rclone/cmd/mount/test/seeker.go
2017-02-17 11:37:19 +00:00

115 lines
2.4 KiB
Go

// +build ignore
// Read two files with lots of seeking to stress test the seek code
package main
import (
"bytes"
"flag"
"io"
"io/ioutil"
"log"
"math/rand"
"os"
"time"
)
var (
// Flags
iterations = flag.Int("n", 1E6, "Iterations to try")
maxBlockSize = flag.Int("b", 1024*1024, "Max block size to read")
)
func init() {
rand.Seed(time.Now().UnixNano())
}
func randomSeekTest(size int64, in1, in2 *os.File, file1, file2 string) {
start := rand.Int63n(size)
blockSize := rand.Intn(*maxBlockSize)
if int64(blockSize) > size-start {
blockSize = int(size - start)
}
log.Printf("Reading %d from %d", blockSize, start)
_, err := in1.Seek(start, 0)
if err != nil {
log.Fatalf("Seek failed on %q: %v", file1, err)
}
_, err = in2.Seek(start, 0)
if err != nil {
log.Fatalf("Seek failed on %q: %v", file2, err)
}
buf1 := make([]byte, blockSize)
n1, err := io.ReadFull(in1, buf1)
if err != nil {
log.Fatalf("Read failed on %q: %v", file1, err)
}
buf2 := make([]byte, blockSize)
n2, err := io.ReadFull(in2, buf2)
if err != nil {
log.Fatalf("Read failed on %q: %v", file2, err)
}
if n1 != n2 {
log.Fatalf("Read different lengths %d (%q) != %d (%q)", n1, file1, n2, file2)
}
if !bytes.Equal(buf1, buf2) {
log.Printf("Dumping different blocks")
err = ioutil.WriteFile("/tmp/z1", buf1, 0777)
if err != nil {
log.Fatalf("Failed to write /tmp/z1: %v", err)
}
err = ioutil.WriteFile("/tmp/z2", buf2, 0777)
if err != nil {
log.Fatalf("Failed to write /tmp/z2: %v", err)
}
log.Fatalf("Read different contents - saved in /tmp/z1 and /tmp/z2")
}
}
func main() {
flag.Parse()
args := flag.Args()
if len(args) != 2 {
log.Fatalf("Require 2 files as argument")
}
file1, file2 := args[0], args[1]
in1, err := os.Open(file1)
if err != nil {
log.Fatalf("Couldn't open %q: %v", file1, err)
}
in2, err := os.Open(file2)
if err != nil {
log.Fatalf("Couldn't open %q: %v", file2, err)
}
fi1, err := in1.Stat()
if err != nil {
log.Fatalf("Couldn't stat %q: %v", file1, err)
}
fi2, err := in2.Stat()
if err != nil {
log.Fatalf("Couldn't stat %q: %v", file2, err)
}
if fi1.Size() != fi2.Size() {
log.Fatalf("Files not the same size")
}
for i := 0; i < *iterations; i++ {
randomSeekTest(fi1.Size(), in1, in2, file1, file2)
}
err = in1.Close()
if err != nil {
log.Fatalf("Error closing %q: %v", file1, err)
}
err = in2.Close()
if err != nil {
log.Fatalf("Error closing %q: %v", file2, err)
}
}