Mercurial > hg > nginx-vendor-current
view src/core/ngx_radix_tree.c @ 196:8759b346e431 NGINX_0_3_45
nginx 0.3.45
*) Feature: the "ssl_verify_client", "ssl_verify_depth", and
"ssl_client_certificate" directives.
*) Change: the $request_method variable now returns the main request
method.
*) Change: the ° symbol codes were changed in koi-win conversion
table.
*) Feature: the euro и N symbols were added to koi-win conversion table.
*) Bugfix: if nginx distributed the requests among several backends and
some backend failed, then requests intended for this backend was
directed to one live backend only instead of being distributed among
the rest.
author | Igor Sysoev <http://sysoev.ru> |
---|---|
date | Sat, 06 May 2006 00:00:00 +0400 |
parents | 408f195b3482 |
children | f745bf973510 |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> static void *ngx_radix_alloc(ngx_radix_tree_t *tree); ngx_radix_tree_t * ngx_radix_tree_create(ngx_pool_t *pool, ngx_int_t preallocate) { uint32_t key, mask, inc; ngx_radix_tree_t *tree; tree = ngx_palloc(pool, sizeof(ngx_radix_tree_t)); if (tree == NULL) { return NULL; } tree->pool = pool; tree->free = NULL; tree->start = NULL; tree->size = 0; tree->root = ngx_radix_alloc(tree); if (tree->root == NULL) { return NULL; } tree->root->right = NULL; tree->root->left = NULL; tree->root->parent = NULL; tree->root->value = NGX_RADIX_NO_VALUE; if (preallocate == 0) { return tree; } /* * The preallocation the first nodes: 0, 1, 00, 01, 10, 11, 000, 001, etc. * increases the TLB hits even if for the first lookup iterations. * On the 32-bit platforms the 7 preallocated bits takes continuous 4K, * 8 - 8K, 9 - 16K, etc. On the 64-bit platforms the 6 preallocated bits * takes continuous 4K, 7 - 8K, 8 - 16K, etc. There is no sense to * to preallocate more than one page, because further preallocation * distributes the only bit per page. Instead, the random insertion * may distribute several bits per page. * * Thus, by default we preallocate maximum * 6 bits on amd64 (64-bit platform and 4K pages) * 7 bits on i386 (32-bit platform and 4K pages) * 7 bits on sparc64 in 64-bit mode (8K pages) * 8 bits on sparc64 in 32-bit mode (8K pages) */ if (preallocate == -1) { switch (ngx_pagesize / sizeof(ngx_radix_tree_t)) { /* amd64 */ case 128: preallocate = 6; break; /* i386, sparc64 */ case 256: preallocate = 7; break; /* sparc64 in 32-bit mode */ default: preallocate = 8; } } mask = 0; inc = 0x80000000; while (preallocate--) { key = 0; mask >>= 1; mask |= 0x80000000; do { if (ngx_radix32tree_insert(tree, key, mask, NGX_RADIX_NO_VALUE) != NGX_OK) { return NULL; } key += inc; } while (key); inc >>= 1; } return tree; } ngx_int_t ngx_radix32tree_insert(ngx_radix_tree_t *tree, uint32_t key, uint32_t mask, uintptr_t value) { uint32_t bit; ngx_radix_node_t *node, *next; bit = 0x80000000; node = tree->root; next = tree->root; while (bit & mask) { if (key & bit) { next = node->right; } else { next = node->left; } if (next == NULL) { break; } bit >>= 1; node = next; } if (next) { if (node->value != NGX_RADIX_NO_VALUE) { return NGX_BUSY; } node->value = value; return NGX_OK; } while (bit & mask) { next = ngx_radix_alloc(tree); if (next == NULL) { return NGX_ERROR; } next->right = NULL; next->left = NULL; next->parent = node; next->value = NGX_RADIX_NO_VALUE; if (key & bit) { node->right = next; } else { node->left = next; } bit >>= 1; node = next; } node->value = value; return NGX_OK; } ngx_int_t ngx_radix32tree_delete(ngx_radix_tree_t *tree, uint32_t key, uint32_t mask) { uint32_t bit; ngx_radix_node_t *node; bit = 0x80000000; node = tree->root; while (node && (bit & mask)) { if (key & bit) { node = node->right; } else { node = node->left; } bit >>= 1; } if (node == NULL) { return NGX_ERROR; } if (node->right || node->left) { if (node->value != NGX_RADIX_NO_VALUE) { node->value = NGX_RADIX_NO_VALUE; return NGX_OK; } return NGX_ERROR; } for ( ;; ) { if (node->parent->right == node) { node->parent->right = NULL; } else { node->parent->left = NULL; } node->right = tree->free; tree->free = node; node = node->parent; if (node->right || node->left) { break; } if (node->value != NGX_RADIX_NO_VALUE) { break; } if (node->parent == NULL) { break; } } return NGX_OK; } uintptr_t ngx_radix32tree_find(ngx_radix_tree_t *tree, uint32_t key) { uint32_t bit; uintptr_t value; ngx_radix_node_t *node; bit = 0x80000000; value = NGX_RADIX_NO_VALUE; node = tree->root; while (node) { if (node->value != NGX_RADIX_NO_VALUE) { value = node->value; } if (key & bit) { node = node->right; } else { node = node->left; } bit >>= 1; } return value; } static void * ngx_radix_alloc(ngx_radix_tree_t *tree) { char *p; if (tree->free) { p = (char *) tree->free; tree->free = tree->free->right; return p; } if (tree->size < sizeof(ngx_radix_node_t)) { tree->start = ngx_palloc(tree->pool, ngx_pagesize); if (tree->start == NULL) { return NULL; } tree->size = ngx_pagesize; } p = tree->start; tree->start += sizeof(ngx_radix_node_t); tree->size -= sizeof(ngx_radix_node_t); return p; }