ulid (version 0.3.1)

generate: Generate ULID

Description

generate() generates a new Universally Unique Lexicographically Sortable Identifier. Several aliases are available for convience and backwards-compatibility.

This function generates a new Universally Unique Lexicographically Sortable Identifier from a vector of POSIXct timestamps.

As described in the ulid specification repo, and slightly edited here, UUID use can be suboptimal for many uses-cases because:(grifted from https://github.com/ulid/spec)

UUID can be suboptimal for many uses-cases because:

• It isn't the most character efficient way of encoding 128 bits of randomness

• UUID v1/v2 is impractical in many environments, as it requires access to a unique, stable MAC address

• UUID v3/v5 requires a unique seed and produces randomly distributed IDs, which can cause fragmentation in many data structures

• UUID v4 provides no other information than randomness which can cause fragmentation in many data structures

Instead, an alternative is proposed in ULID:

ulid() // 01ARZ3NDEKTSV4RRFFQ69G5FAV

with the following properties:

• 128-bit compatibility with UUID

• 1.21e+24 unique ULIDs per millisecond

• Lexicographically sortable!

• Canonically encoded as a 26 character string, as opposed to the 36 character UUID

• Uses Crockford's base32 for better efficiency and readability (5 bits per character)

• Case insensitive

• No special characters (URL safe)

• Monotonic sort order (correctly detects and handles the same millisecond)

01AN4Z07BY      79KA1307SR9X4MV3
|----------|    |----------------|
  Timestamp          Randomness
   48bits              80bits

Components

Timestamp

• 48 bit integer

• UNIX-time in milliseconds

• Will not run out of space until the year 10889 AD.

Randomness

• 80 bits

• Cryptographically secure source of randomness, if possible

Sorting

The left-most character must be sorted first, and the right-most character sorted last (lexical order). The default ASCII character set must be used. Within the same millisecond, sort order is not guaranteed.

Usage

generate(n = 1L)
unmarshal(ulids)
ts_generate(tsv)
ulid(n = 1L)
ulid_generate(n = 1L)
ULIDgenerate(n = 1L)

Value

data frame (tibble)

Arguments

n

number of id's to generate (default = 1)

ulids

character ULIDs (e.g. created with ULIDgenerate())

tsv

vector of POSIXct values

Author

Bob Rudis ([e-mail]) wrote the package based on ulid C++ library by Suyash Verma.

Dirk Eddelbuettel now maintains the package.

See Also

The ulid specification provides the reference.

Examples

ULIDgenerate()
unmarshal(ULIDgenerate())
ts_generate(as.POSIXct("2017-11-01 15:00:00", origin="1970-01-01"))