diff options
Diffstat (limited to 'src/hashmap.c')
| -rw-r--r-- | src/hashmap.c | 731 |
1 files changed, 731 insertions, 0 deletions
diff --git a/src/hashmap.c b/src/hashmap.c new file mode 100644 index 0000000000..6928118615 --- /dev/null +++ b/src/hashmap.c @@ -0,0 +1,731 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#include "util.h" +#include "hashmap.h" +#include "macro.h" + +#define NBUCKETS 127 + +struct hashmap_entry { + const void *key; + void *value; + struct hashmap_entry *bucket_next, *bucket_previous; + struct hashmap_entry *iterate_next, *iterate_previous; +}; + +struct Hashmap { + hash_func_t hash_func; + compare_func_t compare_func; + + struct hashmap_entry *iterate_list_head, *iterate_list_tail; + unsigned n_entries; + + bool from_pool; +}; + +#define BY_HASH(h) ((struct hashmap_entry**) ((uint8_t*) (h) + ALIGN(sizeof(Hashmap)))) + +struct pool { + struct pool *next; + unsigned n_tiles; + unsigned n_used; +}; + +static struct pool *first_hashmap_pool = NULL; +static void *first_hashmap_tile = NULL; + +static struct pool *first_entry_pool = NULL; +static void *first_entry_tile = NULL; + +static void* allocate_tile(struct pool **first_pool, void **first_tile, size_t tile_size) { + unsigned i; + + if (*first_tile) { + void *r; + + r = *first_tile; + *first_tile = * (void**) (*first_tile); + return r; + } + + if (_unlikely_(!*first_pool) || _unlikely_((*first_pool)->n_used >= (*first_pool)->n_tiles)) { + unsigned n; + size_t size; + struct pool *p; + + n = *first_pool ? (*first_pool)->n_tiles : 0; + n = MAX(512U, n * 2); + size = PAGE_ALIGN(ALIGN(sizeof(struct pool)) + n*tile_size); + n = (size - ALIGN(sizeof(struct pool))) / tile_size; + + p = malloc(size); + if (!p) + return NULL; + + p->next = *first_pool; + p->n_tiles = n; + p->n_used = 0; + + *first_pool = p; + } + + i = (*first_pool)->n_used++; + + return ((uint8_t*) (*first_pool)) + ALIGN(sizeof(struct pool)) + i*tile_size; +} + +static void deallocate_tile(void **first_tile, void *p) { + * (void**) p = *first_tile; + *first_tile = p; +} + +#ifndef __OPTIMIZE__ + +static void drop_pool(struct pool *p) { + while (p) { + struct pool *n; + n = p->next; + free(p); + p = n; + } +} + +__attribute__((destructor)) static void cleanup_pool(void) { + /* Be nice to valgrind */ + + drop_pool(first_hashmap_pool); + drop_pool(first_entry_pool); +} + +#endif + +unsigned string_hash_func(const void *p) { + unsigned hash = 5381; + const signed char *c; + + /* DJB's hash function */ + + for (c = p; *c; c++) + hash = (hash << 5) + hash + (unsigned) *c; + + return hash; +} + +int string_compare_func(const void *a, const void *b) { + return strcmp(a, b); +} + +unsigned trivial_hash_func(const void *p) { + return PTR_TO_UINT(p); +} + +int trivial_compare_func(const void *a, const void *b) { + return a < b ? -1 : (a > b ? 1 : 0); +} + +Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func) { + bool b; + Hashmap *h; + size_t size; + + b = is_main_thread(); + + size = ALIGN(sizeof(Hashmap)) + NBUCKETS * sizeof(struct hashmap_entry*); + + if (b) { + h = allocate_tile(&first_hashmap_pool, &first_hashmap_tile, size); + if (!h) + return NULL; + + memset(h, 0, size); + } else { + h = malloc0(size); + + if (!h) + return NULL; + } + + h->hash_func = hash_func ? hash_func : trivial_hash_func; + h->compare_func = compare_func ? compare_func : trivial_compare_func; + + h->n_entries = 0; + h->iterate_list_head = h->iterate_list_tail = NULL; + + h->from_pool = b; + + return h; +} + +int hashmap_ensure_allocated(Hashmap **h, hash_func_t hash_func, compare_func_t compare_func) { + assert(h); + + if (*h) + return 0; + + if (!(*h = hashmap_new(hash_func, compare_func))) + return -ENOMEM; + + return 0; +} + +static void link_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) { + assert(h); + assert(e); + + /* Insert into hash table */ + e->bucket_next = BY_HASH(h)[hash]; + e->bucket_previous = NULL; + if (BY_HASH(h)[hash]) + BY_HASH(h)[hash]->bucket_previous = e; + BY_HASH(h)[hash] = e; + + /* Insert into iteration list */ + e->iterate_previous = h->iterate_list_tail; + e->iterate_next = NULL; + if (h->iterate_list_tail) { + assert(h->iterate_list_head); + h->iterate_list_tail->iterate_next = e; + } else { + assert(!h->iterate_list_head); + h->iterate_list_head = e; + } + h->iterate_list_tail = e; + + h->n_entries++; + assert(h->n_entries >= 1); +} + +static void unlink_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) { + assert(h); + assert(e); + + /* Remove from iteration list */ + if (e->iterate_next) + e->iterate_next->iterate_previous = e->iterate_previous; + else + h->iterate_list_tail = e->iterate_previous; + + if (e->iterate_previous) + e->iterate_previous->iterate_next = e->iterate_next; + else + h->iterate_list_head = e->iterate_next; + + /* Remove from hash table bucket list */ + if (e->bucket_next) + e->bucket_next->bucket_previous = e->bucket_previous; + + if (e->bucket_previous) + e->bucket_previous->bucket_next = e->bucket_next; + else + BY_HASH(h)[hash] = e->bucket_next; + + assert(h->n_entries >= 1); + h->n_entries--; +} + +static void remove_entry(Hashmap *h, struct hashmap_entry *e) { + unsigned hash; + + assert(h); + assert(e); + + hash = h->hash_func(e->key) % NBUCKETS; + + unlink_entry(h, e, hash); + + if (h->from_pool) + deallocate_tile(&first_entry_tile, e); + else + free(e); +} + +void hashmap_free(Hashmap*h) { + + if (!h) + return; + + hashmap_clear(h); + + if (h->from_pool) + deallocate_tile(&first_hashmap_tile, h); + else + free(h); +} + +void hashmap_free_free(Hashmap *h) { + void *p; + + while ((p = hashmap_steal_first(h))) + free(p); + + hashmap_free(h); +} + +void hashmap_clear(Hashmap *h) { + if (!h) + return; + + while (h->iterate_list_head) + remove_entry(h, h->iterate_list_head); +} + +static struct hashmap_entry *hash_scan(Hashmap *h, unsigned hash, const void *key) { + struct hashmap_entry *e; + assert(h); + assert(hash < NBUCKETS); + + for (e = BY_HASH(h)[hash]; e; e = e->bucket_next) + if (h->compare_func(e->key, key) == 0) + return e; + + return NULL; +} + +int hashmap_put(Hashmap *h, const void *key, void *value) { + struct hashmap_entry *e; + unsigned hash; + + assert(h); + + hash = h->hash_func(key) % NBUCKETS; + + if ((e = hash_scan(h, hash, key))) { + + if (e->value == value) + return 0; + + return -EEXIST; + } + + if (h->from_pool) + e = allocate_tile(&first_entry_pool, &first_entry_tile, sizeof(struct hashmap_entry)); + else + e = new(struct hashmap_entry, 1); + + if (!e) + return -ENOMEM; + + e->key = key; + e->value = value; + + link_entry(h, e, hash); + + return 1; +} + +int hashmap_replace(Hashmap *h, const void *key, void *value) { + struct hashmap_entry *e; + unsigned hash; + + assert(h); + + hash = h->hash_func(key) % NBUCKETS; + + if ((e = hash_scan(h, hash, key))) { + e->key = key; + e->value = value; + return 0; + } + + return hashmap_put(h, key, value); +} + +void* hashmap_get(Hashmap *h, const void *key) { + unsigned hash; + struct hashmap_entry *e; + + if (!h) + return NULL; + + hash = h->hash_func(key) % NBUCKETS; + + if (!(e = hash_scan(h, hash, key))) + return NULL; + + return e->value; +} + +void* hashmap_remove(Hashmap *h, const void *key) { + struct hashmap_entry *e; + unsigned hash; + void *data; + + if (!h) + return NULL; + + hash = h->hash_func(key) % NBUCKETS; + + if (!(e = hash_scan(h, hash, key))) + return NULL; + + data = e->value; + remove_entry(h, e); + + return data; +} + +int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value) { + struct hashmap_entry *e; + unsigned old_hash, new_hash; + + if (!h) + return -ENOENT; + + old_hash = h->hash_func(old_key) % NBUCKETS; + if (!(e = hash_scan(h, old_hash, old_key))) + return -ENOENT; + + new_hash = h->hash_func(new_key) % NBUCKETS; + if (hash_scan(h, new_hash, new_key)) + return -EEXIST; + + unlink_entry(h, e, old_hash); + + e->key = new_key; + e->value = value; + + link_entry(h, e, new_hash); + + return 0; +} + +int hashmap_remove_and_replace(Hashmap *h, const void *old_key, const void *new_key, void *value) { + struct hashmap_entry *e, *k; + unsigned old_hash, new_hash; + + if (!h) + return -ENOENT; + + old_hash = h->hash_func(old_key) % NBUCKETS; + if (!(e = hash_scan(h, old_hash, old_key))) + return -ENOENT; + + new_hash = h->hash_func(new_key) % NBUCKETS; + + if ((k = hash_scan(h, new_hash, new_key))) + if (e != k) + remove_entry(h, k); + + unlink_entry(h, e, old_hash); + + e->key = new_key; + e->value = value; + + link_entry(h, e, new_hash); + + return 0; +} + +void* hashmap_remove_value(Hashmap *h, const void *key, void *value) { + struct hashmap_entry *e; + unsigned hash; + + if (!h) + return NULL; + + hash = h->hash_func(key) % NBUCKETS; + + if (!(e = hash_scan(h, hash, key))) + return NULL; + + if (e->value != value) + return NULL; + + remove_entry(h, e); + + return value; +} + +void *hashmap_iterate(Hashmap *h, Iterator *i, const void **key) { + struct hashmap_entry *e; + + assert(i); + + if (!h) + goto at_end; + + if (*i == ITERATOR_LAST) + goto at_end; + + if (*i == ITERATOR_FIRST && !h->iterate_list_head) + goto at_end; + + e = *i == ITERATOR_FIRST ? h->iterate_list_head : (struct hashmap_entry*) *i; + + if (e->iterate_next) + *i = (Iterator) e->iterate_next; + else + *i = ITERATOR_LAST; + + if (key) + *key = e->key; + + return e->value; + +at_end: + *i = ITERATOR_LAST; + + if (key) + *key = NULL; + + return NULL; +} + +void *hashmap_iterate_backwards(Hashmap *h, Iterator *i, const void **key) { + struct hashmap_entry *e; + + assert(i); + + if (!h) + goto at_beginning; + + if (*i == ITERATOR_FIRST) + goto at_beginning; + + if (*i == ITERATOR_LAST && !h->iterate_list_tail) + goto at_beginning; + + e = *i == ITERATOR_LAST ? h->iterate_list_tail : (struct hashmap_entry*) *i; + + if (e->iterate_previous) + *i = (Iterator) e->iterate_previous; + else + *i = ITERATOR_FIRST; + + if (key) + *key = e->key; + + return e->value; + +at_beginning: + *i = ITERATOR_FIRST; + + if (key) + *key = NULL; + + return NULL; +} + +void *hashmap_iterate_skip(Hashmap *h, const void *key, Iterator *i) { + unsigned hash; + struct hashmap_entry *e; + + if (!h) + return NULL; + + hash = h->hash_func(key) % NBUCKETS; + + if (!(e = hash_scan(h, hash, key))) + return NULL; + + *i = (Iterator) e; + + return e->value; +} + +void* hashmap_first(Hashmap *h) { + + if (!h) + return NULL; + + if (!h->iterate_list_head) + return NULL; + + return h->iterate_list_head->value; +} + +void* hashmap_first_key(Hashmap *h) { + + if (!h) + return NULL; + + if (!h->iterate_list_head) + return NULL; + + return (void*) h->iterate_list_head->key; +} + +void* hashmap_last(Hashmap *h) { + + if (!h) + return NULL; + + if (!h->iterate_list_tail) + return NULL; + + return h->iterate_list_tail->value; +} + +void* hashmap_steal_first(Hashmap *h) { + void *data; + + if (!h) + return NULL; + + if (!h->iterate_list_head) + return NULL; + + data = h->iterate_list_head->value; + remove_entry(h, h->iterate_list_head); + + return data; +} + +void* hashmap_steal_first_key(Hashmap *h) { + void *key; + + if (!h) + return NULL; + + if (!h->iterate_list_head) + return NULL; + + key = (void*) h->iterate_list_head->key; + remove_entry(h, h->iterate_list_head); + + return key; +} + +unsigned hashmap_size(Hashmap *h) { + + if (!h) + return 0; + + return h->n_entries; +} + +bool hashmap_isempty(Hashmap *h) { + + if (!h) + return true; + + return h->n_entries == 0; +} + +int hashmap_merge(Hashmap *h, Hashmap *other) { + struct hashmap_entry *e; + + assert(h); + + if (!other) + return 0; + + for (e = other->iterate_list_head; e; e = e->iterate_next) { + int r; + + if ((r = hashmap_put(h, e->key, e->value)) < 0) + if (r != -EEXIST) + return r; + } + + return 0; +} + +void hashmap_move(Hashmap *h, Hashmap *other) { + struct hashmap_entry *e, *n; + + assert(h); + + /* The same as hashmap_merge(), but every new item from other + * is moved to h. This function is guaranteed to succeed. */ + + if (!other) + return; + + for (e = other->iterate_list_head; e; e = n) { + unsigned h_hash, other_hash; + + n = e->iterate_next; + + h_hash = h->hash_func(e->key) % NBUCKETS; + + if (hash_scan(h, h_hash, e->key)) + continue; + + other_hash = other->hash_func(e->key) % NBUCKETS; + + unlink_entry(other, e, other_hash); + link_entry(h, e, h_hash); + } +} + +int hashmap_move_one(Hashmap *h, Hashmap *other, const void *key) { + unsigned h_hash, other_hash; + struct hashmap_entry *e; + + if (!other) + return 0; + + assert(h); + + h_hash = h->hash_func(key) % NBUCKETS; + if (hash_scan(h, h_hash, key)) + return -EEXIST; + + other_hash = other->hash_func(key) % NBUCKETS; + if (!(e = hash_scan(other, other_hash, key))) + return -ENOENT; + + unlink_entry(other, e, other_hash); + link_entry(h, e, h_hash); + + return 0; +} + +Hashmap *hashmap_copy(Hashmap *h) { + Hashmap *copy; + + assert(h); + + if (!(copy = hashmap_new(h->hash_func, h->compare_func))) + return NULL; + + if (hashmap_merge(copy, h) < 0) { + hashmap_free(copy); + return NULL; + } + + return copy; +} + +char **hashmap_get_strv(Hashmap *h) { + char **sv; + Iterator it; + char *item; + int n; + + sv = new(char*, h->n_entries+1); + if (!sv) + return NULL; + + n = 0; + HASHMAP_FOREACH(item, h, it) + sv[n++] = item; + sv[n] = NULL; + + return sv; +} |