1 /*
2 * Copyright 2012, The Android Open Source Project
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 #include "bcc/Support/OutputFile.h"
18
19 #include <cstdlib>
20
21 #include <llvm/Support/raw_ostream.h>
22
23 #include "bcc/Support/Log.h"
24
25 using namespace bcc;
26
CreateTemporary(const std::string & pFileTemplate,unsigned pFlags)27 OutputFile *OutputFile::CreateTemporary(const std::string &pFileTemplate,
28 unsigned pFlags) {
29 char *tmp_filename = NULL;
30 int tmp_fd;
31 OutputFile *result = NULL;
32
33 // Allocate memory to hold the generated unique temporary filename.
34 tmp_filename =
35 new (std::nothrow) char [ pFileTemplate.length() + /* .XXXXXX */7 + 1 ];
36 if (tmp_filename == NULL) {
37 ALOGE("Out of memory when allocates memory for filename %s in "
38 "OutputFile::CreateTemporary()!", pFileTemplate.c_str());
39 return NULL;
40 }
41
42 // Construct filename template for mkstemp().
43 if (pFileTemplate.length() > 0)
44 ::memcpy(tmp_filename, pFileTemplate.c_str(), pFileTemplate.length());
45 ::strncpy(tmp_filename + pFileTemplate.length(), ".XXXXXX", 7);
46
47 // POSIX mkstemp() never returns EINTR.
48 tmp_fd = ::mkstemp(tmp_filename);
49 if (tmp_fd < 0) {
50 llvm::error_code err(errno, llvm::posix_category());
51 ALOGE("Failed to create temporary file using mkstemp() for %s! (%s)",
52 tmp_filename, err.message().c_str());
53 delete [] tmp_filename;
54 return NULL;
55 }
56
57 // Create result OutputFile. Temporary file is always truncated.
58 result = new (std::nothrow) OutputFile(tmp_filename,
59 pFlags | FileBase::kTruncate);
60 if (result == NULL) {
61 ALOGE("Out of memory when creates OutputFile for %s!", tmp_filename);
62 // Fall through to the clean-up codes.
63 } else {
64 if (result->hasError()) {
65 ALOGE("Failed to open temporary output file %s! (%s)",
66 result->getName().c_str(), result->getErrorMessage().c_str());
67 delete result;
68 result = NULL;
69 // Fall through to the clean-up codes.
70 }
71 }
72
73 // Clean up.
74 delete [] tmp_filename;
75 ::close(tmp_fd);
76
77 return result;
78 }
79
OutputFile(const std::string & pFilename,unsigned pFlags)80 OutputFile::OutputFile(const std::string &pFilename, unsigned pFlags)
81 : super(pFilename, pFlags) { }
82
write(const void * pBuf,size_t count)83 ssize_t OutputFile::write(const void *pBuf, size_t count) {
84 if ((mFD < 0) || hasError()) {
85 return -1;
86 }
87
88 if ((count <= 0) || (pBuf == NULL)) {
89 // Keep safe and issue a warning.
90 ALOGW("OutputFile::write: count = %zu, buffer = %p", count, pBuf);
91 return 0;
92 }
93
94 while (count > 0) {
95 ssize_t write_size = ::write(mFD, pBuf, count);
96
97 if (write_size > 0) {
98 return write_size;
99 } else if ((errno == EAGAIN) || (errno == EINTR)) {
100 // If the errno is EAGAIN or EINTR, then we try to write again.
101 //
102 // Fall-through
103 } else {
104 detectError();
105 return -1;
106 }
107 }
108 // unreachable
109 return 0;
110 }
111
truncate()112 void OutputFile::truncate() {
113 if (mFD < 0) {
114 return;
115 }
116
117 do {
118 if (::ftruncate(mFD, 0) == 0) {
119 return;
120 }
121 } while (errno == EINTR);
122 detectError();
123
124 return;
125 }
126
dup()127 llvm::raw_fd_ostream *OutputFile::dup() {
128 int newfd;
129
130 do {
131 newfd = ::dup(mFD);
132 if (newfd < 0) {
133 if (errno != EINTR) {
134 detectError();
135 return NULL;
136 }
137 // EINTR
138 continue;
139 }
140 // dup() returns ok.
141 break;
142 } while (true);
143
144 llvm::raw_fd_ostream *result =
145 new (std::nothrow) llvm::raw_fd_ostream(newfd, /* shouldClose */true);
146
147 if (result == NULL) {
148 mError.assign(llvm::errc::not_enough_memory, llvm::system_category());
149 }
150
151 return result;
152 }
153