6 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
34 /* Initializes a buffer with a certain amount of allocated space */
35 void buffer_init(Buffer* buffer, unsigned int space)
37 buffer->data = (guchar*)g_malloc(space);
38 buffer->allocated = space;
40 buffer->first_free = 0;
43 /* Frees the memory used by a buffer, and the buffer struct */
44 void buffer_free(Buffer* buffer)
49 /* Assures that there are 'space' bytes at the end of the used space
50 so that another routine can copy directly into the buffer space. After
51 doing that, the routine will also want to run
52 buffer_increase_length(). */
53 void buffer_assure_space(Buffer* buffer, unsigned int space)
55 unsigned int available_at_end = buffer->allocated - buffer->first_free;
56 unsigned int space_used;
57 int space_at_beginning;
59 /* If we've got the space already, good! */
60 if (space <= available_at_end) {
64 /* Maybe we don't have the space available at the end, but we would
65 if we moved the used space back to the beginning of the
66 allocation. The buffer could have become fragmented through lots
67 of calls to buffer_remove_start(). I'm using buffer->start as the
68 same as 'available_at_start' in this comparison. */
70 /* or maybe there's just no more room. */
72 space_at_beginning = buffer->start >= space;
73 if (space_at_beginning || buffer->start > 0) {
74 space_used = buffer->first_free - buffer->start;
75 /* this memory copy better be safe for overlapping memory regions! */
76 memmove(buffer->data, buffer->data + buffer->start, space_used);
78 buffer->first_free = space_used;
80 /*if (buffer->start >= space) {*/
81 if (space_at_beginning) {
85 /* We'll allocate more space */
86 buffer->allocated += space + 1024;
87 buffer->data = (guchar*)g_realloc(buffer->data, buffer->allocated);
90 void buffer_append(Buffer* buffer, guchar *from, unsigned int bytes)
92 buffer_assure_space(buffer, bytes);
93 memcpy(buffer->data + buffer->first_free, from, bytes);
94 buffer->first_free += bytes;
97 void buffer_remove_start(Buffer* buffer, unsigned int bytes)
99 if (buffer->start + bytes > buffer->first_free) {
100 g_error("buffer_remove_start trying to remove %d bytes. s=%d ff=%d!\n",
101 bytes, buffer->start, buffer->first_free);
104 buffer->start += bytes;
106 if (buffer->start == buffer->first_free) {
108 buffer->first_free = 0;
113 #ifndef SOME_FUNCTIONS_ARE_DEFINES
114 void buffer_clean(Buffer* buffer)
116 buffer_remove_start(buffer, buffer_length(buffer));
120 #ifndef SOME_FUNCTIONS_ARE_DEFINES
121 void buffer_increase_length(Buffer* buffer, unsigned int bytes)
123 buffer->first_free += bytes;
127 #ifndef SOME_FUNCTIONS_ARE_DEFINES
128 unsigned int buffer_length(Buffer* buffer)
130 return buffer->first_free - buffer->start;
134 #ifndef SOME_FUNCTIONS_ARE_DEFINES
135 guchar* buffer_start_ptr(Buffer* buffer)
137 return buffer->data + buffer->start;
141 #ifndef SOME_FUNCTIONS_ARE_DEFINES
142 guchar* buffer_end_ptr(Buffer* buffer)
144 return buffer->data + buffer->first_free;
148 #ifndef SOME_FUNCTIONS_ARE_DEFINES
149 void buffer_append_buffer(Buffer* buffer, Buffer* src_buffer)
151 buffer_append(buffer, buffer_start_ptr(src_buffer), buffer_length(src_buffer));