bufio: make Reader buffer transient
Share garbage between different bufio Readers. When a Reader
has zero buffered data, put its buffer into a pool.
This acknowledges that most bufio.Readers eventually get
read to completion, and their buffers are then no longer
needed.
benchmark old ns/op new ns/op delta
BenchmarkReaderEmpty 2993 1058 -64.65%
benchmark old allocs new allocs delta
BenchmarkReaderEmpty 3 2 -33.33%
benchmark old bytes new bytes delta
BenchmarkReaderEmpty 4278 133 -96.89%
Update #5100
R=r
CC=adg, dvyukov, gobot, golang-dev, rogpeppe
https://golang.org/cl/8819049
diff --git a/src/pkg/bufio/bufio_test.go b/src/pkg/bufio/bufio_test.go
index 79ed0f1..bc5e53a 100644
--- a/src/pkg/bufio/bufio_test.go
+++ b/src/pkg/bufio/bufio_test.go
@@ -1083,3 +1083,18 @@
io.Copy(dst, src)
}
}
+
+func BenchmarkReaderEmpty(b *testing.B) {
+ b.ReportAllocs()
+ str := strings.Repeat("x", 16<<10)
+ for i := 0; i < b.N; i++ {
+ br := NewReader(strings.NewReader(str))
+ n, err := io.Copy(ioutil.Discard, br)
+ if err != nil {
+ b.Fatal(err)
+ }
+ if n != int64(len(str)) {
+ b.Fatal("wrong length")
+ }
+ }
+}
