initial commit

1 files changed, 325 insertions, 0 deletions

diff --git a/hashmap.c b/hashmap.c
new file mode 100644
index 0000000000..1b2e059dde
--- /dev/null
+++ b/hashmap.c
@@ -0,0 +1,325 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#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;
+};
+
+#define BY_HASH(h) ((struct hashmap_entry**) ((uint8_t*) (h) + ALIGN(sizeof(Hashmap))))
+
+unsigned string_hash_func(const void *p) {
+        unsigned hash = 0;
+        const char *c;
+
+        for (c = p; *c; c++)
+                hash = 31 * 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) {
+        Hashmap *h;
+
+        if (!(h = malloc0(ALIGN(sizeof(Hashmap)) + NBUCKETS * ALIGN(sizeof(struct hashmap_entry*)))))
+                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;
+
+        return h;
+}
+
+static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
+        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 {
+                unsigned hash = h->hash_func(e->key) % NBUCKETS;
+                BY_HASH(h)[hash] = e->bucket_next;
+        }
+
+        free(e);
+
+        assert(h->n_entries >= 1);
+        h->n_entries--;
+}
+
+void hashmap_free(Hashmap*h) {
+
+        if (!h)
+                return;
+
+        while (h->iterate_list_head)
+                remove_entry(h, h->iterate_list_head);
+
+        free(h);
+}
+
+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 (hash_scan(h, hash, key))
+                return -EEXIST;
+
+        if (!(e = new(struct hashmap_entry, 1)))
+                return -ENOMEM;
+
+        e->key = key;
+        e->value = value;
+
+        /* 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);
+
+        return 0;
+}
+
+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;
+}
+
+void *hashmap_iterate(Hashmap *h, void **state, const void **key) {
+        struct hashmap_entry *e;
+
+        assert(state);
+
+        if (!h)
+                goto at_end;
+
+        if (*state == (void*) -1)
+                goto at_end;
+
+        if (!*state && !h->iterate_list_head)
+                goto at_end;
+
+        e = *state ? *state : h->iterate_list_head;
+
+        if (e->iterate_next)
+                *state = e->iterate_next;
+        else
+                *state = (void*) -1;
+
+        if (key)
+                *key = e->key;
+
+        return e->value;
+
+at_end:
+        *state = (void *) -1;
+
+        if (key)
+                *key = NULL;
+
+        return NULL;
+}
+
+void *hashmap_iterate_backwards(Hashmap *h, void **state, const void **key) {
+        struct hashmap_entry *e;
+
+        assert(state);
+
+        if (!h)
+                goto at_beginning;
+
+        if (*state == (void*) -1)
+                goto at_beginning;
+
+        if (!*state && !h->iterate_list_tail)
+                goto at_beginning;
+
+        e = *state ? *state : h->iterate_list_tail;
+
+        if (e->iterate_previous)
+                *state = e->iterate_previous;
+        else
+                *state = (void*) -1;
+
+        if (key)
+                *key = e->key;
+
+        return e->value;
+
+at_beginning:
+        *state = (void *) -1;
+
+        if (key)
+                *key = NULL;
+
+        return NULL;
+}
+
+void* hashmap_first(Hashmap *h) {
+
+        if (!h)
+                return NULL;
+
+        if (!h->iterate_list_head)
+                return NULL;
+
+        return h->iterate_list_head->value;
+}
+
+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;
+}
+
+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;
+}