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
OutputFile(const std::string & pFilename,unsigned pFlags)27 OutputFile::OutputFile(const std::string &pFilename, unsigned pFlags)
28 : super(pFilename, pFlags) { }
29
write(const void * pBuf,size_t count)30 ssize_t OutputFile::write(const void *pBuf, size_t count) {
31 if ((mFD < 0) || hasError()) {
32 return -1;
33 }
34
35 if ((count <= 0) || (pBuf == nullptr)) {
36 // Keep safe and issue a warning.
37 ALOGW("OutputFile::write: count = %zu, buffer = %p", count, pBuf);
38 return 0;
39 }
40
41 while (count > 0) {
42 ssize_t write_size = ::write(mFD, pBuf, count);
43
44 if (write_size > 0) {
45 return write_size;
46 } else if ((errno == EAGAIN) || (errno == EINTR)) {
47 // If the errno is EAGAIN or EINTR, then we try to write again.
48 //
49 // Fall-through
50 } else {
51 detectError();
52 return -1;
53 }
54 }
55 // unreachable
56 return 0;
57 }
58
truncate()59 void OutputFile::truncate() {
60 if (mFD < 0) {
61 return;
62 }
63
64 do {
65 if (::ftruncate(mFD, 0) == 0) {
66 return;
67 }
68 } while (errno == EINTR);
69 detectError();
70
71 return;
72 }
73
dup()74 llvm::raw_fd_ostream *OutputFile::dup() {
75 int newfd;
76
77 do {
78 newfd = ::dup(mFD);
79 if (newfd < 0) {
80 if (errno != EINTR) {
81 detectError();
82 return nullptr;
83 }
84 // EINTR
85 continue;
86 }
87 // dup() returns ok.
88 break;
89 } while (true);
90
91 llvm::raw_fd_ostream *result =
92 new (std::nothrow) llvm::raw_fd_ostream(newfd, /* shouldClose */true);
93
94 if (result == nullptr) {
95 mError = std::make_error_code(std::errc::not_enough_memory);
96 }
97
98 return result;
99 }
100