blob: 81f3eb63b3300ed62ef4b7a8d4a952cb28758f0d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
/*
* Copyright 2022 Google LLC
*
* 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 com.google.android.libraries.mobiledatadownload.file.openers;
import android.net.Uri;
import com.google.android.libraries.mobiledatadownload.file.Behavior;
import com.google.android.libraries.mobiledatadownload.file.OpenContext;
import com.google.android.libraries.mobiledatadownload.file.Opener;
import com.google.protobuf.MessageLite;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
/** Writes a proto to a file atomically. */
public final class WriteProtoOpener implements Opener<Void> {
private final MessageLite proto;
private Behavior[] behaviors;
private WriteProtoOpener(MessageLite proto) {
this.proto = proto;
}
public static WriteProtoOpener create(MessageLite proto) {
return new WriteProtoOpener(proto);
}
/**
* Supports adding options to writes. For example, SyncBehavior will force data to be flushed and
* durably persisted.
*/
public WriteProtoOpener withBehaviors(Behavior... behaviors) {
this.behaviors = behaviors;
return this;
}
@Override
public Void open(OpenContext openContext) throws IOException {
Uri tempUri = ScratchFile.scratchUri(openContext.encodedUri());
OutputStream backendOutput = openContext.backend().openForWrite(tempUri);
List<OutputStream> chain = openContext.chainTransformsForWrite(backendOutput);
if (behaviors != null) {
for (Behavior behavior : behaviors) {
behavior.forOutputChain(chain);
}
}
try (OutputStream out = chain.get(0)) {
proto.writeTo(out);
if (behaviors != null) {
for (Behavior behavior : behaviors) {
behavior.commit();
}
}
} catch (Exception ex) {
try {
openContext.backend().deleteFile(tempUri);
} catch (FileNotFoundException ex2) {
// Ignore.
}
if (ex instanceof IOException) {
throw (IOException) ex;
}
throw new IOException(ex);
}
openContext.backend().rename(tempUri, openContext.encodedUri());
return null;
}
}
|
