1 files changed, 111 insertions, 0 deletions
diff --git a/pkg/v1/random/index.go b/pkg/v1/random/index.go
new file mode 100644
index 0000000..89a8843
--- /dev/null
+++ b/pkg/v1/random/index.go
@@ -0,0 +1,111 @@
+// Copyright 2018 Google LLC All Rights Reserved.
+//
+// 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 random
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/partial"
+	"github.com/google/go-containerregistry/pkg/v1/types"
+)
+
+type randomIndex struct {
+	images   map[v1.Hash]v1.Image
+	manifest *v1.IndexManifest
+}
+
+// Index returns a pseudo-randomly generated ImageIndex with count images, each
+// having the given number of layers of size byteSize.
+func Index(byteSize, layers, count int64) (v1.ImageIndex, error) {
+	manifest := v1.IndexManifest{
+		SchemaVersion: 2,
+		MediaType:     types.OCIImageIndex,
+		Manifests:     []v1.Descriptor{},
+	}
+
+	images := make(map[v1.Hash]v1.Image)
+	for i := int64(0); i < count; i++ {
+		img, err := Image(byteSize, layers)
+		if err != nil {
+			return nil, err
+		}
+
+		rawManifest, err := img.RawManifest()
+		if err != nil {
+			return nil, err
+		}
+		digest, size, err := v1.SHA256(bytes.NewReader(rawManifest))
+		if err != nil {
+			return nil, err
+		}
+		mediaType, err := img.MediaType()
+		if err != nil {
+			return nil, err
+		}
+
+		manifest.Manifests = append(manifest.Manifests, v1.Descriptor{
+			Digest:    digest,
+			Size:      size,
+			MediaType: mediaType,
+		})
+
+		images[digest] = img
+	}
+
+	return &randomIndex{
+		images:   images,
+		manifest: &manifest,
+	}, nil
+}
+
+func (i *randomIndex) MediaType() (types.MediaType, error) {
+	return i.manifest.MediaType, nil
+}
+
+func (i *randomIndex) Digest() (v1.Hash, error) {
+	return partial.Digest(i)
+}
+
+func (i *randomIndex) Size() (int64, error) {
+	return partial.Size(i)
+}
+
+func (i *randomIndex) IndexManifest() (*v1.IndexManifest, error) {
+	return i.manifest, nil
+}
+
+func (i *randomIndex) RawManifest() ([]byte, error) {
+	m, err := i.IndexManifest()
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(m)
+}
+
+func (i *randomIndex) Image(h v1.Hash) (v1.Image, error) {
+	if img, ok := i.images[h]; ok {
+		return img, nil
+	}
+
+	return nil, fmt.Errorf("image not found: %v", h)
+}
+
+func (i *randomIndex) ImageIndex(h v1.Hash) (v1.ImageIndex, error) {
+	// This is a single level index (for now?).
+	return nil, fmt.Errorf("image not found: %v", h)
+}