1 files changed, 94 insertions, 0 deletions
diff --git a/hash.c b/hash.c
new file mode 100644
index 0000000..ea36860
--- /dev/null
+++ b/hash.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2008 Stig Venaas <venaas@uninett.no>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include "list.h"
+#include "hash.h"
+
+struct entry {
+    void *key;
+    uint32_t keylen;
+    void *data;
+};
+	
+/* allocates and initialises hash structure; returns NULL if malloc fails */
+struct hash *hash_create() {
+    struct hash *h = malloc(sizeof(struct hash));
+    if (!h)
+	return NULL;
+    h->hashlist = list_create();
+    if (!h->hashlist) {
+	free(h);
+	return NULL;
+    }
+    pthread_mutex_init(&h->mutex, NULL);
+    return h;
+}
+
+/* frees all memory associated with the hash */
+void hash_destroy(struct hash *h) {
+    struct list_node *ln;
+    
+    if (!h)
+	return;
+    for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
+	free(((struct entry *)ln->data)->key);
+	free(((struct entry *)ln->data)->data);
+    }
+    list_destroy(h->hashlist);
+    pthread_mutex_destroy(&h->mutex);
+}
+
+/* insert entry in hash; returns 1 if ok, 0 if malloc fails */
+int hash_insert(struct hash *h, void *key, uint32_t keylen, void *data) {
+    struct entry *e;
+
+    if (!h)
+	return 0;
+    e = malloc(sizeof(struct entry));
+    if (!e)
+	return 0;
+    e->key = malloc(keylen);
+    if (!e->key) {
+	free(e);
+	return 0;
+    }
+    memcpy(e->key, key, keylen);
+    e->keylen = keylen;
+    e->data = data;
+    pthread_mutex_lock(&h->mutex);
+    if (!list_push(h->hashlist, e)) {
+	pthread_mutex_unlock(&h->mutex);
+	free(e->key);
+	free(e);
+	return 0;
+    }
+    pthread_mutex_unlock(&h->mutex);
+    return 1;
+}
+
+/* reads entry from hash */
+void *hash_read(struct hash *h, void *key, uint32_t keylen) {
+    struct list_node *ln;
+    struct entry *e;
+    
+    if (!h)
+	return 0;
+    pthread_mutex_lock(&h->mutex);
+    for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
+	e = (struct entry *)ln->data;
+	if (e->keylen == keylen && !memcmp(e->key, key, keylen)) {
+	        pthread_mutex_unlock(&h->mutex);
+		return e->data;
+	}
+    }
+    pthread_mutex_unlock(&h->mutex);
+    return NULL;
+}