Add DB name stuff to randomize package

boil/randomize/random.go

@@ -0,0 +1,121 @@
+package randomize
+
+import (
+	"crypto/md5"
+	"fmt"
+	"math/rand"
+)
+
+const alphabetAll = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+const alphabetLowerAlpha = "abcdefghijklmnopqrstuvwxyz"
+
+func randStr(s *Seed, ln int) string {
+	str := make([]byte, ln)
+	for i := 0; i < ln; i++ {
+		str[i] = byte(alphabetAll[s.nextInt()%len(alphabetAll)])
+	}
+
+	return string(str)
+}
+
+func randByteSlice(s *Seed, ln int) []byte {
+	str := make([]byte, ln)
+	for i := 0; i < ln; i++ {
+		str[i] = byte(s.nextInt() % 256)
+	}
+
+	return str
+}
+
+func randPoint() string {
+	a := rand.Intn(100)
+	b := a + 1
+	return fmt.Sprintf("(%d,%d)", a, b)
+}
+
+func randBox() string {
+	a := rand.Intn(100)
+	b := a + 1
+	c := a + 2
+	d := a + 3
+	return fmt.Sprintf("(%d,%d),(%d,%d)", a, b, c, d)
+}
+
+func randCircle() string {
+	a, b, c := rand.Intn(100), rand.Intn(100), rand.Intn(100)
+	return fmt.Sprintf("((%d,%d),%d)", a, b, c)
+}
+
+func randNetAddr() string {
+	return fmt.Sprintf(
+		"%d.%d.%d.%d",
+		rand.Intn(254)+1,
+		rand.Intn(254)+1,
+		rand.Intn(254)+1,
+		rand.Intn(254)+1,
+	)
+}
+
+func randMacAddr() string {
+	buf := make([]byte, 6)
+	_, err := rand.Read(buf)
+	if err != nil {
+		panic(err)
+	}
+
+	// Set the local bit
+	buf[0] |= 2
+	return fmt.Sprintf(
+		"%02x:%02x:%02x:%02x:%02x:%02x",
+		buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
+	)
+}
+
+func randLsn() string {
+	a := rand.Int63n(9000000)
+	b := rand.Int63n(9000000)
+	return fmt.Sprintf("%d/%d", a, b)
+}
+
+func randTxID() string {
+	// Order of integers is relevant
+	a := rand.Intn(200) + 100
+	b := a + 100
+	c := a
+	d := a + 50
+	return fmt.Sprintf("%d:%d:%d,%d", a, b, c, d)
+}
+
+func randMoney(s *Seed) string {
+	return fmt.Sprintf("%d.00", s.nextInt())
+}
+
+// StableDBName takes a database name in, and generates
+// a random string using the database name as the rand Seed.
+// getDBNameHash is used to generate unique test database names.
+func StableDBName(input string) string {
+	return randStrFromSource(stableSource(input), 40)
+}
+
+// stableSource takes an input value, and produces a random
+// seed from it that will produce very few collisions in
+// a 40 character random string made from a different alphabet.
+func stableSource(input string) *rand.Rand {
+	sum := md5.Sum([]byte(input))
+	var seed int64
+	for i, byt := range sum {
+		seed ^= int64(byt) << uint((i*4)%64)
+	}
+	return rand.New(rand.NewSource(seed))
+}
+
+func randStrFromSource(r *rand.Rand, length int) string {
+	ln := len(alphabetLowerAlpha)
+
+	output := make([]rune, length)
+	for i := 0; i < length; i++ {
+		output[i] = rune(alphabetLowerAlpha[r.Intn(ln)])
+	}
+
+	return string(output)
+}

boil/randomize/random_test.go

@@ -0,0 +1,19 @@
+package randomize
+
+import "testing"
+
+func TestStableDBName(t *testing.T) {
+	t.Parallel()
+
+	db := "awesomedb"
+
+	one, two := StableDBName(db), StableDBName(db)
+
+	if len(one) != 40 {
+		t.Error("want 40 characters:", len(one), one)
+	}
+
+	if one != two {
+		t.Error("it should always produce the same value")
+	}
+}

boil/randomize/randomize.go

@@ -4,7 +4,6 @@ package randomize
 import (
 	"database/sql"
 	"fmt"
-	"math/rand"
 	"reflect"
 	"regexp"
 	"sort"
@@ -572,86 +571,3 @@ func getVariableRandValue(s *Seed, kind reflect.Kind, typ reflect.Type) interfac
 
 	return nil
 }
-
-const alphabet = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
-
-func randStr(s *Seed, ln int) string {
-	str := make([]byte, ln)
-	for i := 0; i < ln; i++ {
-		str[i] = byte(alphabet[s.nextInt()%len(alphabet)])
-	}
-
-	return string(str)
-}
-
-func randByteSlice(s *Seed, ln int) []byte {
-	str := make([]byte, ln)
-	for i := 0; i < ln; i++ {
-		str[i] = byte(s.nextInt() % 256)
-	}
-
-	return str
-}
-
-func randPoint() string {
-	a := rand.Intn(100)
-	b := a + 1
-	return fmt.Sprintf("(%d,%d)", a, b)
-}
-
-func randBox() string {
-	a := rand.Intn(100)
-	b := a + 1
-	c := a + 2
-	d := a + 3
-	return fmt.Sprintf("(%d,%d),(%d,%d)", a, b, c, d)
-}
-
-func randCircle() string {
-	a, b, c := rand.Intn(100), rand.Intn(100), rand.Intn(100)
-	return fmt.Sprintf("((%d,%d),%d)", a, b, c)
-}
-
-func randNetAddr() string {
-	return fmt.Sprintf(
-		"%d.%d.%d.%d",
-		rand.Intn(254)+1,
-		rand.Intn(254)+1,
-		rand.Intn(254)+1,
-		rand.Intn(254)+1,
-	)
-}
-
-func randMacAddr() string {
-	buf := make([]byte, 6)
-	_, err := rand.Read(buf)
-	if err != nil {
-		panic(err)
-	}
-
-	// Set the local bit
-	buf[0] |= 2
-	return fmt.Sprintf(
-		"%02x:%02x:%02x:%02x:%02x:%02x",
-		buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
-	)
-}
-
-func randLsn() string {
-	a := rand.Int63n(9000000)
-	b := rand.Int63n(9000000)
-	return fmt.Sprintf("%d/%d", a, b)
-}
-
-func randTxID() string {
-	// Order of integers is relevant
-	a := rand.Intn(200) + 100
-	b := a + 100
-	c := a
-	d := a + 50
-	return fmt.Sprintf("%d:%d:%d,%d", a, b, c, d)
-}
-
-func randMoney(s *Seed) string {
-	return fmt.Sprintf("%d.00", s.nextInt())
-}