| 1 | /* |
| 2 | * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org> |
| 3 | * |
| 4 | * Jansson is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the MIT license. See LICENSE for details. |
| 6 | */ |
| 7 | |
| 8 | #ifndef _GNU_SOURCE |
| 9 | #define _GNU_SOURCE |
| 10 | #endif |
| 11 | |
| 12 | #include <stdlib.h> |
| 13 | #include <string.h> |
| 14 | #include "jansson_private.h" |
| 15 | #include "strbuffer.h" |
| 16 | |
| 17 | #define STRBUFFER_MIN_SIZE 16 |
| 18 | #define STRBUFFER_FACTOR 2 |
| 19 | #define STRBUFFER_SIZE_MAX ((size_t)-1) |
| 20 | |
| 21 | int strbuffer_init(strbuffer_t *strbuff) |
| 22 | { |
| 23 | strbuff->size = STRBUFFER_MIN_SIZE; |
| 24 | strbuff->length = 0; |
| 25 | |
| 26 | strbuff->value = jsonp_malloc(strbuff->size); |
| 27 | if(!strbuff->value) |
| 28 | return -1; |
| 29 | |
| 30 | /* initialize to empty */ |
| 31 | strbuff->value[0] = '\0'; |
| 32 | return 0; |
| 33 | } |
| 34 | |
| 35 | void strbuffer_close(strbuffer_t *strbuff) |
| 36 | { |
| 37 | if(strbuff->value) |
| 38 | jsonp_free(strbuff->value); |
| 39 | |
| 40 | strbuff->size = 0; |
| 41 | strbuff->length = 0; |
| 42 | strbuff->value = NULL; |
| 43 | } |
| 44 | |
| 45 | void strbuffer_clear(strbuffer_t *strbuff) |
| 46 | { |
| 47 | strbuff->length = 0; |
| 48 | strbuff->value[0] = '\0'; |
| 49 | } |
| 50 | |
| 51 | const char *strbuffer_value(const strbuffer_t *strbuff) |
| 52 | { |
| 53 | return strbuff->value; |
| 54 | } |
| 55 | |
| 56 | char *strbuffer_steal_value(strbuffer_t *strbuff) |
| 57 | { |
| 58 | char *result = strbuff->value; |
| 59 | strbuff->value = NULL; |
| 60 | return result; |
| 61 | } |
| 62 | |
| 63 | int strbuffer_append_byte(strbuffer_t *strbuff, char byte) |
| 64 | { |
| 65 | return strbuffer_append_bytes(strbuff, &byte, 1); |
| 66 | } |
| 67 | |
| 68 | int strbuffer_append_bytes(strbuffer_t *strbuff, const char *data, size_t size) |
| 69 | { |
| 70 | if(size >= strbuff->size - strbuff->length) |
| 71 | { |
| 72 | size_t new_size; |
| 73 | char *new_value; |
| 74 | |
| 75 | /* avoid integer overflow */ |
| 76 | if (strbuff->size > STRBUFFER_SIZE_MAX / STRBUFFER_FACTOR |
| 77 | || size > STRBUFFER_SIZE_MAX - 1 |
| 78 | || strbuff->length > STRBUFFER_SIZE_MAX - 1 - size) |
| 79 | return -1; |
| 80 | |
| 81 | new_size = max(strbuff->size * STRBUFFER_FACTOR, |
| 82 | strbuff->length + size + 1); |
| 83 | |
| 84 | new_value = jsonp_malloc(new_size); |
| 85 | if(!new_value) |
| 86 | return -1; |
| 87 | |
| 88 | memcpy(new_value, strbuff->value, strbuff->length); |
| 89 | |
| 90 | jsonp_free(strbuff->value); |
| 91 | strbuff->value = new_value; |
| 92 | strbuff->size = new_size; |
| 93 | } |
| 94 | |
| 95 | memcpy(strbuff->value + strbuff->length, data, size); |
| 96 | strbuff->length += size; |
| 97 | strbuff->value[strbuff->length] = '\0'; |
| 98 | |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | char strbuffer_pop(strbuffer_t *strbuff) |
| 103 | { |
| 104 | if(strbuff->length > 0) { |
| 105 | char c = strbuff->value[--strbuff->length]; |
| 106 | strbuff->value[strbuff->length] = '\0'; |
| 107 | return c; |
| 108 | } |
| 109 | else |
| 110 | return '\0'; |
| 111 | } |