fix hashmap

include/hashmap.h

@@ -14,19 +14,46 @@ struct hashmap {
 	struct hashmap *next;
 };
 
-/* Calculate the hash code of a file descriptor */
+/**
+ * @brief Calculates the hash code of a given file descriptor
+ *
+ * @param sockfd[in] The file descriptor
+ * @return int Returns the hash code
+ */
 int hash(int sockfd);
 
-/* Initialize the hash map */
+/**
+ * @brief Initializes the hash map
+ *
+ * @param map[out] The hash map uninitialized
+ */
 void hm_init(struct hashmap *map);
 
-/* Insert a new key in the hash map */
-void hm_insert(struct hashmap *map, int sockfd, struct sockaddr_storage *sas);
+/**
+ * @brief Inserts a key in the hash map
+ *
+ * @param map[out] The hash map
+ * @param sockfd[in] The file descriptor (value)
+ * @param sas[in] The sockaddr (value)
+ */
+void hm_push(struct hashmap *map, int sockfd, struct sockaddr_storage *sas);
 
-/* Search for a key in the hash map */
+/**
+ * @brief Searches for a key in the hash map
+ *
+ * @param map[in] The hash map
+ * @param sockfd[in] The file descriptor (key)
+ * @return struct hashmap* Returns NULL or the key pointer
+ */
 struct hashmap *hm_lookup(struct hashmap *map, int sockfd);
 
-/* Clean up the hash map */
+/**
+ * @brief Cleans the hash map
+ *
+ * @param map[out] The hash map
+ */
 void hm_free(struct hashmap *map);
 
+void hm_insert(struct hashmap *map, int sockfd, struct sockaddr_storage *sas);
+
 #endif

src/hashmap.c

@@ -3,6 +3,7 @@
 int hash(int sockfd) { return sockfd % HASHMAP_MAX_CLIENTS; }
 
 void hm_init(struct hashmap *map) {
+	/* Initialize everything to 0 for the struct, then -1 for fd and next to NULL */
 	memset(map, 0, sizeof(struct hashmap) * HASHMAP_MAX_CLIENTS);
 
 	for (size_t i = 0; i < HASHMAP_MAX_CLIENTS; ++i) {
@@ -11,21 +12,23 @@ void hm_init(struct hashmap *map) {
 	}
 }
 
+/* This function will add a key even if it exists (use hm_push() instead) */
 void hm_insert(struct hashmap *map, int sockfd, struct sockaddr_storage *sas) {
 	int index = hash(sockfd);
 
 	if (map[index].sockfd == -1) {
+		/* Current slot is empty */
 		map[index].sockfd = sockfd;
 		map[index].sas = *sas;
+		map[index].next = NULL;
 	} else {
-		/* Go through the linked list and append the new item */
-		struct hashmap *p;
-		for (p = &map[index]; p->next != NULL; p = p->next);
+		/* Append the new key to the head (not the first element because it belongs to the array) of the linked
+		 * list */
+		struct hashmap *p = &map[index];
 		struct hashmap *new = malloc(sizeof(struct hashmap));
 		new->sockfd = sockfd;
 		new->sas = *sas;
-		new->next = NULL;
-
+		new->next = p->next;
 		p->next = new;
 	}
 }
@@ -35,7 +38,7 @@ struct hashmap *hm_lookup(struct hashmap *map, int sockfd) {
 
 	if (map[index].sockfd != sockfd) {
 		struct hashmap *p;
-		for (p = map[index].next; p->sockfd != sockfd; p = p->next);
+		for (p = map[index].next; p != NULL && p->sockfd != sockfd; p = p->next);
 		return p;
 	} else {
 		return &map[index];
@@ -44,4 +47,25 @@ struct hashmap *hm_lookup(struct hashmap *map, int sockfd) {
 	return NULL;
 }
 
-void hm_free(struct hashmap *map) {}
+void hm_push(struct hashmap *map, int sockfd, struct sockaddr_storage *sas) {
+	if (hm_lookup(map, sockfd) == NULL) {
+		hm_insert(map, sockfd, sas);
+	}
+}
+
+void hm_free(struct hashmap *map) {
+	struct hashmap *p, *next;
+
+	for (size_t i = 0; i < HASHMAP_MAX_CLIENTS; ++i) {
+		if (map[i].next != NULL) {
+			/* Free the malloc */
+			p = map[i].next;
+			next = p->next;
+			do {
+				free(p);
+				p = next;
+				next = p != NULL ? p->next : NULL;
+			} while (p != NULL);
+		}
+	}
+}

src/server.c

@@ -78,7 +78,7 @@ void handle_clients(int sockfd) {
 
 				setnonblocking(client_fd);
 				epoll_ctl_add(epfd, client_fd, EPOLLIN);
-				hm_insert(clients, client_fd, &their_sa);
+				hm_push(clients, client_fd, &their_sa);
 
 				int bytes_sent = send(client_fd, msg, msg_len, 0);
 				fprintf(stdout, "[server] Sent %d bytes\n", bytes_sent);
@@ -113,9 +113,13 @@ void handle_clients(int sockfd) {
 	free(revents);
 	close(epfd);
 
+	/* Close all the file descriptors */
 	for (size_t i = 0; i < HASHMAP_MAX_CLIENTS; ++i) {
 		close(clients[i].sockfd);
+		/* TODO: close collisions */
 	}
+
+	hm_free(clients);
 }
 
 void epoll_ctl_add(int epfd, int sockfd, uint32_t events) {