Golang FileSystem.Open方法代码示例

// readIndex calls x.Read with the index's backing file.
func readIndex(fs rwvfs.FileSystem, name string, x persistedIndex) (err error) {
	vlog.Printf("%s: reading index...", name)
	var f vfs.ReadSeekCloser
	f, err = fs.Open(fmt.Sprintf(indexFilename, name))
	if err != nil {
		vlog.Printf("%s: failed to read index: %s.", name, err)
		if os.IsNotExist(err) {
			return &errIndexNotExist{name: name, err: err}
		}
		return err
	}
	defer func() {
		err2 := f.Close()
		if err == nil {
			err = err2
		}
	}()

	r, err := gzip.NewReader(f)
	if err != nil {
		return err
	}

	if err := x.Read(r); err != nil {
		return err
	}
	if err := r.Close(); err != nil {
		return err
	}
	vlog.Printf("%s: done reading index.", name)
	return nil
}

func testWrite(t *testing.T, fs rwvfs.FileSystem, path string) {
	label := fmt.Sprintf("%T", fs)

	w, err := fs.Create(path)
	if err != nil {
		t.Fatalf("%s: WriterOpen: %s", label, err)
	}

	input := []byte("qux")
	_, err = w.Write(input)
	if err != nil {
		t.Fatalf("%s: Write: %s", label, err)
	}

	err = w.Close()
	if err != nil {
		t.Fatalf("%s: w.Close: %s", label, err)
	}

	var r io.ReadCloser
	r, err = fs.Open(path)
	if err != nil {
		t.Fatalf("%s: Open: %s", label, err)
	}
	var output []byte
	output, err = ioutil.ReadAll(r)
	if err != nil {
		t.Fatalf("%s: ReadAll: %s", label, err)
	}
	if !bytes.Equal(output, input) {
		t.Errorf("%s: got output %q, want %q", label, output, input)
	}

	r, err = fs.Open(path)
	if err != nil {
		t.Fatalf("%s: Open: %s", label, err)
	}
	output, err = ioutil.ReadAll(r)
	if err != nil {
		t.Fatalf("%s: ReadAll: %s", label, err)
	}
	if !bytes.Equal(output, input) {
		t.Errorf("%s: got output %q, want %q", label, output, input)
	}

	if err := fs.Remove(path); err != nil {
		t.Errorf("%s: Remove(%q): %s", label, path, err)
	}
	time.Sleep(time.Second)

	fi, err := fs.Stat(path)
	if err != nil && !os.IsNotExist(err) {
		t.Errorf("%s: Stat(%q): want os.IsNotExist-satisfying error, got %q", label, path, err)
	} else if err == nil {
		t.Errorf("%s: Stat(%q): want file to not exist, got existing file with FileInfo %+v", label, path, fi)
	}
}

// openFetcher calls fs.OpenFetcher if it implemented the
// FetcherOpener interface; otherwise it calls fs.Open.
func openFetcherOrOpen(fs rwvfs.FileSystem, name string) (vfs.ReadSeekCloser, error) {
	if fo, ok := fs.(rwvfs.FetcherOpener); ok {
		return fo.OpenFetcher(name)
	}
	return fs.Open(name)
}

func Write(t *testing.T, fs rwvfs.FileSystem) {
	label := fmt.Sprintf("%T", fs)
	fs.Mkdir("/foo")
	defer fs.Remove("/foo")
	path := "/foo/bar"

	w, err := fs.Create(path)
	if err != nil {
		t.Fatalf("%s: WriterOpen: %s", label, err)
	}

	input := []byte("qux")
	_, err = w.Write(input)
	if err != nil {
		t.Fatalf("%s: Write: %s", label, err)
	}

	err = w.Close()
	if err != nil {
		t.Fatalf("%s: w.Close: %s", label, err)
	}

	var r io.ReadCloser
	r, err = fs.Open(path)
	if err != nil {
		t.Fatalf("%s: Open: %s", label, err)
	}
	var output []byte
	output, err = ioutil.ReadAll(r)
	if err != nil {
		t.Fatalf("%s: ReadAll: %s", label, err)
	}
	err = r.Close()
	if err != nil {
		t.Fatalf("%s: r.Close: %s", label, err)
	}
	if !bytes.Equal(output, input) {
		t.Errorf("%s: got output %q, want %q", label, output, input)
	}

	IsFile(t, label, fs, path)
	IsDir(t, label, fs, "/foo")
	infos, err := fs.ReadDir("/foo")
	if err != nil {
		t.Fatalf("%s: ReadDir: %s", label, err)
	}
	if len(infos) != 1 || infos[0].Name() != "bar" {
		t.Fatalf("%s: ReadDir: got %v, want file 'bar'", label, infos)
	}

	r, err = fs.Open(path)
	if err != nil {
		t.Fatalf("%s: Open: %s", label, err)
	}
	output, err = ioutil.ReadAll(r)
	if err != nil {
		t.Fatalf("%s: ReadAll: %s", label, err)
	}
	err = r.Close()
	if err != nil {
		t.Fatalf("%s: r.Close: %s", label, err)
	}
	if !bytes.Equal(output, input) {
		t.Errorf("%s: got output %q, want %q", label, output, input)
	}

	err = fs.Remove(path)
	if err != nil {
		t.Errorf("%s: Remove(%q): %s", label, path, err)
	}
	PathDoesNotExist(t, label, fs, path)
}

func testStat(t *testing.T, fs rwvfs.FileSystem, path string) {
	label := fmt.Sprintf("Stat %T", fs)

	cases := []struct {
		parent, child string
		checkDirs     []string
	}{
		{pathpkg.Join(path, "p"), pathpkg.Join(path, "p/c"), nil},
		{pathpkg.Join(path, "."), pathpkg.Join(path, "c"), nil},
		{pathpkg.Join(path, "p1/p2"), pathpkg.Join(path, "p1/p2/p3/c"), []string{"p1", "p1/p2/p3"}},
		{pathpkg.Join(path, "p1"), pathpkg.Join(path, "p1/p2/p3/c"), []string{"p1/p2", "p1/p2/p3"}},
	}

	// Clean out bucket.
	for _, x := range cases {
		removeFile(t, fs, x.parent)
		removeFile(t, fs, x.child)
	}
	removeFile(t, fs, path)

	if path != "." {
		if _, err := fs.Stat(path); !os.IsNotExist(err) {
			t.Fatalf("%s: Stat(%s): got error %v, want os.IsNotExist-satisfying", label, path, err)
		}
	}
	if _, err := fs.Stat(path + "/z"); !os.IsNotExist(err) {
		t.Fatalf("%s: Stat(%s): got error %v, want os.IsNotExist-satisfying", label, path+"/z", err)
	}

	// Not sure of the best way to treat S3 keys that are
	// delimiter-prefixes of other keys, since they can either be like
	// dirs or files. But let's just choose a way and add a test so we
	// can change the behavior easily later.

	for _, x := range cases {
		t.Logf("# parent %q, child %q", x.parent, x.child)

		createFile(t, fs, x.parent, []byte("x"))
		createFile(t, fs, x.child, []byte("x"))

		parentFI, err := fs.Stat(x.parent)
		if err != nil {
			t.Fatalf("%s: Stat(%s): %s", label, x.parent, err)
		}
		if !parentFI.Mode().IsDir() {
			t.Fatalf("%s: Stat(%s) got Mode().IsDir() == false, want true", label, x.parent)
		}

		childFI, err := fs.Stat(x.child)
		if err != nil {
			t.Fatalf("%s: Stat(%s): %s", label, x.child, err)
		}
		if !childFI.Mode().IsRegular() {
			t.Fatalf("%s: Stat(%s) got Mode().IsRegular() == false, want true", label, x.child)
		}

		// Should not exist.
		doesntExist := pathpkg.Join(x.child, "doesntexist")
		if _, err := fs.Stat(doesntExist); !os.IsNotExist(err) {
			t.Fatalf("%s: Stat(%s): got error %v, want os.IsNotExist-satisfying", label, doesntExist, err)
		}

		for _, dir := range x.checkDirs {
			dir = pathpkg.Join(path, dir)
			fi, err := fs.Stat(dir)
			if err != nil {
				t.Fatalf("%s: Stat(%s): %s", label, dir, err)
			}
			if !fi.Mode().IsDir() {
				t.Fatalf("%s: Stat(%s): not dir, want dir", label, dir)
			}
		}

		if x.parent != "." {
			// Check that the parent file can be opened like a file.
			f, err := fs.Open(x.parent)
			if err != nil {
				t.Fatalf("%s: Open(%s): %s", label, x.parent, err)
			}
			f.Close()
		}

		// Clean up
		if err := fs.Remove(x.parent); err != nil {
			t.Errorf("%s: Remove(%q): %s", label, x.parent, err)
		}
		if err := fs.Remove(x.child); err != nil {
			t.Errorf("%s: Remove(%q): %s", label, x.child, err)
		}
	}
}

func testOpen(t *testing.T, fs rwvfs.FileSystem) {
	const path = "testOpen"

	var buf bytes.Buffer
	for i := uint8(0); i < 255; i++ {
		for j := uint8(0); j < 255; j++ {
			buf.Write([]byte{i, j})
		}
	}
	fullData := []byte(base64.StdEncoding.EncodeToString(buf.Bytes()))[10:]
	fullLen := int64(len(fullData))
	createFile(t, fs, path, fullData)

	{
		// Full reads.
		f, err := fs.Open(path)
		if err != nil {
			t.Fatal(err)
		}
		b, err := ioutil.ReadAll(f)
		if err != nil {
			t.Fatal(err)
		}
		if err := f.Close(); err != nil {
			t.Fatal(err)
		}

		if !bytes.Equal(b, fullData) {
			t.Errorf("full read: got %q, want %q", b, fullData)
		}
	}

	{
		// Partial reads.
		rrt := &rangeRecordingTransport{}
		fs.(*S3FS).config.Client = &http.Client{Transport: rrt}

		var f vfs.ReadSeekCloser

		cases := [][2]int64{
			{0, 0},
			{0, 1},
			{0, 2},
			{1, 1},
			{0, 3},
			{1, 3},
			{2, 3},
			{0, 2},
			{0, 3},
			{3, 4},
			{0, fullLen / 2},
			{1, fullLen / 2},
			{fullLen / 3, fullLen / 2},
			{0, fullLen - 1},
			{1, fullLen - 1},
			{fullLen / 2, fullLen/2 + 1333},
			{fullLen / 2, fullLen/2 + 1},
			{fullLen / 2, fullLen/2 + 2},
			{fullLen / 2, fullLen / 2},
			{fullLen - 10, fullLen - 1},
		}
		for _, autofetch := range []bool{false, true} {
			for _, reuse := range []bool{false, true} {
				for i, c := range cases {
					if !reuse || i == 0 {
						var err error
						f, err = fs.(rwvfs.FetcherOpener).OpenFetcher(path)
						if err != nil {
							t.Fatal(err)
						}
					}

					f.(interface {
						SetAutofetch(bool)
					}).SetAutofetch(true)

					rrt.reset()

					start, end := c[0], c[1]
					label := fmt.Sprintf("range %d-%d (autofetch=%v, reuse=%v)", start, end, autofetch, reuse)

					fetchEnd := end
					if autofetch {
						// Short fetch.
						fetchEnd = (start + end) / 2
						if fetchEnd < start {
							fetchEnd = end
						}
					}
					if err := f.(rwvfs.Fetcher).Fetch(start, fetchEnd); err != nil {
						t.Error(err)
						continue
					}

					n, err := f.Seek(start, 0)
					if err != nil {
						t.Errorf("%s: %s", label, err)
						continue
					}
					if n != start {
//.........这里部分代码省略.........