1/*
2Copyright 2011 The Perkeep Authors
3
4Licensed under the Apache License, Version 2.0 (the "License");
5you may not use this file except in compliance with the License.
6You may obtain a copy of the License at
7
8     http://www.apache.org/licenses/LICENSE-2.0
9
10Unless required by applicable law or agreed to in writing, software
11distributed under the License is distributed on an "AS IS" BASIS,
12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13See the License for the specific language governing permissions and
14limitations under the License.
15*/
16
17package test
18
19import (
20	"context"
21	"io"
22
23	"perkeep.org/pkg/blob"
24	"perkeep.org/pkg/blobserver"
25	"perkeep.org/pkg/blobserver/memory"
26)
27
28// Fetcher is an in-memory implementation of the blobserver Storage
29// interface.  It started as just a fetcher and grew. It also includes
30// other convenience methods for testing.
31type Fetcher struct {
32	memory.Storage
33
34	// ReceiveErr optionally returns the error to return on receive.
35	ReceiveErr error
36
37	// FetchErr, if non-nil, specifies the error to return on the next fetch call.
38	// If it returns nil, fetches proceed as normal.
39	FetchErr func() error
40}
41
42var (
43	_ blobserver.Storage      = (*Fetcher)(nil)
44	_ blobserver.BlobStreamer = (*Fetcher)(nil)
45)
46
47func (tf *Fetcher) Fetch(ctx context.Context, ref blob.Ref) (file io.ReadCloser, size uint32, err error) {
48	if tf.FetchErr != nil {
49		if err = tf.FetchErr(); err != nil {
50			return
51		}
52	}
53	file, size, err = tf.Storage.Fetch(ctx, ref)
54	if err != nil {
55		return
56	}
57	return file, size, nil
58}
59
60func (tf *Fetcher) SubFetch(ctx context.Context, ref blob.Ref, offset, length int64) (io.ReadCloser, error) {
61	if tf.FetchErr != nil {
62		if err := tf.FetchErr(); err != nil {
63			return nil, err
64		}
65	}
66	rc, err := tf.Storage.SubFetch(ctx, ref, offset, length)
67	if err != nil {
68		return rc, err
69	}
70	return rc, nil
71}
72
73func (tf *Fetcher) ReceiveBlob(ctx context.Context, br blob.Ref, source io.Reader) (blob.SizedRef, error) {
74	sb, err := tf.Storage.ReceiveBlob(ctx, br, source)
75	if err != nil {
76		return sb, err
77	}
78	if err := tf.ReceiveErr; err != nil {
79		tf.RemoveBlobs(ctx, []blob.Ref{br})
80		return sb, err
81	}
82	return sb, nil
83}
84
85func (tf *Fetcher) AddBlob(b *Blob) {
86	_, err := tf.ReceiveBlob(context.Background(), b.BlobRef(), b.Reader())
87	if err != nil {
88		panic(err)
89	}
90}
91