mirror of
https://github.com/moparisthebest/curl
synced 2024-11-08 10:35:05 -05:00
2c16681225
With the curl memory tracking feature decoupled from the debug build feature, CURLDEBUG and DEBUGBUILD preprocessor symbol definitions are used as follows: CURLDEBUG used for curl debug memory tracking specific code (--enable-curldebug) DEBUGBUILD used for debug enabled specific code (--enable-debug)
440 lines
11 KiB
C
440 lines
11 KiB
C
/***************************************************************************
|
|
* _ _ ____ _
|
|
* Project ___| | | | _ \| |
|
|
* / __| | | | |_) | |
|
|
* | (__| |_| | _ <| |___
|
|
* \___|\___/|_| \_\_____|
|
|
*
|
|
* Copyright (C) 1997 - 2009, Daniel Stenberg, <daniel@haxx.se>, et al.
|
|
*
|
|
* This software is licensed as described in the file COPYING, which
|
|
* you should have received as part of this distribution. The terms
|
|
* are also available at http://curl.haxx.se/docs/copyright.html.
|
|
*
|
|
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
|
* copies of the Software, and permit persons to whom the Software is
|
|
* furnished to do so, under the terms of the COPYING file.
|
|
*
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
* KIND, either express or implied.
|
|
*
|
|
* $Id$
|
|
***************************************************************************/
|
|
|
|
#include "setup.h"
|
|
|
|
#include "splay.h"
|
|
|
|
/*
|
|
* This macro compares two node keys i and j and returns:
|
|
*
|
|
* negative value: when i is smaller than j
|
|
* zero : when i is equal to j
|
|
* positive when : when i is larger than j
|
|
*/
|
|
#define compare(i,j) Curl_splaycomparekeys((i),(j))
|
|
|
|
/*
|
|
* Splay using the key i (which may or may not be in the tree.) The starting
|
|
* root is t.
|
|
*/
|
|
struct Curl_tree *Curl_splay(struct timeval i,
|
|
struct Curl_tree *t)
|
|
{
|
|
struct Curl_tree N, *l, *r, *y;
|
|
long comp;
|
|
|
|
if(t == NULL)
|
|
return t;
|
|
N.smaller = N.larger = NULL;
|
|
l = r = &N;
|
|
|
|
for (;;) {
|
|
comp = compare(i, t->key);
|
|
if(comp < 0) {
|
|
if(t->smaller == NULL)
|
|
break;
|
|
if(compare(i, t->smaller->key) < 0) {
|
|
y = t->smaller; /* rotate smaller */
|
|
t->smaller = y->larger;
|
|
y->larger = t;
|
|
t = y;
|
|
if(t->smaller == NULL)
|
|
break;
|
|
}
|
|
r->smaller = t; /* link smaller */
|
|
r = t;
|
|
t = t->smaller;
|
|
}
|
|
else if(comp > 0) {
|
|
if(t->larger == NULL)
|
|
break;
|
|
if(compare(i, t->larger->key) > 0) {
|
|
y = t->larger; /* rotate larger */
|
|
t->larger = y->smaller;
|
|
y->smaller = t;
|
|
t = y;
|
|
if(t->larger == NULL)
|
|
break;
|
|
}
|
|
l->larger = t; /* link larger */
|
|
l = t;
|
|
t = t->larger;
|
|
}
|
|
else
|
|
break;
|
|
}
|
|
|
|
l->larger = t->smaller; /* assemble */
|
|
r->smaller = t->larger;
|
|
t->smaller = N.larger;
|
|
t->larger = N.smaller;
|
|
|
|
return t;
|
|
}
|
|
|
|
/* Insert key i into the tree t. Return a pointer to the resulting tree or
|
|
NULL if something went wrong. */
|
|
struct Curl_tree *Curl_splayinsert(struct timeval i,
|
|
struct Curl_tree *t,
|
|
struct Curl_tree *node)
|
|
{
|
|
static struct timeval KEY_NOTUSED = {-1,-1}; /* key that will *NEVER* appear */
|
|
|
|
if(node == NULL)
|
|
return t;
|
|
|
|
if(t != NULL) {
|
|
t = Curl_splay(i,t);
|
|
if(compare(i, t->key)==0) {
|
|
/* There already exists a node in the tree with the very same key. Build
|
|
a linked list of nodes. We make the new 'node' struct the new master
|
|
node and make the previous node the first one in the 'same' list. */
|
|
|
|
node->same = t;
|
|
node->key = i;
|
|
node->smaller = t->smaller;
|
|
node->larger = t->larger;
|
|
|
|
t->smaller = node; /* in the sub node for this same key, we use the
|
|
smaller pointer to point back to the master
|
|
node */
|
|
|
|
t->key = KEY_NOTUSED; /* and we set the key in the sub node to NOTUSED
|
|
to quickly identify this node as a subnode */
|
|
|
|
return node; /* new root node */
|
|
}
|
|
}
|
|
|
|
if(t == NULL) {
|
|
node->smaller = node->larger = NULL;
|
|
}
|
|
else if(compare(i, t->key) < 0) {
|
|
node->smaller = t->smaller;
|
|
node->larger = t;
|
|
t->smaller = NULL;
|
|
|
|
}
|
|
else {
|
|
node->larger = t->larger;
|
|
node->smaller = t;
|
|
t->larger = NULL;
|
|
}
|
|
node->key = i;
|
|
|
|
node->same = NULL; /* no identical node (yet) */
|
|
return node;
|
|
}
|
|
|
|
#if 0
|
|
/* Deletes 'i' from the tree if it's there (with an exact match). Returns a
|
|
pointer to the resulting tree.
|
|
|
|
Function not used in libcurl.
|
|
*/
|
|
struct Curl_tree *Curl_splayremove(struct timeval i,
|
|
struct Curl_tree *t,
|
|
struct Curl_tree **removed)
|
|
{
|
|
struct Curl_tree *x;
|
|
|
|
*removed = NULL; /* default to no removed */
|
|
|
|
if(t==NULL)
|
|
return NULL;
|
|
|
|
t = Curl_splay(i,t);
|
|
if(compare(i, t->key) == 0) { /* found it */
|
|
|
|
/* FIRST! Check if there is a list with identical sizes */
|
|
if((x = t->same) != NULL) {
|
|
/* there is, pick one from the list */
|
|
|
|
/* 'x' is the new root node */
|
|
|
|
x->key = t->key;
|
|
x->larger = t->larger;
|
|
x->smaller = t->smaller;
|
|
|
|
*removed = t;
|
|
return x; /* new root */
|
|
}
|
|
|
|
if(t->smaller == NULL) {
|
|
x = t->larger;
|
|
}
|
|
else {
|
|
x = Curl_splay(i, t->smaller);
|
|
x->larger = t->larger;
|
|
}
|
|
*removed = t;
|
|
|
|
return x;
|
|
}
|
|
else
|
|
return t; /* It wasn't there */
|
|
}
|
|
#endif
|
|
|
|
/* Finds and deletes the best-fit node from the tree. Return a pointer to the
|
|
resulting tree. best-fit means the node with the given or lower key */
|
|
struct Curl_tree *Curl_splaygetbest(struct timeval i,
|
|
struct Curl_tree *t,
|
|
struct Curl_tree **removed)
|
|
{
|
|
struct Curl_tree *x;
|
|
|
|
if(!t) {
|
|
*removed = NULL; /* none removed since there was no root */
|
|
return NULL;
|
|
}
|
|
|
|
t = Curl_splay(i,t);
|
|
if(compare(i, t->key) < 0) {
|
|
/* too big node, try the smaller chain */
|
|
if(t->smaller)
|
|
t=Curl_splay(t->smaller->key, t);
|
|
else {
|
|
/* fail */
|
|
*removed = NULL;
|
|
return t;
|
|
}
|
|
}
|
|
|
|
if(compare(i, t->key) >= 0) { /* found it */
|
|
/* FIRST! Check if there is a list with identical keys */
|
|
x = t->same;
|
|
if(x) {
|
|
/* there is, pick one from the list */
|
|
|
|
/* 'x' is the new root node */
|
|
|
|
x->key = t->key;
|
|
x->larger = t->larger;
|
|
x->smaller = t->smaller;
|
|
|
|
*removed = t;
|
|
return x; /* new root */
|
|
}
|
|
|
|
if(t->smaller == NULL) {
|
|
x = t->larger;
|
|
}
|
|
else {
|
|
x = Curl_splay(i, t->smaller);
|
|
x->larger = t->larger;
|
|
}
|
|
*removed = t;
|
|
|
|
return x;
|
|
}
|
|
else {
|
|
*removed = NULL; /* no match */
|
|
return t; /* It wasn't there */
|
|
}
|
|
}
|
|
|
|
|
|
/* Deletes the very node we point out from the tree if it's there. Stores a
|
|
pointer to the new resulting tree in 'newroot'.
|
|
|
|
Returns zero on success and non-zero on errors! TODO: document error codes.
|
|
When returning error, it does not touch the 'newroot' pointer.
|
|
|
|
NOTE: when the last node of the tree is removed, there's no tree left so
|
|
'newroot' will be made to point to NULL.
|
|
*/
|
|
int Curl_splayremovebyaddr(struct Curl_tree *t,
|
|
struct Curl_tree *removenode,
|
|
struct Curl_tree **newroot)
|
|
{
|
|
static struct timeval KEY_NOTUSED = {-1,-1}; /* key that will *NEVER* appear */
|
|
struct Curl_tree *x;
|
|
|
|
if(!t || !removenode)
|
|
return 1;
|
|
|
|
if(compare(KEY_NOTUSED, removenode->key) == 0) {
|
|
/* Key set to NOTUSED means it is a subnode within a 'same' linked list
|
|
and thus we can unlink it easily. The 'smaller' link of a subnode
|
|
links to the parent node. */
|
|
if(removenode->smaller == NULL)
|
|
return 3;
|
|
|
|
removenode->smaller->same = removenode->same;
|
|
if(removenode->same)
|
|
removenode->same->smaller = removenode->smaller;
|
|
|
|
/* Ensures that double-remove gets caught. */
|
|
removenode->smaller = NULL;
|
|
|
|
/* voila, we're done! */
|
|
*newroot = t; /* return the same root */
|
|
return 0;
|
|
}
|
|
|
|
t = Curl_splay(removenode->key, t);
|
|
|
|
/* First make sure that we got the same root node as the one we want
|
|
to remove, as otherwise we might be trying to remove a node that
|
|
isn't actually in the tree.
|
|
|
|
We cannot just compare the keys here as a double remove in quick
|
|
succession of a node with key != KEY_NOTUSED && same != NULL
|
|
could return the same key but a different node. */
|
|
if(t != removenode)
|
|
return 2;
|
|
|
|
/* Check if there is a list with identical sizes, as then we're trying to
|
|
remove the root node of a list of nodes with identical keys. */
|
|
x = t->same;
|
|
if(x) {
|
|
/* 'x' is the new root node, we just make it use the root node's
|
|
smaller/larger links */
|
|
|
|
x->key = t->key;
|
|
x->larger = t->larger;
|
|
x->smaller = t->smaller;
|
|
}
|
|
else {
|
|
/* Remove the root node */
|
|
if(t->smaller == NULL)
|
|
x = t->larger;
|
|
else {
|
|
x = Curl_splay(removenode->key, t->smaller);
|
|
x->larger = t->larger;
|
|
}
|
|
}
|
|
|
|
*newroot = x; /* store new root pointer */
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef DEBUGBUILD
|
|
|
|
void Curl_splayprint(struct Curl_tree * t, int d, char output)
|
|
{
|
|
struct Curl_tree *node;
|
|
int i;
|
|
int count;
|
|
if(t == NULL)
|
|
return;
|
|
|
|
Curl_splayprint(t->larger, d+1, output);
|
|
for (i=0; i<d; i++)
|
|
if(output)
|
|
fprintf(stderr, " ");
|
|
|
|
if(output) {
|
|
#ifdef TEST_SPLAY
|
|
fprintf(stderr, "%ld[%d]", (long)t->key.tv_usec, i);
|
|
#else
|
|
fprintf(stderr, "%ld.%ld[%d]", (long)t->key.tv_sec, (long)t->key.tv_usec, i);
|
|
#endif
|
|
}
|
|
|
|
for(count=0, node = t->same; node; node = node->same, count++)
|
|
;
|
|
|
|
if(output) {
|
|
if(count)
|
|
fprintf(stderr, " [%d more]\n", count);
|
|
else
|
|
fprintf(stderr, "\n");
|
|
}
|
|
|
|
Curl_splayprint(t->smaller, d+1, output);
|
|
}
|
|
#endif
|
|
|
|
#ifdef TEST_SPLAY
|
|
|
|
/*#define TEST2 */
|
|
#define MAX 50
|
|
#define TEST2
|
|
|
|
/* A sample use of these functions. Start with the empty tree, insert some
|
|
stuff into it, and then delete it */
|
|
int main(int argc, argv_item_t argv[])
|
|
{
|
|
struct Curl_tree *root, *t;
|
|
void *ptrs[MAX];
|
|
int adds=0;
|
|
int rc;
|
|
|
|
static const long sizes[]={
|
|
50, 60, 50, 100, 60, 200, 120, 300, 400, 200, 256, 122, 60, 120, 200, 300,
|
|
220, 80, 90, 50, 100, 60, 200, 120, 300, 400, 200, 256, 122, 60, 120, 200,
|
|
300, 220, 80, 90, 50, 100, 60, 200, 120, 300, 400, 200, 256, 122, 60, 120,
|
|
200, 300, 220, 80, 90};
|
|
int i;
|
|
root = NULL; /* the empty tree */
|
|
|
|
for (i = 0; i < MAX; i++) {
|
|
struct timeval key;
|
|
ptrs[i] = t = malloc(sizeof(struct Curl_tree));
|
|
|
|
key.tv_sec = 0;
|
|
#ifdef TEST2
|
|
key.tv_usec = sizes[i];
|
|
#elif defined(TEST1)
|
|
key.tv_usec = (541*i)%1023;
|
|
#elif defined(TEST3)
|
|
key.tv_usec = 100;
|
|
#endif
|
|
|
|
t->payload = (void *)key.tv_usec; /* for simplicity */
|
|
if(!t) {
|
|
puts("out of memory!");
|
|
return 0;
|
|
}
|
|
root = Curl_splayinsert(key, root, t);
|
|
}
|
|
|
|
#if 0
|
|
puts("Result:");
|
|
Curl_splayprint(root, 0, 1);
|
|
#endif
|
|
|
|
#if 1
|
|
for (i = 0; i < MAX; i++) {
|
|
int rem = (i+7)%MAX;
|
|
struct Curl_tree *r;
|
|
printf("Tree look:\n");
|
|
Curl_splayprint(root, 0, 1);
|
|
printf("remove pointer %d, payload %ld\n", rem,
|
|
(long)((struct Curl_tree *)ptrs[rem])->payload);
|
|
rc = Curl_splayremovebyaddr(root, (struct Curl_tree *)ptrs[rem], &root);
|
|
if(rc)
|
|
/* failed! */
|
|
printf("remove %d failed!\n", rem);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /* TEST_SPLAY */
|