| /* |
| * Copyright (C) 2009-2011 the libgit2 contributors |
| * |
| * This file is part of libgit2, distributed under the GNU GPL v2 with |
| * a Linking Exception. For full terms see the included COPYING file. |
| */ |
| |
| #include "common.h" |
| #include "repository.h" |
| #include "commit.h" |
| |
| #define MAX_LOOPS 5 |
| static const double max_load_factor = 0.65; |
| |
| static int resize_to(git_hashtable *self, size_t new_size); |
| static int set_size(git_hashtable *self, size_t new_size); |
| static git_hashtable_node *node_with_hash(git_hashtable *self, const void *key, int hash_id); |
| static void node_swap_with(git_hashtable_node *self, git_hashtable_node *other); |
| static int node_insert(git_hashtable *self, git_hashtable_node *new_node); |
| static int insert_nodes(git_hashtable *self, git_hashtable_node *old_nodes, size_t old_size); |
| |
| static int resize_to(git_hashtable *self, size_t new_size) |
| { |
| git_hashtable_node *old_nodes = self->nodes; |
| size_t old_size = self->size; |
| |
| self->is_resizing = 1; |
| |
| do { |
| self->size = new_size; |
| self->size_mask = new_size - 1; |
| self->key_count = 0; |
| self->nodes = git__calloc(1, sizeof(git_hashtable_node) * self->size); |
| |
| if (self->nodes == NULL) |
| return GIT_ENOMEM; |
| |
| if (insert_nodes(self, old_nodes, old_size) == 0) |
| self->is_resizing = 0; |
| else { |
| new_size *= 2; |
| git__free(self->nodes); |
| } |
| } while(self->is_resizing); |
| |
| git__free(old_nodes); |
| return GIT_SUCCESS; |
| } |
| |
| static int set_size(git_hashtable *self, size_t new_size) |
| { |
| self->nodes = git__realloc(self->nodes, new_size * sizeof(git_hashtable_node)); |
| if (self->nodes == NULL) |
| return GIT_ENOMEM; |
| |
| if (new_size > self->size) { |
| memset(&self->nodes[self->size], 0x0, (new_size - self->size) * sizeof(git_hashtable_node)); |
| } |
| |
| self->size = new_size; |
| self->size_mask = new_size - 1; |
| return GIT_SUCCESS; |
| } |
| |
| static git_hashtable_node *node_with_hash(git_hashtable *self, const void *key, int hash_id) |
| { |
| size_t pos = self->hash(key, hash_id) & self->size_mask; |
| return git_hashtable_node_at(self->nodes, pos); |
| } |
| |
| static void node_swap_with(git_hashtable_node *self, git_hashtable_node *other) |
| { |
| git_hashtable_node tmp = *self; |
| *self = *other; |
| *other = tmp; |
| } |
| |
| static int node_insert(git_hashtable *self, git_hashtable_node *new_node) |
| { |
| int iteration, hash_id; |
| |
| for (iteration = 0; iteration < MAX_LOOPS; iteration++) { |
| for (hash_id = 0; hash_id < GIT_HASHTABLE_HASHES; ++hash_id) { |
| git_hashtable_node *node; |
| node = node_with_hash(self, new_node->key, hash_id); |
| node_swap_with(new_node, node); |
| if(new_node->key == 0x0){ |
| self->key_count++; |
| return GIT_SUCCESS; |
| } |
| } |
| } |
| |
| if (self->is_resizing) |
| return git__throw(GIT_EBUSY, "Failed to insert node. Hashtable is currently resizing"); |
| |
| resize_to(self, self->size * 2); |
| git_hashtable_insert(self, new_node->key, new_node->value); |
| return GIT_SUCCESS; |
| } |
| |
| static int insert_nodes(git_hashtable *self, git_hashtable_node *old_nodes, size_t old_size) |
| { |
| size_t i; |
| |
| for (i = 0; i < old_size; ++i) { |
| git_hashtable_node *node = git_hashtable_node_at(old_nodes, i); |
| if (node->key && git_hashtable_insert(self, node->key, node->value) < GIT_SUCCESS) |
| return GIT_ENOMEM; |
| } |
| |
| return GIT_SUCCESS; |
| } |
| |
| git_hashtable *git_hashtable_alloc(size_t min_size, |
| git_hash_ptr hash, |
| git_hash_keyeq_ptr key_eq) |
| { |
| git_hashtable *table; |
| |
| assert(hash && key_eq); |
| |
| if ((table = git__malloc(sizeof(git_hashtable))) == NULL) |
| return NULL; |
| |
| memset(table, 0x0, sizeof(git_hashtable)); |
| |
| if (min_size < 8) |
| min_size = 8; |
| |
| /* round up size to closest power of 2 */ |
| min_size--; |
| min_size |= min_size >> 1; |
| min_size |= min_size >> 2; |
| min_size |= min_size >> 4; |
| min_size |= min_size >> 8; |
| min_size |= min_size >> 16; |
| |
| table->hash = hash; |
| table->key_equal = key_eq; |
| |
| set_size(table, min_size + 1); |
| |
| return table; |
| } |
| |
| void git_hashtable_clear(git_hashtable *self) |
| { |
| assert(self); |
| |
| memset(self->nodes, 0x0, sizeof(git_hashtable_node) * self->size); |
| self->key_count = 0; |
| } |
| |
| void git_hashtable_free(git_hashtable *self) |
| { |
| assert(self); |
| |
| git__free(self->nodes); |
| git__free(self); |
| } |
| |
| |
| int git_hashtable_insert2(git_hashtable *self, const void *key, void *value, void **old_value) |
| { |
| int hash_id; |
| git_hashtable_node *node; |
| |
| assert(self && self->nodes); |
| |
| *old_value = NULL; |
| |
| for (hash_id = 0; hash_id < GIT_HASHTABLE_HASHES; ++hash_id) { |
| node = node_with_hash(self, key, hash_id); |
| |
| if (!node->key) { |
| node->key = key; |
| node->value = value; |
| self->key_count++; |
| return GIT_SUCCESS; |
| } |
| |
| if (key == node->key || self->key_equal(key, node->key) == 0) { |
| *old_value = node->value; |
| node->key = key; |
| node->value = value; |
| return GIT_SUCCESS; |
| } |
| } |
| |
| /* no space in table; must do cuckoo dance */ |
| { |
| git_hashtable_node x; |
| x.key = key; |
| x.value = value; |
| return node_insert(self, &x); |
| } |
| } |
| |
| void *git_hashtable_lookup(git_hashtable *self, const void *key) |
| { |
| int hash_id; |
| git_hashtable_node *node; |
| |
| assert(self && self->nodes); |
| |
| for (hash_id = 0; hash_id < GIT_HASHTABLE_HASHES; ++hash_id) { |
| node = node_with_hash(self, key, hash_id); |
| if (node->key && self->key_equal(key, node->key) == 0) |
| return node->value; |
| } |
| |
| return NULL; |
| } |
| |
| int git_hashtable_remove2(git_hashtable *self, const void *key, void **old_value) |
| { |
| int hash_id; |
| git_hashtable_node *node; |
| |
| assert(self && self->nodes); |
| |
| for (hash_id = 0; hash_id < GIT_HASHTABLE_HASHES; ++hash_id) { |
| node = node_with_hash(self, key, hash_id); |
| if (node->key && self->key_equal(key, node->key) == 0) { |
| *old_value = node->value; |
| node->key = NULL; |
| node->value = NULL; |
| self->key_count--; |
| return GIT_SUCCESS; |
| } |
| } |
| |
| return git__throw(GIT_ENOTFOUND, "Entry not found in hash table"); |
| } |
| |
| int git_hashtable_merge(git_hashtable *self, git_hashtable *other) |
| { |
| if (resize_to(self, (self->size + other->size) * 2) < GIT_SUCCESS) |
| return GIT_ENOMEM; |
| |
| return insert_nodes(self, other->nodes, other->key_count); |
| } |
| |
| |
| /** |
| * Standard string |
| */ |
| uint32_t git_hash__strhash_cb(const void *key, int hash_id) |
| { |
| static uint32_t hash_seeds[GIT_HASHTABLE_HASHES] = { |
| 2147483647, |
| 0x5d20bb23, |
| 0x7daaab3c |
| }; |
| |
| return git__hash(key, strlen((const char *)key), hash_seeds[hash_id]); |
| } |