlib.rb', line 3286

def inflate_table(type, lens, codes, table, offset, bits, work)
  lbase = [
      3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
      35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0]
  lext = [
      16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
      19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 201, 196]
  dbase = [
      1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
      257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
      8193, 12289, 16385, 24577, 0, 0]
  dext = [
      16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22,
      23, 23, 24, 24, 25, 25, 26, 26, 27, 27,
      28, 28, 29, 29, 64, 64]

  this = Code.new

  count = Array.new(MAXBITS + 1, 0)
  offs = Array.new(MAXBITS + 1, 0)
  for sym in 0 ... codes
    count[lens[sym]] += 1
  end

  root = bits

  max = 0
  MAXBITS.downto(1) do |i|
    max = i
    break if count[max] != 0
  end

  root = max if root > max
  if max == 0
    this.op = 64
    this.bits = 1
    this.val = 0
    table[offset] = this.dup
    offset += 1
    table[offset] = this.dup
    offset += 1
    bits = 1
    return [0, bits, offset]
  end
  for min in 1 .. MAXBITS
    break if count[min] != 0
  end
  root = min if root < min

  left = 1
  for len in 1 .. MAXBITS
    left <<= 1
    left -= count[len]
    return [-1, bits, offset]  if left < 0
  end
  if left > 0 && (type == CODES || max != 1)
    return [-1, bits, offset]
  end

  offs[1] = 0
  for len in 1 ... MAXBITS
    offs[len + 1] = offs[len] + count[len]
  end

  for sym in 0 ... codes
    if lens[sym] != 0
      work[offs[lens[sym]]] = sym
      offs[lens[sym]] += 1
    end
  end

  case type
  when CODES
    extra = Bytef.new(work)
    base = Bytef.new(work)
    _end = 19
  when LENS
    base = Bytef.new(lbase)
    base -= 257
    extra = Bytef.new(lext)
    extra -= 257
    _end = 256
  else
    base = Bytef.new(dbase)
    extra = Bytef.new(dext)
    _end = -1
  end

  huff = 0
  sym = 0
  len = min
  _next = Bytef.new(table, offset)
  curr = root
  drop = 0
  low = -1
  used = 1 << root
  mask = used - 1

  if type == LENS && used >= ENOUGH - MAXD
    return [1, bits, offset]
  end
  loop do
    this.bits = (len - drop)
    if (work[sym]) < _end
      this.op = 0
      this.val = work[sym]
    elsif (work[sym]) > _end
      this.op = (extra[work[sym]])
      this.val = base[work[sym]]
    else
      this.op = (32 + 64)
      this.val = 0
    end
    incr = 1 << (len - drop)
    fill = 1 << curr
    min = fill
    loop do
      fill -= incr
      _next[((huff >> drop) + fill)] = this.dup
      break if fill == 0
    end
    incr = 1 << (len - 1)
    while (huff & incr) != 0
      incr >>= 1
    end
    if incr != 0
      huff &= incr - 1
      huff += incr
    else
      huff = 0
    end
    sym += 1
    count[len] -= 1
    if count[len] == 0
      break if len == max
      len = lens[work[sym]]
    end

    if len > root && (huff & mask) != low
      if drop == 0
        drop = root
      end

      _next += min

      curr = len - drop
      left = (1 << curr)
      while curr + drop < max
        left -= count[curr + drop]
        break if left <= 0
        curr += 1
        left <<= 1
      end

      used += 1 << curr
      if type == LENS && used >= ENOUGH - MAXD
        return [1, bits, offset]
      end
      low = huff & mask
      table[offset + low] = Code.new
      table[offset + low].op = curr
      table[offset + low].bits = root
      table[offset + low].val = (_next.offset - offset)
    end
  end
  this.op = 64
  this.bits = (len - drop)
  this.val = 0
  while huff != 0
    if drop != 0 && (huff & mask) != low
      drop = 0
      len = root
      _next.offset = offset
      this.bits = len
    end

    _next[(huff >> drop)] = this.dup
    incr = 1 << (len - 1)
    while (huff & incr) != 0
      incr >>= 1
    end
    if incr != 0
      huff &= incr - 1
      huff += incr
    else
      huff = 0
    end
  end

  offset += used
  bits = root
  [0, bits, offset]
end

.inflateCopy(dest, source) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 4903

def inflateCopy(dest, source)
  if dest.nil? || source.nil? || source.state.nil?
    return Z_STREAM_ERROR
  end
  state = source.state

  copy = Inflate_state.new()
  return Z_MEM_ERROR if copy.nil?
  window = nil
  if state.window
    window = 0.chr * (1 << state.wbits)
    if window.nil?
      copy = nil
      return Z_MEM_ERROR
    end
  end

  dest = source.dup
  copy = state.dup
  if state.lencode.offset >= 0 &&
      state.lencode.offset <= 0 + ENOUGH - 1
    copy.lencode.offset = 0 + (state.lencode.offset - 0)
    copy.distcode.offset = 0 + (state.distcode.offset - 0)
  end
  copy.next.offset = 0 + (state.next.offset - 0)
  if window
    wsize = 1 << state.wbits
    window[0, wsize] = state.window[0, wsize]
  end
  copy.window = window
  dest.state = copy
  Z_OK
end

.inflateEnd(strm) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 4774

def inflateEnd(strm)
  if strm.nil? || strm.state.nil?
    return Z_STREAM_ERROR
  end
  state = strm.state
  state.window = nil
  strm.state = nil
  Z_OK
end

.inflateGetHeader(strm, head) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 4818

def inflateGetHeader(strm, head)
  return Z_STREAM_ERROR if strm.nil? || strm.state.nil?
  state = strm.state
  return Z_STREAM_ERROR if (state.wrap & 2) == 0

  state.head = head
  head.done = 0
  Z_OK
end

.inflateInit(strm) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 3788

def inflateInit(strm)
  inflateInit_(strm, ZLIB_VERSION, strm.size)
end

.inflateInit2(strm, windowBits) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 3793

def inflateInit2(strm, windowBits)
  inflateInit2_(strm, windowBits, ZLIB_VERSION, strm.size)
end

.inflateInit2_(strm, windowBits, version, stream_size) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 3835

def inflateInit2_(strm, windowBits, version, stream_size)
  if version.nil? || version[0] != ZLIB_VERSION[0] ||
      stream_size != strm.size
    return Z_VERSION_ERROR
  end
  return Z_STREAM_ERROR if strm.nil?
  strm.msg = ''
  state = Inflate_state.new
  state.lens = Array.new(320, 0)
  state.work = Array.new(288, 0)
  state.codes = Array.new(ENOUGH, 0)
  return Z_MEM_ERROR if state.nil?
  strm.state = state
  if windowBits < 0
    state.wrap = 0
    windowBits = -windowBits
  else
    state.wrap = (windowBits >> 4) + 1
    windowBits &= 15 if windowBits < 48
  end
  if windowBits < 8 || windowBits > 15
    ZFREE(strm, state)
    strm.state = nil
    return Z_STREAM_ERROR
  end
  state.wbits = windowBits
  state.window = nil
  inflateReset(strm)
end

.inflateInit_(strm, version, stream_size) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 3866

def inflateInit_(strm, version, stream_size)
  inflateInit2_(strm, DEF_WBITS, version, stream_size)
end

.inflatePrime(strm, bits, value) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 3824

def inflatePrime(strm, bits, value)
  return Z_STREAM_ERROR if strm.nil? || strm.state.nil?
  state = strm.state
  return Z_STREAM_ERROR if bits > 16 || state.bits + bits > 32
  value &= (1 << bits) - 1
  state.hold += value << state.bits
  state.bits += bits
  Z_OK
end

.inflateReset(strm) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 3798

def inflateReset(strm)
  return Z_STREAM_ERROR if strm.nil? || strm.state.nil?
  state = strm.state
  strm.total_in = strm.total_out = state.total = 0
  strm.msg = ''
  strm.adler = 1
  state.mode = HEAD
  state.last = 0
  state.havedict = 0
  state.dmax = 32768
  state.head = nil
  state.wsize = 0
  state.whave = 0
  state.write = 0
  state.hold = 0
  state.bits = 0
  state.lens = Bytef.new(Array.new(320, 0))
  state.work = Array.new(288, 0)
  state.codes = Array.new(ENOUGH, 0)
  state.next = Bytef.new(state.codes)
  state.distcode = Bytef.new(state.codes)
  state.lencode = Bytef.new(state.codes)
  Z_OK
end

.inflateSetDictionary(strm, dictionary, dictLength) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 4785

def inflateSetDictionary(strm, dictionary, dictLength)
  return Z_STREAM_ERROR if strm.nil? || strm.state.nil?
  state = strm.state
  if state.wrap != 0 && state.mode != DICT
    return Z_STREAM_ERROR
  end

  if state.mode == DICT
    id = adler32(0, nil)
    id = adler32(id, dictionary, dictLength)
    if id != state.check
      return Z_DATA_ERROR
    end
  end

  if updatewindow(strm, strm.avail_out)
    state.mode = MEM
    return Z_MEM_ERROR
  end
  if dictLength > state.wsize
    state.window[0, state.wsize] =
      dictionary[dictLength - state.wsize, state.wsize]
    state.whave = state.wsize
  else
    state.window[state.wsize - dictLength, dictLength] =
      dictionary[0, dictLength]
    state.whave = dictLength
  end
  state.havedict = 1
  Z_OK
end

.inflateSync(strm) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 4855

def inflateSync(strm)
  return Z_STREAM_ERROR if strm.nil? || strm.state.nil?
  state = strm.state
  return Z_BUF_ERROR if strm.avail_in == 0 && state.bits < 8

  buf = 0.chr * 4
  if state.mode != SYNC
    state.mode = SYNC
    state.hold <<= state.bits & 7
    state.bits -= state.bits & 7
    len = 0
    while state.bits >= 8
      buf[len] = state.hold.chr
      len += 1
      state.hold >>= 8
      state.bits -= 8
    end
    state.have = 0
    _, state.have = syncsearch(state.have, buf, len)
  end

  len, state.have = syncsearch(state.have, strm.next_in, strm.avail_in)
  strm.avail_in -= len
  strm.next_in += len
  strm.total_in += len
  return Z_DATA_ERROR if state.have != 4
  _in = strm.total_in
  out = strm.total_out
  inflateReset(strm)
  strm.total_in = _in
  strm.total_out = out
  state.mode = TYPE
  Z_OK
end

.inflateSyncPoint(strm) ⇒ Object

Returns true if inflate is currently at the end of a block generated by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored block. When decompressing, PPP checks that at the end of input packet, inflate is waiting for these length bytes.



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# File 'lib/pr/rbzlib.rb', line 4896

def inflateSyncPoint(strm)
  return Z_STREAM_ERROR if strm.nil? || strm.state.nil?
  state = strm.state
  state.mode == STORED && state.bits == 0
end

.init_block(s) ⇒ Object

Initialize a new block.



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# File 'lib/pr/rbzlib.rb', line 2663

def init_block(s)
  for n in 0 ... L_CODES
    s.dyn_ltree[n].fc = 0
  end
  for n in 0 ... D_CODES
    s.dyn_dtree[n].fc = 0
  end
  for n in 0 ... BL_CODES
    s.bl_tree[n].fc = 0
  end
  s.dyn_ltree[END_BLOCK].fc = 1
  s.static_len = 0
  s.opt_len = 0
  s.matches = 0
  s.last_lit = 0
end

.INITBITS ⇒ Object

Clear the input bit accumulator



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# File 'lib/pr/rbzlib.rb', line 4065

def INITBITS
  @@hold = 0
  @@bits = 0
end

.INSERT_STRING(s, str, match_head) ⇒ Object

Insert string str in the dictionary and set match_head to the previous head of the hash chain (the most recent string with same hash key). Return the previous length of the hash chain. If this file is compiled with -DFASTEST, the compression level is forced to 1, and no hash chains are maintained. IN assertion: all calls to to INSERT_STRING are made with consecutive

input characters and the first MIN_MATCH bytes of str are valid
(except for the last MIN_MATCH-1 bytes of the input file).



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# File 'lib/pr/rbzlib.rb', line 1212

def INSERT_STRING(s, str, match_head)
  s.ins_h = ((s.ins_h << s.hash_shift) ^ (s.window[str + 2].ord)) & s.hash_mask

  match_head = s.head[s.ins_h]
  s.prev[(str) & s.w_mask] = match_head
  s.head[s.ins_h] = str
  match_head
end

.lm_init(s) ⇒ Object

Initialize the “longest match” routines for a new zlib stream



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# File 'lib/pr/rbzlib.rb', line 1901

def lm_init(s)
  s.window_size = (2 * s.w_size)

  s.head = Array.new(s.hash_size, 0)
  s.head[s.hash_size - 1] = ZNIL

  s.max_lazy_match   = @@configuration_table[s.level].max_lazy
  s.good_match       = @@configuration_table[s.level].good_length
  s.nice_match       = @@configuration_table[s.level].nice_length
  s.max_chain_length = @@configuration_table[s.level].max_chain

  s.strstart = 0
  s.block_start = (0)
  s.lookahead = 0
  s.prev_length = MIN_MATCH - 1
  s.match_length = MIN_MATCH - 1
  s.match_available = false
  s.ins_h = 0
end

.LOAD(strm, state) ⇒ Object

Load registers with state in inflate() for speed



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# File 'lib/pr/rbzlib.rb', line 4045

def LOAD(strm, state)
  @@put = strm.next_out
  @@left = strm.avail_out
  @@next = strm.next_in
  @@have = strm.avail_in
  @@hold = state.hold
  @@bits = state.bits
end

.longest_match(s, cur_match) ⇒ Object

Set match_start to the longest match starting at the given string and return its length. Matches shorter or equal to prev_length are discarded, in which case the result is equal to prev_length and match_start is garbage. IN assertions: cur_match is the head of the hash chain for the current

string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1

OUT assertion: the match length is not greater than s->lookahead.



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# File 'lib/pr/rbzlib.rb', line 1928

def longest_match(s, cur_match)
  chain_length = s.max_chain_length
  scan = s.strstart
  best_len = s.prev_length
  nice_match = s.nice_match

  _MAX_DIST = s.w_size - MIN_LOOKAHEAD

  if s.strstart > (_MAX_DIST)
    limit = s.strstart - _MAX_DIST
  else
    limit = ZNIL
  end

  prev = s.prev
  wmask = s.w_mask

  strend = s.strstart + MAX_MATCH
  scan_end1  = s.window[scan + best_len - 1]
  scan_end   = s.window[scan + best_len]

  if s.prev_length >= s.good_match
    chain_length >>= 2
  end

  if nice_match > s.lookahead
    nice_match = s.lookahead
  end

  begin
    match = cur_match

    if (s.window[match + best_len] != scan_end) ||
       (s.window[match + best_len - 1] != scan_end1) ||
       (s.window[match] != s.window[scan])
    then
      cur_match = prev[cur_match & wmask]
      chain_length -= 1
      next
    end

    match += 1

    if s.window[match] != s.window[scan + 1]
      cur_match = prev[cur_match & wmask]
      chain_length -= 1
      next
    end

    scan += 2
    match += 1

      # Seems redundant, but mimics the C code
    loop do
      break if s.window[scan += 1] != s.window[match += 1]
      break if s.window[scan += 1] != s.window[match += 1]
      break if s.window[scan += 1] != s.window[match += 1]
      break if s.window[scan += 1] != s.window[match += 1]
      break if s.window[scan += 1] != s.window[match += 1]
      break if s.window[scan += 1] != s.window[match += 1]
      break if s.window[scan += 1] != s.window[match += 1]
      break if s.window[scan += 1] != s.window[match += 1]
      break if scan >= strend
    end

    len = MAX_MATCH - (strend - scan)
    scan = strend
    scan -= MAX_MATCH

    if len > best_len
      s.match_start = cur_match
      best_len = len
      break if len >= nice_match
      scan_end1 = s.window[scan + best_len - 1]
      scan_end  = s.window[scan + best_len]
    end

    cur_match = prev[cur_match & wmask]
    chain_length -= 1
  end until (cur_match <= limit) || chain_length == 0

  if best_len <= s.lookahead
    best_len
  else
    s.lookahead
  end
end

.longest_match_fast(s, cur_match) ⇒ Object

Optimized version for level == 1 or strategy == Z_RLE only



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# File 'lib/pr/rbzlib.rb', line 2017

def longest_match_fast(s, cur_match)
  scan = Bytef.new(s.window, s.strstart)
  strend = Bytef.new(s.window, s.strstart + MAX_MATCH)

  match = Bytef.new(s.window, cur_match)

  return (MIN_MATCH - 1) if match[0] != scan[0] || match[1] != scan[1]

  scan += 2
  match += 2
  loop do
    scan += 1
    match += 1
    break if scan.get == match.get
    scan += 1
    match += 1
    break if scan.get == match.get
    scan += 1
    match += 1
    break if scan.get == match.get
    scan += 1
    match += 1
    break if scan.get == match.get
    scan += 1
    match += 1
    break if scan.get == match.get
    scan += 1
    match += 1
    break if scan.get == match.get
    scan += 1
    match += 1
    break if scan.get == match.get
    scan += 1
    match += 1
    break if scan.get == match.get
    break if scan.offset >= strend.offset
  end

  len = MAX_MATCH - (strend.offset - scan.offset)

  return (MIN_MATCH - 1) if len < MIN_MATCH

  s.match_start = cur_match
  len <= s.lookahead ? len : s.lookahead
end

.NEEDBITS(n) ⇒ Object

Assure that there are at least n bits in the bit accumulator. If there is not enough available input to do that, then return from inflate().



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# File 'lib/pr/rbzlib.rb', line 4083

def NEEDBITS(n)
  while @@bits < (n)
    PULLBYTE()
  end
end

.pqdownheap(s, tree, k) ⇒ Object

Restore the heap property by moving down the tree starting at node k, exchanging a node with the smallest of its two sons if necessary, stopping when the heap property is re-established (each father smaller than its two sons).



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# File 'lib/pr/rbzlib.rb', line 2705

def pqdownheap(s, tree, k)
  v = s.heap[k]
  j = k << 1
  while j <= s.heap_len
    if (j < s.heap_len) &&
      ( (tree[s.heap[j + 1]].fc < tree[s.heap[j]].fc) ||
      ((tree[s.heap[j + 1]].fc == tree[s.heap[j]].fc) &&
       (s.depth[s.heap[j + 1]] <= s.depth[s.heap[j]])) )
      j += 1
    end
    break if  (tree[v].fc < tree[s.heap[j]].fc) ||
       ((tree[v].fc == tree[s.heap[j]].fc) &&
        (s.depth[v] <= s.depth[s.heap[j]]))

    s.heap[k] = s.heap[j]
    k = j

    j <<= 1
  end
  s.heap[k] = v
end

.PULLBYTE ⇒ Object

Get a byte of input into the bit accumulator, or return from inflate() if there is no input available.



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# File 'lib/pr/rbzlib.rb', line 4072

def PULLBYTE
  throw :inf_leave if @@have == 0
  @@have -= 1
  @@next.get
  @@hold += (@@next.get) << @@bits
  @@next += 1
  @@bits += 8
end

.putLong(s, x) ⇒ Object

Outputs a long in LSB order to the given file



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# File 'lib/pr/rbzlib.rb', line 1112

def putLong(s, x)
  4.times{
    c = x & 0xFF
    s.putc(c)
    x = x >> 8
  }
end

.putShortMSB(s, b) ⇒ Object

Put a short in the pending buffer. The 16-bit value is put in MSB order. IN assertion: the stream state is correct and there is enough room in pending_buf.



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# File 'lib/pr/rbzlib.rb', line 1477

def putShortMSB(s, b)
  s.pending_buf[s.pending] = (b >> 8)
  s.pending += 1
  s.pending_buf[s.pending] = (b & 0xff)
  s.pending += 1
end

.read_buf(strm, buf, offset, size) ⇒ Object

Read a new buffer from the current input stream, update the adler32 and total number of bytes read. All deflate() input goes through this function so some applications may wish to modify it to avoid allocating a large strm->next_in buffer and copying from it. (See also flush_pending()).



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# File 'lib/pr/rbzlib.rb', line 1875

def read_buf(strm, buf, offset, size)
  len = strm.avail_in

  if len > size
    len = size
  end
  if len == 0
    return 0
  end

  strm.avail_in -= len

  if strm.state.wrap == 1
    strm.adler = adler32(strm.adler, strm.next_in.current, len)
  elsif strm.state.wrap == 2
    strm.adler = crc32(strm.adler, strm.next_in.current, len)
  end

  buf[offset, len] = strm.next_in.current[0, len]
  strm.next_in += len
  strm.total_in += len

  len
end

.RESTORE(strm, state) ⇒ Object

Restore state from registers in inflate()



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# File 'lib/pr/rbzlib.rb', line 4055

def RESTORE(strm, state)
  strm.next_out = @@put
  strm.avail_out = @@left
  strm.next_in = @@next
  strm.avail_in = @@have
  state.hold = @@hold
  state.bits = @@bits
end

.REVERSE(q) ⇒ Object

Reverse the bytes in a 32-bit value



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# File 'lib/pr/rbzlib.rb', line 4107

def REVERSE(q)
  ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) +
   (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
end

.scan_tree(s, tree, max_code) ⇒ Object

Scan a literal or distance tree to determine the frequencies of the codes in the bit length tree.



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# File 'lib/pr/rbzlib.rb', line 2887

def scan_tree(s, tree, max_code)
  prevlen = -1
  nextlen = tree[0].dl
  count = 0
  max_count = 7
  min_count = 4

  if nextlen == 0
    max_count = 138
    min_count = 3
  end
  tree[max_code + 1].dl = 0xffff

  for n in 0 .. max_code
    curlen = nextlen
    nextlen = tree[n + 1].dl
    count += 1
    if (count < max_count) && (curlen == nextlen)
      next
    elsif count < min_count
      s.bl_tree[curlen].fc += count
    elsif curlen != 0
      if curlen != prevlen
        s.bl_tree[curlen].fc += 1
      end
      s.bl_tree[REP_3_6].fc += 1
    elsif count <= 10
      s.bl_tree[REPZ_3_10].fc += 1
    else
      s.bl_tree[REPZ_11_138].fc += 1
    end
    count = 0
    prevlen = curlen
    if nextlen == 0
      max_count = 138
      min_count = 3
    elsif curlen == nextlen
      max_count = 6
      min_count = 3
    else
      max_count = 7
      min_count = 4
    end
  end
end

.send_all_trees(s, lcodes, dcodes, blcodes) ⇒ Object

Send the header for a block using dynamic Huffman trees: the counts, the lengths of the bit length codes, the literal tree and the distance tree. IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.



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# File 'lib/pr/rbzlib.rb', line 3008

def send_all_trees(s, lcodes, dcodes, blcodes)
  send_bits(s, lcodes - 257, 5)
  send_bits(s, dcodes - 1,   5)
  send_bits(s, blcodes - 4,  4)
  for rank in 0 ... blcodes
    send_bits(s, s.bl_tree[@@bl_order[rank]].dl, 3)
  end

  send_tree(s, s.dyn_ltree, lcodes - 1)

  send_tree(s, s.dyn_dtree, dcodes - 1)
end

.send_bits(s, value, length) ⇒ Object

Send a value on a given number of bits. IN assertion: length <= 16 and value fits in length bits.



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# File 'lib/pr/rbzlib.rb', line 2609

def send_bits(s, value, length)
  if s.bi_valid > Buf_size - length
    s.bi_buf |= (value << s.bi_valid)
    s.bi_buf &= 0xffff
    s.pending_buf[s.pending] = s.bi_buf & 0xff
    s.pending += 1
    s.pending_buf[s.pending] = s.bi_buf >> 8
    s.pending += 1
    s.bi_buf = value >> (Buf_size - s.bi_valid)
    s.bi_valid += length - Buf_size
  else
    s.bi_buf |= (value << s.bi_valid)
    s.bi_valid += length
  end
end

.send_tree(s, tree, max_code) ⇒ Object

Send a literal or distance tree in compressed form, using the codes in bl_tree.



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# File 'lib/pr/rbzlib.rb', line 2935

def send_tree(s, tree, max_code)
  prevlen = -1
  nextlen = tree[0].dl
  count = 0
  max_count = 7
  min_count = 4

  if nextlen == 0
    max_count = 138
    min_count = 3
  end
  for n in 0 .. max_code
    curlen = nextlen
    nextlen = tree[n + 1].dl
    count += 1
    if (count < max_count) && (curlen == nextlen)
      next
    elsif count < min_count
      loop do
        send_bits(s, s.bl_tree[curlen].fc, s.bl_tree[curlen].dl)
        count -= 1
        break if count == 0
      end
    elsif curlen != 0
      if curlen != prevlen
        send_bits(s, s.bl_tree[curlen].fc, s.bl_tree[curlen].dl)
        count -= 1
      end
      send_bits(s, s.bl_tree[REP_3_6].fc, s.bl_tree[REP_3_6].dl)
      send_bits(s, count - 3, 2)
    elsif count <= 10
      send_bits(s, s.bl_tree[REPZ_3_10].fc, s.bl_tree[REPZ_3_10].dl)
      send_bits(s, count - 3, 3)
    else
      send_bits(s, s.bl_tree[REPZ_11_138].fc, s.bl_tree[REPZ_11_138].dl)
      send_bits(s, count - 11, 7)
    end
    count = 0
    prevlen = curlen
    if nextlen == 0
      max_count = 138
      min_count = 3
    elsif curlen == nextlen
      max_count = 6
      min_count = 3
    else
      max_count = 7
      min_count = 4
    end
  end
end

.set_data_type(s) ⇒ Object

Set the data type to BINARY or TEXT, using a crude approximation: set it to Z_TEXT if all symbols are either printable characters (33 to 255) or white spaces (9 to 13, or 32); or set it to Z_BINARY otherwise. IN assertion: the fields Freq of dyn_ltree are set.



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# File 'lib/pr/rbzlib.rb', line 3113

def set_data_type(s)
  for n in 0 ... 9
    break if s.dyn_ltree[n].fc != 0
  end
  if n == 9
    for n in 14 ... 32
      break if s.dyn_ltree[n].fc != 0
    end
  end
  s.strm.data_type = (n == 32) ? Z_TEXT : Z_BINARY
end

.syncsearch(have, buf, len) ⇒ Object

Search buf for the pattern: 0, 0, 0xff, 0xff. Return when found or when out of input. When called, *have is the number of pattern bytes found in order so far, in 0..3. On return *have is updated to the new state. If on return *have equals four, then the pattern was found and the return value is how many bytes were read including the last byte of the pattern. If *have is less than four, then the pattern has not been found yet and the return value is len. In the latter case, syncsearch() can be called again with more data and the *have state. *have is initialized to zero for the first call.



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# File 'lib/pr/rbzlib.rb', line 4837

def syncsearch(have, buf, len)
  got = have
  _next = 0
  while _next < len && got < 4
    if (buf[_next]) == (got < 2 ? 0 : 0xff)
      got += 1
    elsif buf[_next] != 0
      got = 0
    else
      got = 4 - got
    end
    _next += 1
  end
  have = got
  [_next, have]
end

.uncompress(dest, destLen, source, sourceLen) ⇒ Object

Decompresses the source buffer into the destination buffer. sourceLen is the byte length of the source buffer. Upon entry, destLen is the total size of the destination buffer, which must be large enough to hold the entire uncompressed data. (The size of the uncompressed data must have been saved previously by the compressor and transmitted to the decompressor by some mechanism outside the scope of this compression library.) Upon exit, destLen is the actual size of the compressed buffer.

This function can be used to decompress a whole file at once if the

input file is mmap’ed.

uncompress returns Z_OK if success, Z_MEM_ERROR if there was not

enough memory, Z_BUF_ERROR if there was not enough room in the output buffer, or Z_DATA_ERROR if the input data was corrupted.



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# File 'lib/pr/rbzlib.rb', line 4950

def uncompress(dest, destLen, source, sourceLen)
  stream = Z_stream.new
  stream.next_in = Bytef.new(source)
  stream.avail_in = sourceLen
  return [Z_BUF_ERROR, destLen] if stream.avail_in != sourceLen

  stream.next_out = Bytef.new(dest)
  stream.avail_out = destLen
  return [Z_BUF_ERROR, destLen] if stream.avail_out != destLen

  err = inflateInit(stream)
  return [err, destLen] if err != Z_OK

  err = inflate(stream, Z_FINISH)
  if err != Z_STREAM_END
    inflateEnd(stream)
    if err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0)
      return [Z_DATA_ERROR, destLen]
    end
    return [err, destLen]
  end
  destLen = stream.total_out

  err = inflateEnd(stream)
  [err, destLen]
end

.UPDATE(state, check, buf) ⇒ Object

check function to use adler32() for zlib or crc32() for gzip



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# File 'lib/pr/rbzlib.rb', line 4022

def UPDATE(state, check, buf)
  state.flags != 0 ? crc32(check, buf) : adler32(check, buf)
end

.updatewindow(strm, out) ⇒ Object

Update the window with the last wsize (normally 32K) bytes written before returning. If window does not exist yet, create it. This is only called when a window is already in use, or when output has been written during this inflate call, but the end of the deflate stream has not been reached yet. It is also called to create a window for dictionary data when a dictionary is loaded.

Providing output buffers larger than 32K to inflate() should provide a speed advantage, since only the last 32K of output is copied to the sliding window upon return from inflate(), and since all distances after the first 32K of output will fall in the output data, making match copies simpler and faster. The advantage may be dependent on the size of the processor’s data caches.



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# File 'lib/pr/rbzlib.rb', line 3981

def updatewindow(strm, out)
  state = strm.state

  if state.window.nil?
    state.window = 0.chr * (1 << state.wbits)
    return true if state.window.nil?
  end

  if state.wsize == 0
    state.wsize = 1 << state.wbits
    state.write = 0
    state.whave = 0
  end

  copy = out - strm.avail_out
  if copy >= state.wsize
    state.window[0, state.wsize] =
      strm.next_out.buffer[strm.next_out.offset - state.wsize, state.wsize]
    state.write = 0
    state.whave = state.wsize
  else
    dist = state.wsize - state.write
    dist = copy if dist > copy
    state.window[state.write, dist] =
      strm.next_out.buffer[strm.next_out.offset - copy, dist]
    copy -= dist
    if copy != 0
      state.window[0, copy] =
        strm.next_out.buffer[strm.next_out.offset - copy, copy]
      state.write = copy
      state.whave = state.wsize
    else
      state.write += dist
      state.write = 0 if state.write == state.wsize
      state.whave += dist if state.whave < state.wsize
    end
  end
  false
end

Instance Method Details

#z_error(m) ⇒ Object

Raises:

  • (RuntimeError) 


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# File 'lib/pr/rbzlib.rb', line 141

def z_error(m)
  raise RuntimeError, m
end

#zError(err) ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 133

def zError(err)
  @@z_errmsg[Z_NEED_DICT - err]
end

#zlibVersion ⇒ Object 



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# File 'lib/pr/rbzlib.rb', line 137

def zlibVersion
  ZLIB_VERSION
end