grpc-go/mem/buffer_slice_test.go

487 lines
9.8 KiB
Go

/*
*
* Copyright 2024 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package mem_test
import (
"bytes"
"crypto/rand"
"errors"
"fmt"
"io"
"testing"
"google.golang.org/grpc/mem"
)
const (
minReadSize = 1
// Should match the constant in buffer_slice.go (another package)
readAllBufSize = 32 * 1024 // 32 KiB
)
func newBuffer(data []byte, pool mem.BufferPool) mem.Buffer {
return mem.NewBuffer(&data, pool)
}
func (s) TestBufferSlice_Len(t *testing.T) {
tests := []struct {
name string
in mem.BufferSlice
want int
}{
{
name: "empty",
in: nil,
want: 0,
},
{
name: "single",
in: mem.BufferSlice{newBuffer([]byte("abcd"), nil)},
want: 4,
},
{
name: "multiple",
in: mem.BufferSlice{
newBuffer([]byte("abcd"), nil),
newBuffer([]byte("abcd"), nil),
newBuffer([]byte("abcd"), nil),
},
want: 12,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
if got := tt.in.Len(); got != tt.want {
t.Errorf("BufferSlice.Len() = %v, want %v", got, tt.want)
}
})
}
}
func (s) TestBufferSlice_Ref(t *testing.T) {
// Create a new buffer slice and a reference to it.
bs := mem.BufferSlice{
newBuffer([]byte("abcd"), nil),
newBuffer([]byte("abcd"), nil),
}
bs.Ref()
// Free the original buffer slice and verify that the reference can still
// read data from it.
bs.Free()
got := bs.Materialize()
want := []byte("abcdabcd")
if !bytes.Equal(got, want) {
t.Errorf("BufferSlice.Materialize() = %s, want %s", string(got), string(want))
}
}
func (s) TestBufferSlice_MaterializeToBuffer(t *testing.T) {
tests := []struct {
name string
in mem.BufferSlice
pool mem.BufferPool
wantData []byte
}{
{
name: "single",
in: mem.BufferSlice{newBuffer([]byte("abcd"), nil)},
pool: nil, // MaterializeToBuffer should not use the pool in this case.
wantData: []byte("abcd"),
},
{
name: "multiple",
in: mem.BufferSlice{
newBuffer([]byte("abcd"), nil),
newBuffer([]byte("abcd"), nil),
newBuffer([]byte("abcd"), nil),
},
pool: mem.DefaultBufferPool(),
wantData: []byte("abcdabcdabcd"),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
defer tt.in.Free()
got := tt.in.MaterializeToBuffer(tt.pool)
defer got.Free()
if !bytes.Equal(got.ReadOnlyData(), tt.wantData) {
t.Errorf("BufferSlice.MaterializeToBuffer() = %s, want %s", string(got.ReadOnlyData()), string(tt.wantData))
}
})
}
}
func (s) TestBufferSlice_Reader(t *testing.T) {
bs := mem.BufferSlice{
newBuffer([]byte("abcd"), nil),
newBuffer([]byte("abcd"), nil),
newBuffer([]byte("abcd"), nil),
}
wantData := []byte("abcdabcdabcd")
reader := bs.Reader()
var gotData []byte
// Read into a buffer of size 1 until EOF, and verify that the data matches.
for {
buf := make([]byte, 1)
n, err := reader.Read(buf)
if n > 0 {
gotData = append(gotData, buf[:n]...)
}
if err == io.EOF {
break
}
if err != nil {
t.Fatalf("BufferSlice.Reader() failed unexpectedly: %v", err)
}
}
if !bytes.Equal(gotData, wantData) {
t.Errorf("BufferSlice.Reader() returned data %v, want %v", string(gotData), string(wantData))
}
// Reader should have released its references to the underlying buffers, but
// bs still holds its reference and it should be able to read data from it.
gotData = bs.Materialize()
if !bytes.Equal(gotData, wantData) {
t.Errorf("BufferSlice.Materialize() = %s, want %s", string(gotData), string(wantData))
}
}
// TestBufferSlice_ReadAll_Reads exercises ReadAll by allowing it to read
// various combinations of data, empty data, EOF.
func (s) TestBufferSlice_ReadAll_Reads(t *testing.T) {
testcases := []struct {
name string
reads []readStep
wantErr string
wantBufs int
}{
{
name: "EOF",
reads: []readStep{
{
err: io.EOF,
},
},
},
{
name: "data,EOF",
reads: []readStep{
{
n: minReadSize,
},
{
err: io.EOF,
},
},
wantBufs: 1,
},
{
name: "data+EOF",
reads: []readStep{
{
n: minReadSize,
err: io.EOF,
},
},
wantBufs: 1,
},
{
name: "0,data+EOF",
reads: []readStep{
{},
{
n: minReadSize,
err: io.EOF,
},
},
wantBufs: 1,
},
{
name: "0,data,EOF",
reads: []readStep{
{},
{
n: minReadSize,
},
{
err: io.EOF,
},
},
wantBufs: 1,
},
{
name: "data,data+EOF",
reads: []readStep{
{
n: minReadSize,
},
{
n: minReadSize,
err: io.EOF,
},
},
wantBufs: 1,
},
{
name: "error",
reads: []readStep{
{
err: errors.New("boom"),
},
},
wantErr: "boom",
},
{
name: "data+error",
reads: []readStep{
{
n: minReadSize,
err: errors.New("boom"),
},
},
wantErr: "boom",
wantBufs: 1,
},
{
name: "data,data+error",
reads: []readStep{
{
n: minReadSize,
},
{
n: minReadSize,
err: errors.New("boom"),
},
},
wantErr: "boom",
wantBufs: 1,
},
{
name: "data,data+EOF - whole buf",
reads: []readStep{
{
n: minReadSize,
},
{
n: readAllBufSize - minReadSize,
err: io.EOF,
},
},
wantBufs: 1,
},
{
name: "data,data,EOF - whole buf",
reads: []readStep{
{
n: minReadSize,
},
{
n: readAllBufSize - minReadSize,
},
{
err: io.EOF,
},
},
wantBufs: 1,
},
{
name: "data,data,EOF - 2 bufs",
reads: []readStep{
{
n: readAllBufSize,
},
{
n: minReadSize,
},
{
n: readAllBufSize - minReadSize,
},
{
n: minReadSize,
},
{
err: io.EOF,
},
},
wantBufs: 3,
},
}
for _, tc := range testcases {
t.Run(tc.name, func(t *testing.T) {
pool := &testPool{
allocated: make(map[*[]byte]struct{}),
}
r := &stepReader{
reads: tc.reads,
}
data, err := mem.ReadAll(r, pool)
if tc.wantErr != "" {
if err == nil || err.Error() != tc.wantErr {
t.Fatalf("ReadAll() returned err %v, wanted %q", err, tc.wantErr)
}
} else {
if err != nil {
t.Fatal(err)
}
}
gotData := data.Materialize()
if !bytes.Equal(r.read, gotData) {
t.Fatalf("ReadAll() returned data %q, wanted %q", gotData, r.read)
}
if len(data) != tc.wantBufs {
t.Fatalf("ReadAll() returned %d bufs, wanted %d bufs", len(data), tc.wantBufs)
}
// all but last should be full buffers
for i := 0; i < len(data)-1; i++ {
if data[i].Len() != readAllBufSize {
t.Fatalf("ReadAll() returned data length %d, wanted %d", data[i].Len(), readAllBufSize)
}
}
data.Free()
if len(pool.allocated) > 0 {
t.Fatalf("got %d allocated buffers, wanted none", len(pool.allocated))
}
})
}
}
func (s) TestBufferSlice_ReadAll_WriteTo(t *testing.T) {
testcases := []struct {
name string
size int
}{
{
name: "small",
size: minReadSize,
},
{
name: "exact size",
size: readAllBufSize,
},
{
name: "big",
size: readAllBufSize * 3,
},
}
for _, tc := range testcases {
t.Run(tc.name, func(t *testing.T) {
pool := &testPool{
allocated: make(map[*[]byte]struct{}),
}
buf := make([]byte, tc.size)
_, err := rand.Read(buf)
if err != nil {
t.Fatal(err)
}
r := bytes.NewBuffer(buf)
data, err := mem.ReadAll(r, pool)
if err != nil {
t.Fatal(err)
}
gotData := data.Materialize()
if !bytes.Equal(buf, gotData) {
t.Fatalf("ReadAll() = %q, wanted %q", gotData, buf)
}
data.Free()
if len(pool.allocated) > 0 {
t.Fatalf("wanted no allocated buffers, got %d", len(pool.allocated))
}
})
}
}
func ExampleNewWriter() {
var bs mem.BufferSlice
pool := mem.DefaultBufferPool()
writer := mem.NewWriter(&bs, pool)
for _, data := range [][]byte{
[]byte("abcd"),
[]byte("abcd"),
[]byte("abcd"),
} {
n, err := writer.Write(data)
fmt.Printf("Wrote %d bytes, err: %v\n", n, err)
}
fmt.Println(string(bs.Materialize()))
// Output:
// Wrote 4 bytes, err: <nil>
// Wrote 4 bytes, err: <nil>
// Wrote 4 bytes, err: <nil>
// abcdabcdabcd
}
var (
_ io.Reader = (*stepReader)(nil)
_ mem.BufferPool = (*testPool)(nil)
)
// readStep describes what a single stepReader.Read should do - how much data
// to return and what error to return.
type readStep struct {
n int
err error
}
// stepReader implements io.Reader that reads specified amount of data and/or
// returns the specified error in specified steps.
// The read data is accumulated in the read field.
type stepReader struct {
reads []readStep
read []byte
}
func (s *stepReader) Read(buf []byte) (int, error) {
if len(s.reads) == 0 {
panic("unexpected Read() call")
}
read := s.reads[0]
s.reads = s.reads[1:]
_, err := rand.Read(buf[:read.n])
if err != nil {
panic(err)
}
s.read = append(s.read, buf[:read.n]...)
return read.n, read.err
}
// testPool is an implementation of BufferPool that allows to ensure that:
// - there are matching Put calls for all Get calls.
// - there are no unexpected Put calls.
type testPool struct {
allocated map[*[]byte]struct{}
}
func (t *testPool) Get(length int) *[]byte {
buf := make([]byte, length)
t.allocated[&buf] = struct{}{}
return &buf
}
func (t *testPool) Put(buf *[]byte) {
if _, ok := t.allocated[buf]; !ok {
panic("unexpected put")
}
delete(t.allocated, buf)
}