Class: SSRS::UUID
- Inherits:
-
Struct
- Object
- Struct
- SSRS::UUID
- Includes:
- Comparable
- Defined in:
- lib/ssrs/UUID.rb,
lib/ssrs/UUID.rb
Overview
Pure ruby UUID generator, which is compatible with RFC4122
Constant Summary collapse
- STATE_FILE =
'ruby-uuid'
- NameSpace_DNS =
Pre-defined UUID Namespaces described in RFC4122 Appendix C.
parse "6ba7b810-9dad-11d1-80b4-00c04fd430c8"
- NameSpace_URL =
parse "6ba7b811-9dad-11d1-80b4-00c04fd430c8"
- NameSpace_OID =
parse "6ba7b812-9dad-11d1-80b4-00c04fd430c8"
- NameSpace_X500 =
parse "6ba7b814-9dad-11d1-80b4-00c04fd430c8"
- Nil =
The Nil UUID in RFC4122 Section 4.1.7
parse "00000000-0000-0000-0000-000000000000"
Instance Attribute Summary collapse
-
#raw_bytes ⇒ Object
Returns the value of attribute raw_bytes.
Class Method Summary collapse
-
.create(clock = nil, time = nil, mac_addr = nil) ⇒ Object
create the “version 1” UUID with current system clock, current UTC timestamp, and the IEEE 802 address (so-called MAC address).
-
.create_md5(str, namespace) ⇒ Object
UUID generation using MD5 (for backward compat.).
-
.create_random ⇒ Object
UUID generation using random-number generator.
-
.create_sha1(str, namespace) ⇒ Object
UUID generation using SHA1.
-
.mask(str) ⇒ Object
:nodoc.
-
.pack(tl, tm, th, ch, cl, n) ⇒ Object
The ‘primitive constructor’ of this class Note UUID.pack(uuid.unpack) == uuid.
-
.parse(obj) ⇒ Object
A simple GUID parser: just ignores unknown characters and convert hexadecimal dump into 16-octet object.
-
.read_state(fp) ⇒ Object
:nodoc:.
-
.write_state(fp, c, m) ⇒ Object
:nodoc:.
Instance Method Summary collapse
-
#<=>(other) ⇒ Object
UUIDs are comparable (don’t know what benefits are there, though).
-
#==(other) ⇒ Object
Two UUIDs are said to be equal if and only if their (byte-order canonicalized) integer representations are equivallent.
-
#to_int ⇒ Object
(also: #to_i)
Convert into 128-bit unsigned integer Typically a Bignum instance, but can be a Fixnum.
-
#to_s ⇒ Object
(also: #guid)
Generate the string representation (a.k.a GUID) of this UUID.
-
#to_uri ⇒ Object
(also: #urn)
Convert into a RFC4122-comforming URN representation.
-
#unpack ⇒ Object
The ‘primitive deconstructor’, or the dual to pack.
Instance Attribute Details
#raw_bytes ⇒ Object
Returns the value of attribute raw_bytes
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# File 'lib/ssrs/UUID.rb', line 32 def raw_bytes @raw_bytes end |
Class Method Details
.create(clock = nil, time = nil, mac_addr = nil) ⇒ Object
create the “version 1” UUID with current system clock, current UTC timestamp, and the IEEE 802 address (so-called MAC address).
Speed notice: it’s slow. It writes some data into hard drive on every invokation. If you want to speed this up, try remounting tmpdir with a memory based filesystem (such as tmpfs). STILL slow? then no way but rewrite it with c :)
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# File 'lib/ssrs/UUID.rb', line 115 def create( clock=nil, time=nil, mac_addr=nil ) c = t = m = nil Dir.chdir Dir.tmpdir do unless FileTest.exist? STATE_FILE then # Generate a pseudo MAC address because we have no pure-ruby way # to know the MAC address of the NIC this system uses. Note # that cheating with pseudo arresses here is completely legal: # see Section 4.5 of RFC4122 for details. sha1 = Digest::SHA1.new 256.times do r = [rand(0x100000000)].pack "N" sha1.update r end str = sha1.digest r = rand 34 # 40-6 node = str[r, 6] || str node[0] |= 0x01 # multicast bit k = rand 0x40000 open STATE_FILE, 'wb' do |fp| fp.flock IO::LOCK_EX write_state fp, k, node fp.chmod 0o777 # must be world writable end end open STATE_FILE, 'r+b' do |fp| fp.flock IO::LOCK_EX c, m = read_state fp c = clock % 0x4000 if clock m = mac_addr if mac_addr t = time if t.nil? then # UUID epoch is 1582/Oct/15 tt = Time.now t = tt.to_i*10000000 + tt.tv_usec*10 + 0x01B21DD213814000 end c = c.succ # important; increment here write_state fp, c, m end end tl = t & 0xFFFF_FFFF tm = t >> 32 tm = tm & 0xFFFF th = t >> 48 th = th & 0x0FFF th = th | 0x1000 cl = c & 0xFF ch = c & 0x3F00 ch = ch >> 8 ch = ch | 0x80 pack tl, tm, th, cl, ch, m end |
.create_md5(str, namespace) ⇒ Object
UUID generation using MD5 (for backward compat.)
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# File 'lib/ssrs/UUID.rb', line 65 def create_md5 str, namespace md5 = Digest::MD5.new md5.update namespace.raw_bytes md5.update str sum = md5.digest raw = mask sum[0..16] ret = new raw ret.raw_bytes.freeze ret.freeze ret end |
.create_random ⇒ Object
UUID generation using random-number generator. From it’s random nature, there’s no warranty that the created ID is really universaly unique.
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# File 'lib/ssrs/UUID.rb', line 80 def create_random rnd = [ rand(0x100000000), rand(0x100000000), rand(0x100000000), rand(0x100000000), ].pack "N4" raw = mask rnd ret = new raw ret.raw_bytes.freeze ret.freeze ret end |
.create_sha1(str, namespace) ⇒ Object
UUID generation using SHA1. Recommended over create_md5. Namespace object is another UUID, some of them are pre-defined below.
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# File 'lib/ssrs/UUID.rb', line 52 def create_sha1 str, namespace sha1 = Digest::SHA1.new sha1.update namespace.raw_bytes sha1.update str sum = sha1.digest raw = mask sum[0..15] ret = new raw ret.raw_bytes.freeze ret.freeze ret end |
.mask(str) ⇒ Object
:nodoc
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# File 'lib/ssrs/UUID.rb', line 37 def mask str # :nodoc v = str[7] v = v & 0b00001111 v = v | 0b01010000 str[7] = v r = str[8] r = r & 0b00111111 r = r | 0b10000000 str[8] = r str end |
.pack(tl, tm, th, ch, cl, n) ⇒ Object
The ‘primitive constructor’ of this class Note UUID.pack(uuid.unpack) == uuid
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# File 'lib/ssrs/UUID.rb', line 182 def pack tl, tm, th, ch, cl, n raw = [tl, tm, th, ch, cl, n].pack "NnnCCa6" ret = new raw ret.raw_bytes.freeze ret.freeze ret end |
.parse(obj) ⇒ Object
A simple GUID parser: just ignores unknown characters and convert hexadecimal dump into 16-octet object.
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# File 'lib/ssrs/UUID.rb', line 170 def parse obj str = obj.to_s.sub %r/\Aurn:uuid:/, '' str.gsub! %r/[^0-9A-Fa-f]/, '' raw = str[0..31].to_a.pack 'H*' ret = new raw ret.raw_bytes.freeze ret.freeze ret end |
.read_state(fp) ⇒ Object
:nodoc:
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# File 'lib/ssrs/UUID.rb', line 94 def read_state fp # :nodoc: fp.rewind Marshal.load fp.read end |
.write_state(fp, c, m) ⇒ Object
:nodoc:
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# File 'lib/ssrs/UUID.rb', line 99 def write_state fp, c, m # :nodoc: fp.rewind str = Marshal.dump [c, m] fp.write str end |
Instance Method Details
#<=>(other) ⇒ Object
UUIDs are comparable (don’t know what benefits are there, though).
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# File 'lib/ssrs/UUID.rb', line 231 def <=> other to_s <=> other.to_s end |
#==(other) ⇒ Object
Two UUIDs are said to be equal if and only if their (byte-order canonicalized) integer representations are equivallent. Refer RFC4122 for details.
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# File 'lib/ssrs/UUID.rb', line 225 def == other to_i == other.to_i end |
#to_int ⇒ Object Also known as: to_i
Convert into 128-bit unsigned integer Typically a Bignum instance, but can be a Fixnum.
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# File 'lib/ssrs/UUID.rb', line 214 def to_int tmp = self.raw_bytes.unpack "C*" tmp.inject do |r, i| r * 256 | i end end |
#to_s ⇒ Object Also known as: guid
Generate the string representation (a.k.a GUID) of this UUID
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# File 'lib/ssrs/UUID.rb', line 198 def to_s a = unpack tmp = a[-1].unpack 'C*' a[-1] = sprintf '%02x%02x%02x%02x%02x%02x', *tmp "%08x-%04x-%04x-%02x%02x-%s" % a end |
#to_uri ⇒ Object Also known as: urn
Convert into a RFC4122-comforming URN representation
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# File 'lib/ssrs/UUID.rb', line 207 def to_uri "urn:uuid:" + self.to_s end |
#unpack ⇒ Object
The ‘primitive deconstructor’, or the dual to pack. Note UUID.pack(uuid.unpack) == uuid
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# File 'lib/ssrs/UUID.rb', line 193 def unpack raw_bytes.unpack "NnnCCa6" end |