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 23 LineBuffer::LineBuffer(int fd, char* buffer, size_t buffer_len) : fd_(fd), buffer_(buffer), buffer_len_(buffer_len) { 24 } 25 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