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package tempfile
// Need access to internal variables, so can't use _test package
import (
"bytes"
"fmt"
"io/ioutil"
mrand "math/rand"
"os"
testing "testing"
"github.com/stretchr/testify/require"
tmrand "github.com/tendermint/tendermint/libs/rand"
)
func TestWriteFileAtomic(t *testing.T) {
var (
data = []byte(tmrand.Str(mrand.Intn(2048)))
old = tmrand.Bytes(mrand.Intn(2048))
perm os.FileMode = 0600
)
f, err := ioutil.TempFile("/tmp", "write-atomic-test-")
if err != nil {
t.Fatal(err)
}
defer os.Remove(f.Name())
if err = ioutil.WriteFile(f.Name(), old, 0600); err != nil {
t.Fatal(err)
}
if err = WriteFileAtomic(f.Name(), data, perm); err != nil {
t.Fatal(err)
}
rData, err := ioutil.ReadFile(f.Name())
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(data, rData) {
t.Fatalf("data mismatch: %v != %v", data, rData)
}
stat, err := os.Stat(f.Name())
if err != nil {
t.Fatal(err)
}
if have, want := stat.Mode().Perm(), perm; have != want {
t.Errorf("have %v, want %v", have, want)
}
}
// This tests atomic write file when there is a single duplicate file.
// Expected behavior is for a new file to be created, and the original write file to be unaltered.
func TestWriteFileAtomicDuplicateFile(t *testing.T) {
var (
defaultSeed uint64 = 1
testString = "This is a glorious test string"
expectedString = "Did the test file's string appear here?"
fileToWrite = "/tmp/TestWriteFileAtomicDuplicateFile-test.txt"
)
// Create a file at the seed, and reset the seed.
atomicWriteFileRand = defaultSeed
firstFileRand := randWriteFileSuffix()
atomicWriteFileRand = defaultSeed
fname := "/tmp/" + atomicWriteFilePrefix + firstFileRand
f, err := os.OpenFile(fname, atomicWriteFileFlag, 0777)
defer os.Remove(fname)
// Defer here, in case there is a panic in WriteFileAtomic.
defer os.Remove(fileToWrite)
require.NoError(t, err)
_, err = f.WriteString(testString)
require.NoError(t, err)
err = WriteFileAtomic(fileToWrite, []byte(expectedString), 0777)
require.NoError(t, err)
// Check that the first atomic file was untouched
firstAtomicFileBytes, err := ioutil.ReadFile(fname)
require.NoError(t, err, "Error reading first atomic file")
require.Equal(t, []byte(testString), firstAtomicFileBytes, "First atomic file was overwritten")
// Check that the resultant file is correct
resultantFileBytes, err := ioutil.ReadFile(fileToWrite)
require.NoError(t, err, "Error reading resultant file")
require.Equal(t, []byte(expectedString), resultantFileBytes, "Written file had incorrect bytes")
// Check that the intermediate write file was deleted
// Get the second write files' randomness
atomicWriteFileRand = defaultSeed
_ = randWriteFileSuffix()
secondFileRand := randWriteFileSuffix()
_, err = os.Stat("/tmp/" + atomicWriteFilePrefix + secondFileRand)
require.True(t, os.IsNotExist(err), "Intermittent atomic write file not deleted")
}
// This tests atomic write file when there are many duplicate files.
// Expected behavior is for a new file to be created under a completely new seed,
// and the original write files to be unaltered.
func TestWriteFileAtomicManyDuplicates(t *testing.T) {
var (
defaultSeed uint64 = 2
testString = "This is a glorious test string, from file %d"
expectedString = "Did any of the test file's string appear here?"
fileToWrite = "/tmp/TestWriteFileAtomicDuplicateFile-test.txt"
)
// Initialize all of the atomic write files
atomicWriteFileRand = defaultSeed
for i := 0; i < atomicWriteFileMaxNumConflicts+2; i++ {
fileRand := randWriteFileSuffix()
fname := "/tmp/" + atomicWriteFilePrefix + fileRand
f, err := os.OpenFile(fname, atomicWriteFileFlag, 0777)
require.Nil(t, err)
_, err = f.WriteString(fmt.Sprintf(testString, i))
require.NoError(t, err)
defer os.Remove(fname)
}
atomicWriteFileRand = defaultSeed
// Defer here, in case there is a panic in WriteFileAtomic.
defer os.Remove(fileToWrite)
err := WriteFileAtomic(fileToWrite, []byte(expectedString), 0777)
require.NoError(t, err)
// Check that all intermittent atomic file were untouched
atomicWriteFileRand = defaultSeed
for i := 0; i < atomicWriteFileMaxNumConflicts+2; i++ {
fileRand := randWriteFileSuffix()
fname := "/tmp/" + atomicWriteFilePrefix + fileRand
firstAtomicFileBytes, err := ioutil.ReadFile(fname)
require.Nil(t, err, "Error reading first atomic file")
require.Equal(t, []byte(fmt.Sprintf(testString, i)), firstAtomicFileBytes,
"atomic write file %d was overwritten", i)
}
// Check that the resultant file is correct
resultantFileBytes, err := ioutil.ReadFile(fileToWrite)
require.Nil(t, err, "Error reading resultant file")
require.Equal(t, []byte(expectedString), resultantFileBytes, "Written file had incorrect bytes")
}