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output: rmarkdown::github_document
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[](https://travis-ci.org/hrbrmstr/ulid)
[](https://ci.appveyor.com/project/hrbrmstr/ulid)
[](https://codecov.io/gh/hrbrmstr/ulid)
[](https://cran.r-project.org/package=ulid)
# ulid
Universally Unique Lexicographically Sortable Identifiers
## Description
(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, herein is proposed ULID:
```javascript
ulid() // 01ARZ3NDEKTSV4RRFFQ69G5FAV
```
- 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
- Won't run out of space till 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.
## What's Inside The Tin
The following functions are implemented:
- `ULIDgenerate` / `generate` / `ulid_generate`: Generate a time-based ULID
- `ts_generate`: Generate ULID from timestamps
- `unmarshal`: Unmarshal a ULID into a data frame with timestamp and random bitstring columns
## Installation
```{r nstall-ex, results='asis', echo = FALSE}
hrbrpkghelpr::install_block()
```
```{r message=FALSE, warning=FALSE, error=FALSE, include=FALSE}
options(width=120)
```
## Usage
```{r message=FALSE, warning=FALSE, error=FALSE}
library(ulid)
# current verison
packageVersion("ulid")
```
### One
```{r}
ulid::ULIDgenerate()
```
### Many
```{r}
(u <- ulid::ULIDgenerate(20))
```
### Unmarshal
```{r}
unmarshal(u)
```
### Use defined timestamps
```{r}
(ut <- ts_generate(as.POSIXct("2017-11-01 15:00:00", origin="1970-01-01")))
unmarshal(ut)
```
## Package Code Metrics
```{r}
cloc::cloc_pkg_md()
```
