* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
- * Copyright (C) 1997 - 2009, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1997 - 2017, 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.
+ * are also available at https://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
*
***************************************************************************/
-#include "setup.h"
+#include "curl_setup.h"
#include "splay.h"
* 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 *Curl_splay(struct curltime i,
struct Curl_tree *t)
{
struct Curl_tree N, *l, *r, *y;
N.smaller = N.larger = NULL;
l = r = &N;
- for (;;) {
+ for(;;) {
comp = compare(i, t->key);
if(comp < 0) {
if(t->smaller == NULL)
}
/* 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,
+ * NULL if something went wrong.
+ *
+ * @unittest: 1309
+ */
+struct Curl_tree *Curl_splayinsert(struct curltime i,
struct Curl_tree *t,
struct Curl_tree *node)
{
- static struct timeval KEY_NOTUSED = {-1,-1}; /* key that will *NEVER* appear */
+ static const struct curltime KEY_NOTUSED = {
+ (time_t)-1, (unsigned int)-1
+ }; /* will *NEVER* appear */
if(node == NULL)
return t;
if(t != NULL) {
- t = Curl_splay(i,t);
- if(compare(i, t->key)==0) {
+ 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;
+ a doubly-linked circular list of nodes. We add the new 'node' struct
+ to the end of this list. */
- t->smaller = node; /* in the sub node for this same key, we use the
- smaller pointer to point back to the master
- node */
+ node->key = KEY_NOTUSED; /* we set the key in the sub node to NOTUSED
+ to quickly identify this node as a subnode */
+ node->samen = t;
+ node->samep = t->samep;
+ t->samep->samen = node;
+ t->samep = 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 */
+ return t; /* the root node always stays the same */
}
}
}
node->key = i;
- node->same = NULL; /* no identical node (yet) */
+ /* no identical nodes (yet), we are the only one in the list of nodes */
+ node->samen = node;
+ node->samep = node;
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,
+ resulting tree. best-fit means the smallest node if it is not larger than
+ the key */
+struct Curl_tree *Curl_splaygetbest(struct curltime i,
struct Curl_tree *t,
struct Curl_tree **removed)
{
+ static struct curltime tv_zero = {0, 0};
struct Curl_tree *x;
if(!t) {
return NULL;
}
- t = Curl_splay(i,t);
+ /* find smallest */
+ t = Curl_splay(tv_zero, 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;
- }
+ /* even the smallest is too big */
+ *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 */
+ /* FIRST! Check if there is a list with identical keys */
+ x = t->samen;
+ if(x != t) {
+ /* there is, pick one from the list */
- /* 'x' is the new root node */
+ /* 'x' is the new root node */
- x->key = t->key;
- x->larger = t->larger;
- x->smaller = t->smaller;
-
- *removed = t;
- return x; /* new root */
- }
+ x->key = t->key;
+ x->larger = t->larger;
+ x->smaller = t->smaller;
+ x->samep = t->samep;
+ t->samep->samen = x;
- if(t->smaller == NULL) {
- x = t->larger;
- }
- else {
- x = Curl_splay(i, t->smaller);
- x->larger = t->larger;
- }
*removed = t;
-
- return x;
+ return x; /* new root */
}
- else {
- *removed = NULL; /* no match */
- return t; /* It wasn't there */
- }
-}
+ /* we splayed the tree to the smallest element, there is no smaller */
+ x = t->larger;
+ *removed = t;
-/* Deletes the very node we point out from the tree if it's there. Stores a
- pointer to the new resulting tree in 'newroot'.
+ return x;
+}
- 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.
-*/
+/* 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.
+ *
+ * @unittest: 1309
+ */
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 */
+ static const struct curltime KEY_NOTUSED = {
+ (time_t)-1, (unsigned int)-1
+ }; /* will *NEVER* appear */
struct Curl_tree *x;
if(!t || !removenode)
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)
+ and thus we can unlink it easily. */
+ if(removenode->samen == removenode)
+ /* A non-subnode should never be set to KEY_NOTUSED */
return 3;
- removenode->smaller->same = removenode->same;
- if(removenode->same)
- removenode->same->smaller = removenode->smaller;
+ removenode->samep->samen = removenode->samen;
+ removenode->samen->samep = removenode->samep;
/* Ensures that double-remove gets caught. */
- removenode->smaller = NULL;
+ removenode->samen = removenode;
- /* voila, we're done! */
*newroot = t; /* return the same root */
return 0;
}
/* 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 = t->samen;
+ if(x != t) {
/* '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;
+ x->samep = t->samep;
+ t->samep->samen = x;
}
else {
/* Remove the root node */
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));
- if(!t) {
- puts("out of memory!");
- return 0;
- }
-
- 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 */
- 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 */
projects / platform / upstream / curl.git / blobdiff