+/*
+ * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
+ */
+
+/** \file playlist_selector.c The playlist audio file selector of paraslash */
+
+#include "server.h"
+#include "db.h"
+#include "error.h"
+#include "net.h"
+#include "string.h"
+#include "ipc.h"
+
+/**
+ * structure used for transmission of the playlist
+ *
+ * There's one such struct which gets initialized during startup. It lives in
+ * shared memory and is used by com_lpl().
+ */
+struct pls_client_data {
+/** allocated and set by com_lpl() (child) */
+ int shm_id;
+/** the size of the shared memory area identified by \a shm_id */
+ size_t size;
+/** initially locked, gets unlocked by parent when it is done */
+ int mutex;
+/** return value, set by parent */
+ int retval;
+};
+
+/** data specific to the playlist selector */
+struct private_pls_data {
+/** guards against concurrent client access */
+ int client_mutex;
+/** guards against concurrent parent-child access */
+ int server_mutex;
+/** pointer to the client data */
+ struct pls_client_data *client_data;
+/** id of the shm corresponding to \a client_data */
+ int client_data_shm_id;
+};
+
+/** we refuse to load playlists bigger than that */
+#define MAX_PLAYLIST_BYTES (1024 * 1024)
+
+static unsigned playlist_len, playlist_size, current_playlist_entry;
+static char **playlist;
+static struct audio_file_selector *self;
+
+static int com_ppl(int, int, char **);
+static int com_lpl(int, int, char **);
+extern struct misc_meta_data *mmd;
+
+/* array of commands that are supported by this database tool */
+static struct server_command cmds[] = {
+{
+.name = "ppl",
+.handler = com_ppl,
+.perms = DB_READ,
+.description = "print playlist",
+.synopsis = "ppl",
+.help =
+"Print out the current playlist"
+}, {
+.name = "lpl",
+.handler = com_lpl,
+.perms = DB_WRITE,
+.description = "load playlist",
+.synopsis = "lpl",
+.help =
+"Read a new playlist from stdin. Example:\n"
+"\tfind /audio -name '*.mp3' | para_client lpl"
+}, {
+.name = NULL,
+}
+};
+
+static void playlist_add(char *path)
+{
+ if (playlist_len >= playlist_size) {
+ playlist_size = 2 * playlist_size + 1;
+ playlist = para_realloc(playlist, playlist_size * sizeof(char *));
+ }
+ PARA_DEBUG_LOG("adding #%d/%d: %s\n", playlist_len, playlist_size, path);
+ playlist[playlist_len++] = para_strdup(path);
+}
+
+static int send_playlist_to_server(const char *buf, size_t size)
+{
+ struct private_pls_data *ppd = self->private_data;
+ int ret, shm_mutex = -1, shm_id = -1;
+ void *shm = NULL;
+
+ PARA_DEBUG_LOG("new playlist (%d bytes)\n", size);
+
+ ret = mutex_new();
+ if (ret < 0)
+ return ret;
+ shm_mutex = ret;
+
+ ret = shm_new(size);
+ if (ret < 0)
+ goto out;
+ shm_id = ret;
+
+ ret = shm_attach(shm_id, ATTACH_RW, &shm);
+ if (ret < 0)
+ goto out;
+ mutex_lock(shm_mutex);
+ memcpy(shm, buf, size);
+ mutex_lock(ppd->client_mutex);
+ mutex_lock(ppd->server_mutex);
+ ppd->client_data->size = size;
+ ppd->client_data->shm_id = shm_id;
+ ppd->client_data->mutex = shm_mutex;
+ kill(getppid(), SIGUSR1); /* wake up the server */
+ mutex_unlock(ppd->server_mutex);
+ mutex_lock(shm_mutex); /* wait until server is done */
+ mutex_unlock(shm_mutex);
+ ret = ppd->client_data->retval;
+ mutex_unlock(ppd->client_mutex);
+ shm_detach(shm);
+out:
+ if (shm_id >= 0)
+ shm_destroy(shm_id);
+ mutex_destroy(shm_mutex);
+ PARA_DEBUG_LOG("returning %d\n", ret);
+ return ret;
+}
+
+static int com_lpl(int fd, __unused int argc, __unused char *argv[])
+{
+ unsigned loaded = 0;
+ size_t bufsize = 4096; /* guess that's enough */
+ char *buf = para_malloc(bufsize);
+ ssize_t ret;
+ ret = send_buffer(fd, AWAITING_DATA_MSG);
+ if (ret < 0)
+ goto out;
+again:
+ ret = recv_bin_buffer(fd, buf + loaded, bufsize - loaded);
+ if (ret < 0)
+ goto out;
+ if (!ret) {
+ ret = send_playlist_to_server(buf, loaded);
+ goto out;
+ }
+ loaded += ret;
+ ret = -E_LOAD_PLAYLIST;
+ if (loaded >= MAX_PLAYLIST_BYTES)
+ goto out;
+ if (loaded >= bufsize) {
+ bufsize *= 2;
+ buf = para_realloc(buf, bufsize);
+ }
+ goto again;
+out:
+ free(buf);
+ return ret;
+}
+
+static int com_ppl(int fd, __unused int argc, __unused char *argv[])
+{
+ unsigned i;
+
+ PARA_DEBUG_LOG("sending playlist to client (%d entries)\n", playlist_len);
+ for (i = 0; i < playlist_len; i++) {
+ int ret = send_va_buffer(fd, "%s\n", playlist[
+ (i + current_playlist_entry) % playlist_len]);
+ if (ret < 0)
+ return ret;
+ }
+ return 1;
+}
+
+static char **pls_get_audio_file_list(unsigned int num)
+{
+ char **file_list;
+ unsigned i;
+
+ num = MIN(num, playlist_len);
+ if (!num)
+ return NULL;
+ file_list = para_malloc((num + 1) * sizeof(char *));
+ for (i = 0; i < num; i++) {
+ unsigned j = (current_playlist_entry + i) % playlist_len;
+ file_list[i] = para_strdup(playlist[j]);
+ }
+ file_list[i] = NULL;
+ return file_list;
+}
+
+static void free_playlist_contents(void)
+{
+ int i;
+
+ PARA_DEBUG_LOG("freeing playlist (%d entries)\n", playlist_len);
+ for (i = 0; i < playlist_len; i++)
+ free(playlist[i]);
+ current_playlist_entry = 0;
+ playlist_len = 0;
+}
+
+static void pls_shutdown(void)
+{
+ struct private_pls_data *ppd = self->private_data;
+
+ shm_detach(ppd->client_data);
+ shm_destroy(ppd->client_data_shm_id);
+ mutex_destroy(ppd->server_mutex);
+ mutex_destroy(ppd->client_mutex);
+ free(ppd);
+ free_playlist_contents();
+ free(playlist);
+ playlist = NULL;
+ playlist_len = 0;
+ playlist_size = 0;
+}
+
+static void pls_post_select(__unused fd_set *rfds, __unused fd_set *wfds)
+{
+ struct private_pls_data *ppd = self->private_data;
+ struct pls_client_data *pcd = ppd->client_data;
+ int ret;
+ void *shm;
+
+ mutex_lock(ppd->server_mutex);
+ if (!pcd->size)
+ goto out;
+ free_playlist_contents();
+ ret = shm_attach(pcd->shm_id, ATTACH_RW, &shm);
+ if (ret < 0) {
+ PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
+ goto out;
+ }
+ PARA_DEBUG_LOG("loading new playlist (%d bytes)\n", pcd->size);
+ ret = for_each_line((char *)shm, pcd->size, &playlist_add);
+ shm_detach(shm);
+ PARA_NOTICE_LOG("new playlist (%d entries)\n", playlist_len);
+ pcd->retval = 1;
+ pcd->size = 0;
+ mutex_unlock(pcd->mutex);
+out:
+ mutex_unlock(ppd->server_mutex);
+}
+
+void pls_update_audio_file(char *audio_file)
+{
+ unsigned i;
+
+ for (i = 0; i < playlist_len; i++) {
+ unsigned j = (current_playlist_entry + i) % playlist_len;
+ if (strcmp(playlist[j], audio_file))
+ continue;
+ current_playlist_entry = (j + 1) % playlist_len;
+ }
+}
+
+/**
+ * the init function for the playlist selector
+ *
+ * Init all function pointers of \a db
+ *
+ * \sa struct audio_file_selector, misc_meta_data::dbinfo, mysql.c random_dbtool.c
+ */
+int playlist_selector_init(struct audio_file_selector *db)
+{
+ int ret;
+ struct private_pls_data *ppd = NULL;
+ void *shm = NULL;
+
+ self = db;
+ db->cmd_list = cmds;
+ db->get_audio_file_list = pls_get_audio_file_list;
+ db->shutdown = pls_shutdown;
+ db->post_select = pls_post_select;
+ db->update_audio_file = pls_update_audio_file;
+ ppd = para_calloc(sizeof(struct private_pls_data));
+ db->private_data = ppd;
+
+ ppd->client_mutex = -1;
+ ppd->server_mutex = -1;
+ ppd->client_data_shm_id = -1;
+ ppd->client_data = NULL;
+
+ ret = mutex_new();
+ if (ret < 0)
+ goto err_out;
+ ppd->client_mutex = ret;
+
+ ret = mutex_new();
+ if (ret < 0)
+ goto err_out;
+ ppd->server_mutex = ret;
+
+ ret = shm_new(sizeof(struct pls_client_data));
+ if (ret < 0)
+ goto err_out;
+ ppd->client_data_shm_id = ret;
+
+ ret = shm_attach(ppd->client_data_shm_id, ATTACH_RW, &shm);
+ if (ret < 0)
+ goto err_out;
+ ppd->client_data = shm;
+ ppd->client_data->size = 0;
+ sprintf(mmd->dbinfo, "playlist selector initialized");
+ return 1;
+err_out:
+ if (ppd->client_data_shm_id >= 0)
+ shm_destroy(ppd->client_data_shm_id);
+ if (ppd->client_mutex >= 0)
+ mutex_destroy(ppd->client_mutex);
+ if (ppd->server_mutex >= 0)
+ mutex_destroy(ppd->server_mutex);
+ free(ppd);
+ return ret;
+}
projects / paraslash.git / commitdiff