Most of a red-black tree implementation for wmem, based heavily on the emem

version.

One plane trip's worth of work.

svn path=/trunk/; revision=49945

epan/CMakeLists.txt

@@ -1387,6 +1387,7 @@ set(WMEM_FILES
 	wmem/wmem_stack.c
 	wmem/wmem_strbuf.c
 	wmem/wmem_strutl.c
+	wmem/wmem_tree.c
 	wmem/wmem_user_cb.c
 )
 

epan/wmem/Makefile.common

@@ -33,6 +33,7 @@ LIBWMEM_SRC =				\
 	wmem_stack.c			\
 	wmem_strbuf.c			\
 	wmem_strutl.c			\
+	wmem_tree.c			\
 	wmem_user_cb.c
 
 LIBWMEM_INCLUDES =			\
@@ -47,6 +48,7 @@ LIBWMEM_INCLUDES =			\
 	wmem_stack.h			\
 	wmem_strbuf.h			\
 	wmem_strutl.h			\
+	wmem_tree.h			\
 	wmem_user_cb.h			\
 	wmem_user_cb_int.h
 

epan/wmem/wmem.h

@@ -32,6 +32,7 @@
 #include "wmem_stack.h"
 #include "wmem_strbuf.h"
 #include "wmem_strutl.h"
+#include "wmem_tree.h"
 #include "wmem_user_cb.h"
 
 #endif /* __WMEM_H__ */

epan/wmem/wmem_test.c

@@ -71,11 +71,13 @@ wmem_allocator_force_new(const wmem_allocator_type_t type)
     return allocator;
 }
 
-/* Some helpers for properly testing the user callback functionality */
+/* Some helpers for properly testing callback functionality */
 wmem_allocator_t *expected_allocator;
 void             *expected_user_data;
 gboolean          expected_final;
 int               cb_called_count;
+int               cb_continue_count;
+gboolean          value_seen[CONTAINER_ITERS];
 
 static void
 wmem_test_cb(wmem_allocator_t *allocator, gboolean final, void *user_data)
@@ -87,6 +89,20 @@ wmem_test_cb(wmem_allocator_t *allocator, gboolean final, void *user_data)
     cb_called_count++;
 }
 
+static gboolean
+wmem_test_foreach_cb(void *value, void *user_data)
+{
+    g_assert(user_data == expected_user_data);
+
+    g_assert(! value_seen[GPOINTER_TO_INT(value)]);
+    value_seen[GPOINTER_TO_INT(value)] = TRUE;
+
+    cb_called_count++;
+    cb_continue_count--;
+
+    return (cb_continue_count == 0);
+}
+
 /* ALLOCATOR TESTING FUNCTIONS (/wmem/allocator/) */
 
 static void
@@ -549,6 +565,93 @@ wmem_test_strbuf(void)
     wmem_destroy_allocator(allocator);
 }
 
+static void
+wmem_test_tree(void)
+{
+    wmem_allocator_t   *allocator, *extra_allocator;
+    wmem_tree_t        *tree;
+    guint32             i;
+    int                 seen_values = 0;
+
+    allocator       = wmem_allocator_force_new(WMEM_ALLOCATOR_STRICT);
+    extra_allocator = wmem_allocator_force_new(WMEM_ALLOCATOR_STRICT);
+
+    tree = wmem_tree_new(allocator);
+    g_assert(tree);
+
+    for (i=0; i<CONTAINER_ITERS; i++) {
+        g_assert(wmem_tree_lookup32(tree, i) == NULL);
+        if (i > 0) {
+            g_assert(wmem_tree_lookup32_le(tree, i) == GINT_TO_POINTER(i-1));
+        }
+        wmem_tree_insert32(tree, i, GINT_TO_POINTER(i));
+        g_assert(wmem_tree_lookup32(tree, i) == GINT_TO_POINTER(i));
+    }
+    wmem_free_all(allocator);
+
+    tree = wmem_tree_new(allocator);
+    for (i=0; i<CONTAINER_ITERS; i++) {
+        guint32 rand = g_test_rand_int();
+        wmem_tree_insert32(tree, rand, GINT_TO_POINTER(i));
+        g_assert(wmem_tree_lookup32(tree, rand) == GINT_TO_POINTER(i));
+    }
+    wmem_free_all(allocator);
+
+    tree = wmem_tree_new_autoreset(allocator, extra_allocator);
+    for (i=0; i<CONTAINER_ITERS; i++) {
+        g_assert(wmem_tree_lookup32(tree, i) == NULL);
+        wmem_tree_insert32(tree, i, GINT_TO_POINTER(i));
+        g_assert(wmem_tree_lookup32(tree, i) == GINT_TO_POINTER(i));
+    }
+    wmem_free_all(extra_allocator);
+    for (i=0; i<CONTAINER_ITERS; i++) {
+        g_assert(wmem_tree_lookup32(tree, i) == NULL);
+        g_assert(wmem_tree_lookup32_le(tree, i) == NULL);
+    }
+    wmem_free_all(allocator);
+
+    /* TODO:
+     * - test string functions
+     * - test array functions
+     */
+
+    tree = wmem_tree_new(allocator);
+    expected_user_data = GINT_TO_POINTER(g_test_rand_int());
+    for (i=0; i<CONTAINER_ITERS; i++) {
+        value_seen[i] = FALSE;
+        wmem_tree_insert32(tree, g_test_rand_int(), GINT_TO_POINTER(i));
+    }
+
+    cb_called_count    = 0;
+    cb_continue_count  = CONTAINER_ITERS;
+    wmem_tree_foreach(tree, wmem_test_foreach_cb, expected_user_data);
+    g_assert(cb_called_count   == CONTAINER_ITERS);
+    g_assert(cb_continue_count == 0);
+
+    for (i=0; i<CONTAINER_ITERS; i++) {
+        g_assert(value_seen[i]);
+        value_seen[i] = FALSE;
+    }
+
+    cb_called_count    = 0;
+    cb_continue_count  = 10;
+    wmem_tree_foreach(tree, wmem_test_foreach_cb, expected_user_data);
+    g_assert(cb_called_count   == 10);
+    g_assert(cb_continue_count == 0);
+
+    for (i=0; i<CONTAINER_ITERS; i++) {
+        if (value_seen[i]) {
+            seen_values++;
+        }
+    }
+    g_assert(seen_values == 10);
+
+    wmem_free_all(allocator);
+
+    wmem_destroy_allocator(extra_allocator);
+    wmem_destroy_allocator(allocator);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -566,6 +669,7 @@ main(int argc, char **argv)
     g_test_add_func("/wmem/datastruct/slist",  wmem_test_slist);
     g_test_add_func("/wmem/datastruct/stack",  wmem_test_stack);
     g_test_add_func("/wmem/datastruct/strbuf", wmem_test_strbuf);
+    g_test_add_func("/wmem/datastruct/tree",   wmem_test_tree);
 
     return g_test_run();
 }

epan/wmem/wmem_tree.c

@@ -0,0 +1,681 @@
+/* wmem_tree.c
+ * Wireshark Memory Manager Red-Black Tree
+ * Based on the red-black tree implementation in epan/emem.*
+ * Copyright 2013, Evan Huus <eapache@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <ctype.h>
+#include <string.h>
+#include <glib.h>
+
+#include "config.h"
+#include "wmem_core.h"
+#include "wmem_tree.h"
+#include "wmem_user_cb.h"
+
+struct _wmem_tree_node_t {
+    struct _wmem_tree_node_t *parent;
+    struct _wmem_tree_node_t *left;
+    struct _wmem_tree_node_t *right;
+    void *data;
+    guint32 key32;
+    struct {
+#define WMEM_TREE_RB_COLOR_RED		0
+#define WMEM_TREE_RB_COLOR_BLACK	1
+        guint32 rb_color:1;
+#define WMEM_TREE_NODE_IS_DATA		0
+#define WMEM_TREE_NODE_IS_SUBTREE	1
+        guint32 is_subtree:1;
+    } u;
+};
+
+typedef struct _wmem_tree_node_t wmem_tree_node_t;
+
+struct _wmem_tree_t {
+    wmem_allocator_t *master;
+    wmem_allocator_t *allocator;
+    wmem_tree_node_t *root;
+};
+
+static wmem_tree_node_t *
+node_uncle(wmem_tree_node_t *node)
+{
+    wmem_tree_node_t *parent, *grandparent;
+
+    parent = node->parent;
+    if (parent == NULL) {
+        return NULL;
+    }
+
+    grandparent = parent->parent;
+    if (grandparent == NULL) {
+        return NULL;
+    }
+
+    if (parent == grandparent->left) {
+        return grandparent->right;
+    }
+    else {
+        return grandparent->left;
+    }
+}
+
+static void rb_insert_case1(wmem_tree_t *tree, wmem_tree_node_t *node);
+static void rb_insert_case2(wmem_tree_t *tree, wmem_tree_node_t *node);
+
+static void
+rotate_left(wmem_tree_t *tree, wmem_tree_node_t *node)
+{
+    if (node->parent) {
+        if (node->parent->left == node) {
+            node->parent->left = node->right;
+        }
+        else {
+            node->parent->right = node->right;
+        }
+    }
+    else {
+        tree->root = node->right;
+    }
+
+    node->right->parent = node->parent;
+    node->parent        = node->right;
+    node->right         = node->right->left;
+    if (node->right) {
+        node->right->parent = node;
+    }
+    node->parent->left = node;
+}
+
+static void
+rotate_right(wmem_tree_t *tree, wmem_tree_node_t *node)
+{
+    if (node->parent) {
+        if (node->parent->left == node) {
+            node->parent->left = node->left;
+        }
+        else {
+            node->parent->right = node->left;
+        }
+    }
+    else {
+        tree->root = node->left;
+    }
+
+    node->left->parent = node->parent;
+    node->parent       = node->left;
+    node->left         = node->left->right;
+    if (node->left) {
+        node->left->parent = node;
+    }
+    node->parent->right = node;
+}
+
+static void
+rb_insert_case5(wmem_tree_t *tree, wmem_tree_node_t *node)
+{
+    wmem_tree_node_t *parent, *grandparent;
+
+    parent      = node->parent;
+    grandparent = parent->parent;
+
+    parent->u.rb_color      = WMEM_TREE_RB_COLOR_BLACK;
+    grandparent->u.rb_color = WMEM_TREE_RB_COLOR_RED;
+
+    if (node == parent->left && parent == grandparent->left) {
+        rotate_right(tree, grandparent);
+    }
+    else {
+        rotate_left(tree, grandparent);
+    }
+}
+
+static void
+rb_insert_case4(wmem_tree_t *tree, wmem_tree_node_t *node)
+{
+    wmem_tree_node_t *parent, *grandparent;
+
+    parent      = node->parent;
+    grandparent = parent->parent;
+    if (!grandparent) {
+        return;
+    }
+
+    if (node == parent->right && parent == grandparent->left) {
+        rotate_left(tree, parent);
+        node = node->left;
+    }
+    else if (node == parent->left && parent == grandparent->right) {
+        rotate_right(tree, parent);
+        node = node->right;
+    }
+
+    rb_insert_case5(tree, node);
+}
+
+static void
+rb_insert_case3(wmem_tree_t *tree, wmem_tree_node_t *node)
+{
+    wmem_tree_node_t *parent, *grandparent, *uncle;
+
+    uncle = node_uncle(node);
+
+    if (uncle && uncle->u.rb_color == WMEM_TREE_RB_COLOR_RED) {
+        parent      = node->parent;
+        grandparent = parent->parent;
+
+        parent->u.rb_color      = WMEM_TREE_RB_COLOR_BLACK;
+        uncle->u.rb_color       = WMEM_TREE_RB_COLOR_BLACK;
+        grandparent->u.rb_color = WMEM_TREE_RB_COLOR_RED;
+
+        rb_insert_case1(tree, grandparent);
+    }
+    else {
+        rb_insert_case4(tree, node);
+    }
+}
+
+static void
+rb_insert_case2(wmem_tree_t *tree, wmem_tree_node_t *node)
+{
+    /* parent is always non-NULL here */
+    if (node->parent->u.rb_color == WMEM_TREE_RB_COLOR_RED) {
+        rb_insert_case3(tree, node);
+    }
+}
+
+static void
+rb_insert_case1(wmem_tree_t *tree, wmem_tree_node_t *node)
+{
+    wmem_tree_node_t *parent = node->parent;
+
+    if (parent == NULL) {
+        node->u.rb_color = WMEM_TREE_RB_COLOR_BLACK;
+    }
+    else {
+        rb_insert_case2(tree, node);
+    }
+}
+
+wmem_tree_t *
+wmem_tree_new(wmem_allocator_t *allocator)
+{
+    wmem_tree_t *tree;
+
+    tree = wmem_new(allocator, wmem_tree_t);
+    tree->master    = allocator;
+    tree->allocator = allocator;
+    tree->root      = NULL;
+
+    return tree;
+}
+
+static void
+wmem_tree_reset(wmem_allocator_t *allocator _U_, gboolean final _U_,
+        void *user_data)
+{
+    wmem_tree_t *tree = (wmem_tree_t *)user_data;
+
+    tree->root = NULL;
+}
+
+wmem_tree_t *
+wmem_tree_new_autoreset(wmem_allocator_t *master, wmem_allocator_t *slave)
+{
+    wmem_tree_t *tree;
+
+    tree = wmem_new(master, wmem_tree_t);
+    tree->master    = master;
+    tree->allocator = slave;
+    tree->root      = NULL;
+
+    wmem_register_cleanup_callback(slave, TRUE, wmem_tree_reset, tree);
+
+    return tree;
+}
+
+static wmem_tree_node_t *
+create_node(wmem_allocator_t *allocator, wmem_tree_node_t *parent,
+        guint32 key, void *data, int color, gboolean is_subtree)
+{
+    wmem_tree_node_t *new_node;
+
+    new_node = wmem_new(allocator, wmem_tree_node_t);
+
+    new_node->left         = NULL;
+    new_node->right        = NULL;
+    new_node->parent       = parent;
+    new_node->key32        = key;
+    new_node->data         = data;
+    new_node->u.rb_color   = color;
+    new_node->u.is_subtree = is_subtree;
+
+    return new_node;
+}
+
+static void *
+lookup_or_insert32(wmem_tree_t *tree, guint32 key, void*(*func)(void*),
+        void *data, gboolean is_subtree, gboolean replace)
+{
+    wmem_tree_node_t *node = tree->root;
+    wmem_tree_node_t *new_node;
+
+    /* is this the first node ?*/
+    if (!node) {
+        new_node = create_node(tree->allocator, NULL, key, func(data),
+                WMEM_TREE_RB_COLOR_BLACK, is_subtree);
+        tree->root = new_node;
+        return new_node->data;
+    }
+
+    /* it was not the new root so walk the tree until we find where to
+     * insert this new leaf.
+     */
+    while (TRUE) {
+        /* this node already exists, so modify if we were asked to,
+         * then return it */
+        if (key == node->key32) {
+            if (replace) {
+                node->data = func(data);
+            }
+            return node->data;
+        }
+        else if (key < node->key32) {
+            if (node->left) {
+                node = node->left;
+                continue;
+            }
+            /* new node to the left */
+            new_node = create_node(tree->allocator, node, key, func(data),
+                    WMEM_TREE_RB_COLOR_RED, is_subtree);
+            node->left = new_node;
+            break;
+        }
+        else if (key > node->key32) {
+            if (node->right) {
+                node = node->right;
+                continue;
+            }
+            /* new node to the left */
+            new_node = create_node(tree->allocator, node, key, func(data),
+                    WMEM_TREE_RB_COLOR_RED, is_subtree);
+            node->right = new_node;
+            break;
+        }
+    }
+
+    rb_insert_case1(tree, new_node);
+
+    return node->data;
+}
+
+static void *
+identity(void *in)
+{
+    return in;
+}
+
+void
+wmem_tree_insert32(wmem_tree_t *tree, guint32 key, void *data)
+{
+    lookup_or_insert32(tree, key, &identity, data,
+            WMEM_TREE_NODE_IS_DATA, TRUE);
+}
+
+void *
+wmem_tree_lookup32(wmem_tree_t *tree, guint32 key)
+{
+    wmem_tree_node_t *node = tree->root;
+
+    while (node) {
+        if (key == node->key32) {
+            return node->data;
+        }
+        else if (key < node->key32) {
+            node = node->left;
+        }
+        else if (key > node->key32) {
+            node = node->right;
+        }
+    }
+
+    return NULL;
+}
+
+void *
+wmem_tree_lookup32_le(wmem_tree_t *tree, guint32 key)
+{
+    wmem_tree_node_t *node = tree->root;
+
+    while (node) {
+        if (key == node->key32) {
+            return node->data;
+        }
+        else if (key < node->key32) {
+            if (node->left == NULL) {
+                break;
+            }
+            node = node->left;
+        }
+        else if (key > node->key32) {
+            if (node->right == NULL) {
+                break;
+            }
+            node = node->right;
+        }
+    }
+
+    if (!node) {
+        return NULL;
+    }
+
+    /* If we are still at the root of the tree this means that this node
+     * is either smaller than the search key and then we return this
+     * node or else there is no smaller key available and then
+     * we return NULL.
+     */
+    if (node->parent == NULL) {
+        if (key > node->key32) {
+            return node->data;
+        } else {
+            return NULL;
+        }
+    }
+
+    if (node->key32 <= key) {
+        /* if our key is <= the search key, we have the right node */
+        return node->data;
+    }
+    else if (node == node->parent->left) {
+        /* our key is bigger than the search key and we're a left child,
+         * we have to check if any of our ancestors are smaller. */
+        while (node) {
+            if (key > node->key32) {
+                return node->data;
+            }
+            node=node->parent;
+        }
+        return NULL;
+    }
+    else {
+        /* our key is bigger than the search key and we're a right child,
+         * our parent is the one we want */
+        return node->parent->data;
+    }
+}
+
+/* YOU MUST g_free THE RETURN VALUE OF THIS FUNCTION AFTER USING IT */
+static guint32 *
+wmem_pack_string_key(const gchar *key, guint32 flags, guint32 *packed_len)
+{
+    guint32 *aligned = NULL;
+    guint32 len = (guint32) strlen(key);
+    guint32 divx = (len+3)/4 + 1;
+    guint32 i;
+    guint32 tmp;
+
+    aligned = (guint32 *)g_malloc(divx * sizeof (guint32));
+
+    /* pack the bytes one one by one into guint32s */
+    tmp = 0;
+    for (i = 0; i < len; i++) {
+        unsigned char ch;
+
+        ch = (unsigned char)key[i];
+        if ((flags & WMEM_TREE_STRING_NOCASE) && isupper(ch)) {
+            ch = tolower(ch);
+        }
+        tmp <<= 8;
+        tmp |= ch;
+        if (i % 4 == 3) {
+            aligned[i/4] = tmp;
+            tmp = 0;
+        }
+    }
+
+    /* add required padding to the last uint32 */
+    if (i % 4 != 0) {
+        while (i % 4 != 0) {
+            i++;
+            tmp <<= 8;
+        }
+        aligned[i/4-1] = tmp;
+    }
+
+    /* add the terminator */
+    aligned[divx-1] = 0x00000001;
+
+    *packed_len = divx;
+    return aligned;
+}
+
+void
+wmem_tree_insert_string(wmem_tree_t *tree, const gchar* key, void *data,
+        guint32 flags)
+{
+    wmem_tree_key_t packed_key[2];
+    guint32 *aligned;
+    guint32 packed_len;
+
+    aligned = wmem_pack_string_key(key, flags, &packed_len);
+
+    packed_key[0].length = packed_len;
+    packed_key[0].key    = aligned;
+    packed_key[1].length = 0;
+    packed_key[1].key    = NULL;
+
+    wmem_tree_insert32_array(tree, packed_key, data);
+
+    g_free(aligned);
+}
+
+void *
+wmem_tree_lookup_string(wmem_tree_t* tree, const gchar* key, guint32 flags)
+{
+    wmem_tree_key_t packed_key[2];
+    guint32 *aligned=NULL;
+    guint32 packed_len;
+    void *ret;
+
+    aligned = wmem_pack_string_key(key, flags, &packed_len);
+
+    packed_key[0].length = packed_len;
+    packed_key[0].key    = aligned;
+    packed_key[1].length = 0;
+    packed_key[1].key    = NULL;
+
+    ret = wmem_tree_lookup32_array(tree, packed_key);
+
+    g_free(aligned);
+
+    return ret;
+}
+
+static void *
+wmem_tree_create_subtree(void *parent_tree)
+{
+    return wmem_tree_new(((wmem_tree_t *)parent_tree)->allocator);
+}
+
+void
+wmem_tree_insert32_array(wmem_tree_t *tree, wmem_tree_key_t *key, void *data)
+{
+    wmem_tree_t *insert_tree = NULL;
+    wmem_tree_key_t *cur_key;
+    guint32 i, insert_key32 = 0;
+
+    for (cur_key = key; cur_key->length > 0; cur_key++) {
+        if(cur_key->length > 100) {
+            /* XXX FIXME DISSECTOR_ASSERT_NOT_REACHED(); */
+        }
+
+        for (i = 0; i < cur_key->length; i++) {
+            /* Insert using the previous key32 */
+            if (!insert_tree) {
+                insert_tree = tree;
+            } else {
+                insert_tree = (wmem_tree_t *)lookup_or_insert32(insert_tree,
+                        insert_key32, wmem_tree_create_subtree, tree,
+                        WMEM_TREE_NODE_IS_SUBTREE, FALSE);
+            }
+            insert_key32 = cur_key->key[i];
+        }
+    }
+
+    if (!insert_tree) {
+        /* We didn't get a valid key. Should we return NULL instead? */
+        /* XXX FIXME DISSECTOR_ASSERT_NOT_REACHED(); */
+    }
+
+    wmem_tree_insert32(insert_tree, insert_key32, data);
+}
+
+void *
+wmem_tree_lookup32_array(wmem_tree_t *tree, wmem_tree_key_t *key)
+{
+    wmem_tree_t *lookup_tree = NULL;
+    wmem_tree_key_t *cur_key;
+    guint32 i, lookup_key32 = 0;
+
+    for (cur_key = key; cur_key->length > 0; cur_key++) {
+        if(cur_key->length > 100) {
+            /* XXX FIXME DISSECTOR_ASSERT_NOT_REACHED(); */
+        }
+
+        for (i = 0; i < cur_key->length; i++) {
+            /* Lookup using the previous key32 */
+            if (!lookup_tree) {
+                lookup_tree = tree;
+            } else {
+                lookup_tree = (wmem_tree_t *)wmem_tree_lookup32(lookup_tree,
+                        lookup_key32);
+                if (!lookup_tree) {
+                    return NULL;
+                }
+            }
+            lookup_key32 = cur_key->key[i];
+        }
+    }
+
+    if(!lookup_tree) {
+        /* We didn't get a valid key. Should we return NULL instead? */
+        /* XXX FIXME DISSECTOR_ASSERT_NOT_REACHED(); */
+    }
+
+    return wmem_tree_lookup32(lookup_tree, lookup_key32);
+}
+
+void *
+wmem_tree_lookup32_array_le(wmem_tree_t *tree, wmem_tree_key_t *key)
+{
+    wmem_tree_t *lookup_tree = NULL;
+    wmem_tree_key_t *cur_key;
+    guint32 i, lookup_key32 = 0;
+
+    for (cur_key = key; cur_key->length > 0; cur_key++) {
+        if(cur_key->length > 100) {
+            /* XXX FIXME DISSECTOR_ASSERT_NOT_REACHED(); */
+        }
+
+        for (i = 0; i < cur_key->length; i++) {
+            /* Lookup using the previous key32 */
+            if (!lookup_tree) {
+                lookup_tree = tree;
+            } else {
+                lookup_tree = (wmem_tree_t *)wmem_tree_lookup32_le(lookup_tree,
+                        lookup_key32);
+                if (!lookup_tree) {
+                    return NULL;
+                }
+            }
+            lookup_key32 = cur_key->key[i];
+        }
+    }
+
+    if(!lookup_tree) {
+        /* We didn't get a valid key. Should we return NULL instead? */
+        /* XXX FIXME DISSECTOR_ASSERT_NOT_REACHED(); */
+    }
+
+    return wmem_tree_lookup32_le(lookup_tree, lookup_key32);
+
+}
+
+static gboolean
+wmem_tree_foreach_nodes(wmem_tree_node_t* node, wmem_foreach_func callback,
+        void *user_data)
+{
+    gboolean stop_traverse = FALSE;
+
+    if (!node) {
+        return FALSE;
+    }
+
+    if (node->left) {
+        if (wmem_tree_foreach_nodes(node->left, callback, user_data)) {
+            return TRUE;
+        }
+    }
+
+    if (node->u.is_subtree == WMEM_TREE_NODE_IS_SUBTREE) {
+        stop_traverse = wmem_tree_foreach((wmem_tree_t *)node->data,
+                callback, user_data);
+    } else {
+        stop_traverse = callback(node->data, user_data);
+    }
+
+    if (stop_traverse) {
+        return TRUE;
+    }
+
+    if(node->right) {
+        if (wmem_tree_foreach_nodes(node->right, callback, user_data)) {
+            return TRUE;
+        }
+    }
+
+    return FALSE;
+}
+
+gboolean
+wmem_tree_foreach(wmem_tree_t* tree, wmem_foreach_func callback,
+        void *user_data)
+{
+    if(!tree->root)
+        return FALSE;
+
+    return wmem_tree_foreach_nodes(tree->root, callback, user_data);
+}
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */

epan/wmem/wmem_tree.h

@@ -0,0 +1,177 @@
+/* wmem_tree.h
+ * Definitions for the Wireshark Memory Manager Red-Black Tree
+ * Based on the red-black tree implementation in epan/emem.*
+ * Copyright 2013, Evan Huus <eapache@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __WMEM_TREE_H_
+#define __WMEM_TREE_H__
+
+#include "wmem_core.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/** @addtogroup wmem
+ *  @{
+ *    @defgroup wmem-tree Red-Black Tree
+ *
+ *    A red-black tree implementation on top of wmem.
+ *
+ *    @{
+ */
+
+struct _wmem_tree_t;
+typedef struct _wmem_tree_t wmem_tree_t;
+
+/** Creates a tree with the given allocator scope */
+WS_DLL_PUBLIC
+wmem_tree_t *
+wmem_tree_new(wmem_allocator_t *allocator)
+G_GNUC_MALLOC;
+
+/** Creates a tree with two allocator scope. The base structure lives in the
+ * master scope, however the data lives in the slave scope. Every time free_all
+ * occurs in the slave scope the tree is transparently emptied without affecting
+ * the location of the structure.
+ */
+WS_DLL_PUBLIC
+wmem_tree_t *
+wmem_tree_new_autoreset(wmem_allocator_t *master, wmem_allocator_t *slave)
+G_GNUC_MALLOC;
+
+/** Insert a node indexed by a guint32 key value. */
+WS_DLL_PUBLIC
+void
+wmem_tree_insert32(wmem_tree_t *tree, guint32 key, void *data);
+
+/** Look up a node in the tree indexed by a guint32 integer value */
+WS_DLL_PUBLIC
+void *
+wmem_tree_lookup32(wmem_tree_t *tree, guint32 key);
+
+/** Look up a node in the tree indexed by a guint32 integer value.
+ * Returns the node that has the largest key that is less than or equal
+ * to the search key, or NULL if no such key exists.
+ */
+WS_DLL_PUBLIC
+void *
+wmem_tree_lookup32_le(wmem_tree_t *tree, guint32 key);
+
+/** case insensitive strings as keys */
+#define WMEM_TREE_STRING_NOCASE			0x00000001
+/** Insert a new value under a string key */
+WS_DLL_PUBLIC
+void
+wmem_tree_insert_string(wmem_tree_t *tree, const gchar* key, void *data,
+        guint32 flags);
+
+/** Lookup the value under a string key */
+WS_DLL_PUBLIC
+void *
+wmem_tree_lookup_string(wmem_tree_t* tree, const gchar* key, guint32 flags);
+
+typedef struct _wmem_tree_key_t {
+    guint32 length;    /**< length in guint32 words */
+    guint32 *key;
+} wmem_tree_key_t;
+
+/** Insert a node indexed by a sequence of guint32 key values.
+ *
+ * Note: all the "key" members of the "key" argument MUST be aligned on
+ * 32-bit boundaries; otherwise, this code will crash on platforms such
+ * as SPARC that require aligned pointers.
+ *
+ * If you use ...32_array() calls you MUST make sure that every single node
+ * you add to a specific tree always has a key of exactly the same number of
+ * keylen words or things will most likely crash. Or at least that every single
+ * item that sits behind the same top level node always have exactly the same
+ * number of words.
+ *
+ * One way to guarantee this is the way that NFS does this for the
+ * nfs_name_snoop_known tree which holds filehandles for both v2 and v3.
+ * v2 filehandles are always 32 bytes (8 words) while v3 filehandles can have
+ * any length (though 32 bytes are most common).
+ * The NFS dissector handles this by providing a guint32 containing the length
+ * as the very first item in this vector :
+ *
+ *			emem_tree_key_t fhkey[3];
+ *
+ *			fhlen=nns->fh_length;
+ *			fhkey[0].length=1;
+ *			fhkey[0].key=&fhlen;
+ *			fhkey[1].length=fhlen/4;
+ *			fhkey[1].key=nns->fh;
+ *			fhkey[2].length=0;
+ */
+WS_DLL_PUBLIC
+void
+wmem_tree_insert32_array(wmem_tree_t *tree, wmem_tree_key_t *key, void *data);
+
+/** Look up a node in the tree indexed by a sequence of guint32 integer values.
+ */
+WS_DLL_PUBLIC
+void *
+wmem_tree_lookup32_array(wmem_tree_t *tree, wmem_tree_key_t *key);
+
+/** Look up a node in the tree indexed by a multi-part tree value.
+ * The function will return the node that has the largest key that is
+ * equal to or smaller than the search key, or NULL if no such key was
+ * found.
+ * Note:  The key returned will be "less" in key order.  The usefullness
+ * of the returned node must be verified prior to use.
+ */
+WS_DLL_PUBLIC
+void *
+wmem_tree_lookup32_array_le(wmem_tree_t *tree, wmem_tree_key_t *key);
+
+/** traverse a tree. if the callback returns TRUE the traversal will end */
+typedef gboolean (*wmem_foreach_func)(void *value, void *userdata);
+
+WS_DLL_PUBLIC
+gboolean
+wmem_tree_foreach(wmem_tree_t* tree, wmem_foreach_func callback,
+        void *user_data);
+
+/**   @}
+ *  @} */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* __WMEM_SLIST_H__ */
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */