uuids.cov

```
        - # This file is a part of Julia. License is MIT: https://julialang.org/license
        - 
        - module UUIDs
        - 
        - using Random
        - 
        - import SHA
        - 
        - export UUID, uuid1, uuid4, uuid5, uuid_version
        - 
        - import Base: UUID
        - 
        - """
        -     uuid_version(u::UUID) -> Int
        - 
        - Inspects the given UUID and returns its version
        - (see [RFC 4122](https://www.ietf.org/rfc/rfc4122)).
        - 
        - # Examples
        - ```jldoctest
        - julia> uuid_version(uuid4())
        - 4
        - ```
        - """
        6 uuid_version(u::UUID) = Int((u.value >> 76) & 0xf)
        - 
        - # Some UUID namespaces provided in the appendix of RFC 4122
        - # https://tools.ietf.org/html/rfc4122.html#appendix-C
        - const namespace_dns  = UUID(0x6ba7b8109dad11d180b400c04fd430c8) # 6ba7b810-9dad-11d1-80b4-00c04fd430c8
        - const namespace_url  = UUID(0x6ba7b8119dad11d180b400c04fd430c8) # 6ba7b811-9dad-11d1-80b4-00c04fd430c8
        - const namespace_oid  = UUID(0x6ba7b8129dad11d180b400c04fd430c8) # 6ba7b812-9dad-11d1-80b4-00c04fd430c8
        - const namespace_x500 = UUID(0x6ba7b8149dad11d180b400c04fd430c8) # 6ba7b814-9dad-11d1-80b4-00c04fd430c8
        - 
        - """
        -     uuid1([rng::AbstractRNG=GLOBAL_RNG]) -> UUID
        - 
        - Generates a version 1 (time-based) universally unique identifier (UUID), as specified
        - by RFC 4122. Note that the Node ID is randomly generated (does not identify the host)
        - according to section 4.5 of the RFC.
        - 
        - # Examples
        - ```jldoctest; filter = r"[a-z0-9]{8}-([a-z0-9]{4}-){3}[a-z0-9]{12}"
        - julia> rng = MersenneTwister(1234);
        - 
        - julia> uuid1(rng)
        - UUID("cfc395e8-590f-11e8-1f13-43a2532b2fa8")
        - ```
        - """
        - function uuid1(rng::AbstractRNG=Random.default_rng())
        4     u = rand(rng, UInt128)
        - 
        -     # mask off clock sequence and node
        1     u &= 0x00000000000000003fffffffffffffff
        - 
        -     # set the unicast/multicast bit and version
        1     u |= 0x00000000000010000000010000000000
        - 
        -     # 0x01b21dd213814000 is the number of 100 nanosecond intervals
        -     # between the UUID epoch and Unix epoch
        1     timestamp = round(UInt64, time() * 1e7) + 0x01b21dd213814000
        1     ts_low = timestamp & typemax(UInt32)
        1     ts_mid = (timestamp >> 32) & typemax(UInt16)
        1     ts_hi = (timestamp >> 48) & 0x0fff
        - 
        1     u |= UInt128(ts_low) << 96
        1     u |= UInt128(ts_mid) << 80
        1     u |= UInt128(ts_hi) << 64
        - 
        1     UUID(u)
        - end
        - 
        - """
        -     uuid4([rng::AbstractRNG=GLOBAL_RNG]) -> UUID
        - 
        - Generates a version 4 (random or pseudo-random) universally unique identifier (UUID),
        - as specified by RFC 4122.
        - 
        - # Examples
        - ```jldoctest
        - julia> rng = MersenneTwister(1234);
        - 
        - julia> uuid4(rng)
        - UUID("196f2941-2d58-45ba-9f13-43a2532b2fa8")
        - ```
        - """
        - function uuid4(rng::AbstractRNG=Random.default_rng())
        7     u = rand(rng, UInt128)
        3     u &= 0xffffffffffff0fff3fffffffffffffff
        3     u |= 0x00000000000040008000000000000000
        3     UUID(u)
        - end
        - 
        - """
        -     uuid5(ns::UUID, name::String) -> UUID
        - 
        - Generates a version 5 (namespace and domain-based) universally unique identifier (UUID),
        - as specified by RFC 4122.
        - 
        - !!! compat "Julia 1.1"
        -     This function requires at least Julia 1.1.
        - 
        - # Examples
        - ```jldoctest
        - julia> rng = MersenneTwister(1234);
        - 
        - julia> u4 = uuid4(rng)
        - UUID("196f2941-2d58-45ba-9f13-43a2532b2fa8")
        - 
        - julia> u5 = uuid5(u4, "julia")
        - UUID("b37756f8-b0c0-54cd-a466-19b3d25683bc")
        - ```
        - """
        - function uuid5(ns::UUID, name::String)
       20     nsbytes = zeros(UInt8, 16)
       10     nsv = ns.value
       10     for idx in Base.OneTo(16)
      160         nsbytes[idx] = nsv >> 120
      310         nsv = nsv << 8
        -     end
       10     hash_result = SHA.sha1(append!(nsbytes, convert(Vector{UInt8}, codeunits(unescape_string(name)))))
        -     # set version number to 5
       10     hash_result[7] = (hash_result[7] & 0x0F) | (0x50)
       10     hash_result[9] = (hash_result[9] & 0x3F) | (0x80)
        -     v = zero(UInt128)
        -     #use only the first 16 bytes of the SHA1 hash
       10     for idx in Base.OneTo(16)
      310         v = (v << 0x08) | hash_result[idx]
        -     end
       10     return UUID(v)
        - end
        - 
        - end
        - 

```