1/* 2 * buffer.c -- generic memory buffer . 3 * 4 * Copyright (c) 2001-2006, NLnet Labs. All rights reserved. 5 * 6 * See LICENSE for the license. 7 * 8 */ 9 10#include "config.h" 11#include <stdlib.h> 12#include <stdio.h> 13 14#include "buffer.h" 15 16static void 17buffer_cleanup(void *arg) 18{ 19 buffer_type *buffer = (buffer_type *) arg; 20 assert(!buffer->_fixed); 21 free(buffer->_data); 22} 23 24buffer_type * 25buffer_create(region_type *region, size_t capacity) 26{ 27 buffer_type *buffer 28 = (buffer_type *) region_alloc(region, sizeof(buffer_type)); 29 if (!buffer) 30 return NULL; 31 32 buffer->_data = (uint8_t *) xalloc(capacity); 33 buffer->_position = 0; 34 buffer->_limit = buffer->_capacity = capacity; 35 buffer->_fixed = 0; 36 buffer_invariant(buffer); 37 38 region_add_cleanup(region, buffer_cleanup, buffer); 39 40 return buffer; 41} 42 43void 44buffer_create_from(buffer_type *buffer, void *data, size_t size) 45{ 46 assert(data); 47 48 buffer->_position = 0; 49 buffer->_limit = buffer->_capacity = size; 50 buffer->_data = (uint8_t *) data; 51 buffer->_fixed = 1; 52 53 buffer_invariant(buffer); 54} 55 56void 57buffer_clear(buffer_type *buffer) 58{ 59 buffer_invariant(buffer); 60 61 buffer->_position = 0; 62 buffer->_limit = buffer->_capacity; 63} 64 65void 66buffer_flip(buffer_type *buffer) 67{ 68 buffer_invariant(buffer); 69 70 buffer->_limit = buffer->_position; 71 buffer->_position = 0; 72} 73 74void 75buffer_rewind(buffer_type *buffer) 76{ 77 buffer_invariant(buffer); 78 79 buffer->_position = 0; 80} 81 82void 83buffer_set_capacity(buffer_type *buffer, size_t capacity) 84{ 85 buffer_invariant(buffer); 86 assert(buffer->_position <= capacity); 87 buffer->_data = (uint8_t *) xrealloc(buffer->_data, capacity); 88 buffer->_limit = buffer->_capacity = capacity; 89} 90 91void 92buffer_reserve(buffer_type *buffer, size_t amount) 93{ 94 buffer_invariant(buffer); 95 assert(!buffer->_fixed); 96 if (buffer->_capacity < buffer->_position + amount) { 97 size_t new_capacity = buffer->_capacity * 3 / 2; 98 if (new_capacity < buffer->_position + amount) { 99 new_capacity = buffer->_position + amount; 100 } 101 buffer_set_capacity(buffer, new_capacity); 102 } 103 buffer->_limit = buffer->_capacity; 104} 105 106int 107buffer_printf(buffer_type *buffer, const char *format, ...) 108{ 109 va_list args; 110 int written; 111 size_t remaining; 112 113 buffer_invariant(buffer); 114 assert(buffer->_limit == buffer->_capacity); 115 116 remaining = buffer_remaining(buffer); 117 va_start(args, format); 118 written = vsnprintf((char *) buffer_current(buffer), remaining, 119 format, args); 120 va_end(args); 121 if (written >= 0 && (size_t) written >= remaining) { 122 buffer_reserve(buffer, written + 1); 123 va_start(args, format); 124 written = vsnprintf((char *) buffer_current(buffer), 125 buffer_remaining(buffer), 126 format, args); 127 va_end(args); 128 } 129 buffer->_position += written; 130 return written; 131} 132