1 /*
2 * Copyright © 2017 Thomas Helland
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
25 #include "string_buffer.h"
26
27 static bool
ensure_capacity(struct _mesa_string_buffer * str,uint32_t needed_capacity)28 ensure_capacity(struct _mesa_string_buffer *str, uint32_t needed_capacity)
29 {
30 if (needed_capacity <= str->capacity)
31 return true;
32
33 /* Too small, double until we can fit the new string */
34 uint32_t new_capacity = str->capacity * 2;
35 while (needed_capacity > new_capacity)
36 new_capacity *= 2;
37
38 str->buf = reralloc_array_size(str, str->buf, sizeof(char), new_capacity);
39 if (str->buf == NULL)
40 return false;
41
42 str->capacity = new_capacity;
43 return true;
44 }
45
46 struct _mesa_string_buffer *
_mesa_string_buffer_create(void * mem_ctx,uint32_t initial_capacity)47 _mesa_string_buffer_create(void *mem_ctx, uint32_t initial_capacity)
48 {
49 struct _mesa_string_buffer *str;
50 str = ralloc(mem_ctx, struct _mesa_string_buffer);
51
52 if (str == NULL)
53 return NULL;
54
55 /* If no initial capacity is set then set it to something */
56 str->capacity = initial_capacity ? initial_capacity : 32;
57 str->buf = ralloc_array(str, char, str->capacity);
58
59 if (!str->buf) {
60 ralloc_free(str);
61 return NULL;
62 }
63
64 str->length = 0;
65 str->buf[str->length] = '\0';
66 return str;
67 }
68
69 bool
_mesa_string_buffer_append_all(struct _mesa_string_buffer * str,uint32_t num_args,...)70 _mesa_string_buffer_append_all(struct _mesa_string_buffer *str,
71 uint32_t num_args, ...)
72 {
73 int i;
74 char* s;
75 va_list args;
76 va_start(args, num_args);
77 for (i = 0; i < num_args; i++) {
78 s = va_arg(args, char*);
79 if (!_mesa_string_buffer_append_len(str, s, strlen(s))) {
80 va_end(args);
81 return false;
82 }
83 }
84 va_end(args);
85 return true;
86 }
87
88 bool
_mesa_string_buffer_append_len(struct _mesa_string_buffer * str,const char * c,uint32_t len)89 _mesa_string_buffer_append_len(struct _mesa_string_buffer *str,
90 const char *c, uint32_t len)
91 {
92 uint32_t needed_length = str->length + len + 1;
93
94 /* Check if we're overflowing uint32_t */
95 if (needed_length < str->length)
96 return false;
97
98 if (!ensure_capacity(str, needed_length))
99 return false;
100
101 memcpy(str->buf + str->length, c, len);
102 str->length += len;
103 str->buf[str->length] = '\0';
104 return true;
105 }
106
107 bool
_mesa_string_buffer_vprintf(struct _mesa_string_buffer * str,const char * format,va_list args)108 _mesa_string_buffer_vprintf(struct _mesa_string_buffer *str,
109 const char *format, va_list args)
110 {
111 /* We're looping two times to avoid duplicating code */
112 for (uint32_t i = 0; i < 2; i++) {
113 va_list arg_copy;
114 va_copy(arg_copy, args);
115 uint32_t space_left = str->capacity - str->length;
116
117 int32_t len = vsnprintf(str->buf + str->length,
118 space_left, format, arg_copy);
119 va_end(arg_copy);
120
121 /* Error in vsnprintf() or measured len overflows size_t */
122 if (unlikely(len < 0 || str->length + len + 1 < str->length))
123 return false;
124
125 /* There was enough space for the string; we're done */
126 if (len < space_left) {
127 str->length += len;
128 return true;
129 }
130
131 /* Not enough space, resize and retry */
132 ensure_capacity(str, str->length + len + 1);
133 }
134
135 return false;
136 }
137
138 bool
_mesa_string_buffer_printf(struct _mesa_string_buffer * str,const char * format,...)139 _mesa_string_buffer_printf(struct _mesa_string_buffer *str,
140 const char *format, ...)
141 {
142 bool res;
143 va_list args;
144 va_start(args, format);
145 res = _mesa_string_buffer_vprintf(str, format, args);
146 va_end(args);
147 return res;
148 }
149