mirror of https://github.com/containers/podman.git
124 lines
3.1 KiB
Go
124 lines
3.1 KiB
Go
package compression
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"testing"
|
|
|
|
"github.com/sirupsen/logrus"
|
|
"github.com/stretchr/testify/assert"
|
|
)
|
|
|
|
type memorySparseFile struct {
|
|
buffer bytes.Buffer
|
|
pos int64
|
|
sparse int64
|
|
}
|
|
|
|
func (m *memorySparseFile) Seek(offset int64, whence int) (int64, error) {
|
|
logrus.Debugf("Seek %d %d", offset, whence)
|
|
var newPos int64
|
|
switch whence {
|
|
case io.SeekStart:
|
|
panic("unexpected")
|
|
case io.SeekCurrent:
|
|
newPos = m.pos + offset
|
|
if offset < -1 {
|
|
panic("unexpected")
|
|
}
|
|
m.sparse += offset
|
|
case io.SeekEnd:
|
|
newPos = int64(m.buffer.Len()) + offset
|
|
default:
|
|
return 0, errors.New("unsupported seek whence")
|
|
}
|
|
|
|
if newPos < 0 {
|
|
return 0, errors.New("negative position is not allowed")
|
|
}
|
|
|
|
m.pos = newPos
|
|
return newPos, nil
|
|
}
|
|
|
|
func (m *memorySparseFile) Write(b []byte) (n int, err error) {
|
|
logrus.Debugf("Write %d", len(b))
|
|
if int64(m.buffer.Len()) < m.pos {
|
|
padding := make([]byte, m.pos-int64(m.buffer.Len()))
|
|
_, err := m.buffer.Write(padding)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
}
|
|
|
|
n, err = m.buffer.Write(b)
|
|
m.pos += int64(n)
|
|
return n, err
|
|
}
|
|
|
|
func testInputWithWriteLen(t *testing.T, input []byte, minSparse int64, chunkSize int) {
|
|
m := &memorySparseFile{}
|
|
sparseWriter := NewSparseWriter(m)
|
|
|
|
for i := 0; i < len(input); i += chunkSize {
|
|
end := i + chunkSize
|
|
if end > len(input) {
|
|
end = len(input)
|
|
}
|
|
_, err := sparseWriter.Write(input[i:end])
|
|
if err != nil {
|
|
t.Fatalf("Expected no error, got %v", err)
|
|
}
|
|
}
|
|
err := sparseWriter.Close()
|
|
if err != nil {
|
|
t.Fatalf("Expected no error, got %v", err)
|
|
}
|
|
assert.Equal(t, string(input), m.buffer.String())
|
|
assert.GreaterOrEqual(t, m.sparse, minSparse)
|
|
}
|
|
|
|
func testInput(t *testing.T, name string, inputBytes []byte, minSparse int64) {
|
|
currentLen := 1
|
|
for {
|
|
t.Run(fmt.Sprintf("%s@%d", name, currentLen), func(t *testing.T) {
|
|
testInputWithWriteLen(t, inputBytes, minSparse, currentLen)
|
|
})
|
|
currentLen <<= 1
|
|
if currentLen > len(inputBytes) {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
func TestSparseWriter(t *testing.T) {
|
|
testInput(t, "small contents", []byte("hello"), 0)
|
|
testInput(t, "small zeroes", append(make([]byte, 100), []byte("hello")...), 0)
|
|
testInput(t, "empty", []byte(""), 0)
|
|
testInput(t, "small iterated", []byte{'a', 0, 'a', 0, 'a', 0}, 0)
|
|
testInput(t, "small iterated2", []byte{0, 'a', 0, 'a', 0, 'a'}, 0)
|
|
|
|
// add "hello" at the beginning
|
|
const largeSize = 1024 * 1024
|
|
largeInput := make([]byte, largeSize)
|
|
copy(largeInput, []byte("hello"))
|
|
testInput(t, "sparse end", largeInput, largeSize-5-1) // -1 for the final byte establishing file size
|
|
|
|
// add "hello" at the end
|
|
largeInput = make([]byte, largeSize)
|
|
copy(largeInput[largeSize-5:], []byte("hello"))
|
|
testInput(t, "sparse beginning", largeInput, largeSize-5)
|
|
|
|
// add "hello" in the middle
|
|
largeInput = make([]byte, largeSize)
|
|
copy(largeInput[len(largeInput)/2:], []byte("hello"))
|
|
testInput(t, "sparse both ends", largeInput, largeSize-5-1) // -1 for the final byte establishing file size
|
|
|
|
largeInput = make([]byte, largeSize)
|
|
copy(largeInput[0:5], []byte("hello"))
|
|
copy(largeInput[largeSize-5:], []byte("HELLO"))
|
|
testInput(t, "sparse middle", largeInput, largeSize-10)
|
|
}
|