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Christopher Palow provided the patch (edited by me) that introduces

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the use of microsecond resolution keys for internal splay trees.

http://curl.haxx.se/mail/lib-2008-04/0513.html
This commit is contained in:
Yang Tse
2008-05-07 15:41:41 +00:00
parent 082237e2b5
commit eb68aa38e3
5 changed files with 76 additions and 51 deletions
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62
lib/splay.c
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@@ -5,7 +5,7 @@
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1997 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
* Copyright (C) 1997 - 2008, 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
@@ -23,24 +23,26 @@
#include "setup.h"
#include <stdio.h>
#include <stdlib.h>
#include "splay.h"
#define compare(i,j) ((i)-(j))
/* Set this to a key value that will *NEVER* appear otherwise */
#define KEY_NOTUSED -1
/*
* 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(int i, struct Curl_tree *t)
struct Curl_tree *Curl_splay(struct timeval i,
struct Curl_tree *t)
{
struct Curl_tree N, *l, *r, *y;
int comp;
long comp;
if(t == NULL)
return t;
@@ -93,10 +95,12 @@ struct Curl_tree *Curl_splay(int i, struct Curl_tree *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(int i,
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;
@@ -149,7 +153,8 @@ struct Curl_tree *Curl_splayinsert(int i,
Function not used in libcurl.
*/
struct Curl_tree *Curl_splayremove(int i, struct Curl_tree *t,
struct Curl_tree *Curl_splayremove(struct timeval i,
struct Curl_tree *t,
struct Curl_tree **removed)
{
struct Curl_tree *x;
@@ -163,7 +168,7 @@ struct Curl_tree *Curl_splayremove(int i, struct Curl_tree *t,
if(compare(i, t->key) == 0) { /* found it */
/* FIRST! Check if there is a list with identical sizes */
if((x = t->same)) {
if((x = t->same) != NULL) {
/* there is, pick one from the list */
/* 'x' is the new root node */
@@ -193,8 +198,9 @@ struct Curl_tree *Curl_splayremove(int i, struct Curl_tree *t,
#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 number */
struct Curl_tree *Curl_splaygetbest(int i, struct Curl_tree *t,
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;
@@ -217,7 +223,7 @@ struct Curl_tree *Curl_splaygetbest(int i, struct Curl_tree *t,
}
if(compare(i, t->key) >= 0) { /* found it */
/* FIRST! Check if there is a list with identical sizes */
/* FIRST! Check if there is a list with identical keys */
x = t->same;
if(x) {
/* there is, pick one from the list */
@@ -263,12 +269,13 @@ 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(KEY_NOTUSED == removenode->key) {
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. */
@@ -341,7 +348,11 @@ void Curl_splayprint(struct Curl_tree * t, int d, char output)
printf(" ");
if(output) {
printf("%d[%d]", t->key, i);
#ifdef TEST_SPLAY
printf("%ld[%d]", t->key.tv_usec, i);
#else
printf("%ld.%ld[%d]", t->key.tv_sec, t->key.tv_usec, i);
#endif
}
for(count=0, node = t->same; node; node = node->same, count++)
@@ -382,18 +393,19 @@ int main(int argc, argv_item_t argv[])
root = NULL; /* the empty tree */
for (i = 0; i < MAX; i++) {
int key;
struct timeval key;
ptrs[i] = t = (struct Curl_tree *)malloc(sizeof(struct Curl_tree));
key.tv_sec = 0;
#ifdef TEST2
key = sizes[i];
key.tv_usec = sizes[i];
#elif defined(TEST1)
key = (541*i)%1023;
key.tv_usec = (541*i)%1023;
#elif defined(TEST3)
key = 100;
key.tv_usec = 100;
#endif
t->payload = (void *)key; /* for simplicity */
t->payload = (void *)key.tv_usec; /* for simplicity */
if(!t) {
puts("out of memory!");
return 0;
@@ -412,8 +424,8 @@ int main(int argc, argv_item_t argv[])
struct Curl_tree *r;
printf("Tree look:\n");
Curl_splayprint(root, 0, 1);
printf("remove pointer %d, payload %d\n", rem,
(int)((struct Curl_tree *)ptrs[rem])->payload);
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! */