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
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
// Copyright 2014 The Bazel Authors. 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 com.google.devtools.build.lib.vfs;
import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
import com.google.devtools.build.lib.profiler.Profiler;
import com.google.devtools.build.lib.profiler.ProfilerTask;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/** This class implements the FileSystem interface using direct calls to the UNIX filesystem. */
@ThreadSafe
public abstract class AbstractFileSystem extends FileSystem {
protected static final String ERR_PERMISSION_DENIED = " (Permission denied)";
protected static final Profiler profiler = Profiler.instance();
public AbstractFileSystem() {}
public AbstractFileSystem(DigestHashFunction digestFunction) {
super(digestFunction);
}
@Override
protected InputStream getInputStream(Path path) throws IOException {
// This loop is a workaround for an apparent bug in FileInputStream.open, which delegates
// ultimately to JVM_Open in the Hotspot JVM. This call is not EINTR-safe, so we must do the
// retry here.
for (; ; ) {
try {
return createFileInputStream(path);
} catch (FileNotFoundException e) {
if (e.getMessage().endsWith("(Interrupted system call)")) {
continue;
} else {
throw e;
}
}
}
}
/** Returns either normal or profiled FileInputStream. */
private InputStream createFileInputStream(Path path) throws FileNotFoundException {
final String name = path.toString();
if (profiler.isActive()
&& (profiler.isProfiling(ProfilerTask.VFS_READ)
|| profiler.isProfiling(ProfilerTask.VFS_OPEN))) {
long startTime = Profiler.nanoTimeMaybe();
try {
// Replace default FileInputStream instance with the custom one that does profiling.
return new ProfiledFileInputStream(name);
} finally {
profiler.logSimpleTask(startTime, ProfilerTask.VFS_OPEN, name);
}
} else {
// Use normal FileInputStream instance if profiler is not enabled.
return new FileInputStream(path.toString());
}
}
/**
* Returns either normal or profiled FileOutputStream. Should be used by subclasses to create
* default OutputStream instance.
*/
protected OutputStream createFileOutputStream(Path path, boolean append)
throws FileNotFoundException {
final String name = path.toString();
if (profiler.isActive()
&& (profiler.isProfiling(ProfilerTask.VFS_WRITE)
|| profiler.isProfiling(ProfilerTask.VFS_OPEN))) {
long startTime = Profiler.nanoTimeMaybe();
try {
return new ProfiledFileOutputStream(name, append);
} finally {
profiler.logSimpleTask(startTime, ProfilerTask.VFS_OPEN, name);
}
} else {
return new FileOutputStream(name, append);
}
}
@Override
protected OutputStream getOutputStream(Path path, boolean append) throws IOException {
try {
return createFileOutputStream(path, append);
} catch (FileNotFoundException e) {
// Why does it throw a *FileNotFoundException* if it can't write?
// That does not make any sense! And its in a completely different
// format than in other situations, no less!
if (e.getMessage().equals(path + ERR_PERMISSION_DENIED)) {
throw new FileAccessException(e.getMessage());
}
throw e;
}
}
private static final class ProfiledFileInputStream extends FileInputStream {
private final String name;
public ProfiledFileInputStream(String name) throws FileNotFoundException {
super(name);
this.name = name;
}
@Override
public int read() throws IOException {
long startTime = Profiler.nanoTimeMaybe();
try {
// Note that FileInputStream#read() does *not* call any of our overridden methods,
// so there's no concern with double counting here.
return super.read();
} finally {
profiler.logSimpleTask(startTime, ProfilerTask.VFS_READ, name);
}
}
@Override
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
long startTime = Profiler.nanoTimeMaybe();
try {
return super.read(b, off, len);
} finally {
profiler.logSimpleTask(startTime, ProfilerTask.VFS_READ, name);
}
}
}
private static final class ProfiledFileOutputStream extends FileOutputStream {
private final String name;
public ProfiledFileOutputStream(String name, boolean append) throws FileNotFoundException {
super(name, append);
this.name = name;
}
@Override
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
long startTime = Profiler.nanoTimeMaybe();
try {
super.write(b, off, len);
} finally {
profiler.logSimpleTask(startTime, ProfilerTask.VFS_WRITE, name);
}
}
}
}
|
