diff options
Diffstat (limited to 'src/std_gc')
| -rw-r--r-- | src/std_gc/hash_map.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/std_gc/hash_map.c b/src/std_gc/hash_map.c new file mode 100644 index 0000000..1960ffc --- /dev/null +++ b/src/std_gc/hash_map.c @@ -0,0 +1,194 @@ +#include "../../include/std_gc/hash_map.h" +#include <assert.h> +#include <string.h> +#include <stdio.h> +#include <gc.h> + +typedef struct TslHashMapNode TslHashMapNode; +struct TslHashMapNode { + uint64_t hash; + TslValue key; + TslValue value; + TslHashMapNode *next; +}; + +void tsl_hash_map_init(TslHashMap *self) { + self->buckets_data = NULL; + self->buckets_size = 0; + self->buckets_capacity = 0; +} + +/* TODO: Remove if (data) and if (output) */ +static int tsl_hash_map_append_bucket(TslHashMapNode **head_node, uint64_t hash, const TslValue *key, TslValue *value, TslValue **output) { + TslHashMapNode *next_node; + + if(output) + *output = NULL; + + next_node = GC_MALLOC(sizeof(TslHashMapNode)); + if(!next_node) { + fprintf(stderr, "Error: hash map insert failed. Reason: out of memory\n"); + return 0; + } + + next_node->hash = hash; + next_node->key = *key; + if(value) + next_node->value = *value; + + if(output) + *output = &next_node->value; + + if(*head_node) { + next_node->next = (*head_node)->next; + (*head_node)->next = next_node; + } else { + next_node->next = NULL; + *head_node = next_node; + } + + return 1; +} + +static size_t tsl_hash_map_get_index(TslHashMap *self, uint64_t hash) { + assert((self->buckets_capacity >> 3) > 0); + /* >>3 = 8 = sizeof(TslHashMapNode*) */ + return hash & ((self->buckets_capacity >> 3) - 1); +} + +static void tsl_hash_map_reorder_nodes(TslHashMap *self, size_t old_capacity) { + TslHashMapNode **bucket = (TslHashMapNode**)self->buckets_data; + TslHashMapNode **bucket_end = (TslHashMapNode**)((char*)self->buckets_data + old_capacity); + size_t bucket_index = 0; + while(bucket != bucket_end) { + TslHashMapNode *node = *bucket; + TslHashMapNode *prev_node = node; /* Set to node for optimization reason, where prev_node->next = node->next; which becomes no-op */ + int all_nodes_moved = 1; + + while(node) { + size_t index = tsl_hash_map_get_index(self, node->hash); + if(index != bucket_index) { + TslHashMapNode **new_bucket = (TslHashMapNode**)self->buckets_data + index; + prev_node->next = node->next; + if(*new_bucket) { + node->next = (*new_bucket)->next; + (*new_bucket)->next = node; + } else { + node->next = NULL; + *new_bucket = node; + } + } else { + all_nodes_moved = 0; + } + + prev_node = node; + node = node->next; + } + + if(all_nodes_moved) + *bucket = NULL; + + ++bucket_index; + ++bucket; + } +} + +static int tsl_hash_map_ensure_bucket_capacity_for_one_new_item(TslHashMap *self) { + void *new_ptr; + size_t new_capacity = self->buckets_capacity; + size_t new_size = self->buckets_size + sizeof(TslHashMapNode*); + size_t old_capacity = self->buckets_capacity; + self->buckets_size = new_size; + if(new_size <= self->buckets_capacity) + return 1; + + if(new_capacity == 0) + new_capacity = sizeof(TslHashMapNode*) << 3; + + while(new_capacity < new_size) { + new_capacity <<= 1; + } + + new_ptr = GC_REALLOC(self->buckets_data, new_capacity); + if(!new_ptr) { + fprintf(stderr, "Error: hash map realloc failed. Reason: out of memory\n"); + return 0; + } + + self->buckets_data = new_ptr; + self->buckets_capacity = new_capacity; + { + /* TODO: Remove this. This is not needed since GC_REALLOC sets the data to 0 */ + TslHashMapNode **bucket = (TslHashMapNode**)((char*)self->buckets_data + old_capacity); + TslHashMapNode **bucket_end = (TslHashMapNode**)((char*)self->buckets_data + new_capacity); + while(bucket != bucket_end) { + *bucket = NULL; + ++bucket; + } + } + + if(old_capacity == 0) + return 1; + + tsl_hash_map_reorder_nodes(self, old_capacity); + return 1; +} + +int tsl_hash_map_insert(TslHashMap *self, const TslValue *key, TslValue *value) { + uint64_t hash = tsl_value_hash(key); + size_t index; + TslHashMapNode **bucket; + assert(!tsl_hash_map_get(self, key)); + if(!tsl_hash_map_ensure_bucket_capacity_for_one_new_item(self)) + return 0; + + index = tsl_hash_map_get_index(self, hash); + bucket = (TslHashMapNode**)self->buckets_data + index; + return tsl_hash_map_append_bucket(bucket, hash, key, value, NULL); +} + +TslValue* tsl_hash_map_get(TslHashMap *self, const TslValue *key) { + uint64_t hash; + size_t index; + TslHashMapNode *node; + if(self->buckets_capacity == 0) + return NULL; + + hash = tsl_value_hash(key); + index = tsl_hash_map_get_index(self, hash); + node = *((TslHashMapNode**)self->buckets_data + index); + while(node) { + if(hash == node->hash && tsl_value_equals(key, &node->key)) + return &node->value; + node = node->next; + } + + return NULL; +} + +TslValue* tsl_hash_map_get_or_create(TslHashMap *self, const TslValue *key) { + uint64_t hash; + size_t index; + TslHashMapNode **bucket; + TslHashMapNode *node; + TslValue *value; + if(self->buckets_capacity == 0) { + if(!tsl_hash_map_ensure_bucket_capacity_for_one_new_item(self)) + return NULL; + } + + hash = tsl_value_hash(key); + index = tsl_hash_map_get_index(self, hash); + bucket = (TslHashMapNode**)self->buckets_data + index; + node = *bucket; + while(node) { + if(hash == node->hash && tsl_value_equals(key, &node->key)) + return &node->value; + node = node->next; + } + + if(!tsl_hash_map_append_bucket(bucket, hash, key, NULL, &value)) + return NULL; + + return value; +} |