Refactor pkg/common, Fixes #11599

Signed-off-by: Antonio Murdaca <me@runcom.ninja>

stringid/README.md

@@ -0,0 +1 @@
+This package provides helper functions for dealing with string identifiers

stringid/stringid.go

@@ -1,4 +1,4 @@
-package common
+package stringid
 
 import (
 	"crypto/rand"
@@ -36,12 +36,3 @@ func GenerateRandomID() string {
 		return value
 	}
 }
-
-func RandomString() string {
-	id := make([]byte, 32)
-
-	if _, err := io.ReadFull(rand.Reader, id); err != nil {
-		panic(err) // This shouldn't happen
-	}
-	return hex.EncodeToString(id)
-}

stringid/stringid_test.go

@@ -1,8 +1,14 @@
-package common
+package stringid
 
-import (
-	"testing"
-)
+import "testing"
+
+func TestGenerateRandomID(t *testing.T) {
+	id := GenerateRandomID()
+
+	if len(id) != 64 {
+		t.Fatalf("Id returned is incorrect: %s", id)
+	}
+}
 
 func TestShortenId(t *testing.T) {
 	id := GenerateRandomID()
@@ -27,33 +33,3 @@ func TestShortenIdInvalid(t *testing.T) {
 		t.Fatalf("Id returned is incorrect: truncate on %s returned %s", id, truncID)
 	}
 }
-
-func TestGenerateRandomID(t *testing.T) {
-	id := GenerateRandomID()
-
-	if len(id) != 64 {
-		t.Fatalf("Id returned is incorrect: %s", id)
-	}
-}
-
-func TestRandomString(t *testing.T) {
-	id := RandomString()
-	if len(id) != 64 {
-		t.Fatalf("Id returned is incorrect: %s", id)
-	}
-}
-
-func TestRandomStringUniqueness(t *testing.T) {
-	repeats := 25
-	set := make(map[string]struct{}, repeats)
-	for i := 0; i < repeats; i = i + 1 {
-		id := RandomString()
-		if len(id) != 64 {
-			t.Fatalf("Id returned is incorrect: %s", id)
-		}
-		if _, ok := set[id]; ok {
-			t.Fatalf("Random number is repeated")
-		}
-		set[id] = struct{}{}
-	}
-}

stringutils/README.md

@@ -0,0 +1 @@
+This package provides helper functions for dealing with strings

stringutils/stringutils.go

@@ -0,0 +1,43 @@
+package stringutils
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"io"
+	mathrand "math/rand"
+	"time"
+)
+
+// Generate 32 chars random string
+func GenerateRandomString() string {
+	id := make([]byte, 32)
+
+	if _, err := io.ReadFull(rand.Reader, id); err != nil {
+		panic(err) // This shouldn't happen
+	}
+	return hex.EncodeToString(id)
+}
+
+// Generate alpha only random stirng with length n
+func GenerateRandomAlphaOnlyString(n int) string {
+	// make a really long string
+	letters := []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	b := make([]byte, n)
+	r := mathrand.New(mathrand.NewSource(time.Now().UTC().UnixNano()))
+	for i := range b {
+		b[i] = letters[r.Intn(len(letters))]
+	}
+	return string(b)
+}
+
+// Generate Ascii random stirng with length n
+func GenerateRandomAsciiString(n int) string {
+	chars := "abcdefghijklmnopqrstuvwxyz" +
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
+		"~!@#$%^&*()-_+={}[]\\|<,>.?/\"';:` "
+	res := make([]byte, n)
+	for i := 0; i < n; i++ {
+		res[i] = chars[mathrand.Intn(len(chars))]
+	}
+	return string(res)
+}

stringutils/stringutils_test.go

@@ -0,0 +1,25 @@
+package stringutils
+
+import "testing"
+
+func TestRandomString(t *testing.T) {
+	str := GenerateRandomString()
+	if len(str) != 64 {
+		t.Fatalf("Id returned is incorrect: %s", str)
+	}
+}
+
+func TestRandomStringUniqueness(t *testing.T) {
+	repeats := 25
+	set := make(map[string]struct{}, repeats)
+	for i := 0; i < repeats; i = i + 1 {
+		str := GenerateRandomString()
+		if len(str) != 64 {
+			t.Fatalf("Id returned is incorrect: %s", str)
+		}
+		if _, ok := set[str]; ok {
+			t.Fatalf("Random number is repeated")
+		}
+		set[str] = struct{}{}
+	}
+}

truncindex/truncindex_test.go

@@ -4,7 +4,7 @@ import (
 	"math/rand"
 	"testing"
 
-	"github.com/docker/docker/pkg/common"
+	"github.com/docker/docker/pkg/stringid"
 )
 
 // Test the behavior of TruncIndex, an index for querying IDs from a non-conflicting prefix.
@@ -111,7 +111,7 @@ func assertIndexGet(t *testing.T, index *TruncIndex, input, expectedResult strin
 func BenchmarkTruncIndexAdd100(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -127,7 +127,7 @@ func BenchmarkTruncIndexAdd100(b *testing.B) {
 func BenchmarkTruncIndexAdd250(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -143,7 +143,7 @@ func BenchmarkTruncIndexAdd250(b *testing.B) {
 func BenchmarkTruncIndexAdd500(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -160,7 +160,7 @@ func BenchmarkTruncIndexGet100(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	index := NewTruncIndex([]string{})
 	for _, id := range testSet {
@@ -184,7 +184,7 @@ func BenchmarkTruncIndexGet250(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	index := NewTruncIndex([]string{})
 	for _, id := range testSet {
@@ -208,7 +208,7 @@ func BenchmarkTruncIndexGet500(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	index := NewTruncIndex([]string{})
 	for _, id := range testSet {
@@ -231,7 +231,7 @@ func BenchmarkTruncIndexGet500(b *testing.B) {
 func BenchmarkTruncIndexDelete100(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -254,7 +254,7 @@ func BenchmarkTruncIndexDelete100(b *testing.B) {
 func BenchmarkTruncIndexDelete250(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -277,7 +277,7 @@ func BenchmarkTruncIndexDelete250(b *testing.B) {
 func BenchmarkTruncIndexDelete500(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -300,7 +300,7 @@ func BenchmarkTruncIndexDelete500(b *testing.B) {
 func BenchmarkTruncIndexNew100(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -311,7 +311,7 @@ func BenchmarkTruncIndexNew100(b *testing.B) {
 func BenchmarkTruncIndexNew250(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -322,7 +322,7 @@ func BenchmarkTruncIndexNew250(b *testing.B) {
 func BenchmarkTruncIndexNew500(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, common.GenerateRandomID())
+		testSet = append(testSet, stringid.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -334,7 +334,7 @@ func BenchmarkTruncIndexAddGet100(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		id := common.GenerateRandomID()
+		id := stringid.GenerateRandomID()
 		testSet = append(testSet, id)
 		l := rand.Intn(12) + 12
 		testKeys = append(testKeys, id[:l])
@@ -359,7 +359,7 @@ func BenchmarkTruncIndexAddGet250(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		id := common.GenerateRandomID()
+		id := stringid.GenerateRandomID()
 		testSet = append(testSet, id)
 		l := rand.Intn(12) + 12
 		testKeys = append(testKeys, id[:l])
@@ -384,7 +384,7 @@ func BenchmarkTruncIndexAddGet500(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		id := common.GenerateRandomID()
+		id := stringid.GenerateRandomID()
 		testSet = append(testSet, id)
 		l := rand.Intn(12) + 12
 		testKeys = append(testKeys, id[:l])