vectorio_buffered_test.go

/*
Copyright 2015 Google Inc. All Rights Reserved.

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 vectorio_test

import (
	"bytes"
	"io/ioutil"
	"os"
	"syscall"
	"testing"

	"github.com/google/vectorio"
)

func TestBufferedWritev(t *testing.T) {
	f, err := os.Create("testbufferedwritev")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	data := []byte("foobarbaz")
	data_desired := []byte("foobazbar")

	bw, _ := vectorio.NewBufferedWritev(f)

	bw.WriteIovec(syscall.Iovec{&data[0], 3})
	bw.WriteIovec(syscall.Iovec{&data[6], 3})
	bw.Write(data[3:6])

	nw, err := bw.Flush()
	if err != nil {
		t.Errorf("Flush threw error: %s", err)
	}
	if nw != 3*3 {
		t.Errorf("Flush wrote wrong number of bytes, expected 3 * 3 but got %d", nw)
	}

	stats, err := f.Stat()
	if err != nil {
		t.Errorf("Stat threw error: %s", err)
	}
	filesize := stats.Size()
	if filesize != int64(len(data)) {
		t.Errorf("Length %d of input does not match %d written bytes", len(data), filesize)
	}

	f.Seek(0, 0)
	fromdisk, err := ioutil.ReadAll(f)
	if err != nil {
		t.Errorf("can't read file back, %s", err)
	}
	if bytes.Compare(fromdisk, data_desired) != 0 {
		t.Errorf("contents of file don't match input, %s != %s or %d != %d", fromdisk, data_desired, len(fromdisk), len(data_desired))
	}
	os.Remove("testbufferedwritev")
}

func TestBufferedWritevHuge(t *testing.T) {
	f, err := os.Create("testbufferedwritevhuge")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	data := []byte("foobarba")
	final := []byte("attheend")

	bw, _ := vectorio.NewBufferedWritev(f)

	// write a little more than our buffer size
	for i := 0; i < 1024; i++ {
		bw.Write(data)
	}
	bw.Write(final)

	_, err = bw.Flush()
	if err != nil {
		t.Errorf("Flush threw error: %s", err)
	}

	stats, err := f.Stat()
	if err != nil {
		t.Errorf("Stat threw error: %s", err)
	}
	filesize := stats.Size()
	if filesize != int64(1024*len(data)+len(final)) {
		t.Errorf("Length %d of input does not match %d written bytes", len(data), filesize)
	}

	// Maybe make this validate file contents later??
	f.Seek(0, 0)
	fromdisk, err := ioutil.ReadAll(f)
	if err != nil {
		t.Errorf("can't read file back, %s", err)
	}
	compared := fromdisk[1024*8:]
	if bytes.Compare(compared, final) != 0 {
		t.Errorf("contents of file don't match input, %s != %s or %d != %d", compared, final, len(compared), len(final))
	}
	os.Remove("testbufferedwritevhuge")
}