Class: Zlib::GzipWriter
Overview
Zlib::GzipWriter is a class for writing gzipped files. GzipWriter should be used with an instance of IO, or IO-like, object.
Following two example generate the same result.
Zlib::GzipWriter.open('hoge.gz') do |gz|
gz.write 'jugemu jugemu gokou no surikire...'
end
File.open('hoge.gz', 'w') do |f|
gz = Zlib::GzipWriter.new(f)
gz.write 'jugemu jugemu gokou no surikire...'
gz.close
end
To make like gzip(1) does, run following:
orig = 'hoge.txt'
Zlib::GzipWriter.open('hoge.gz') do |gz|
gz.mtime = File.mtime(orig)
gz.orig_name = orig
gz.write IO.binread(orig)
end
NOTE: Due to the limitation of Ruby’s finalizer, you must explicitly close GzipWriter objects by Zlib::GzipWriter#close etc. Otherwise, GzipWriter will be not able to write the gzip footer and will generate a broken gzip file.
Class Method Summary collapse
-
.Zlib::GzipWriter.open(filename, level = nil, strategy = nil) {|gz| ... } ⇒ Object
Opens a file specified by
filename
for writing gzip compressed data, and returns a GzipWriter object associated with that file.
Instance Method Summary collapse
-
#<< ⇒ Object
Same as IO.
-
#comment=(str) ⇒ Object
Specify the comment (
str
) in the gzip header. -
#flush(flush = nil) ⇒ Object
Flushes all the internal buffers of the GzipWriter object.
-
#Zlib::GzipWriter.new(io, level = nil, strategy = nil, options = {}) ⇒ Object
constructor
Creates a GzipWriter object associated with
io
. -
#mtime=(mtime) ⇒ Object
Specify the modification time (
mtime
) in the gzip header. -
#orig_name=(str) ⇒ Object
Specify the original name (
str
) in the gzip header. -
#pos ⇒ Object
Total number of input bytes read so far.
-
#print ⇒ Object
Same as IO.
-
#printf ⇒ Object
Same as IO.
-
#putc(ch) ⇒ Object
Same as IO.
-
#puts ⇒ Object
Same as IO.
-
#tell ⇒ Object
Total number of input bytes read so far.
-
#write(str) ⇒ Object
Same as IO.
Methods inherited from GzipFile
#close, #closed?, #comment, #crc, #finish, #level, #mtime, #orig_name, #os_code, #sync, #sync=, #to_io, wrap
Constructor Details
#Zlib::GzipWriter.new(io, level = nil, strategy = nil, options = {}) ⇒ Object
Creates a GzipWriter object associated with io
. level
and strategy
should be the same as the arguments of Zlib::Deflate.new. The GzipWriter object writes gzipped data to io
. io
must respond to the write
method that behaves the same as IO#write.
The options
hash may be used to set the encoding of the data. :external_encoding
, :internal_encoding
and :encoding
may be set as in IO::new.
3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 |
# File 'zlib.c', line 3510
static VALUE
rb_gzwriter_initialize(int argc, VALUE *argv, VALUE obj)
{
struct gzfile *gz;
VALUE io, level, strategy, opt = Qnil;
int err;
if (argc > 1) {
opt = rb_check_convert_type(argv[argc-1], T_HASH, "Hash", "to_hash");
if (!NIL_P(opt)) argc--;
}
rb_scan_args(argc, argv, "12", &io, &level, &strategy);
TypedData_Get_Struct(obj, struct gzfile, &gzfile_data_type, gz);
/* this is undocumented feature of zlib */
gz->level = ARG_LEVEL(level);
err = deflateInit2(&gz->z.stream, gz->level, Z_DEFLATED,
-MAX_WBITS, DEF_MEM_LEVEL, ARG_STRATEGY(strategy));
if (err != Z_OK) {
raise_zlib_error(err, gz->z.stream.msg);
}
gz->io = io;
ZSTREAM_READY(&gz->z);
rb_gzfile_ecopts(gz, opt);
if (rb_respond_to(io, id_path)) {
gz->path = rb_funcall(gz->io, id_path, 0);
rb_define_singleton_method(obj, "path", rb_gzfile_path, 0);
}
return obj;
}
|
Class Method Details
.Zlib::GzipWriter.open(filename, level = nil, strategy = nil) {|gz| ... } ⇒ Object
Opens a file specified by filename
for writing gzip compressed data, and returns a GzipWriter object associated with that file. Further details of this method are found in Zlib::GzipWriter.new and Zlib::GzipFile.wrap.
3491 3492 3493 3494 3495 |
# File 'zlib.c', line 3491
static VALUE
rb_gzwriter_s_open(int argc, VALUE *argv, VALUE klass)
{
return gzfile_s_open(argc, argv, klass, "wb");
}
|
Instance Method Details
#<< ⇒ Object
Same as IO.
#comment=(str) ⇒ Object
Specify the comment (str
) in the gzip header.
3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 |
# File 'zlib.c', line 3271
static VALUE
rb_gzfile_set_comment(VALUE obj, VALUE str)
{
struct gzfile *gz = get_gzfile(obj);
VALUE s;
char *p;
if (gz->z.flags & GZFILE_FLAG_HEADER_FINISHED) {
rb_raise(cGzError, "header is already written");
}
s = rb_str_dup(rb_str_to_str(str));
p = memchr(RSTRING_PTR(s), '\0', RSTRING_LEN(s));
if (p) {
rb_str_resize(s, p - RSTRING_PTR(s));
}
gz->comment = s;
return str;
}
|
#flush(flush = nil) ⇒ Object
Flushes all the internal buffers of the GzipWriter object. The meaning of flush
is same as in Zlib::Deflate#deflate. Zlib::SYNC_FLUSH
is used if flush
is omitted. It is no use giving flush Zlib::NO_FLUSH
.
3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 |
# File 'zlib.c', line 3551
static VALUE
rb_gzwriter_flush(int argc, VALUE *argv, VALUE obj)
{
struct gzfile *gz = get_gzfile(obj);
VALUE v_flush;
int flush;
rb_scan_args(argc, argv, "01", &v_flush);
flush = FIXNUMARG(v_flush, Z_SYNC_FLUSH);
if (flush != Z_NO_FLUSH) { /* prevent Z_BUF_ERROR */
zstream_run(&gz->z, (Bytef*)"", 0, flush);
}
gzfile_write_raw(gz);
if (rb_respond_to(gz->io, id_flush)) {
rb_funcall(gz->io, id_flush, 0);
}
return obj;
}
|
#mtime=(mtime) ⇒ Object
Specify the modification time (mtime
) in the gzip header. Using a Fixnum or Integer
3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 |
# File 'zlib.c', line 3226
static VALUE
rb_gzfile_set_mtime(VALUE obj, VALUE mtime)
{
struct gzfile *gz = get_gzfile(obj);
VALUE val;
if (gz->z.flags & GZFILE_FLAG_HEADER_FINISHED) {
rb_raise(cGzError, "header is already written");
}
val = rb_Integer(mtime);
gz->mtime = NUM2UINT(val);
return mtime;
}
|
#orig_name=(str) ⇒ Object
Specify the original name (str
) in the gzip header.
3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 |
# File 'zlib.c', line 3247
static VALUE
rb_gzfile_set_orig_name(VALUE obj, VALUE str)
{
struct gzfile *gz = get_gzfile(obj);
VALUE s;
char *p;
if (gz->z.flags & GZFILE_FLAG_HEADER_FINISHED) {
rb_raise(cGzError, "header is already written");
}
s = rb_str_dup(rb_str_to_str(str));
p = memchr(RSTRING_PTR(s), '\0', RSTRING_LEN(s));
if (p) {
rb_str_resize(s, p - RSTRING_PTR(s));
}
gz->orig_name = s;
return str;
}
|
#pos ⇒ Object
Total number of input bytes read so far.
3395 3396 3397 3398 3399 |
# File 'zlib.c', line 3395
static VALUE
rb_gzfile_total_in(VALUE obj)
{
return rb_uint2inum(get_gzfile(obj)->z.stream.total_in);
}
|
#print ⇒ Object
Same as IO.
#printf ⇒ Object
Same as IO.
#putc(ch) ⇒ Object
Same as IO.
3593 3594 3595 3596 3597 3598 3599 3600 3601 |
# File 'zlib.c', line 3593
static VALUE
rb_gzwriter_putc(VALUE obj, VALUE ch)
{
struct gzfile *gz = get_gzfile(obj);
char c = NUM2CHR(ch);
gzfile_write(gz, (Bytef*)&c, 1);
return ch;
}
|
#puts ⇒ Object
Same as IO.
#tell ⇒ Object
Total number of input bytes read so far.
3395 3396 3397 3398 3399 |
# File 'zlib.c', line 3395
static VALUE
rb_gzfile_total_in(VALUE obj)
{
return rb_uint2inum(get_gzfile(obj)->z.stream.total_in);
}
|
#write(str) ⇒ Object
Same as IO.
3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 |
# File 'zlib.c', line 3575
static VALUE
rb_gzwriter_write(VALUE obj, VALUE str)
{
struct gzfile *gz = get_gzfile(obj);
if (!RB_TYPE_P(str, T_STRING))
str = rb_obj_as_string(str);
if (gz->enc2 && gz->enc2 != rb_ascii8bit_encoding()) {
str = rb_str_conv_enc(str, rb_enc_get(str), gz->enc2);
}
gzfile_write(gz, (Bytef*)RSTRING_PTR(str), RSTRING_LEN(str));
RB_GC_GUARD(str);
return INT2FIX(RSTRING_LEN(str));
}
|