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wireshark/epan/wmem/wmem_tree.c

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/* 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 <stdio.h>
#include <glib.h>
#include "config.h"
#include "wmem_core.h"
#include "wmem_tree.h"
#include "wmem_user_cb.h"
typedef enum _wmem_node_color_t {
WMEM_NODE_COLOR_RED,
WMEM_NODE_COLOR_BLACK
} wmem_node_color_t;
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;
wmem_node_color_t color;
gboolean is_subtree;
};
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;
guint master_cb_id;
guint slave_cb_id;
};
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->color = WMEM_NODE_COLOR_BLACK;
grandparent->color = WMEM_NODE_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->color == WMEM_NODE_COLOR_RED) {
parent = node->parent;
grandparent = parent->parent;
parent->color = WMEM_NODE_COLOR_BLACK;
uncle->color = WMEM_NODE_COLOR_BLACK;
grandparent->color = WMEM_NODE_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->color == WMEM_NODE_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->color = WMEM_NODE_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 gboolean
wmem_tree_reset_cb(wmem_allocator_t *allocator _U_, wmem_cb_event_t event,
void *user_data)
{
wmem_tree_t *tree = (wmem_tree_t *)user_data;
tree->root = NULL;
if (event == WMEM_CB_DESTROY_EVENT) {
wmem_unregister_callback(tree->master, tree->master_cb_id);
wmem_free(tree->master, tree);
}
return TRUE;
}
static gboolean
wmem_tree_destroy_cb(wmem_allocator_t *allocator _U_, wmem_cb_event_t event _U_,
void *user_data)
{
wmem_tree_t *tree = (wmem_tree_t *)user_data;
wmem_unregister_callback(tree->allocator, tree->slave_cb_id);
return FALSE;
}
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;
tree->master_cb_id = wmem_register_callback(master, wmem_tree_destroy_cb,
tree);
tree->slave_cb_id = wmem_register_callback(slave, wmem_tree_reset_cb,
tree);
return tree;
}
static wmem_tree_node_t *
create_node(wmem_allocator_t *allocator, wmem_tree_node_t *parent, guint32 key,
void *data, wmem_node_color_t color, gboolean is_subtree)
{
wmem_tree_node_t *node;
node = wmem_new(allocator, wmem_tree_node_t);
node->left = NULL;
node->right = NULL;
node->parent = parent;
node->key32 = key;
node->data = data;
node->color = color;
node->is_subtree = is_subtree;
return node;
}
#define CREATE_DATA(TRANSFORM, DATA) ((TRANSFORM) ? (TRANSFORM)(DATA) : (DATA))
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 = NULL;
/* is this the first node ?*/
if (!node) {
new_node = create_node(tree->allocator, NULL, key,
CREATE_DATA(func, data), WMEM_NODE_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 (!new_node) {
/* this node already exists, so just return the data pointer*/
if (key == node->key32) {
if (replace) {
node->data = CREATE_DATA(func, data);
}
return node->data;
}
else if (key < node->key32) {
if (node->left) {
node = node->left;
}
else {
/* new node to the left */
new_node = create_node(tree->allocator, node, key,
CREATE_DATA(func, data), WMEM_NODE_COLOR_RED,
is_subtree);
node->left = new_node;
}
}
else if (key > node->key32) {
if (node->right) {
node = node->right;
}
else {
/* new node to the right */
new_node = create_node(tree->allocator, node, key,
CREATE_DATA(func, data), WMEM_NODE_COLOR_RED,
is_subtree);
node->right = new_node;
}
}
}
/* node will now point to the newly created node */
rb_insert_case1(tree, new_node);
return new_node->data;
}
void
wmem_tree_insert32(wmem_tree_t *tree, guint32 key, void *data)
{
lookup_or_insert32(tree, key, NULL, data, FALSE, 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;
}
}
/* Strings are stored as an array of uint32 containing the string characters
with 4 characters in each uint32.
The first byte of the string is stored as the most significant byte.
If the string is not a multiple of 4 characters in length the last
uint32 containing the string bytes are padded with 0 bytes.
After the uint32's containing the string, there is one final terminator
uint32 with the value 0x00000001
*/
static guint32 *
pack_string(const gchar *key, guint32 *divx, guint32 flags)
{
guint32 *aligned = NULL;
guint32 len = (guint32) strlen(key);
guint32 i;
guint32 tmp;
*divx = (len+3)/4 + 1;
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) {
if (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;
return aligned;
}
void
wmem_tree_insert_string(wmem_tree_t* tree, const gchar* k, void* v, guint32 flags)
{
wmem_tree_key_t key[2];
guint32 *aligned;
guint32 divx;
aligned = pack_string(k, &divx, flags);
key[0].length = divx;
key[0].key = aligned;
key[1].length = 0;
key[1].key = NULL;
wmem_tree_insert32_array(tree, key, v);
g_free(aligned);
}
void *
wmem_tree_lookup_string(wmem_tree_t* tree, const gchar* k, guint32 flags)
{
wmem_tree_key_t key[2];
guint32 *aligned;
guint32 divx;
void *ret;
aligned = pack_string(k, &divx, flags);
key[0].length = divx;
key[0].key = aligned;
key[1].length = 0;
key[1].key = NULL;
ret = wmem_tree_lookup32_array(tree, key);
g_free(aligned);
return ret;
}
static void *
create_sub_tree(void* d)
{
return wmem_tree_new(((wmem_tree_t *)d)->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++) {
g_assert(cur_key->length < 100);
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, create_sub_tree, tree, TRUE, FALSE);
}
insert_key32 = cur_key->key[i];
}
}
g_assert(insert_tree);
wmem_tree_insert32(insert_tree, insert_key32, data);
}
void *
wmem_tree_lookup32_array_helper(wmem_tree_t *tree, wmem_tree_key_t *key,
void*(*helper)(wmem_tree_t*, guint32))
{
wmem_tree_t *lookup_tree = NULL;
wmem_tree_key_t *cur_key;
guint32 i, lookup_key32 = 0;
g_assert(tree);
for (cur_key = key; cur_key->length > 0; cur_key++) {
g_assert(cur_key->length < 100);
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 *)(*helper)(lookup_tree, lookup_key32);
if (!lookup_tree) {
return NULL;
}
}
lookup_key32 = cur_key->key[i];
}
}
/* Assert if we didn't get any valid keys */
g_assert(lookup_tree);
return (*helper)(lookup_tree, lookup_key32);
}
void *
wmem_tree_lookup32_array(wmem_tree_t *tree, wmem_tree_key_t *key)
{
return wmem_tree_lookup32_array_helper(tree, key, wmem_tree_lookup32);
}
void *
wmem_tree_lookup32_array_le(wmem_tree_t *tree, wmem_tree_key_t *key)
{
return wmem_tree_lookup32_array_helper(tree, key, wmem_tree_lookup32_le);
}
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->is_subtree == TRUE) {
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);
}
static void wmem_print_subtree(wmem_tree_t *tree, guint32 level);
static void
wmem_tree_print_nodes(const char *prefix, wmem_tree_node_t *node, guint32 level)
{
guint32 i;
if (!node)
return;
for (i=0; i<level; i++) {
printf(" ");
}
printf("%sNODE:%p parent:%p left:%p right:%p colour:%s key:%u %s:%p\n",
prefix,
(void *)node, (void *)node->parent,
(void *)node->left, (void *)node->right,
node->color?"Black":"Red", node->key32,
node->is_subtree?"tree":"data", node->data);
if (node->left)
wmem_tree_print_nodes("L-", node->left, level+1);
if (node->right)
wmem_tree_print_nodes("R-", node->right, level+1);
if (node->is_subtree)
wmem_print_subtree((wmem_tree_t *)node->data, level+1);
}
static void
wmem_print_subtree(wmem_tree_t *tree, guint32 level)
{
guint32 i;
if (!tree)
return;
for (i=0; i<level; i++) {
printf(" ");
}
printf("WMEM tree:%p root:%p\n", (void *)tree, (void *)tree->root);
if (tree->root) {
wmem_tree_print_nodes("Root-", tree->root, level);
}
}
void
wmem_print_tree(wmem_tree_t *tree)
{
wmem_print_subtree(tree, 0);
}
/*
* 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:
*/
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