Merge pull request #195 from ktock/import-esgz

Make estargz lib importable independently

Author: AkihiroSuda

estargz/build.go

@@ -28,8 +28,8 @@ import (
 	"sync"
 
 	"github.com/containerd/stargz-snapshotter/estargz/stargz"
-	"github.com/containerd/stargz-snapshotter/util/positionwatcher"
-	"github.com/containerd/stargz-snapshotter/util/tempfiles"
+	"github.com/containerd/stargz-snapshotter/estargz/tempfiles"
+	"github.com/containerd/stargz-snapshotter/estargz/positionwatcher"
 	digest "github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"

estargz/go.mod

@@ -0,0 +1,10 @@
+module github.com/containerd/stargz-snapshotter/estargz
+
+go 1.13
+
+require (
+	github.com/hashicorp/go-multierror v1.1.0
+	github.com/opencontainers/go-digest v1.0.0
+	github.com/pkg/errors v0.9.1
+	golang.org/x/sync v0.0.0-20201207232520-09787c993a3a
+)

estargz/go.sum

@@ -0,0 +1,10 @@
+github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
+github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-multierror v1.1.0 h1:B9UzwGQJehnUY1yNrnwREHc3fGbC2xefo8g4TbElacI=
+github.com/hashicorp/go-multierror v1.1.0/go.mod h1:spPvp8C1qA32ftKqdAHm4hHTbPw+vmowP0z+KUhOZdA=
+github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
+github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/sync v0.0.0-20201207232520-09787c993a3a h1:DcqTD9SDLc+1P/r1EmRBwnVsrOwW+kk2vWf9n+1sGhs=
+golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=

estargz/positionwatcher/positionwatcher.go

@@ -0,0 +1,77 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package positionwatcher
+
+import (
+	"fmt"
+	"io"
+	"sync"
+)
+
+func NewPositionWatcher(r io.ReaderAt) (*PositionWatcher, error) {
+	if r == nil {
+		return nil, fmt.Errorf("Target ReaderAt is empty")
+	}
+	pos := int64(0)
+	return &PositionWatcher{r: r, cPos: &pos}, nil
+}
+
+type PositionWatcher struct {
+	r    io.ReaderAt
+	cPos *int64
+
+	mu sync.Mutex
+}
+
+func (pwr *PositionWatcher) Read(p []byte) (int, error) {
+	pwr.mu.Lock()
+	defer pwr.mu.Unlock()
+
+	n, err := pwr.r.ReadAt(p, *pwr.cPos)
+	if err == nil {
+		*pwr.cPos += int64(n)
+	}
+	return n, err
+}
+
+func (pwr *PositionWatcher) Seek(offset int64, whence int) (int64, error) {
+	pwr.mu.Lock()
+	defer pwr.mu.Unlock()
+
+	switch whence {
+	default:
+		return 0, fmt.Errorf("Unknown whence: %v", whence)
+	case io.SeekStart:
+	case io.SeekCurrent:
+		offset += *pwr.cPos
+	case io.SeekEnd:
+		return 0, fmt.Errorf("Unsupported whence: %v", whence)
+	}
+
+	if offset < 0 {
+		return 0, fmt.Errorf("invalid offset")
+	}
+	*pwr.cPos = offset
+	return offset, nil
+}
+
+func (pwr *PositionWatcher) CurrentPos() int64 {
+	pwr.mu.Lock()
+	defer pwr.mu.Unlock()
+
+	return *pwr.cPos
+}

estargz/positionwatcher/positionwatcher_test.go

@@ -0,0 +1,202 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package positionwatcher
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+type operations func(*PositionWatcher) error
+
+func TestPositionWatcher(t *testing.T) {
+	tests := []struct {
+		name    string
+		ops     operations
+		wantPos int64
+	}{
+		{
+			name: "nop",
+			ops: func(pw *PositionWatcher) error {
+				return nil
+			},
+			wantPos: 0,
+		},
+		{
+			name: "read",
+			ops: func(pw *PositionWatcher) error {
+				size := 5
+				if _, err := pw.Read(make([]byte, size)); err != nil {
+					return err
+				}
+				return nil
+			},
+			wantPos: 5,
+		},
+		{
+			name: "readtwice",
+			ops: func(pw *PositionWatcher) error {
+				size1, size2 := 5, 3
+				if _, err := pw.Read(make([]byte, size1)); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Read(make([]byte, size2)); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				return nil
+			},
+			wantPos: 8,
+		},
+		{
+			name: "seek_start",
+			ops: func(pw *PositionWatcher) error {
+				size := int64(5)
+				if _, err := pw.Seek(size, io.SeekStart); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				return nil
+			},
+			wantPos: 5,
+		},
+		{
+			name: "seek_start_twice",
+			ops: func(pw *PositionWatcher) error {
+				size1, size2 := int64(5), int64(3)
+				if _, err := pw.Seek(size1, io.SeekStart); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Seek(size2, io.SeekStart); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				return nil
+			},
+			wantPos: 3,
+		},
+		{
+			name: "seek_current",
+			ops: func(pw *PositionWatcher) error {
+				size := int64(5)
+				if _, err := pw.Seek(size, io.SeekCurrent); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				return nil
+			},
+			wantPos: 5,
+		},
+		{
+			name: "seek_current_twice",
+			ops: func(pw *PositionWatcher) error {
+				size1, size2 := int64(5), int64(3)
+				if _, err := pw.Seek(size1, io.SeekCurrent); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Seek(size2, io.SeekCurrent); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				return nil
+			},
+			wantPos: 8,
+		},
+		{
+			name: "seek_current_twice_negative",
+			ops: func(pw *PositionWatcher) error {
+				size1, size2 := int64(5), int64(-3)
+				if _, err := pw.Seek(size1, io.SeekCurrent); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Seek(size2, io.SeekCurrent); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				return nil
+			},
+			wantPos: 2,
+		},
+		{
+			name: "mixed",
+			ops: func(pw *PositionWatcher) error {
+				size1, size2, size3, size4, size5 := int64(5), int64(-3), int64(4), int64(-1), int64(6)
+				if _, err := pw.Read(make([]byte, size1)); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Seek(size2, io.SeekCurrent); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Seek(size3, io.SeekStart); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Seek(size4, io.SeekCurrent); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				if _, err := pw.Read(make([]byte, size5)); err != nil {
+					if err != io.EOF {
+						return err
+					}
+				}
+				return nil
+			},
+			wantPos: 9,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			pw, err := NewPositionWatcher(bytes.NewReader(make([]byte, 100)))
+			if err != nil {
+				t.Fatalf("failed to make position watcher: %q", err)
+			}
+
+			if err := tt.ops(pw); err != nil {
+				t.Fatalf("failed to operate position watcher: %q", err)
+			}
+
+			gotPos := pw.CurrentPos()
+			if tt.wantPos != gotPos {
+				t.Errorf("current position: %d; want %d", gotPos, tt.wantPos)
+			}
+		})
+	}
+
+}

estargz/tempfiles/tempfiles.go

@@ -0,0 +1,60 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package tempfiles
+
+import (
+	"io/ioutil"
+	"os"
+	"sync"
+
+	"github.com/hashicorp/go-multierror"
+)
+
+func NewTempFiles() *TempFiles {
+	return &TempFiles{}
+}
+
+type TempFiles struct {
+	files   []*os.File
+	filesMu sync.Mutex
+}
+
+func (tf *TempFiles) TempFile(dir, pattern string) (*os.File, error) {
+	f, err := ioutil.TempFile(dir, pattern)
+	if err != nil {
+		return nil, err
+	}
+	tf.filesMu.Lock()
+	tf.files = append(tf.files, f)
+	tf.filesMu.Unlock()
+	return f, nil
+}
+
+func (tf *TempFiles) CleanupAll() (allErr error) {
+	tf.filesMu.Lock()
+	defer tf.filesMu.Unlock()
+	for _, f := range tf.files {
+		if err := f.Close(); err != nil {
+			allErr = multierror.Append(allErr, err)
+		}
+		if err := os.Remove(f.Name()); err != nil {
+			allErr = multierror.Append(allErr, err)
+		}
+	}
+	tf.files = nil
+	return nil
+}