[deb_ffmpeg.git] / ffmpeg / libavutil / tree.c

/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "error.h"
#include "log.h"
#include "mem.h"
#include "tree.h"

typedef struct AVTreeNode {
    struct AVTreeNode *child[2];
    void *elem;
    int state;
} AVTreeNode;

const int av_tree_node_size = sizeof(AVTreeNode);

struct AVTreeNode *av_tree_node_alloc(void)
{
    return av_mallocz(sizeof(struct AVTreeNode));
}

void *av_tree_find(const AVTreeNode *t, void *key,
                   int (*cmp)(void *key, const void *b), void *next[2])
{
    if (t) {
        unsigned int v = cmp(key, t->elem);
        if (v) {
            if (next)
                next[v >> 31] = t->elem;
            return av_tree_find(t->child[(v >> 31) ^ 1], key, cmp, next);
        } else {
            if (next) {
                av_tree_find(t->child[0], key, cmp, next);
                av_tree_find(t->child[1], key, cmp, next);
            }
            return t->elem;
        }
    }
    return NULL;
}

void *av_tree_insert(AVTreeNode **tp, void *key,
                     int (*cmp)(void *key, const void *b), AVTreeNode **next)
{
    AVTreeNode *t = *tp;
    if (t) {
        unsigned int v = cmp(t->elem, key);
        void *ret;
        if (!v) {
            if (*next)
                return t->elem;
            else if (t->child[0] || t->child[1]) {
                int i = !t->child[0];
                void *next_elem[2];
                av_tree_find(t->child[i], key, cmp, next_elem);
                key = t->elem = next_elem[i];
                v   = -i;
            } else {
                *next = t;
                *tp   = NULL;
                return NULL;
            }
        }
        ret = av_tree_insert(&t->child[v >> 31], key, cmp, next);
        if (!ret) {
            int i              = (v >> 31) ^ !!*next;
            AVTreeNode **child = &t->child[i];
            t->state += 2 * i - 1;

            if (!(t->state & 1)) {
                if (t->state) {
                    /* The following code is equivalent to
                     * if ((*child)->state * 2 == -t->state)
                     *     rotate(child, i ^ 1);
                     * rotate(tp, i);
                     *
                     * with rotate():
                     * static void rotate(AVTreeNode **tp, int i)
                     * {
                     *     AVTreeNode *t= *tp;
                     *
                     *     *tp = t->child[i];
                     *     t->child[i] = t->child[i]->child[i ^ 1];
                     *     (*tp)->child[i ^ 1] = t;
                     *     i = 4 * t->state + 2 * (*tp)->state + 12;
                     *     t->state     = ((0x614586 >> i) & 3) - 1;
                     *     (*tp)->state = ((0x400EEA >> i) & 3) - 1 +
                     *                    ((*tp)->state >> 1);
                     * }
                     * but such a rotate function is both bigger and slower
                     */
                    if ((*child)->state * 2 == -t->state) {
                        *tp                    = (*child)->child[i ^ 1];
                        (*child)->child[i ^ 1] = (*tp)->child[i];
                        (*tp)->child[i]        = *child;
                        *child                 = (*tp)->child[i ^ 1];
                        (*tp)->child[i ^ 1]    = t;

                        (*tp)->child[0]->state = -((*tp)->state > 0);
                        (*tp)->child[1]->state = (*tp)->state < 0;
                        (*tp)->state           = 0;
                    } else {
                        *tp                 = *child;
                        *child              = (*child)->child[i ^ 1];
                        (*tp)->child[i ^ 1] = t;
                        if ((*tp)->state)
                            t->state = 0;
                        else
                            t->state >>= 1;
                        (*tp)->state = -t->state;
                    }
                }
            }
            if (!(*tp)->state ^ !!*next)
                return key;
        }
        return ret;
    } else {
        *tp   = *next;
        *next = NULL;
        if (*tp) {
            (*tp)->elem = key;
            return NULL;
        } else
            return key;
    }
}

void av_tree_destroy(AVTreeNode *t)
{
    if (t) {
        av_tree_destroy(t->child[0]);
        av_tree_destroy(t->child[1]);
        av_free(t);
    }
}

void av_tree_enumerate(AVTreeNode *t, void *opaque,
                       int (*cmp)(void *opaque, void *elem),
                       int (*enu)(void *opaque, void *elem))
{
    if (t) {
        int v = cmp ? cmp(opaque, t->elem) : 0;
        if (v >= 0)
            av_tree_enumerate(t->child[0], opaque, cmp, enu);
        if (v == 0)
            enu(opaque, t->elem);
        if (v <= 0)
            av_tree_enumerate(t->child[1], opaque, cmp, enu);
    }
}

#ifdef TEST

#include "common.h"
#include "lfg.h"

static int check(AVTreeNode *t)
{
    if (t) {
        int left  = check(t->child[0]);
        int right = check(t->child[1]);

        if (left > 999 || right > 999)
            return 1000;
        if (right - left != t->state)
            return 1000;
        if (t->state > 1 || t->state < -1)
            return 1000;
        return FFMAX(left, right) + 1;
    }
    return 0;
}

static void print(AVTreeNode *t, int depth)
{
    int i;
    for (i = 0; i < depth * 4; i++)
        av_log(NULL, AV_LOG_ERROR, " ");
    if (t) {
        av_log(NULL, AV_LOG_ERROR, "Node %p %2d %p\n", t, t->state, t->elem);
        print(t->child[0], depth + 1);
        print(t->child[1], depth + 1);
    } else
        av_log(NULL, AV_LOG_ERROR, "NULL\n");
}

static int cmp(void *a, const void *b)
{
    return (uint8_t *) a - (const uint8_t *) b;
}

int main(int argc, char **argv)
{
    int i;
    void *k;
    AVTreeNode *root = NULL, *node = NULL;
    AVLFG prng;
    int log_level = argc <= 1 ? AV_LOG_INFO : atoi(argv[1]);

    av_log_set_level(log_level);

    av_lfg_init(&prng, 1);

    for (i = 0; i < 10000; i++) {
        intptr_t j = av_lfg_get(&prng) % 86294;

        if (check(root) > 999) {
            av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
            print(root, 0);
            return 1;
        }
        av_log(NULL, AV_LOG_DEBUG, "inserting %4d\n", (int)j);

        if (!node)
            node = av_tree_node_alloc();
        if (!node) {
            av_log(NULL, AV_LOG_ERROR, "Memory allocation failure.\n");
            return 1;
        }
        av_tree_insert(&root, (void *)(j + 1), cmp, &node);

        j = av_lfg_get(&prng) % 86294;
        {
            AVTreeNode *node2 = NULL;
            av_log(NULL, AV_LOG_DEBUG, "removing %4d\n", (int)j);
            av_tree_insert(&root, (void *)(j + 1), cmp, &node2);
            k = av_tree_find(root, (void *)(j + 1), cmp, NULL);
            if (k)
                av_log(NULL, AV_LOG_ERROR, "removal failure %d\n", i);
            av_free(node2);
        }
    }
    av_free(node);

    av_tree_destroy(root);

    return 0;
}
#endif
Commit	Line	Data
2ba45a60 DM	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