1 /* frame_data_sequence.c
2 * Implements a sequence of frame_data structures
6 * Wireshark - Network traffic analyzer
7 * By Gerald Combs <gerald@wireshark.org>
8 * Copyright 1998 Gerald Combs
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
29 #include <epan/packet.h>
31 #include "frame_data_sequence.h"
34 * We store the frame_data structures in a radix tree, with 1024
35 * elements per level. The leaf nodes are arrays of 1024 frame_data
36 * structures; the nodes above them are arrays of 1024 pointers to
37 * the nodes below them. The capture_file structure has a pointer
40 * As frame numbers are 32 bits, and as 1024 is 2^10, that gives us
41 * up to 4 levels of tree.
43 #define LOG2_NODES_PER_LEVEL 10
44 #define NODES_PER_LEVEL (1<<LOG2_NODES_PER_LEVEL)
46 struct _frame_data_sequence {
47 guint32 count; /* Total number of frames */
48 void *ptree_root; /* Pointer to the root node */
52 * For a given frame number, calculate the indices into a level 3
53 * node, a level 2 node, a level 1 node, and a leaf node.
55 #define LEVEL_3_INDEX(framenum) \
56 ((framenum) >> (3*LOG2_NODES_PER_LEVEL))
57 #define LEVEL_2_INDEX(framenum) \
58 (((framenum) >> (2*LOG2_NODES_PER_LEVEL)) & (NODES_PER_LEVEL - 1))
59 #define LEVEL_1_INDEX(framenum) \
60 (((framenum) >> (1*LOG2_NODES_PER_LEVEL)) & (NODES_PER_LEVEL - 1))
61 #define LEAF_INDEX(framenum) \
62 (((framenum) >> (0*LOG2_NODES_PER_LEVEL)) & (NODES_PER_LEVEL - 1))
65 new_frame_data_sequence(void)
67 frame_data_sequence *fds;
69 fds = g_malloc(sizeof *fds);
71 fds->ptree_root = NULL;
76 * Add a new frame_data structure to a frame_data_sequence.
79 frame_data_sequence_add(frame_data_sequence *fds, frame_data *fdata)
84 frame_data ****level3;
88 * The current value of fds->count is the index value for the new frame,
89 * because the index value for a frame is the frame number - 1, and
90 * if we currently have fds->count frames, the the frame number of
91 * the last frame in the collection is fds->count, so its index value
94 if (fds->count == 0) {
95 /* The tree is empty; allocate the first leaf node, which will be
97 leaf = g_malloc((sizeof *leaf)*NODES_PER_LEVEL);
99 fds->ptree_root = leaf;
100 } else if (fds->count < NODES_PER_LEVEL) {
101 /* It's a 1-level tree, and is going to stay that way for now. */
102 leaf = fds->ptree_root;
103 node = &leaf[fds->count];
104 } else if (fds->count == NODES_PER_LEVEL) {
105 /* It's a 1-level tree that will turn into a 2-level tree. */
106 level1 = g_malloc0((sizeof *level1)*NODES_PER_LEVEL);
107 level1[0] = fds->ptree_root;
108 leaf = g_malloc((sizeof *leaf)*NODES_PER_LEVEL);
111 fds->ptree_root = level1;
112 } else if (fds->count < NODES_PER_LEVEL*NODES_PER_LEVEL) {
113 /* It's a 2-level tree, and is going to stay that way for now. */
114 level1 = fds->ptree_root;
115 leaf = level1[fds->count >> LOG2_NODES_PER_LEVEL];
117 leaf = g_malloc((sizeof *leaf)*NODES_PER_LEVEL);
118 level1[fds->count >> LOG2_NODES_PER_LEVEL] = leaf;
120 node = &leaf[LEAF_INDEX(fds->count)];
121 } else if (fds->count == NODES_PER_LEVEL*NODES_PER_LEVEL) {
122 /* It's a 2-level tree that will turn into a 3-level tree */
123 level2 = g_malloc0((sizeof *level2)*NODES_PER_LEVEL);
124 level2[0] = fds->ptree_root;
125 level1 = g_malloc0((sizeof *level1)*NODES_PER_LEVEL);
127 leaf = g_malloc((sizeof *leaf)*NODES_PER_LEVEL);
130 fds->ptree_root = level2;
131 } else if (fds->count < NODES_PER_LEVEL*NODES_PER_LEVEL*NODES_PER_LEVEL) {
132 /* It's a 3-level tree, and is going to stay that way for now. */
133 level2 = fds->ptree_root;
134 level1 = level2[fds->count >> (LOG2_NODES_PER_LEVEL+LOG2_NODES_PER_LEVEL)];
135 if (level1 == NULL) {
136 level1 = g_malloc0((sizeof *level1)*NODES_PER_LEVEL);
137 level2[fds->count >> (LOG2_NODES_PER_LEVEL+LOG2_NODES_PER_LEVEL)] = level1;
139 leaf = level1[LEVEL_1_INDEX(fds->count)];
141 leaf = g_malloc((sizeof *leaf)*NODES_PER_LEVEL);
142 level1[LEVEL_1_INDEX(fds->count)] = leaf;
144 node = &leaf[LEAF_INDEX(fds->count)];
145 } else if (fds->count == NODES_PER_LEVEL*NODES_PER_LEVEL*NODES_PER_LEVEL) {
146 /* It's a 3-level tree that will turn into a 4-level tree */
147 level3 = g_malloc0((sizeof *level3)*NODES_PER_LEVEL);
148 level3[0] = fds->ptree_root;
149 level2 = g_malloc0((sizeof *level2)*NODES_PER_LEVEL);
151 level1 = g_malloc0((sizeof *level1)*NODES_PER_LEVEL);
153 leaf = g_malloc((sizeof *leaf)*NODES_PER_LEVEL);
156 fds->ptree_root = level3;
158 /* fds->count is 2^32-1 at most, and NODES_PER_LEVEL^4
159 2^(LOG2_NODES_PER_LEVEL*4), and LOG2_NODES_PER_LEVEL is 10,
160 so fds->count is always less < NODES_PER_LEVEL^4.
162 XXX - we should fail if fds->count is 2^31-1, or should
163 make the frame numbers 64-bit and just let users run
164 themselves out of address space or swap space. :-) */
165 /* It's a 4-level tree, and is going to stay that way forever. */
166 level3 = fds->ptree_root;
167 level2 = level3[LEVEL_3_INDEX(fds->count)];
168 if (level2 == NULL) {
169 level2 = g_malloc0((sizeof *level2)*NODES_PER_LEVEL);
170 level3[LEVEL_3_INDEX(fds->count)] = level2;
172 level1 = level2[LEVEL_2_INDEX(fds->count)];
173 if (level1 == NULL) {
174 level1 = g_malloc0((sizeof *level1)*NODES_PER_LEVEL);
175 level2[LEVEL_2_INDEX(fds->count)] = level1;
177 leaf = level1[LEVEL_1_INDEX(fds->count)];
179 leaf = g_malloc((sizeof *leaf)*NODES_PER_LEVEL);
180 level1[LEVEL_1_INDEX(fds->count)] = leaf;
182 node = &leaf[LEAF_INDEX(fds->count)];
190 * Find the frame_data for the specified frame number.
193 frame_data_sequence_find(frame_data_sequence *fds, guint32 num)
197 frame_data ***level2;
198 frame_data ****level3;
201 /* There is no frame number 0 */
205 /* Convert it into an index number. */
207 if (num >= fds->count) {
208 /* There aren't that many frames. */
212 if (fds->count <= NODES_PER_LEVEL) {
213 /* It's a 1-level tree. */
214 leaf = fds->ptree_root;
217 if (fds->count <= NODES_PER_LEVEL*NODES_PER_LEVEL) {
218 /* It's a 2-level tree. */
219 level1 = fds->ptree_root;
220 leaf = level1[num >> LOG2_NODES_PER_LEVEL];
221 return &leaf[LEAF_INDEX(num)];
223 if (fds->count <= NODES_PER_LEVEL*NODES_PER_LEVEL*NODES_PER_LEVEL) {
224 /* It's a 3-level tree. */
225 level2 = fds->ptree_root;
226 level1 = level2[num >> (LOG2_NODES_PER_LEVEL+LOG2_NODES_PER_LEVEL)];
227 leaf = level1[(num >> LOG2_NODES_PER_LEVEL) & (NODES_PER_LEVEL - 1)];
228 return &leaf[LEAF_INDEX(num)];
230 /* fds->count is 2^32-1 at most, and NODES_PER_LEVEL^4
231 2^(LOG2_NODES_PER_LEVEL*4), and LOG2_NODES_PER_LEVEL is 10,
232 so fds->count is always less < NODES_PER_LEVEL^4. */
233 /* It's a 4-level tree, and is going to stay that way forever. */
234 level3 = fds->ptree_root;
235 level2 = level3[num >> (LOG2_NODES_PER_LEVEL+LOG2_NODES_PER_LEVEL+LOG2_NODES_PER_LEVEL)];
236 level1 = level2[(num >> (LOG2_NODES_PER_LEVEL+LOG2_NODES_PER_LEVEL)) & (NODES_PER_LEVEL - 1)];
237 leaf = level1[(num >> LOG2_NODES_PER_LEVEL) & (NODES_PER_LEVEL - 1)];
238 return &leaf[LEAF_INDEX(num)];
242 * Free a frame_data_sequence and all the frame_data structures in it.
245 free_frame_data_sequence(frame_data_sequence *fds)
248 frame_data ***level2;
249 frame_data ****level3;
252 if (fds->count == 0) {
253 /* Nothing to free. */
256 if (fds->count <= NODES_PER_LEVEL) {
257 /* It's a 1-level tree. */
258 g_free(fds->ptree_root);
259 } else if (fds->count <= NODES_PER_LEVEL*NODES_PER_LEVEL) {
260 /* It's a 2-level tree. */
261 level1 = fds->ptree_root;
262 for (i = 0; i < NODES_PER_LEVEL && level1[i] != NULL; i++)
265 } else if (fds->count <= NODES_PER_LEVEL*NODES_PER_LEVEL*NODES_PER_LEVEL) {
266 /* It's a 3-level tree. */
267 level2 = fds->ptree_root;
268 for (i = 0; i < NODES_PER_LEVEL && level2[i] != NULL; i++) {
270 for (j = 0; j < NODES_PER_LEVEL && level1[i] != NULL; j++)
277 /* fds->count is 2^32-1 at most, and NODES_PER_LEVEL^4
278 2^(LOG2_NODES_PER_LEVEL*4), and LOG2_NODES_PER_LEVEL is 10,
279 so fds->count is always less < NODES_PER_LEVEL^4. */
280 /* It's a 4-level tree, and is going to stay that way forever. */
281 level3 = fds->ptree_root;
282 for (i = 0; i < NODES_PER_LEVEL && level3[i] != NULL; i++) {
284 for (j = 0; j < NODES_PER_LEVEL && level2[i] != NULL; j++) {
286 for (k = 0; k < NODES_PER_LEVEL && level1[k] != NULL; k++)