1 files changed, 83 insertions, 69 deletions
diff --git a/src/pkg/strconv/itoa_test.go b/src/pkg/strconv/itoa_test.go
index 8514b21e4..d4b09a5d8 100644
--- a/src/pkg/strconv/itoa_test.go
+++ b/src/pkg/strconv/itoa_test.go
@@ -5,13 +5,14 @@
 package strconv_test
 
 import (
+	"runtime"
 	. "strconv"
 	"testing"
 )
 
 type itob64Test struct {
 	in   int64
-	base uint
+	base int
 	out  string
 }
 
@@ -60,73 +61,43 @@ var itob64tests = []itob64Test{
 
 func TestItoa(t *testing.T) {
 	for _, test := range itob64tests {
-		s := Itob64(test.in, test.base)
+		s := FormatInt(test.in, test.base)
 		if s != test.out {
-			t.Errorf("Itob64(%v, %v) = %v want %v",
+			t.Errorf("FormatInt(%v, %v) = %v want %v",
 				test.in, test.base, s, test.out)
 		}
-
-		if test.in >= 0 {
-			s := Uitob64(uint64(test.in), test.base)
-			if s != test.out {
-				t.Errorf("Uitob64(%v, %v) = %v want %v",
-					test.in, test.base, s, test.out)
-			}
+		x := AppendInt([]byte("abc"), test.in, test.base)
+		if string(x) != "abc"+test.out {
+			t.Errorf("AppendInt(%q, %v, %v) = %q want %v",
+				"abc", test.in, test.base, x, test.out)
 		}
 
-		if int64(int(test.in)) == test.in {
-			s := Itob(int(test.in), test.base)
+		if test.in >= 0 {
+			s := FormatUint(uint64(test.in), test.base)
 			if s != test.out {
-				t.Errorf("Itob(%v, %v) = %v want %v",
+				t.Errorf("FormatUint(%v, %v) = %v want %v",
 					test.in, test.base, s, test.out)
 			}
-
-			if test.in >= 0 {
-				s := Uitob(uint(test.in), test.base)
-				if s != test.out {
-					t.Errorf("Uitob(%v, %v) = %v want %v",
-						test.in, test.base, s, test.out)
-				}
+			x := AppendUint(nil, uint64(test.in), test.base)
+			if string(x) != test.out {
+				t.Errorf("AppendUint(%q, %v, %v) = %q want %v",
+					"abc", uint64(test.in), test.base, x, test.out)
 			}
 		}
 
-		if test.base == 10 {
-			s := Itoa64(test.in)
+		if test.base == 10 && int64(int(test.in)) == test.in {
+			s := Itoa(int(test.in))
 			if s != test.out {
-				t.Errorf("Itoa64(%v) = %v want %v",
+				t.Errorf("Itoa(%v) = %v want %v",
 					test.in, s, test.out)
 			}
-
-			if test.in >= 0 {
-				s := Uitob64(uint64(test.in), test.base)
-				if s != test.out {
-					t.Errorf("Uitob64(%v, %v) = %v want %v",
-						test.in, test.base, s, test.out)
-				}
-			}
-
-			if int64(int(test.in)) == test.in {
-				s := Itoa(int(test.in))
-				if s != test.out {
-					t.Errorf("Itoa(%v) = %v want %v",
-						test.in, s, test.out)
-				}
-
-				if test.in >= 0 {
-					s := Uitoa(uint(test.in))
-					if s != test.out {
-						t.Errorf("Uitoa(%v) = %v want %v",
-							test.in, s, test.out)
-					}
-				}
-			}
 		}
 	}
 }
 
 type uitob64Test struct {
 	in   uint64
-	base uint
+	base int
 	out  string
 }
 
@@ -141,34 +112,77 @@ var uitob64tests = []uitob64Test{
 
 func TestUitoa(t *testing.T) {
 	for _, test := range uitob64tests {
-		s := Uitob64(test.in, test.base)
+		s := FormatUint(test.in, test.base)
 		if s != test.out {
-			t.Errorf("Uitob64(%v, %v) = %v want %v",
+			t.Errorf("FormatUint(%v, %v) = %v want %v",
 				test.in, test.base, s, test.out)
 		}
+		x := AppendUint([]byte("abc"), test.in, test.base)
+		if string(x) != "abc"+test.out {
+			t.Errorf("AppendUint(%q, %v, %v) = %q want %v",
+				"abc", test.in, test.base, x, test.out)
+		}
 
-		if uint64(uint(test.in)) == test.in {
-			s := Uitob(uint(test.in), test.base)
-			if s != test.out {
-				t.Errorf("Uitob(%v, %v) = %v want %v",
-					test.in, test.base, s, test.out)
-			}
+	}
+}
+
+func numAllocations(f func()) int {
+	runtime.UpdateMemStats()
+	n0 := runtime.MemStats.Mallocs
+	f()
+	runtime.UpdateMemStats()
+	return int(runtime.MemStats.Mallocs - n0)
+}
+
+var globalBuf [64]byte
+
+func TestAppendUintDoesntAllocate(t *testing.T) {
+	n := numAllocations(func() {
+		var buf [64]byte
+		AppendInt(buf[:0], 123, 10)
+	})
+	want := 1 // TODO(bradfitz): this might be 0, once escape analysis is better
+	if n != want {
+		t.Errorf("with local buffer, did %d allocations, want %d", n, want)
+	}
+	n = numAllocations(func() {
+		AppendInt(globalBuf[:0], 123, 10)
+	})
+	if n != 0 {
+		t.Errorf("with reused buffer, did %d allocations, want 0", n)
+	}
+}
+
+func BenchmarkFormatInt(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, test := range itob64tests {
+			FormatInt(test.in, test.base)
 		}
+	}
+}
 
-		if test.base == 10 {
-			s := Uitoa64(test.in)
-			if s != test.out {
-				t.Errorf("Uitoa64(%v) = %v want %v",
-					test.in, s, test.out)
-			}
+func BenchmarkAppendInt(b *testing.B) {
+	dst := make([]byte, 0, 30)
+	for i := 0; i < b.N; i++ {
+		for _, test := range itob64tests {
+			AppendInt(dst, test.in, test.base)
+		}
+	}
+}
 
-			if uint64(uint(test.in)) == test.in {
-				s := Uitoa(uint(test.in))
-				if s != test.out {
-					t.Errorf("Uitoa(%v) = %v want %v",
-						test.in, s, test.out)
-				}
-			}
+func BenchmarkFormatUint(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, test := range uitob64tests {
+			FormatUint(test.in, test.base)
+		}
+	}
+}
+
+func BenchmarkAppendUint(b *testing.B) {
+	dst := make([]byte, 0, 30)
+	for i := 0; i < b.N; i++ {
+		for _, test := range uitob64tests {
+			AppendUint(dst, test.in, test.base)
 		}
 	}
 }