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