hugo/source/lazy_file_reader_test.go
Tatsushi Demachi 97eb55da89 Add LazyFileReader type to source library
LazyFileReader is an io.Reader implementation to postpone reading the
file contents until it is really needed. It is introduced for improving
performance and memory consumption at reading media files in content
directory.
2015-08-22 19:43:15 +02:00

218 lines
5.6 KiB
Go

package source
import (
"bytes"
"io"
"io/ioutil"
"os"
"testing"
)
func TestNewLazyFileReader(t *testing.T) {
filename := "itdoesnotexistfile"
_, err := NewLazyFileReader(filename)
if err == nil {
t.Errorf("NewLazyFileReader %s: error expected but no error is returned", filename)
}
filename = "lazy_file_reader_test.go"
_, err = NewLazyFileReader(filename)
if err != nil {
t.Errorf("NewLazyFileReader %s: %v", filename, err)
}
}
func TestFilename(t *testing.T) {
filename := "lazy_file_reader_test.go"
rd, err := NewLazyFileReader(filename)
if err != nil {
t.Fatalf("NewLazyFileReader %s: %v", filename, err)
}
if rd.Filename() != filename {
t.Errorf("Filename: expected filename %q, got %q", filename, rd.Filename())
}
}
func TestRead(t *testing.T) {
filename := "lazy_file_reader_test.go"
fi, err := os.Stat(filename)
if err != nil {
t.Fatalf("os.Stat: %v", err)
}
b, err := ioutil.ReadFile(filename)
if err != nil {
t.Fatalf("ioutil.ReadFile: %v", err)
}
rd, err := NewLazyFileReader(filename)
if err != nil {
t.Fatalf("NewLazyFileReader %s: %v", filename, err)
}
tst := func(testcase string) {
p := make([]byte, fi.Size())
n, err := rd.Read(p)
if err != nil {
t.Fatalf("Read %s case: %v", testcase, err)
}
if int64(n) != fi.Size() {
t.Errorf("Read %s case: read bytes length expected %d, got %d", testcase, fi.Size(), n)
}
if !bytes.Equal(b, p) {
t.Errorf("Read %s case: read bytes are different from expected", testcase)
}
}
tst("No cache")
_, err = rd.Seek(0, 0)
if err != nil {
t.Fatalf("Seek: %v", err)
}
tst("Cache")
}
func TestSeek(t *testing.T) {
type testcase struct {
seek int
offset int64
length int
moveto int64
expected []byte
}
filename := "lazy_file_reader_test.go"
b, err := ioutil.ReadFile(filename)
if err != nil {
t.Fatalf("ioutil.ReadFile: %v", err)
}
// no cache case
for i, this := range []testcase{
{seek: os.SEEK_SET, offset: 0, length: 10, moveto: 0, expected: b[:10]},
{seek: os.SEEK_SET, offset: 5, length: 10, moveto: 5, expected: b[5:15]},
{seek: os.SEEK_CUR, offset: 5, length: 10, moveto: 5, expected: b[5:15]}, // current pos = 0
{seek: os.SEEK_END, offset: -1, length: 1, moveto: int64(len(b) - 1), expected: b[len(b)-1:]},
{seek: 3, expected: nil},
{seek: os.SEEK_SET, offset: -1, expected: nil},
} {
rd, err := NewLazyFileReader(filename)
if err != nil {
t.Errorf("[%d] NewLazyFileReader %s: %v", i, filename, err)
continue
}
pos, err := rd.Seek(this.offset, this.seek)
if this.expected == nil {
if err == nil {
t.Errorf("[%d] Seek didn't return an expected error", i)
}
} else {
if err != nil {
t.Errorf("[%d] Seek failed unexpectedly: %v", i, err)
continue
}
if pos != this.moveto {
t.Errorf("[%d] Seek failed to move the pointer: got %d, expected: %d", i, pos, this.moveto)
}
buf := make([]byte, this.length)
n, err := rd.Read(buf)
if err != nil {
t.Errorf("[%d] Read failed unexpectedly: %v", i, err)
}
if !bytes.Equal(this.expected, buf[:n]) {
t.Errorf("[%d] Seek and Read got %q but expected %q", i, buf[:n], this.expected)
}
}
}
// cache case
rd, err := NewLazyFileReader(filename)
if err != nil {
t.Fatalf("NewLazyFileReader %s: %v", filename, err)
}
dummy := make([]byte, len(b))
_, err = rd.Read(dummy)
if err != nil {
t.Fatalf("Read failed unexpectedly: %v", err)
}
for i, this := range []testcase{
{seek: os.SEEK_SET, offset: 0, length: 10, moveto: 0, expected: b[:10]},
{seek: os.SEEK_SET, offset: 5, length: 10, moveto: 5, expected: b[5:15]},
{seek: os.SEEK_CUR, offset: 1, length: 10, moveto: 16, expected: b[16:26]}, // current pos = 15
{seek: os.SEEK_END, offset: -1, length: 1, moveto: int64(len(b) - 1), expected: b[len(b)-1:]},
{seek: 3, expected: nil},
{seek: os.SEEK_SET, offset: -1, expected: nil},
} {
pos, err := rd.Seek(this.offset, this.seek)
if this.expected == nil {
if err == nil {
t.Errorf("[%d] Seek didn't return an expected error", i)
}
} else {
if err != nil {
t.Errorf("[%d] Seek failed unexpectedly: %v", i, err)
continue
}
if pos != this.moveto {
t.Errorf("[%d] Seek failed to move the pointer: got %d, expected: %d", i, pos, this.moveto)
}
buf := make([]byte, this.length)
n, err := rd.Read(buf)
if err != nil {
t.Errorf("[%d] Read failed unexpectedly: %v", i, err)
}
if !bytes.Equal(this.expected, buf[:n]) {
t.Errorf("[%d] Seek and Read got %q but expected %q", i, buf[:n], this.expected)
}
}
}
}
func TestWriteTo(t *testing.T) {
filename := "lazy_file_reader_test.go"
fi, err := os.Stat(filename)
if err != nil {
t.Fatalf("os.Stat: %v", err)
}
b, err := ioutil.ReadFile(filename)
if err != nil {
t.Fatalf("ioutil.ReadFile: %v", err)
}
rd, err := NewLazyFileReader(filename)
if err != nil {
t.Fatalf("NewLazyFileReader %s: %v", filename, err)
}
tst := func(testcase string, expectedSize int64, checkEqual bool) {
buf := bytes.NewBuffer(make([]byte, 0, bytes.MinRead))
n, err := rd.WriteTo(buf)
if err != nil {
t.Fatalf("WriteTo %s case: %v", testcase, err)
}
if n != expectedSize {
t.Errorf("WriteTo %s case: written bytes length expected %d, got %d", testcase, expectedSize, n)
}
if checkEqual && !bytes.Equal(b, buf.Bytes()) {
t.Errorf("WriteTo %s case: written bytes are different from expected", testcase)
}
}
tst("No cache", fi.Size(), true)
tst("No cache 2nd", 0, false)
p := make([]byte, fi.Size())
_, err = rd.Read(p)
if err != nil && err != io.EOF {
t.Fatalf("Read: %v", err)
}
_, err = rd.Seek(0, 0)
if err != nil {
t.Fatalf("Seek: %v", err)
}
tst("Cache", fi.Size(), true)
}