Mercurial > hg > nginx
view src/core/ngx_radix_tree.c @ 5036:6e374742043e stable-1.2
Merge of r4944: removed GLOB_NOSORT glob option.
This will result in alphabetical sorting of included files if
the "include" directive with wildcards is used.
Note that the behaviour is now different from that on Windows, where
alphabetical sorting is not guaranteed for FindFirsFile()/FindNextFile()
(used to be alphabetical on NTFS, but not on FAT).
Approved by Igor Sysoev, prodded by many.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Sat, 09 Feb 2013 21:27:37 +0000 |
parents | a0f1d53546d4 |
children | 6b416e3bdd26 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #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; } /* * Preallocation of first nodes : 0, 1, 00, 01, 10, 11, 000, 001, etc. * increases TLB hits even if for first lookup iterations. * On 32-bit platforms the 7 preallocated bits takes continuous 4K, * 8 - 8K, 9 - 16K, etc. On 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, a 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_node_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_pmemalign(tree->pool, ngx_pagesize, 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; }