LexID: Fast lexicographically orderable/sortable ID

Highly customizable ID generator that can generate ~10 millions IDs per second (single core only).

Consist of 3 segment:

• Unix or UnixNano (current time, 6/11 character)
• Atomic Counter (limit to single core, 6 character)
• Server/Process/Thread Unique Identity (optional, min. 0 character, default: ~0)
• 1 or 2 separator character (default: ~, can be removed, 2x 0-1 character)

Default formats:

• ID(): tttttt~cccccc~i
• NanoID(): ttttttttttt~cccccc~i
• t = timestamp
• c = counter
• i = identity, can be more than 1 character

Based on lexicographically sortable encoding, URL-safe encoding.

Configuration Comparison

Type	Min[Nano] Date Offset	Min[Nano] Time Length	Min Counter Length	Separator	Byte use without Identity	Ordered	Unique
ID	0	6	6	~	13	Y	Y
ID	0	0	0	~	8-13	N	Y
ID	0	6	6		12	Y	Y
ID	0	0	0		6-12	N	N
ID	1577836800	0	0	~	7	N	Y
ID	1577836800	0	0		6	N	N
NanoID	0	11	6	~	19	Y	Y
NanoID	0	0	0	~	14-19	N	Y
NanoID	0	11	6		17	Y	Y
NanoID	0	0	0		12-17	N	N
NanoID	1577836800 000000000	0	0	~	12	N	Y
NanoID	1577836800 000000000	0	0		11	N	N

Note: 1577836800 = unix timestamp of 2021-01-01 00:00:00

Uniqueness configuration (when Separator or Min*TimeLength set, this is the default)

Min length (ID with separator and server identity): 
  6+6+0+1 = 13 bytes (format: `tttttt~cccccc`)
  5+1+0+1 = 7 bytes (with 2020 offset, format: `ttttt`~`c`)
Max length (NanoID with separator and server identity): 
  11+6+N+2 = 19+N bytes (format: `ttttttttttt~cccccc~i`)
  10+1+N+1 = 12+N bytes (with 2020 offset, format: `tttttttttt~c~i`)

Ordered/sortable configuration (when Min*TimeLength set, may unset the Separator)

Min length (ID without separator and server identity): 
  6+6+0+0 = 12 bytes (format: `ttttttcccccc`)
Max length (NanoID without separator and with server identity): 
  11+6+N+0 = 17+N bytes (format: `tttttttttttcccccci`)

Benchmark

cpu: AMD Ryzen 3 3100 4-Core Processor    
BenchmarkShortuuid-8      118908      8572 ns/op
BenchmarkKsuid-8          760924      1493 ns/op
BenchmarkNanoid-8         759548      1485 ns/op
BenchmarkUuid-8           935152      1304 ns/op
BenchmarkTime-8          1690483       720.0 ns/op
BenchmarkSnowflake-8     4911249       244.7 ns/op
BenchmarkLexIdNano-8     8483720       138.8 ns/op <--
BenchmarkLexIdNoSep-8   10396551       116.3 ns/op <--
BenchmarkLexIdNoLex-8   10590300       115.1 ns/op <--
BenchmarkLexId-8         9991906       114.9 ns/op <--
BenchmarkXid-8          13754178        86.02 ns/op
BenchmarkId64-8        276799974         4.362 ns/op

Usage

import "github.com/kokizzu/lexid"

func main() {
	// set if multiserver, can be empty if not multi-server/process/thread/instance
	lexid.Config.Identity = `` // default: ~0
	
	// optional starting counter
	lexid.Config.AtomicCounter = 0
	
	// optional segment separator
	// you can set this to empty string if you keep the Min*Length as default 
	lexid.Config.Separator = `` // default: ~
	
	// optional minimum counter segment length, default: 6
	// if set lower than 6 will not lexicographically orderable anymore
	lexid.Config.MinCounterLength = 0
	
	// optional minimum time segment length, default: 6
	// if set lower than 6 might not lexicographically orderable anymore
	lexid.Config.MinTimeLength = 0
	
	// optional minimum nano time segment length, default: 11
	// if set lower than 11 might not lexicographically orderable anymore
	lexid.Config.MinNanoTimeLength = 0
	
	// optional date offset, can reduce length of the time segment
	lexid.Config.MinDateOffset = lexid.OffsetY2020.Unix()
	lexid.Config.MinNanoDateOffset = lexid.OffsetY2020.UnixNano()
	
	// smaller id, second resolution
	id := lexid.ID()
	
	// larger id, nanosecond resolution (`~5 ms` to be exact)
	nanoid := lexid.NanoID()
	
	// parse to get time, counter, and server id
	seg, err := lexid.Parse(id)
	seg, err = lexid.Parse(nanoid)  
	
	// generate id from segment/component
	id = lexid.FromUnix(time)
	id = lexid.FromUnixCounter(time,counter)
	id = lexid.FromUnixCounterIdent(time,counter,identity)
	id = lexid.FromNano(time)
	id = lexid.FromNanoCounter(time,counter)
	id = lexid.FromNanoCounterIdent(time,counter,identity)
	
	// object-oriented version, 
	// eg. if you need to generate uniquely one per core/thread
	//     or when each database table need different ID format
	gen := lexid.NewGenerator(`~1`) // ~2 for 2nd core, ~3 for 3rd core, and so on
	// gen.Identity = `~1`
	// gen.Separator = `~`
	// gen.AtomicCounter = 0
	// gen.MinCounterLength = 6
	// gen.MinTimeLength = 6
	// gen.MinNanoTimeLength = 11
	// gen.MinDateOffset = 0 
	// gen.MinNanoDateOffset = 0 
	// gen.From*() also exists
	
	id = gen.ID()
	nanoid = gen.NanoID()
}

Example generated ID

shows minimum length and length after 1-10 million generated ID with specific configuration (6-15 characters for ID, 11-20 characters for NanoID).

Default config (fixed length):

ID 
first: 0Vsccp~-----0~0
 len= 15
last: 0Vsccp~--a8P0~0
 len= 15

NanoID
first: 0PDmclT1CmN~-----0~0
 len= 20
last: 0PDmclT1CmN~--a8P0~0
 len= 20

Separatorless config and without Identity:

ID Separator=`` Identity=`` MinTimeLength=6 (default)
first: 0Vsccp-----0
 len= 12
last: 0Vsccp--a8P0
 len= 12

NanoID Separator=`` Identity=`` MinNanoTimeLength=11 (default)
first: 0PDmclT1CmN-----0
 len= 17
last: 0PDmclT1CmN--a8P0
 len= 17

Variable length config (not lexicographically sortable):

ID MinCounterLength=0
first: 0Vsc0a~0~0 
 len= 10
last:  0Vsc0a~2o80~0 
 len= 13

NanoID MinCounterLength=0
first 0PDm7hn0KSs~0~0
 len= 15
last 0PDm7hn0KSs~2o80~0
 len= 18 

Allows duplicate config:

ID Separator=`` Identity=`` MinCounterLength=0
first: 0Vsccp0
 len= 7
last: 0Vsccpa8P0
 len= 10

NanoID Separator=`` Identity=`` MinCounterLength=0
first: 0PDmclT1CmN0
 len= 12
last: 0PDmclT1CmNa8P0
 len= 15

Offsetted config (reduce time segment by 2020-01-01):

ID MinTimeLength=0 MinCounterLength=0
example: 1pkHb~0~0
 len= 9
 
NanoID MinNanoTimeLength=0 MinCounterLength=0
example: 1dGr84ixhV~1~0
 len= 14

Offsetted with minimum length and allows duplicate:

ID MinTimeLength=0 MinCounterLength=0 Separator=`` Identity=``
example: 1pkHb0
 len= 6
 
NanoID MinNanoTimeLength=0 MinCounterLength=0 Separator=`` Identity=``
example: 1dGr84ixhV1
 len= 11

Gotchas

it might not lexicographically ordered/sorted if:

• the AtomicCounter is overflowed on the exact same second, can be happening when your processor able to call ID() function more than 4 billion (MaxUint32=4,294,967,295) times per second.
• you change Separator to other character that have lower value than z (122) of ASCII/UTF-8, the default is ~ (126).
• you set Min*Length less than recommended value, it should be >=6 for MinTimeLength and >=11 for MinNanoTimeLength, and 6 for MinCounterLength.
• you unset Separator and set MinCounterLength lower than 6
• the time segment already pass the MinTimeLength=6, earliest will happen at year 4147.
• you change system time to earlier time.

it might duplicate if:

• your processor too powerful, that it can call the function ID() more than 4 billion times per second, workaround: use NanoID().
• you set the AtomicCounter multiple time on the same second/nanosecond (eg. to a number lower than current counter).
• using same/shared Identity on different server/process/thread.
• unsynchronized time on same server.
• you set Min*DateOffset too low or differently on each run.
• you change Separator to empty string or characters that are in EncodeCB63 with Min*Length less than recommended value.
• you change system time to earlier time.

it will impossible to parse (to get time, counter, and server id) if:

• you unset Separator and Min*Length to lower than recommended value.

hidden logic/implementation detail?

• counter resets to 0 when second changed but only when ID() called, so it would never overflow (unless your processor too powerful).
• nanosecond incremented by 1 every 4 billion NanoID() calls, so it would never collide.

Difference with XID

• have locks, so by default can only utilize single core (unless using the object-oriented version to spawn multiple instance with different server/process/thread Identity)
• 256x more max unique IDs per sec guaranteed: 4 billion vs 16 million
• configurable (length, separator, server/process/thread identity, date offset)
• EncodeCB63 (base64-variant, smaller) vs base32 (20% bigger)
• defaults to string representation (12 to 17+N bytes, smaller) vs have 12-bytes binary representation (20 bytes for string representation, longer)
• server/process/thread Identity are optional
• can be offsetted (subtracted with certain value, eg. 2020-01-01 00:00:00)

See also

id64 - quick non-distributed uint64 id generator (can generate ~276 million ID/second)