Create an implementation of a generic map (#13)

include/lib/list.h

@@ -34,4 +34,4 @@ size_t list_size(struct list *l);
 /** Places the first size number of elements of the list into the given array */
 void list_to_array(struct list *l, void **buffer, size_t size);
 
-#endif //_LIST_H_
+#endif //_LIST_H_

include/lib/map.h

@@ -4,24 +4,39 @@
 
 #include "stdlib/stdtypes.h"
 
-/** Data structure for a generic map */
+/** Structures for a generic map. */
+struct entry {
+    /** The key associated with the entry. */
+    void *key;
+    /** The value associated with the entry. */
+    void *value;
+};
+
 struct map {
-    //TODO
+    /** Table which holds all entries. */
+    struct entry *table;
+    /** Amount of space used. */
+    size_t used;
+    /** Maximum space to allocate for entries */
+    size_t size;
 };
 
-/** Initializes a new hashtable */
-void map_init(struct map *m);
+/** Initializes a new hashmap. Returns `-1` if not allocated. */
+int map_init(struct map *m, size_t size);
 
-/** Frees the hashtable from memory */
+/** Frees the hashtable from memory. */
 void map_free(struct map *m);
 
-/** Adds the key/value pair to the hashtable */
-void map_put(struct map *m, void *key, void *value);
+/** Adds the key/value pair to the hashtable. */
+int map_put(struct map *m, void *key, void *value, size_t size);
+
+/** Gets the value associated with the specified key. */
+void *map_get(struct map *m, void *key, size_t size);
 
-/** Gets the value associated with the specified key */
-void *map_get(struct map *m, void *key);
+/** Checks if key exists in hashmap. */
+bool map_contains(struct map *m, void *key, size_t size);
 
-/** Returns true if the hashtable contains the key, false otherwise */
-bool map_contains(struct map *m, void *key);
+/** Hash function for strings. */
+size_t fnv_1a(char *str);
 
-#endif //_MAP_H_
+#endif //_MAP_H_

include/stdlib/stdtypes.h

@@ -7,6 +7,7 @@
 
 /** Size type */
 typedef unsigned int size_t;
+typedef unsigned long long uint64_t;
 
 #define NULL (void *) 0
 

src/lib/list.c

@@ -86,4 +86,4 @@ void list_to_array(struct list *l, void **buffer, size_t size) {
         buffer[i++] = n->data;
         n = n->next;
     }
-}
+}

src/lib/map.c

@@ -1,2 +1,59 @@
 #include "lib/map.h"
 
+size_t fnv_1a(char *ptr, size_t size) {
+    size_t hash = 0x811C9DC5;
+
+    for (;size--;) {
+        hash ^= ptr[size];
+        hash *= 0x01000193;
+    }
+
+    return hash;
+}
+
+int map_init(struct map *m, size_t size) {
+	m->table = calloc(size, sizeof(struct entry));
+	m->size = size;
+
+	/** Ensure map was allocated. */
+	if (m->table == NULL) return -1;
+	else return 0;
+}
+
+void map_free(struct map *m) {
+	free(m->table);
+}
+
+int map_put(struct map *m, void *key, void *value, size_t size) {
+	size_t idx = fnv_1a(key, size) % m->size;
+	size_t start = idx;
+
+
+	while (m->table[idx].key != NULL) {
+		idx = (++idx) % m->size;
+		if (idx == start) return -1;
+		if (memcmp(key, m->table[idx].key, size) == 0) break;
+	}
+
+	m->table[idx].key = key;
+	m->table[idx].value = value;
+	m->used++;
+
+	return 0;
+}
+
+void *map_get(struct map *m, void *key, size_t size) {
+	size_t idx = fnv_1a(key, size) % m->size;
+
+	if (m->table[idx].key == NULL) return NULL;
+	while (m->table[idx].key != NULL) {
+		if (memcmp(key, m->table[idx].key, size) == 0) return m->table[idx].value;
+		idx = (++idx) % m->size;
+	}
+
+	return NULL;
+}
+
+bool map_contains(struct map *m, void *k, size_t size) {
+	return map_get(m, k, size) != NULL;
+}