FFmpeg: libavutil/tree.c Source File

FFmpeg
tree.c
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1 /*
2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "error.h"
22 #include "log.h"
23 #include "mem.h"
24 #include "tree.h"
25 
26  typedef struct AVTreeNode {
27   struct AVTreeNode *child[2];
28   void *elem;
29   int state;
30 } AVTreeNode;
31 
32  const int av_tree_node_size = sizeof(AVTreeNode);
33 
34  struct AVTreeNode *av_tree_node_alloc(void)
35 {
36  return av_mallocz(sizeof(struct AVTreeNode));
37 }
38 
39  void *av_tree_find(const AVTreeNode *t, void *key,
40  int (*cmp)(void *key, const void *b), void *next[2])
41 {
42  if (t) {
43  unsigned int v = cmp(key, t->elem);
44  if (v) {
45  if (next)
46  next[v >> 31] = t->elem;
47  return av_tree_find(t->child[(v >> 31) ^ 1], key, cmp, next);
48  } else {
49  if (next) {
50  av_tree_find(t->child[0], key, cmp, next);
51  av_tree_find(t->child[1], key, cmp, next);
52  }
53  return t->elem;
54  }
55  }
56  return NULL;
57 }
58 
59  void *av_tree_insert(AVTreeNode **tp, void *key,
60  int (*cmp)(void *key, const void *b), AVTreeNode **next)
61 {
62  AVTreeNode *t = *tp;
63  if (t) {
64  unsigned int v = cmp(t->elem, key);
65  void *ret;
66  if (!v) {
67  if (*next)
68  return t->elem;
69  else if (t->child[0] || t->child[1]) {
70  int i = !t->child[0];
71  void *next_elem[2];
72  av_tree_find(t->child[i], key, cmp, next_elem);
73  key = t->elem = next_elem[i];
74  v = -i;
75  } else {
76  *next = t;
77  *tp = NULL;
78  return NULL;
79  }
80  }
81  ret = av_tree_insert(&t->child[v >> 31], key, cmp, next);
82  if (!ret) {
83  int i = (v >> 31) ^ !!*next;
84  AVTreeNode **child = &t->child[i];
85  t->state += 2 * i - 1;
86 
87  if (!(t->state & 1)) {
88  if (t->state) {
89  /* The following code is equivalent to
90  * if ((*child)->state * 2 == -t->state)
91  * rotate(child, i ^ 1);
92  * rotate(tp, i);
93  *
94  * with rotate():
95  * static void rotate(AVTreeNode **tp, int i)
96  * {
97  * AVTreeNode *t= *tp;
98  *
99  * *tp = t->child[i];
100  * t->child[i] = t->child[i]->child[i ^ 1];
101  * (*tp)->child[i ^ 1] = t;
102  * i = 4 * t->state + 2 * (*tp)->state + 12;
103  * t->state = ((0x614586 >> i) & 3) - 1;
104  * (*tp)->state = ((0x400EEA >> i) & 3) - 1 +
105  * ((*tp)->state >> 1);
106  * }
107  * but such a rotate function is both bigger and slower
108  */
109  if ((*child)->state * 2 == -t->state) {
110  *tp = (*child)->child[i ^ 1];
111  (*child)->child[i ^ 1] = (*tp)->child[i];
112  (*tp)->child[i] = *child;
113  *child = (*tp)->child[i ^ 1];
114  (*tp)->child[i ^ 1] = t;
115 
116  (*tp)->child[0]->state = -((*tp)->state > 0);
117  (*tp)->child[1]->state = (*tp)->state < 0;
118  (*tp)->state = 0;
119  } else {
120  *tp = *child;
121  *child = (*child)->child[i ^ 1];
122  (*tp)->child[i ^ 1] = t;
123  if ((*tp)->state)
124  t->state = 0;
125  else
126  t->state >>= 1;
127  (*tp)->state = -t->state;
128  }
129  }
130  }
131  if (!(*tp)->state ^ !!*next)
132  return key;
133  }
134  return ret;
135  } else {
136  *tp = *next;
137  *next = NULL;
138  if (*tp) {
139  (*tp)->elem = key;
140  return NULL;
141  } else
142  return key;
143  }
144 }
145 
146  void av_tree_destroy(AVTreeNode *t)
147 {
148  if (t) {
149  av_tree_destroy(t->child[0]);
150  av_tree_destroy(t->child[1]);
151  av_free(t);
152  }
153 }
154 
155  void av_tree_enumerate(AVTreeNode *t, void *opaque,
156  int (*cmp)(void *opaque, void *elem),
157  int (*enu)(void *opaque, void *elem))
158 {
159  if (t) {
160  int v = cmp ? cmp(opaque, t->elem) : 0;
161  if (v >= 0)
162  av_tree_enumerate(t->child[0], opaque, cmp, enu);
163  if (v == 0)
164  enu(opaque, t->elem);
165  if (v <= 0)
166  av_tree_enumerate(t->child[1], opaque, cmp, enu);
167  }
168 }
169 
170 #ifdef TEST
171 
172 #include "common.h"
173 #include "lfg.h"
174 
175 static int check(AVTreeNode *t)
176 {
177  if (t) {
178  int left = check(t->child[0]);
179  int right = check(t->child[1]);
180 
181  if (left > 999 || right > 999)
182  return 1000;
183  if (right - left != t->state)
184  return 1000;
185  if (t->state > 1 || t->state < -1)
186  return 1000;
187  return FFMAX(left, right) + 1;
188  }
189  return 0;
190 }
191 
192 static void print(AVTreeNode *t, int depth)
193 {
194  int i;
195  for (i = 0; i < depth * 4; i++)
196  av_log(NULL, AV_LOG_ERROR, " ");
197  if (t) {
198  av_log(NULL, AV_LOG_ERROR, "Node %p %2d %p\n", t, t->state, t->elem);
199  print(t->child[0], depth + 1);
200  print(t->child[1], depth + 1);
201  } else
202  av_log(NULL, AV_LOG_ERROR, "NULL\n");
203 }
204 
205 static int cmp(void *a, const void *b)
206 {
207  return (uint8_t *) a - (const uint8_t *) b;
208 }
209 
210 int main(int argc, char **argv)
211 {
212  int i;
213  void *k;
214  AVTreeNode *root = NULL, *node = NULL;
215  AVLFG prng;
216  int log_level = argc <= 1 ? AV_LOG_INFO : atoi(argv[1]);
217 
218  av_log_set_level(log_level);
219 
220  av_lfg_init(&prng, 1);
221 
222  for (i = 0; i < 10000; i++) {
223  intptr_t j = av_lfg_get(&prng) % 86294;
224 
225  if (check(root) > 999) {
226  av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
227  print(root, 0);
228  return 1;
229  }
230  av_log(NULL, AV_LOG_DEBUG, "inserting %4d\n", (int)j);
231 
232  if (!node)
233  node = av_tree_node_alloc();
234  if (!node) {
235  av_log(NULL, AV_LOG_ERROR, "Memory allocation failure.\n");
236  return 1;
237  }
238  av_tree_insert(&root, (void *)(j + 1), cmp, &node);
239 
240  j = av_lfg_get(&prng) % 86294;
241  {
242  AVTreeNode *node2 = NULL;
243  av_log(NULL, AV_LOG_DEBUG, "removing %4d\n", (int)j);
244  av_tree_insert(&root, (void *)(j + 1), cmp, &node2);
245  k = av_tree_find(root, (void *)(j + 1), cmp, NULL);
246  if (k)
247  av_log(NULL, AV_LOG_ERROR, "removal failure %d\n", i);
248  av_free(node2);
249  }
250  }
251  av_free(node);
252 
253  av_tree_destroy(root);
254 
255  return 0;
256 }
257 #endif
AVLFG
Definition: lfg.h:25
NULL
#define NULL
Definition: coverity.c:32
v
float v
Definition: avf_showspectrum.c:96
mem.h
memory handling functions
av_log_set_level
void av_log_set_level(int level)
Set the log level.
Definition: log.c:382
b
const char * b
Definition: vf_curves.c:109
av_tree_node_alloc
struct AVTreeNode * av_tree_node_alloc(void)
Allocate an AVTreeNode.
Definition: tree.c:34
av_tree_find
void * av_tree_find(const AVTreeNode *t, void *key, int(*cmp)(void *key, const void *b), void *next[2])
Definition: tree.c:39
uint8_t
uint8_t
Definition: audio_convert.c:194
tree.h
A tree container.
child
AVS_FilterInfo AVS_Value child
Definition: avisynth_c.h:594
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
av_tree_destroy
void av_tree_destroy(AVTreeNode *t)
Definition: tree.c:146
av_tree_insert
void * av_tree_insert(AVTreeNode **tp, void *key, int(*cmp)(void *key, const void *b), AVTreeNode **next)
Insert or remove an element.
Definition: tree.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
error.h
error code definitions
AVTreeNode::child
struct AVTreeNode * child[2]
Definition: tree.c:27
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
AVTreeNode::state
int state
Definition: tree.c:29
FFMAX
#define FFMAX(a, b)
Definition: common.h:64
depth
int depth
Definition: v4l.c:61
ret
ret
Definition: avfilter.c:974
cmp
static av_always_inline int cmp(MpegEncContext *s, const int x, const int y, const int subx, const int suby, const int size, const int h, int ref_index, int src_index, me_cmp_func cmp_func, me_cmp_func chroma_cmp_func, const int flags)
compares a block (either a full macroblock or a partition thereof) against a proposed motion-compensa...
Definition: motion_est.c:260
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
av_lfg_get
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:38
av_lfg_init
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:30
av_tree_node_size
const int av_tree_node_size
Definition: tree.c:32
AVTreeNode
Definition: tree.c:26
common.h
common internal and external API header
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
main
int main(int argc, char **argv)
Definition: main.c:22
av_tree_enumerate
void av_tree_enumerate(AVTreeNode *t, void *opaque, int(*cmp)(void *opaque, void *elem), int(*enu)(void *opaque, void *elem))
Apply enu(opaque, &elem) to all the elements in the tree in a given range.
Definition: tree.c:155
av_mallocz
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:250
AVTreeNode::elem
void * elem
Definition: tree.c:28
a
a
Definition: h264pred_template.c:468
check
#define check(x, y, S, v)
Definition: motion_est_template.c:403
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