1	/*
     2	Copyright 2011 The Perkeep Authors
     3	
     4	Licensed under the Apache License, Version 2.0 (the "License");
     5	you may not use this file except in compliance with the License.
     6	You may obtain a copy of the License at
     7	
     8	     http://www.apache.org/licenses/LICENSE-2.0
     9	
    10	Unless required by applicable law or agreed to in writing, software
    11	distributed under the License is distributed on an "AS IS" BASIS,
    12	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13	See the License for the specific language governing permissions and
    14	limitations under the License.
    15	*/
    16	
    17	package test
    18	
    19	import (
    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.
    31	type 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	
    42	var (
    43		_ blobserver.Storage      = (*Fetcher)(nil)
    44		_ blobserver.BlobStreamer = (*Fetcher)(nil)
    45	)
    46	
    47	func (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	
    60	func (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	
    73	func (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	
    85	func (tf *Fetcher) AddBlob(b *Blob) {
    86		_, err := tf.ReceiveBlob(context.Background(), b.BlobRef(), b.Reader())
    87		if err != nil {
    88			panic(err)
    89		}
    90	}