xref: /third_party/mesa3d/src/util/string_buffer.c (revision bf215546)
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
27static bool
28ensure_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
46struct _mesa_string_buffer *
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
69bool
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
88bool
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
107bool
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
138bool
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