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authorLennart Poettering <lennart@poettering.net>2008-06-27 20:12:24 +0200
committerLennart Poettering <lennart@poettering.net>2008-06-27 20:12:24 +0200
commitc26be0d7623434a4595071f8ea7c55aeb240fcca (patch)
tree2a99f2d9e35b6c55671cf369972fd74af701df86 /src/pulsecore/hashmap.c
parent6dca92be9696d6e3b5d4dfe28c6156f73f730dd4 (diff)
modernize hashmap implementation a bit, reduce memory consumption a bit
Diffstat (limited to 'src/pulsecore/hashmap.c')
-rw-r--r--src/pulsecore/hashmap.c155
1 files changed, 92 insertions, 63 deletions
diff --git a/src/pulsecore/hashmap.c b/src/pulsecore/hashmap.c
index b7f4109b..3c6f41ec 100644
--- a/src/pulsecore/hashmap.c
+++ b/src/pulsecore/hashmap.c
@@ -1,7 +1,7 @@
/***
This file is part of PulseAudio.
- Copyright 2004-2006 Lennart Poettering
+ Copyright 2004-2008 Lennart Poettering
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published
@@ -27,7 +27,6 @@
#include <string.h>
#include <pulse/xmalloc.h>
-
#include <pulsecore/idxset.h>
#include <pulsecore/log.h>
#include <pulsecore/flist.h>
@@ -35,37 +34,39 @@
#include "hashmap.h"
-#define BUCKETS 127
+#define NBUCKETS 127
struct hashmap_entry {
- struct hashmap_entry *next, *previous, *bucket_next, *bucket_previous;
- unsigned hash;
const void *key;
void *value;
+
+ struct hashmap_entry *bucket_next, *bucket_previous;
+ struct hashmap_entry *iterate_next, *iterate_previous;
};
struct pa_hashmap {
- unsigned size;
- struct hashmap_entry **data;
- struct hashmap_entry *first_entry;
-
- unsigned n_entries;
pa_hash_func_t hash_func;
pa_compare_func_t compare_func;
+
+ struct hashmap_entry *iterate_list_head, *iterate_list_tail;
+ unsigned n_entries;
};
+#define BY_HASH(h) ((struct hashmap_entry**) ((uint8_t*) (h) + PA_ALIGN(sizeof(pa_hashmap))))
+
PA_STATIC_FLIST_DECLARE(entries, 0, pa_xfree);
pa_hashmap *pa_hashmap_new(pa_hash_func_t hash_func, pa_compare_func_t compare_func) {
pa_hashmap *h;
- h = pa_xnew(pa_hashmap, 1);
- h->data = pa_xnew0(struct hashmap_entry*, h->size = BUCKETS);
- h->first_entry = NULL;
- h->n_entries = 0;
+ h = pa_xmalloc0(PA_ALIGN(sizeof(pa_hashmap)) + NBUCKETS*sizeof(struct hashmap_entry*));
+
h->hash_func = hash_func ? hash_func : pa_idxset_trivial_hash_func;
h->compare_func = compare_func ? compare_func : pa_idxset_trivial_compare_func;
+ h->n_entries = 0;
+ h->iterate_list_head = h->iterate_list_tail = NULL;
+
return h;
}
@@ -73,47 +74,56 @@ static void remove_entry(pa_hashmap *h, struct hashmap_entry *e) {
pa_assert(h);
pa_assert(e);
- if (e->next)
- e->next->previous = e->previous;
- if (e->previous)
- e->previous->next = e->next;
+ /* Remove from iteration list */
+ if (e->iterate_next)
+ e->iterate_next->iterate_previous = e->iterate_previous;
else
- h->first_entry = e->next;
+ 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 {
- pa_assert(e->hash < h->size);
- h->data[e->hash] = e->bucket_next;
+ unsigned hash = h->hash_func(e->key) % NBUCKETS;
+ BY_HASH(h)[hash] = e->bucket_next;
}
if (pa_flist_push(PA_STATIC_FLIST_GET(entries), e) < 0)
pa_xfree(e);
+ pa_assert(h->n_entries >= 1);
h->n_entries--;
}
-void pa_hashmap_free(pa_hashmap*h, void (*free_func)(void *p, void *userdata), void *userdata) {
+void pa_hashmap_free(pa_hashmap*h, pa_free2_cb_t free_cb, void *userdata) {
pa_assert(h);
- while (h->first_entry) {
- if (free_func)
- free_func(h->first_entry->value, userdata);
- remove_entry(h, h->first_entry);
+ while (h->iterate_list_head) {
+ void *data;
+ data = h->iterate_list_head->value;
+ remove_entry(h, h->iterate_list_head);
+
+ if (free_cb)
+ free_cb(data, userdata);
}
- pa_xfree(h->data);
pa_xfree(h);
}
-static struct hashmap_entry *get(pa_hashmap *h, unsigned hash, const void *key) {
+static struct hashmap_entry *hash_scan(pa_hashmap *h, unsigned hash, const void *key) {
struct hashmap_entry *e;
pa_assert(h);
- pa_assert(hash < h->size);
+ pa_assert(hash < NBUCKETS);
- for (e = h->data[hash]; e; e = e->bucket_next)
+ for (e = BY_HASH(h)[hash]; e; e = e->bucket_next)
if (h->compare_func(e->key, key) == 0)
return e;
@@ -123,33 +133,42 @@ static struct hashmap_entry *get(pa_hashmap *h, unsigned hash, const void *key)
int pa_hashmap_put(pa_hashmap *h, const void *key, void *value) {
struct hashmap_entry *e;
unsigned hash;
+
pa_assert(h);
- hash = h->hash_func(key) % h->size;
+ hash = h->hash_func(key) % NBUCKETS;
- if ((e = get(h, hash, key)))
+ if ((e = hash_scan(h, hash, key)))
return -1;
if (!(e = pa_flist_pop(PA_STATIC_FLIST_GET(entries))))
e = pa_xnew(struct hashmap_entry, 1);
- e->hash = hash;
e->key = key;
e->value = value;
- e->previous = NULL;
- e->next = h->first_entry;
- if (h->first_entry)
- h->first_entry->previous = e;
- h->first_entry = e;
-
+ /* Insert into hash table */
+ e->bucket_next = BY_HASH(h)[hash];
e->bucket_previous = NULL;
- e->bucket_next = h->data[hash];
- if (h->data[hash])
- h->data[hash]->bucket_previous = e;
- h->data[hash] = e;
+ 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) {
+ pa_assert(h->iterate_list_head);
+ h->iterate_list_tail->iterate_next = e;
+ } else {
+ pa_assert(!h->iterate_list_head);
+ h->iterate_list_head = e;
+ }
+ h->iterate_list_tail = e;
+
+ h->n_entries++;
+ pa_assert(h->n_entries >= 1);
- h->n_entries ++;
return 0;
}
@@ -159,9 +178,9 @@ void* pa_hashmap_get(pa_hashmap *h, const void *key) {
pa_assert(h);
- hash = h->hash_func(key) % h->size;
+ hash = h->hash_func(key) % NBUCKETS;
- if (!(e = get(h, hash, key)))
+ if (!(e = hash_scan(h, hash, key)))
return NULL;
return e->value;
@@ -174,18 +193,15 @@ void* pa_hashmap_remove(pa_hashmap *h, const void *key) {
pa_assert(h);
- hash = h->hash_func(key) % h->size;
+ hash = h->hash_func(key) % NBUCKETS;
- if (!(e = get(h, hash, key)))
+ if (!(e = hash_scan(h, hash, key)))
return NULL;
data = e->value;
remove_entry(h, e);
- return data;
-}
-unsigned pa_hashmap_size(pa_hashmap *h) {
- return h->n_entries;
+ return data;
}
void *pa_hashmap_iterate(pa_hashmap *h, void **state, const void **key) {
@@ -197,13 +213,13 @@ void *pa_hashmap_iterate(pa_hashmap *h, void **state, const void **key) {
if (*state == (void*) -1)
goto at_end;
- if ((!*state && !h->first_entry))
+ if (!*state && !h->iterate_list_head)
goto at_end;
- e = *state ? *state : h->first_entry;
+ e = *state ? *state : h->iterate_list_head;
- if (e->next)
- *state = e->next;
+ if (e->iterate_next)
+ *state = e->iterate_next;
else
*state = (void*) -1;
@@ -221,24 +237,37 @@ at_end:
return NULL;
}
+void* pa_hashmap_first(pa_hashmap *h) {
+ pa_assert(h);
+
+ if (!h->iterate_list_head)
+ return NULL;
+
+ return h->iterate_list_head->value;
+}
+
void* pa_hashmap_steal_first(pa_hashmap *h) {
void *data;
pa_assert(h);
- if (!h->first_entry)
+ if (!h->iterate_list_head)
return NULL;
- data = h->first_entry->value;
- remove_entry(h, h->first_entry);
+ data = h->iterate_list_head->value;
+ remove_entry(h, h->iterate_list_head);
+
return data;
}
-void *pa_hashmap_get_first(pa_hashmap *h) {
+unsigned pa_hashmap_size(pa_hashmap *h) {
pa_assert(h);
- if (!h->first_entry)
- return NULL;
+ return h->n_entries;
+}
+
+pa_bool_t pa_hashmap_isempty(pa_hashmap *h) {
+ pa_assert(h);
- return h->first_entry->value;
+ return h->n_entries == 0;
}