1 /* 2 * Copyright (C) 2008 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 #ifndef _ADB_UTILS_H 17 #define _ADB_UTILS_H 18 19 /* bounded buffer functions */ 20 21 /* all these functions are used to append data to a bounded buffer. 22 * 23 * after each operation, the buffer is guaranteed to be zero-terminated, 24 * even in the case of an overflow. they all return the new buffer position 25 * which allows one to use them in succession, only checking for overflows 26 * at the end. For example: 27 * 28 * BUFF_DECL(temp,p,end,1024); 29 * char* p; 30 * 31 * p = buff_addc(temp, end, '"'); 32 * p = buff_adds(temp, end, string); 33 * p = buff_addc(temp, end, '"'); 34 * 35 * if (p >= end) { 36 * overflow detected. note that 'temp' is 37 * zero-terminated for safety. 38 * } 39 * return strdup(temp); 40 */ 41 42 /* tries to add a character to the buffer, in case of overflow 43 * this will only write a terminating zero and return buffEnd. 44 */ 45 char* buff_addc (char* buff, char* buffEnd, int c); 46 47 /* tries to add a string to the buffer */ 48 char* buff_adds (char* buff, char* buffEnd, const char* s); 49 50 /* tries to add a bytes to the buffer. the input can contain zero bytes, 51 * but a terminating zero will always be appended at the end anyway 52 */ 53 char* buff_addb (char* buff, char* buffEnd, const void* data, int len); 54 55 /* tries to add a formatted string to a bounded buffer */ 56 char* buff_add (char* buff, char* buffEnd, const char* format, ... ); 57 58 /* convenience macro used to define a bounded buffer, as well as 59 * a 'cursor' and 'end' variables all in one go. 60 * 61 * note: this doesn't place an initial terminating zero in the buffer, 62 * you need to use one of the buff_ functions for this. or simply 63 * do _cursor[0] = 0 manually. 64 */ 65 #define BUFF_DECL(_buff,_cursor,_end,_size) \ 66 char _buff[_size], *_cursor=_buff, *_end = _cursor + (_size) 67 68 #endif /* _ADB_UTILS_H */ 69