+/** The maximal number of simultaneous connections. */
+#define MAX_STAT_CLIENTS 50
+
+/** Flags used for the stat command of para_audiod. */
+enum stat_client_flags {
+ /** Enable parser-friendly output. */
+ SCF_PARSER_FRIENDLY = 1,
+};
+
+/**
+ * Describes a status client of para_audiod.
+ *
+ * There's one such structure per audiod client that sent the 'stat' command.
+ *
+ * A status client is identified by its file descriptor. para_audiod
+ * keeps a list of connected status clients.
+ */
+struct stat_client {
+ /** The stat client's file descriptor. */
+ int fd;
+ /** Bitmask of those status items the client is interested in. */
+ uint64_t item_mask;
+ /** See \ref stat_client flags. s*/
+ unsigned flags;
+ /** Its entry in the list of stat clients. */
+ struct list_head node;
+};
+
+static INITIALIZED_LIST_HEAD(client_list);
+static int num_clients;
+
+/** The list of all status items used by para_{server,audiod,gui}. */
+const char *status_item_list[] = {STATUS_ITEM_ARRAY};
+
+static void dump_stat_client_list(void)
+{
+ struct stat_client *sc;
+
+ list_for_each_entry(sc, &client_list, node)
+ PARA_INFO_LOG("stat client on fd %d\n", sc->fd);
+}
+/**
+ * Add a status client to the list.
+ *
+ * \param fd The file descriptor of the client.
+ * \param mask Bitfield of status items for this client.
+ * \param parser_friendly Enable parser-friendly output mode.
+ *
+ * Only those status items having the bit set in \a mask will be
+ * sent to the client.
+ *
+ * \return Positive value on success, or -E_TOO_MANY_CLIENTS if
+ * the number of connected clients exceeds #MAX_STAT_CLIENTS.
+ */
+static int stat_client_add(int fd, uint64_t mask, int parser_friendly)
+{
+ struct stat_client *new_client;
+
+ if (num_clients >= MAX_STAT_CLIENTS) {
+ PARA_ERROR_LOG("maximal number of stat clients (%d) exceeded\n",
+ MAX_STAT_CLIENTS);
+ return -E_TOO_MANY_CLIENTS;
+ }
+ PARA_INFO_LOG("adding client on fd %d\n", fd);
+ new_client = para_calloc(sizeof(struct stat_client));
+ new_client->fd = fd;
+ new_client->item_mask = mask;
+ if (parser_friendly)
+ new_client->flags = SCF_PARSER_FRIENDLY;
+ para_list_add(&new_client->node, &client_list);
+ dump_stat_client_list();
+ num_clients++;
+ return 1;
+}
+/**
+ * Write a message to all connected status clients.
+ *
+ * \param item_num The number of the status item of \a msg.
+ *
+ * On write errors, remove the status client from the client list and close its
+ * file descriptor.
+ */
+void stat_client_write_item(int item_num)
+{
+ struct stat_client *sc, *tmp;
+ struct para_buffer pb = {.flags = 0};
+ struct para_buffer pfpb = {.flags = PBF_SIZE_PREFIX};
+ const uint64_t one = 1;
+
+ list_for_each_entry_safe(sc, tmp, &client_list, node) {
+ int fd = sc->fd, ret;
+
+ if (!((one << item_num) & sc->item_mask))
+ continue;
+ if (write_ok(fd) > 0) {
+ struct para_buffer *b =
+ (sc->flags & SCF_PARSER_FRIENDLY)? &pfpb : &pb;
+ char *msg = stat_item_values[item_num];
+ if (!b->buf)
+ WRITE_STATUS_ITEM(b, item_num, "%s\n",
+ msg? msg : "");
+ ret = write(fd, b->buf, b->offset);
+ if (ret == b->offset)
+ continue;
+ }
+ /* write error or fd not ready for writing */
+ close(fd);
+ num_clients--;
+ PARA_INFO_LOG("deleting client on fd %d\n", fd);
+ list_del(&sc->node);
+ free(sc);
+ dump_stat_client_list();
+ }
+ free(pb.buf);
+ free(pfpb.buf);
+// if (num_clients)
+// PARA_DEBUG_LOG("%d client(s)\n", num_clients);
+}
+
+/**
+ * Check if string is a known status item.
+ *
+ * \param item Buffer containing the text to check.
+ *
+ * \return If \a item is a valid status item, the number of that status item is
+ * returned. Otherwise, this function returns \p -E_UNKNOWN_STAT_ITEM.
+ */
+static int stat_item_valid(const char *item)
+{
+ int i;
+ if (!item || !*item) {
+ PARA_ERROR_LOG("%s\n", "no item");
+ return -E_UNKNOWN_STAT_ITEM;
+ }
+ FOR_EACH_STATUS_ITEM(i)
+ if (!strcmp(status_item_list[i], item))
+ return i;
+ PARA_ERROR_LOG("invalid stat item: %s\n", item);
+ return -E_UNKNOWN_STAT_ITEM;
+}
+
projects / paraslash.git / blobdiff