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/InputFile.h"
18
19 #include "bcc/Support/Log.h"
20
21 using namespace bcc;
22
InputFile(const std::string & pFilename,unsigned pFlags)23 InputFile::InputFile(const std::string &pFilename, unsigned pFlags)
24 : super(pFilename, pFlags) { }
25
read(void * pBuf,size_t count)26 ssize_t InputFile::read(void *pBuf, size_t count) {
27 if ((mFD < 0) || hasError()) {
28 return -1;
29 }
30
31 if ((count <= 0) || (pBuf == nullptr)) {
32 // Keep safe and issue a warning.
33 ALOGW("InputFile::read: count = %zu, buffer = %p", count, pBuf);
34 return 0;
35 }
36
37 while (count > 0) {
38 ssize_t read_size = ::read(mFD, pBuf, count);
39
40 if (read_size >= 0) {
41 return read_size;
42 } else if ((errno == EAGAIN) || (errno == EINTR)) {
43 // If the errno is EAGAIN or EINTR, then we try to read again.
44 //
45 // Fall-through
46 } else {
47 detectError();
48 return -1;
49 }
50 }
51 // unreachable
52 return 0;
53 }
54