Rename ffmpeg-4.2-fit to ffmpeg-4-fit

trunk/3rdparty/ffmpeg-4-fit/libavutil/tree.c

@@ -0,0 +1,168 @@
+/*
+ * 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)(const 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)(const 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);
+    }
+}