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strconv: some allocation tests

R=rsc, r
CC=golang-dev
https://golang.org/cl/5477084
This commit is contained in:
Brad Fitzpatrick 2011-12-13 14:49:26 -08:00
parent bcbb2f93ee
commit 39213c1fdb
2 changed files with 45 additions and 0 deletions

View File

@ -149,6 +149,23 @@ func TestFtoa(t *testing.T) {
} }
} }
func TestAppendFloatDoesntAllocate(t *testing.T) {
n := numAllocations(func() {
var buf [64]byte
AppendFloat(buf[:0], 1.23, 'g', 5, 64)
})
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() {
AppendFloat(globalBuf[:0], 1.23, 'g', 5, 64)
})
if n != 0 {
t.Errorf("with reused buffer, did %d allocations, want 0", n)
}
}
func BenchmarkFormatFloatDecimal(b *testing.B) { func BenchmarkFormatFloatDecimal(b *testing.B) {
for i := 0; i < b.N; i++ { for i := 0; i < b.N; i++ {
FormatFloat(33909, 'g', -1, 64) FormatFloat(33909, 'g', -1, 64)

View File

@ -5,6 +5,7 @@
package strconv_test package strconv_test
import ( import (
"runtime"
. "strconv" . "strconv"
"testing" "testing"
) )
@ -125,6 +126,33 @@ func TestUitoa(t *testing.T) {
} }
} }
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) { func BenchmarkFormatInt(b *testing.B) {
for i := 0; i < b.N; i++ { for i := 0; i < b.N; i++ {
for _, test := range itob64tests { for _, test := range itob64tests {