1 /*
2 * Copyright (c) 2009-2014 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
strbuffer_init(strbuffer_t * strbuff)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
strbuffer_close(strbuffer_t * strbuff)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
strbuffer_clear(strbuffer_t * strbuff)45 void strbuffer_clear(strbuffer_t *strbuff)
46 {
47 strbuff->length = 0;
48 strbuff->value[0] = '\0';
49 }
50
strbuffer_value(const strbuffer_t * strbuff)51 const char *strbuffer_value(const strbuffer_t *strbuff)
52 {
53 return strbuff->value;
54 }
55
strbuffer_steal_value(strbuffer_t * strbuff)56 char *strbuffer_steal_value(strbuffer_t *strbuff)
57 {
58 char *result = strbuff->value;
59 strbuff->value = NULL;
60 return result;
61 }
62
strbuffer_append(strbuffer_t * strbuff,const char * string)63 int strbuffer_append(strbuffer_t *strbuff, const char *string)
64 {
65 return strbuffer_append_bytes(strbuff, string, strlen(string));
66 }
67
strbuffer_append_byte(strbuffer_t * strbuff,char byte)68 int strbuffer_append_byte(strbuffer_t *strbuff, char byte)
69 {
70 return strbuffer_append_bytes(strbuff, &byte, 1);
71 }
72
strbuffer_append_bytes(strbuffer_t * strbuff,const char * data,size_t size)73 int strbuffer_append_bytes(strbuffer_t *strbuff, const char *data, size_t size)
74 {
75 if(size >= strbuff->size - strbuff->length)
76 {
77 size_t new_size;
78 char *new_value;
79
80 /* avoid integer overflow */
81 if (strbuff->size > STRBUFFER_SIZE_MAX / STRBUFFER_FACTOR
82 || size > STRBUFFER_SIZE_MAX - 1
83 || strbuff->length > STRBUFFER_SIZE_MAX - 1 - size)
84 return -1;
85
86 new_size = max(strbuff->size * STRBUFFER_FACTOR,
87 strbuff->length + size + 1);
88
89 new_value = jsonp_malloc(new_size);
90 if(!new_value)
91 return -1;
92
93 memcpy(new_value, strbuff->value, strbuff->length);
94
95 jsonp_free(strbuff->value);
96 strbuff->value = new_value;
97 strbuff->size = new_size;
98 }
99
100 memcpy(strbuff->value + strbuff->length, data, size);
101 strbuff->length += size;
102 strbuff->value[strbuff->length] = '\0';
103
104 return 0;
105 }
106
strbuffer_pop(strbuffer_t * strbuff)107 char strbuffer_pop(strbuffer_t *strbuff)
108 {
109 if(strbuff->length > 0) {
110 char c = strbuff->value[--strbuff->length];
111 strbuff->value[strbuff->length] = '\0';
112 return c;
113 }
114 else
115 return '\0';
116 }
117