commit 301eb851a2f00812b00d470e98cf014e5ce4d4e2
Author: Yongbin Kim <iam@yongbin.kim>
Date: Mon, 9 Jan 2023 15:30:32 +0000
First commit
Diffstat:
| A | README | | | 28 | ++++++++++++++++++++++++++++ |
| A | go.mod | | | 3 | +++ |
| A | nanoid.go | | | 83 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | nanoid_test.go | | | 51 | +++++++++++++++++++++++++++++++++++++++++++++++++++ |
4 files changed, 165 insertions(+), 0 deletions(-)
diff --git a/README b/README
@@ -0,0 +1,28 @@
+go.lair.cx/nanoid
+=================
+
+This module is a Go port of nanoid.
+
+
+Installation
+------------
+
+ go get -u go.lair.cx/nanoid
+
+
+Usage
+-----
+
+See nanoid_test.go for examples.
+
+
+License
+-------
+
+Public domain. See unlicense.org
+
+
+Report a bug
+------------
+
+Send me a email to <iam@yongbin.kim>. Thanks!
diff --git a/go.mod b/go.mod
@@ -0,0 +1,3 @@
+module go.lair.cx/nanoid
+
+go 1.19
diff --git a/nanoid.go b/nanoid.go
@@ -0,0 +1,83 @@
+package nanoid
+
+import (
+ "io"
+ "sync"
+
+ cryptoRand "crypto/rand"
+)
+
+const (
+ characters = "_-0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ idSize = 21
+)
+
+type NanoID [idSize]byte
+
+type Generator interface {
+ Generate() NanoID
+}
+
+type generator struct {
+ mu sync.Mutex
+ source io.Reader
+ buf []byte
+ bufSize int
+ offset int
+}
+
+func New(n int) Generator {
+ return newWithReader(cryptoRand.Reader, n)
+}
+
+func NewWithReader(r io.Reader, n int) Generator {
+ return newWithReader(r, n)
+}
+
+func newWithReader(source io.Reader, length int) Generator {
+ return &generator{
+ source: source,
+ buf: make([]byte, length*idSize),
+ bufSize: length * idSize,
+ offset: length * idSize,
+ }
+}
+
+func (g *generator) Generate() NanoID {
+ g.mu.Lock()
+ defer g.mu.Unlock()
+
+ if g.offset == g.bufSize {
+ g.source.Read(g.buf)
+ g.offset = 0
+ }
+
+ var id NanoID
+
+ for i := 0; i < idSize; i++ {
+ id[i] = characters[g.buf[g.offset+i]&0b00111111]
+ }
+ g.offset += idSize
+
+ return id
+}
+
+func Generate() NanoID {
+ return New(1).Generate()
+}
+
+func GenerateN(n int) []NanoID {
+ gen := New(n)
+ ids := make([]NanoID, n)
+
+ for i := range ids {
+ ids[i] = gen.Generate()
+ }
+
+ return ids
+}
+
+// String returns the string representation of the id.
+func (id NanoID) String() string {
+ return string(id[:])
+}
diff --git a/nanoid_test.go b/nanoid_test.go
@@ -0,0 +1,51 @@
+package nanoid
+
+import (
+ "math/rand"
+ "testing"
+ "time"
+)
+
+const benchBufLength = 21 * 21 * 7 / 21
+
+var expectedIDs = []NanoID{
+ {0x2d, 0x69, 0x58, 0x30, 0x55, 0x4a, 0x57, 0x5f, 0x2d, 0x68, 0x5a, 0x67, 0x32, 0x70, 0x4e, 0x36, 0x49, 0x64, 0x54, 0x74, 0x51},
+ {0x77, 0x7a, 0x49, 0x43, 0x45, 0x58, 0x4f, 0x38, 0x48, 0x39, 0x50, 0x56, 0x6d, 0x62, 0x4a, 0x36, 0x42, 0x73, 0x75, 0x4c, 0x62},
+ {0x54, 0x34, 0x66, 0x33, 0x64, 0x69, 0x76, 0x53, 0x37, 0x49, 0x77, 0x33, 0x47, 0x76, 0x66, 0x69, 0x6a, 0x53, 0x36, 0x50, 0x6b},
+ {0x63, 0x77, 0x68, 0x65, 0x65, 0x73, 0x46, 0x53, 0x54, 0x4f, 0x61, 0x43, 0x74, 0x4b, 0x32, 0x34, 0x4c, 0x53, 0x56, 0x63, 0x36},
+ {0x56, 0x5a, 0x33, 0x55, 0x46, 0x6e, 0x33, 0x4d, 0x67, 0x35, 0x30, 0x71, 0x4d, 0x4e, 0x43, 0x49, 0x52, 0x73, 0x53, 0x6b, 0x51},
+ {0x6e, 0x2d, 0x64, 0x62, 0x63, 0x61, 0x52, 0x35, 0x73, 0x55, 0x2d, 0x5a, 0x73, 0x42, 0x74, 0x42, 0x64, 0x77, 0x30, 0x64, 0x57},
+ {0x31, 0x69, 0x4e, 0x48, 0x77, 0x6b, 0x59, 0x61, 0x63, 0x78, 0x49, 0x73, 0x36, 0x67, 0x45, 0x74, 0x38, 0x6c, 0x39, 0x39, 0x73},
+ {0x4d, 0x69, 0x41, 0x68, 0x69, 0x51, 0x62, 0x48, 0x44, 0x6c, 0x76, 0x45, 0x73, 0x64, 0x6f, 0x41, 0x49, 0x31, 0x57, 0x53, 0x34},
+ {0x45, 0x75, 0x2d, 0x47, 0x2d, 0x75, 0x35, 0x75, 0x4a, 0x62, 0x47, 0x45, 0x32, 0x51, 0x67, 0x73, 0x75, 0x56, 0x75, 0x78, 0x4c},
+ {0x4a, 0x6b, 0x72, 0x62, 0x65, 0x72, 0x50, 0x32, 0x71, 0x5a, 0x5f, 0x64, 0x38, 0x54, 0x46, 0x63, 0x47, 0x66, 0x47, 0x53, 0x2d},
+}
+
+func TestNanoID(t *testing.T) {
+ randomSource := rand.New(rand.NewSource(0))
+ gen := NewWithReader(randomSource, 1)
+
+ for _, expectedID := range expectedIDs {
+ id := gen.Generate()
+ if id != expectedID {
+ t.Errorf("Expected %s, got %s", expectedID, id)
+ }
+ }
+}
+
+func BenchmarkMathNanoID(b *testing.B) {
+ gen := NewWithReader(rand.New(rand.NewSource(time.Now().UnixNano())), benchBufLength)
+
+ for i := 0; i < b.N; i++ {
+ gen.Generate()
+ }
+}
+
+// BenchmarkNanoID benchmarks the NanoID generation.
+func BenchmarkNanoID(b *testing.B) {
+ gen := New(benchBufLength)
+
+ for i := 0; i < b.N; i++ {
+ gen.Generate()
+ }
+}
