moby/pkg/ioutils/buffer_test.go
Brian Goff 9a25b1d942 Improve performance/reduce allocs of bytespipe
Creates a `fixedBuffer` type that is used to encapsulate functionality
for reading/writing from the underlying byte slices.

Uses lazily-loaded set of sync.Pools for storing buffers that are no
longer needed so they can be re-used.

```
benchmark                     old ns/op     new ns/op     delta
BenchmarkBytesPipeWrite-8     138469        48985         -64.62%
BenchmarkBytesPipeRead-8      130922        56601         -56.77%

benchmark                     old allocs     new allocs     delta
BenchmarkBytesPipeWrite-8     18             8              -55.56%
BenchmarkBytesPipeRead-8      0              0              +0.00%

benchmark                     old bytes     new bytes     delta
BenchmarkBytesPipeWrite-8     66903         1649          -97.54%
BenchmarkBytesPipeRead-8      0             1             +Inf%
```

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
2016-04-05 13:06:04 -04:00

75 lines
1.3 KiB
Go

package ioutils
import (
"bytes"
"testing"
)
func TestFixedBufferWrite(t *testing.T) {
buf := &fixedBuffer{buf: make([]byte, 0, 64)}
n, err := buf.Write([]byte("hello"))
if err != nil {
t.Fatal(err)
}
if n != 5 {
t.Fatalf("expected 5 bytes written, got %d", n)
}
if string(buf.buf[:5]) != "hello" {
t.Fatalf("expected \"hello\", got %q", string(buf.buf[:5]))
}
n, err = buf.Write(bytes.Repeat([]byte{1}, 64))
if err != errBufferFull {
t.Fatalf("expected errBufferFull, got %v - %v", err, buf.buf[:64])
}
}
func TestFixedBufferRead(t *testing.T) {
buf := &fixedBuffer{buf: make([]byte, 0, 64)}
if _, err := buf.Write([]byte("hello world")); err != nil {
t.Fatal(err)
}
b := make([]byte, 5)
n, err := buf.Read(b)
if err != nil {
t.Fatal(err)
}
if n != 5 {
t.Fatalf("expected 5 bytes read, got %d - %s", n, buf.String())
}
if string(b) != "hello" {
t.Fatalf("expected \"hello\", got %q", string(b))
}
n, err = buf.Read(b)
if err != nil {
t.Fatal(err)
}
if n != 5 {
t.Fatalf("expected 5 bytes read, got %d", n)
}
if string(b) != " worl" {
t.Fatalf("expected \" worl\", got %s", string(b))
}
b = b[:1]
n, err = buf.Read(b)
if err != nil {
t.Fatal(err)
}
if n != 1 {
t.Fatalf("expected 1 byte read, got %d - %s", n, buf.String())
}
if string(b) != "d" {
t.Fatalf("expected \"d\", got %s", string(b))
}
}