1 /*
2 * Copyright (C) 2015 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 // Copied from system/extras/memory_replay/LineBuffer.cpp
18 // TODO(ccross): find a way to share between libmemunreachable and memory_replay?
19
20 #include <errno.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include "LineBuffer.h"
25
LineBuffer(int fd,char * buffer,size_t buffer_len)26 LineBuffer::LineBuffer(int fd, char* buffer, size_t buffer_len) : fd_(fd), buffer_(buffer), buffer_len_(buffer_len) {
27 }
28
GetLine(char ** line,size_t * line_len)29 bool LineBuffer::GetLine(char** line, size_t* line_len) {
30 while (true) {
31 if (bytes_ > 0) {
32 char* newline = reinterpret_cast<char*>(memchr(buffer_ + start_, '\n', bytes_));
33 if (newline != nullptr) {
34 *newline = '\0';
35 *line = buffer_ + start_;
36 start_ = newline - buffer_ + 1;
37 bytes_ -= newline - *line + 1;
38 *line_len = newline - *line;
39 return true;
40 }
41 }
42 if (start_ > 0) {
43 // Didn't find anything, copy the current to the front of the buffer.
44 memmove(buffer_, buffer_ + start_, bytes_);
45 start_ = 0;
46 }
47 ssize_t bytes = TEMP_FAILURE_RETRY(read(fd_, buffer_ + bytes_, buffer_len_ - bytes_ - 1));
48 if (bytes <= 0) {
49 if (bytes_ > 0) {
50 // The read data might not contain a nul terminator, so add one.
51 buffer_[bytes_] = '\0';
52 *line = buffer_ + start_;
53 *line_len = bytes_;
54 bytes_ = 0;
55 start_ = 0;
56 return true;
57 }
58 return false;
59 }
60 bytes_ += bytes;
61 }
62 }
63