#include "util.h"
#include "hashmap.h"
#include "macro.h"
+#include "siphash24.h"
+#include "mempool.h"
-#define NBUCKETS 127
+#define INITIAL_N_BUCKETS 31
struct hashmap_entry {
const void *key;
};
struct Hashmap {
- hash_func_t hash_func;
- compare_func_t compare_func;
+ const struct hash_ops *hash_ops;
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 hashmap_entry ** buckets;
+ unsigned n_buckets, n_entries;
-struct pool {
- struct pool *next;
- unsigned n_tiles;
- unsigned n_used;
+ uint8_t hash_key[HASH_KEY_SIZE];
+ bool from_pool:1;
};
-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;
-}
+struct hashmap_tile {
+ Hashmap h;
+ struct hashmap_entry *initial_buckets[INITIAL_N_BUCKETS];
+};
-static void deallocate_tile(void **first_tile, void *p) {
- * (void**) p = *first_tile;
- *first_tile = p;
-}
+static DEFINE_MEMPOOL(hashmap_pool, struct hashmap_tile, 8);
+static DEFINE_MEMPOOL(hashmap_entry_pool, struct hashmap_entry, 64);
#ifdef VALGRIND
-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) {
+__attribute__((destructor)) static void cleanup_pools(void) {
/* Be nice to valgrind */
- drop_pool(first_hashmap_pool);
- drop_pool(first_entry_pool);
+ mempool_drop(&hashmap_entry_pool);
+ mempool_drop(&hashmap_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;
+unsigned long string_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) {
+ uint64_t u;
+ siphash24((uint8_t*) &u, p, strlen(p), hash_key);
+ return (unsigned long) u;
}
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);
+const struct hash_ops string_hash_ops = {
+ .hash = string_hash_func,
+ .compare = string_compare_func
+};
+
+unsigned long trivial_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) {
+ uint64_t u;
+ siphash24((uint8_t*) &u, &p, sizeof(p), hash_key);
+ return (unsigned long) u;
}
int trivial_compare_func(const void *a, const void *b) {
return a < b ? -1 : (a > b ? 1 : 0);
}
-unsigned uint64_hash_func(const void *p) {
- uint64_t u;
-
- assert_cc(sizeof(uint64_t) == 2*sizeof(unsigned));
-
- u = *(const uint64_t*) p;
+const struct hash_ops trivial_hash_ops = {
+ .hash = trivial_hash_func,
+ .compare = trivial_compare_func
+};
- return (unsigned) ((u >> 32) ^ u);
+unsigned long uint64_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) {
+ uint64_t u;
+ siphash24((uint8_t*) &u, p, sizeof(uint64_t), hash_key);
+ return (unsigned long) u;
}
int uint64_compare_func(const void *_a, const void *_b) {
uint64_t a, b;
-
a = *(const uint64_t*) _a;
b = *(const uint64_t*) _b;
+ return a < b ? -1 : (a > b ? 1 : 0);
+}
+const struct hash_ops uint64_hash_ops = {
+ .hash = uint64_hash_func,
+ .compare = uint64_compare_func
+};
+
+#if SIZEOF_DEV_T != 8
+unsigned long devt_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) {
+ uint64_t u;
+ siphash24((uint8_t*) &u, p, sizeof(dev_t), hash_key);
+ return (unsigned long) u;
+}
+
+int devt_compare_func(const void *_a, const void *_b) {
+ dev_t a, b;
+ a = *(const dev_t*) _a;
+ b = *(const dev_t*) _b;
return a < b ? -1 : (a > b ? 1 : 0);
}
-Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func) {
+const struct hash_ops devt_hash_ops = {
+ .hash = devt_hash_func,
+ .compare = devt_compare_func
+};
+#endif
+
+static unsigned bucket_hash(Hashmap *h, const void *p) {
+ return (unsigned) (h->hash_ops->hash(p, h->hash_key) % h->n_buckets);
+}
+
+static void get_hash_key(uint8_t hash_key[HASH_KEY_SIZE], bool reuse_is_ok) {
+ static uint8_t current[HASH_KEY_SIZE];
+ static bool current_initialized = false;
+
+ /* Returns a hash function key to use. In order to keep things
+ * fast we will not generate a new key each time we allocate a
+ * new hash table. Instead, we'll just reuse the most recently
+ * generated one, except if we never generated one or when we
+ * are rehashing an entire hash table because we reached a
+ * fill level */
+
+ if (!current_initialized || !reuse_is_ok) {
+ random_bytes(current, sizeof(current));
+ current_initialized = true;
+ }
+
+ memcpy(hash_key, current, sizeof(current));
+}
+
+Hashmap *hashmap_new(const struct hash_ops *hash_ops) {
bool b;
+ struct hashmap_tile *ht;
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)
+ ht = mempool_alloc_tile(&hashmap_pool);
+ if (!ht)
return NULL;
- memset(h, 0, size);
+ memzero(ht, sizeof(struct hashmap_tile));
} else {
- h = malloc0(size);
+ ht = malloc0(sizeof(struct hashmap_tile));
- if (!h)
+ if (!ht)
return NULL;
}
- h->hash_func = hash_func ? hash_func : trivial_hash_func;
- h->compare_func = compare_func ? compare_func : trivial_compare_func;
+ h = &ht->h;
+ h->hash_ops = hash_ops ? hash_ops : &trivial_hash_ops;
+ h->n_buckets = INITIAL_N_BUCKETS;
h->n_entries = 0;
h->iterate_list_head = h->iterate_list_tail = NULL;
+ h->buckets = ht->initial_buckets;
+
h->from_pool = b;
+ get_hash_key(h->hash_key, true);
+
return h;
}
-int hashmap_ensure_allocated(Hashmap **h, hash_func_t hash_func, compare_func_t compare_func) {
+int hashmap_ensure_allocated(Hashmap **h, const struct hash_ops *hash_ops) {
+ Hashmap *q;
+
assert(h);
if (*h)
return 0;
- if (!(*h = hashmap_new(hash_func, compare_func)))
+ q = hashmap_new(hash_ops);
+ if (!q)
return -ENOMEM;
+ *h = q;
return 0;
}
assert(e);
/* Insert into hash table */
- e->bucket_next = BY_HASH(h)[hash];
+ e->bucket_next = h->buckets[hash];
e->bucket_previous = NULL;
- if (BY_HASH(h)[hash])
- BY_HASH(h)[hash]->bucket_previous = e;
- BY_HASH(h)[hash] = e;
+ if (h->buckets[hash])
+ h->buckets[hash]->bucket_previous = e;
+ h->buckets[hash] = e;
/* Insert into iteration list */
e->iterate_previous = h->iterate_list_tail;
if (e->bucket_previous)
e->bucket_previous->bucket_next = e->bucket_next;
else
- BY_HASH(h)[hash] = e->bucket_next;
+ h->buckets[hash] = e->bucket_next;
assert(h->n_entries >= 1);
h->n_entries--;
assert(h);
assert(e);
- hash = h->hash_func(e->key) % NBUCKETS;
-
+ hash = bucket_hash(h, e->key);
unlink_entry(h, e, hash);
if (h->from_pool)
- deallocate_tile(&first_entry_tile, e);
+ mempool_free_tile(&hashmap_entry_pool, e);
else
free(e);
}
hashmap_clear(h);
+ if (h->buckets != (struct hashmap_entry**) ((uint8_t*) h + ALIGN(sizeof(Hashmap))))
+ free(h->buckets);
+
if (h->from_pool)
- deallocate_tile(&first_hashmap_tile, h);
+ mempool_free_tile(&hashmap_pool, container_of(h, struct hashmap_tile, h));
else
free(h);
}
}
}
-
static struct hashmap_entry *hash_scan(Hashmap *h, unsigned hash, const void *key) {
struct hashmap_entry *e;
assert(h);
- assert(hash < NBUCKETS);
+ assert(hash < h->n_buckets);
- for (e = BY_HASH(h)[hash]; e; e = e->bucket_next)
- if (h->compare_func(e->key, key) == 0)
+ for (e = h->buckets[hash]; e; e = e->bucket_next)
+ if (h->hash_ops->compare(e->key, key) == 0)
return e;
return NULL;
}
-int hashmap_put(Hashmap *h, const void *key, void *value) {
- struct hashmap_entry *e;
- unsigned hash;
+static int resize_buckets(Hashmap *h, unsigned entries_add) {
+ struct hashmap_entry **n, *i;
+ unsigned m, new_n_entries, new_n_buckets;
+ uint8_t nkey[HASH_KEY_SIZE];
assert(h);
- hash = h->hash_func(key) % NBUCKETS;
+ new_n_entries = h->n_entries + entries_add;
- e = hash_scan(h, hash, key);
- if (e) {
+ /* overflow? */
+ if (_unlikely_(new_n_entries < entries_add || new_n_entries > UINT_MAX / 4))
+ return -ENOMEM;
- if (e->value == value)
- return 0;
+ new_n_buckets = new_n_entries * 4 / 3;
- return -EEXIST;
+ if (_likely_(new_n_buckets <= h->n_buckets))
+ return 0;
+
+ /* Increase by four at least */
+ m = MAX((h->n_entries+1)*4-1, new_n_buckets);
+
+ /* If we hit OOM we simply risk packed hashmaps... */
+ n = new0(struct hashmap_entry*, m);
+ if (!n)
+ return -ENOMEM;
+
+ /* Let's use a different randomized hash key for the
+ * extension, so that people cannot guess what we are using
+ * here forever */
+ get_hash_key(nkey, false);
+
+ for (i = h->iterate_list_head; i; i = i->iterate_next) {
+ unsigned long old_bucket, new_bucket;
+
+ old_bucket = h->hash_ops->hash(i->key, h->hash_key) % h->n_buckets;
+
+ /* First, drop from old bucket table */
+ if (i->bucket_next)
+ i->bucket_next->bucket_previous = i->bucket_previous;
+
+ if (i->bucket_previous)
+ i->bucket_previous->bucket_next = i->bucket_next;
+ else
+ h->buckets[old_bucket] = i->bucket_next;
+
+ /* Then, add to new backet table */
+ new_bucket = h->hash_ops->hash(i->key, nkey) % m;
+
+ i->bucket_next = n[new_bucket];
+ i->bucket_previous = NULL;
+ if (n[new_bucket])
+ n[new_bucket]->bucket_previous = i;
+ n[new_bucket] = i;
}
+ if (h->buckets != (struct hashmap_entry**) ((uint8_t*) h + ALIGN(sizeof(Hashmap))))
+ free(h->buckets);
+
+ h->buckets = n;
+ h->n_buckets = m;
+
+ memcpy(h->hash_key, nkey, HASH_KEY_SIZE);
+
+ return 1;
+}
+
+static int __hashmap_put(Hashmap *h, const void *key, void *value, unsigned hash) {
+ /* For when we know no such entry exists yet */
+
+ struct hashmap_entry *e;
+
+ if (resize_buckets(h, 1) > 0)
+ hash = bucket_hash(h, key);
+
if (h->from_pool)
- e = allocate_tile(&first_entry_pool, &first_entry_tile, sizeof(struct hashmap_entry));
+ e = mempool_alloc_tile(&hashmap_entry_pool);
else
e = new(struct hashmap_entry, 1);
return 1;
}
+int hashmap_put(Hashmap *h, const void *key, void *value) {
+ struct hashmap_entry *e;
+ unsigned hash;
+
+ assert(h);
+
+ hash = bucket_hash(h, key);
+ e = hash_scan(h, hash, key);
+ if (e) {
+ if (e->value == value)
+ return 0;
+ return -EEXIST;
+ }
+
+ return __hashmap_put(h, key, value, hash);
+}
+
int hashmap_replace(Hashmap *h, const void *key, void *value) {
struct hashmap_entry *e;
unsigned hash;
assert(h);
- hash = h->hash_func(key) % NBUCKETS;
+ hash = bucket_hash(h, key);
e = hash_scan(h, hash, key);
if (e) {
e->key = key;
return 0;
}
- return hashmap_put(h, key, value);
+ return __hashmap_put(h, key, value, hash);
}
int hashmap_update(Hashmap *h, const void *key, void *value) {
assert(h);
- hash = h->hash_func(key) % NBUCKETS;
+ hash = bucket_hash(h, key);
e = hash_scan(h, hash, key);
if (!e)
return -ENOENT;
if (!h)
return NULL;
- hash = h->hash_func(key) % NBUCKETS;
+ hash = bucket_hash(h, key);
e = hash_scan(h, hash, key);
if (!e)
return NULL;
if (!h)
return NULL;
- hash = h->hash_func(key) % NBUCKETS;
+ hash = bucket_hash(h, key);
e = hash_scan(h, hash, key);
if (!e)
return NULL;
if (!h)
return false;
- hash = h->hash_func(key) % NBUCKETS;
-
- if (!hash_scan(h, hash, key))
- return false;
-
- return true;
+ hash = bucket_hash(h, key);
+ return !!hash_scan(h, hash, key);
}
void* hashmap_remove(Hashmap *h, const void *key) {
if (!h)
return NULL;
- hash = h->hash_func(key) % NBUCKETS;
+ hash = bucket_hash(h, key);
+ e = hash_scan(h, hash, key);
+ if (!e)
+ return NULL;
+
+ data = e->value;
+ remove_entry(h, e);
+
+ return data;
+}
- if (!(e = hash_scan(h, hash, key)))
+void* hashmap_remove2(Hashmap *h, const void *key, void **rkey) {
+ struct hashmap_entry *e;
+ unsigned hash;
+ void *data;
+
+ if (!h) {
+ if (rkey)
+ *rkey = NULL;
return NULL;
+ }
+
+ hash = bucket_hash(h, key);
+ e = hash_scan(h, hash, key);
+ if (!e) {
+ if (rkey)
+ *rkey = NULL;
+ return NULL;
+ }
data = e->value;
+ if (rkey)
+ *rkey = (void*) e->key;
+
remove_entry(h, e);
return data;
if (!h)
return -ENOENT;
- old_hash = h->hash_func(old_key) % NBUCKETS;
- if (!(e = hash_scan(h, old_hash, old_key)))
+ old_hash = bucket_hash(h, old_key);
+ e = hash_scan(h, old_hash, old_key);
+ if (!e)
return -ENOENT;
- new_hash = h->hash_func(new_key) % NBUCKETS;
+ new_hash = bucket_hash(h, new_key);
if (hash_scan(h, new_hash, new_key))
return -EEXIST;
if (!h)
return -ENOENT;
- old_hash = h->hash_func(old_key) % NBUCKETS;
- if (!(e = hash_scan(h, old_hash, old_key)))
+ old_hash = bucket_hash(h, old_key);
+ e = hash_scan(h, old_hash, old_key);
+ if (!e)
return -ENOENT;
- new_hash = h->hash_func(new_key) % NBUCKETS;
-
- if ((k = hash_scan(h, new_hash, new_key)))
+ new_hash = bucket_hash(h, new_key);
+ k = hash_scan(h, new_hash, new_key);
+ if (k)
if (e != k)
remove_entry(h, k);
if (!h)
return NULL;
- hash = h->hash_func(key) % NBUCKETS;
+ hash = bucket_hash(h, key);
- if (!(e = hash_scan(h, hash, key)))
+ e = hash_scan(h, hash, key);
+ if (!e)
return NULL;
if (e->value != value)
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 (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;
return h->n_entries;
}
+unsigned hashmap_buckets(Hashmap *h) {
+
+ if (!h)
+ return 0;
+
+ return h->n_buckets;
+}
+
bool hashmap_isempty(Hashmap *h) {
if (!h)
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;
+ r = hashmap_put(h, e->key, e->value);
+ if (r < 0 && r != -EEXIST)
+ return r;
}
return 0;
}
-void hashmap_move(Hashmap *h, Hashmap *other) {
+int hashmap_reserve(Hashmap *h, unsigned entries_add) {
+ int r;
+
+ assert(h);
+
+ r = resize_buckets(h, entries_add);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+int 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. */
+ * is moved to h. */
if (!other)
- return;
+ return 0;
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;
-
+ h_hash = bucket_hash(h, e->key);
if (hash_scan(h, h_hash, e->key))
continue;
- other_hash = other->hash_func(e->key) % NBUCKETS;
-
+ other_hash = bucket_hash(other, e->key);
unlink_entry(other, e, other_hash);
link_entry(h, e, h_hash);
}
+
+ return 0;
}
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;
+ h_hash = bucket_hash(h, key);
if (hash_scan(h, h_hash, key))
return -EEXIST;
- other_hash = other->hash_func(key) % NBUCKETS;
- if (!(e = hash_scan(other, other_hash, key)))
+ if (!other)
+ return -ENOENT;
+
+ other_hash = bucket_hash(other, key);
+ e = hash_scan(other, other_hash, key);
+ if (!e)
return -ENOENT;
unlink_entry(other, e, other_hash);
assert(h);
- if (!(copy = hashmap_new(h->hash_func, h->compare_func)))
+ copy = hashmap_new(h->hash_ops);
+ if (!copy)
return NULL;
if (hashmap_merge(copy, h) < 0) {
unsigned hash;
struct hashmap_entry *e;
- assert(h);
assert(key);
if (!h)
return NULL;
- hash = h->hash_func(key) % NBUCKETS;
+ hash = bucket_hash(h, key);
e = hash_scan(h, hash, key);
if (!e)
return NULL;