From 9e3399df197c7cea44028a86c961a14df6e62d20 Mon Sep 17 00:00:00 2001 From: Dale Weiler Date: Fri, 23 Nov 2012 06:12:01 +0000 Subject: [PATCH] Implemented hashtable as-per Blubs request --- Makefile | 2 +- gmqcc.h | 32 ++++++++++++ util.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 179 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 5ab8971..7420ccc 100644 --- a/Makefile +++ b/Makefile @@ -3,7 +3,7 @@ PREFIX := /usr/local BINDIR := $(PREFIX)/bin CC ?= clang -CFLAGS += -Wall -I. -pedantic-errors +CFLAGS += -Wall -Wextra -I. -pedantic-errors #turn on tons of warnings if clang is present ifeq ($(CC), clang) CFLAGS += \ diff --git a/gmqcc.h b/gmqcc.h index b5bc5fd..76412ed 100644 --- a/gmqcc.h +++ b/gmqcc.h @@ -255,6 +255,38 @@ void _util_vec_grow(void **a, size_t i, size_t s); #define vec_shrinkto(A,N) (_vec_end(A) = (N)) #define vec_shrinkby(A,N) (_vec_end(A) -= (N)) +typedef struct hash_table_t { + size_t size; + struct hash_node_t **table; +} hash_table_t, *ht; + +/* + * hashtable implementation: + * + * util_htnew(size) -- to make a new hashtable + * util_htset(table, key, value, sizeof(value)) -- to set something in the table + * util_htget(table, key) -- to get something from the table + * util_htdel(table) -- to delete the table + * + * example of use: + * + * ht foo = util_htnew(1024); + * int data = 100; + * char *test = "hello world\n"; + * util_htset(foo, "foo", (void*)&data, sizeof(int)); + * util_gtset(foo, "bar", (void*)test, strlen(test)); + * + * printf("foo: %d, bar %s", + * *((int *)util_htget(foo, "foo")), + * ((char*)util_htget(foo, "bar")) + * ); + * + * util_htdel(foo); + */ +hash_table_t *util_htnew(size_t size); +void util_htset(hash_table_t *ht, const char *key, void *value, size_t size); +void *util_htget(hash_table_t *ht, const char *key); +void util_htdel(hash_table_t *ht); /*===================================================================*/ /*=========================== code.c ================================*/ /*===================================================================*/ diff --git a/util.c b/util.c index 6d94742..078f304 100644 --- a/util.c +++ b/util.c @@ -535,3 +535,149 @@ void _util_vec_grow(void **a, size_t i, size_t s) { *a = (void*)((size_t*)p + 2); _vec_beg(*a) = m; } + +/* + * Hash table for generic data, based on dynamic memory allocations + * all around. This is the internal interface, please look for + * EXPOSED INTERFACE comment below + */ +typedef struct hash_node_t { + char *key; /* the key for this node in table */ + void *value; /* allocated memory storing data */ + size_t size; /* size of data */ + struct hash_node_t *next; /* next node (linked list) */ +} hash_node_t; + + +size_t _util_hthash(hash_table_t *ht, const char *key) { + uint64_t val; + size_t len = strlen(key); + size_t itr = 0; + + + while (val < ((uint64_t)~1) /* MAX SIZE OF UINT64 */ && itr < len) { + val = val << 8; + val += key[itr]; + + itr++; + } + + return val % ht->size; +} + +hash_node_t *_util_htnewpair(const char *key, void *value, size_t size) { + hash_node_t *node; + if (!(node = mem_a(sizeof(hash_node_t)))) + return NULL; + + if (!(node->key = util_strdup(key))) { + mem_d(node); + return NULL; + } + + if (!(node->value = mem_a(size))) { + mem_d(node->key); + mem_d(node); + return NULL; + } + + memcpy(node->value, value, size); + node->size = size; + node->next = NULL; + + return node; +} + +/* + * EXPOSED INTERFACE for the hashtable implementation + * util_htnew(size) -- to make a new hashtable + * util_htset(table, key, value, sizeof(value)) -- to set something in the table + * util_htget(table, key) -- to get something from the table + * util_htdel(table) -- to delete the table + */ +hash_table_t *util_htnew(size_t size) { + hash_table_t *hashtable = NULL; + if (size < 1) + return NULL; + + if (!(hashtable = mem_a(sizeof(hash_table_t)))) + return NULL; + + if (!(hashtable->table = mem_a(sizeof(hash_node_t*) * size))) { + mem_d(hashtable); + return NULL; + } + + hashtable->size = size; + memset(hashtable->table, 0, sizeof(hash_node_t*) * size); + + return hashtable; +} + +void util_htset(hash_table_t *ht, const char *key, void *value, size_t size) { + size_t bin = 0; + hash_node_t *newnode = NULL; + hash_node_t *next = NULL; + hash_node_t *last = NULL; + + bin = _util_hthash(ht, key); + next = ht->table[bin]; + + while (next && next->key && strcmp(key, next->key)) + last = next, next = next->next; + + /* already in table, do a replace */ + if (next && next->key && !strcmp(key, next->key)) { + mem_d(next->value); + next->value = mem_a(size); + next->size = size; + memcpy(next->value, value, size); + } else { + /* not found, grow a pair man :P */ + newnode = _util_htnewpair(key, value, size); + if (next == ht->table[bin]) { + newnode->next = next; + ht->table[bin] = newnode; + } else if (!next) { + last->next = newnode; + } else { + newnode->next = next; + last->next = newnode; + } + } +} + +void *util_htget(hash_table_t *ht, const char *key) { + size_t bin = _util_hthash(ht, key); + hash_node_t *pair = ht->table[bin]; + + while (pair && pair->key && strcmp(key, pair->key) > 0) + pair = pair->next; + + if (!pair || !pair->key || strcmp(key, pair->key) != 0) + return NULL; + + return pair->value; +} + +/* + * Free all allocated data in a hashtable, this is quite the amount + * of work. + */ +void util_htdel(hash_table_t *ht) { + size_t i = 0; + for (; i < ht->size; i++) { + hash_node_t *n = ht->table[i]; + + /* free in list */ + while (n) { + if (n->key) mem_d(n->key); + if (n->value) mem_d(n->value); + n = n->next; + } + + } + /* free table */ + mem_d(ht->table); + mem_d(ht); +}