Timed Uniqe Identifier
npm install tuid
The design goals of this variation is to make identifier growth as time
elapses, which is index-friendly for database.
bash
npm install tuid
`
Usage
javascript
var tuid = requier('tuid');
var generator = tuid.Generator(); // create a generator with random node id
var id = generator.generateSync();
console.log(id.toString()); // prints: 1e660627-c30c-f010-0000-7affa0ae7874
console.log(id.toBuffer().toString('hex')); // prints: 1e660627c30cf01000007affa0ae7874
`$3
#### Generator
*
Constructor, take an optional buffer parameter, the buffer should be
at least 6 byte. Typically it should be the MAC address of one network
interface of the host machine. If the node buffer is not presented,
random 6 bytes will be fetched via .
* generateSync(): Identifier
Generate a Identifier synchronously. Note if identifier is generated
too frequently, exceeding 65536000ops/1ms, an exception will be throw
because due to conflict.
* generate(): Promise
Generate a Identifier. The returned promise is resolved immediately,
unless the identifier generation is exceeding 65536000ops/1ms, in such
situation, the promise will defer to a suitable time.
Implementation Detail
The identifier layout:
Timestamp High 32bit
Timestamp Middle 16bit
Version (0xf) and Timestamp Low 12bit
Clock Sequence
Node 48bit
1e660627
c30c
f010
0000
bdd077ed01e5
As show in above:1. the version changed to
to indicates that this is
not a standard UUID implementation as currently only v1, v3, v4 and v5 is
defined. 2. Timestamp are encoded into a identifier from higher bit
to lower bit in network byte order, to ensure the identifier growth when
treated as a byte string as time elapses. The definition of timestamp is
same with the ones defined in UUID v1, which is count of 100-nanoseconds
since Gregorian Epoch (Oct. 15th, 1587). For system lacks of high
resolution timer, such as Javascript, the lower bit of timestamp can be
emulated by clock sequence.
3. Clock sequence takes two bytes(16bits) and no reserved bits.
4. Node field remains same with UUID v1.
License
`
Copyright (C) 2016 LAN Xingcan
All right reservedPermission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.