+/*
+ * This file is part of DisOrder
+ * Copyright (C) 2008 Richard Kettlewell
+ *
+ * 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 02111-1307
+ * USA
+ */
+
+/** @file server/schedule.c
+ * @brief Scheduled events
+ *
+ * @ref trackdb_scheduledb is a mapping from ID strings to encoded
+ * key-value pairs called 'actiondata'.
+ *
+ * Possible actiondata keys are:
+ * - @b when: when to perform this action (required)
+ * - @b who: originator for action (required)
+ * - @b action: action to perform (required)
+ * - @b track: for @c action=play, the track to play
+ * - @b key: for @c action=set-global, the global pref to set
+ * - @b value: for @c action=set-global, the value to set (omit to unset)
+ * - @b priority: the importance of this action
+ * - @b recurs: how the event recurs; NOT IMPLEMENTED
+ * - ...others to be defined
+ *
+ * Possible actions are:
+ * - @b play: play a track
+ * - @b set-global: set or unset a global pref
+ * - ...others to be defined
+ *
+ * Possible priorities are:
+ * - @b junk: junk actions that are in the past at startup are discarded
+ * - @b normal: normal actions that are in the past at startup are run
+ * immediately. (This the default.)
+ * - ...others to be defined
+ *
+ * On startup the schedule database is read and a timeout set on the event loop
+ * for each action. Similarly when an action is added, a timeout is set on the
+ * event loop. The timeout has the ID attached as user data so that the action
+ * can easily be found again.
+ *
+ * Recurring events are NOT IMPLEMENTED yet but this is the proposed
+ * interface:
+ *
+ * Recurring events are updated with a new 'when' field when they are processed
+ * (event on error). Non-recurring events are just deleted after processing.
+ *
+ * The recurs field is a whitespace-delimited list of criteria:
+ * - nn:nn or nn:nn:nn define a time of day, in local time. There must be
+ * at least one of these but can be more than one.
+ * - a day name (monday, tuesday, ...) defines the days of the week on
+ * which the event will recur. There can be more than one.
+ * - a day number and month name (1 january, 5 february, ...) defines
+ * the days of the year on which the event will recur. There can be
+ * more than one of these.
+ *
+ * Day and month names are case insensitive. Multiple languages are
+ * likely to be supported, especially if people send me pointers to
+ * their month and day names. Abbreviations are NOT supported, as
+ * there is more of a risk of a clash between different languages that
+ * way.
+ *
+ * If there are no week or year days then the event recurs every day.
+ *
+ * If there are both week and year days then the union of them is
+ * taken, rather than the intersection.
+ *
+ * TODO: support recurring events.
+ *
+ * TODO: add disorder-dump support
+ */
+
+#include <config.h>
+#include "types.h"
+
+#include <string.h>
+#include <db.h>
+#include <time.h>
+#include <stddef.h>
+
+#include "trackdb.h"
+#include "trackdb-int.h"
+#include "schedule.h"
+#include "table.h"
+#include "kvp.h"
+#include "log.h"
+#include "queue.h"
+#include "server-queue.h"
+#include "state.h"
+#include "play.h"
+#include "mem.h"
+#include "random.h"
+#include "vector.h"
+
+static int schedule_trigger(ev_source *ev,
+ const struct timeval *now,
+ void *u);
+static int schedule_lookup(const char *id,
+ struct kvp *actiondata);
+
+/** @brief List of required fields in a scheduled event */
+static const char *const schedule_required[] = {"when", "who", "action"};
+
+/** @brief Number of elements in @ref schedule_required */
+#define NREQUIRED (int)(sizeof schedule_required / sizeof *schedule_required)
+
+/** @brief Parse a scheduled event key and data
+ * @param k Pointer to key
+ * @param whenp Where to store timestamp
+ * @return 0 on success, non-0 on error
+ *
+ * Rejects entries that are invalid in various ways.
+ */
+static int schedule_parse(const DBT *k,
+ const DBT *d,
+ char **idp,
+ struct kvp **actiondatap,
+ time_t *whenp) {
+ char *id;
+ struct kvp *actiondata;
+ int n;
+
+ /* Reject bogus keys */
+ if(!k->size || k->size > 128) {
+ error(0, "bogus schedule.db key (%lu bytes)", (unsigned long)k->size);
+ return -1;
+ }
+ id = xstrndup(k->data, k->size);
+ actiondata = kvp_urldecode(d->data, d->size);
+ /* Reject items without the required fields */
+ for(n = 0; n < NREQUIRED; ++n) {
+ if(!kvp_get(actiondata, schedule_required[n])) {
+ error(0, "scheduled event %s: missing required field '%s'",
+ id, schedule_required[n]);
+ return -1;
+ }
+ }
+ /* Return the results */
+ if(idp)
+ *idp = id;
+ if(actiondatap)
+ *actiondatap = actiondata;
+ if(whenp)
+ *whenp = (time_t)atoll(kvp_get(actiondata, "when"));
+ return 0;
+}
+
+/** @brief Delete via a cursor
+ * @return 0 or @c DB_LOCK_DEADLOCK */
+static int cdel(DBC *cursor) {
+ int err;
+
+ switch(err = cursor->c_del(cursor, 0)) {
+ case 0:
+ break;
+ case DB_LOCK_DEADLOCK:
+ error(0, "error deleting from schedule.db: %s", db_strerror(err));
+ break;
+ default:
+ fatal(0, "error deleting from schedule.db: %s", db_strerror(err));
+ }
+ return err;
+}
+
+/** @brief Initialize the schedule
+ * @param ev Event loop
+ * @param tid Transaction ID
+ *
+ * Sets a callback for all action times except for junk actions that are
+ * already in the past, which are discarded.
+ */
+static int schedule_init_tid(ev_source *ev,
+ DB_TXN *tid) {
+ DBC *cursor;
+ DBT k, d;
+ int err;
+
+ cursor = trackdb_opencursor(trackdb_scheduledb, tid);
+ while(!(err = cursor->c_get(cursor, prepare_data(&k), prepare_data(&d),
+ DB_NEXT))) {
+ struct timeval when;
+ struct kvp *actiondata;
+ char *id;
+
+ /* Parse the key. We destroy bogus entries on sight. */
+ if(schedule_parse(&k, &d, &id, &actiondata, &when.tv_sec)) {
+ if((err = cdel(cursor)))
+ goto deadlocked;
+ continue;
+ }
+ when.tv_usec = 0;
+ /* The action might be in the past */
+ if(when.tv_sec < time(0)) {
+ const char *priority = kvp_get(actiondata, "priority");
+
+ if(priority && !strcmp(priority, "junk")) {
+ /* Junk actions that are in the past are discarded during startup */
+ /* TODO recurring events should be handled differently here */
+ if(cdel(cursor))
+ goto deadlocked;
+ /* Skip this time */
+ continue;
+ }
+ }
+ /* Arrange a callback when the scheduled event is due */
+ ev_timeout(ev, 0/*handlep*/, &when, schedule_trigger, id);
+ }
+ switch(err) {
+ case DB_NOTFOUND:
+ err = 0;
+ break;
+ case DB_LOCK_DEADLOCK:
+ error(0, "error querying schedule.db: %s", db_strerror(err));
+ break;
+ default:
+ fatal(0, "error querying schedule.db: %s", db_strerror(err));
+ }
+deadlocked:
+ if(trackdb_closecursor(cursor))
+ err = DB_LOCK_DEADLOCK;
+ return err;
+}
+
+/** @brief Initialize the schedule
+ * @param ev Event loop
+ *
+ * Sets a callback for all action times except for junk actions that are
+ * already in the past, which are discarded.
+ */
+void schedule_init(ev_source *ev) {
+ int e;
+ WITH_TRANSACTION(schedule_init_tid(ev, tid));
+}
+
+/******************************************************************************/
+
+/** @brief Create a scheduled event
+ * @param ev Event loop
+ * @param actiondata Action data
+ *
+ * The caller should set the timeout themselves.
+ */
+static int schedule_add_tid(const char *id,
+ struct kvp *actiondata,
+ DB_TXN *tid) {
+ int err;
+ DBT k, d;
+
+ memset(&k, 0, sizeof k);
+ k.data = (void *)id;
+ k.size = strlen(id);
+ switch(err = trackdb_scheduledb->put(trackdb_scheduledb, tid, &k,
+ encode_data(&d, actiondata), 0)) {
+ case 0:
+ break;
+ case DB_LOCK_DEADLOCK:
+ error(0, "error updating schedule.db: %s", db_strerror(err));
+ return err;
+ case DB_KEYEXIST:
+ return err;
+ default:
+ fatal(0, "error updating schedule.db: %s", db_strerror(err));
+ }
+ return 0;
+}
+
+/** @brief Create a scheduled event
+ * @param ev Event loop
+ * @param actiondata Action actiondata
+ * @return Scheduled event ID or NULL on error
+ *
+ * Events are rejected if they lack the required fields, if the user
+ * is not allowed to perform them or if they are scheduled for a time
+ * in the past.
+ */
+char *schedule_add(ev_source *ev,
+ struct kvp *actiondata) {
+ int e, n;
+ char *id;
+ struct timeval when;
+
+ /* TODO: handle recurring events */
+ /* Check that the required field are present */
+ for(n = 0; n < NREQUIRED; ++n) {
+ if(!kvp_get(actiondata, schedule_required[n])) {
+ error(0, "new scheduled event is missing required field '%s'",
+ schedule_required[n]);
+ return 0;
+ }
+ }
+ /* Check that the user is allowed to do whatever it is */
+ if(schedule_lookup("[new]", actiondata) < 0)
+ return 0;
+ when.tv_sec = atoll(kvp_get(actiondata, "when"));
+ when.tv_usec = 0;
+ /* Reject events in the past */
+ if(when.tv_sec <= time(0)) {
+ error(0, "new scheduled event is in the past");
+ return 0;
+ }
+ do {
+ id = random_id();
+ WITH_TRANSACTION(schedule_add_tid(id, actiondata, tid));
+ } while(e == DB_KEYEXIST);
+ ev_timeout(ev, 0/*handlep*/, &when, schedule_trigger, id);
+ return id;
+}
+
+/******************************************************************************/
+
+/** @brief Get the action data for a scheduled event
+ * @param id Event ID
+ * @return Event data or NULL
+ */
+struct kvp *schedule_get(const char *id) {
+ int e, n;
+ struct kvp *actiondata;
+
+ WITH_TRANSACTION(trackdb_getdata(trackdb_scheduledb, id, &actiondata, tid));
+ /* Check that the required field are present */
+ for(n = 0; n < NREQUIRED; ++n) {
+ if(!kvp_get(actiondata, schedule_required[n])) {
+ error(0, "scheduled event %s is missing required field '%s'",
+ id, schedule_required[n]);
+ return 0;
+ }
+ }
+ return actiondata;
+}
+
+/******************************************************************************/
+
+/** @brief Delete a scheduled event
+ * @param id Event to delete
+ * @return 0 on success, non-0 if it did not exist
+ */
+int schedule_del(const char *id) {
+ int e;
+
+ WITH_TRANSACTION(trackdb_delkey(trackdb_scheduledb, id, tid));
+ return e == 0 ? 0 : -1;
+}
+
+/******************************************************************************/
+
+/** @brief Get a list of scheduled events
+ * @param neventsp Where to put count of events (or NULL)
+ * @return 0-terminate list of ID strings
+ */
+char **schedule_list(int *neventsp) {
+ int e;
+ struct vector v[1];
+
+ WITH_TRANSACTION(trackdb_listkeys(trackdb_scheduledb, v, tid));
+ if(neventsp)
+ *neventsp = v->nvec;
+ return v->vec;
+}
+
+/******************************************************************************/
+
+static void schedule_play(ev_source *ev,
+ const char *id,
+ const char *who,
+ struct kvp *actiondata) {
+ const char *track = kvp_get(actiondata, "track");
+ struct queue_entry *q;
+
+ /* This stuff has rather a lot in common with c_play() */
+ if(!track) {
+ error(0, "scheduled event %s: no track field", id);
+ return;
+ }
+ if(!trackdb_exists(track)) {
+ error(0, "scheduled event %s: no such track as %s", id, track);
+ return;
+ }
+ if(!(track = trackdb_resolve(track))) {
+ error(0, "scheduled event %s: cannot resolve track %s", id, track);
+ return;
+ }
+ info("scheduled event %s: %s play %s", id, who, track);
+ q = queue_add(track, who, WHERE_START);
+ queue_write();
+ if(q == qhead.next && playing)
+ prepare(ev, q);
+ play(ev);
+}
+
+static void schedule_set_global(ev_source attribute((unused)) *ev,
+ const char *id,
+ const char *who,
+ struct kvp *actiondata) {
+ const char *key = kvp_get(actiondata, "key");
+ const char *value = kvp_get(actiondata, "value");
+
+ if(!key) {
+ error(0, "scheduled event %s: no key field", id);
+ return;
+ }
+ if(key[0] == '_') {
+ error(0, "scheduled event %s: cannot set internal global preferences (%s)",
+ id, key);
+ return;
+ }
+ if(value)
+ info("scheduled event %s: %s set-global %s=%s", id, who, key, value);
+ else
+ info("scheduled event %s: %s set-global %s unset", id, who, key);
+ trackdb_set_global(key, value, who);
+}
+
+/** @brief Table of schedule actions
+ *
+ * Must be kept sorted.
+ */
+static struct {
+ const char *name;
+ void (*callback)(ev_source *ev,
+ const char *id, const char *who,
+ struct kvp *actiondata);
+ rights_type right;
+} schedule_actions[] = {
+ { "play", schedule_play, RIGHT_PLAY },
+ { "set-global", schedule_set_global, RIGHT_GLOBAL_PREFS },
+};
+
+/** @brief Look up a scheduled event
+ * @param actiondata Event description
+ * @return index in schedule_actions[] on success, -1 on error
+ *
+ * Unknown events are rejected as are those that the user is not allowed to do.
+ */
+static int schedule_lookup(const char *id,
+ struct kvp *actiondata) {
+ const char *who = kvp_get(actiondata, "who");
+ const char *action = kvp_get(actiondata, "action");
+ const char *rights;
+ struct kvp *userinfo;
+ rights_type r;
+ int n;
+
+ /* Look up the action */
+ n = TABLE_FIND(schedule_actions, typeof(schedule_actions[0]), name, action);
+ if(n < 0) {
+ error(0, "scheduled event %s: unrecognized action '%s'", id, action);
+ return -1;
+ }
+ /* Find the user */
+ if(!(userinfo = trackdb_getuserinfo(who))) {
+ error(0, "scheduled event %s: user '%s' does not exist", id, who);
+ return -1;
+ }
+ /* Check that they have suitable rights */
+ if(!(rights = kvp_get(userinfo, "rights"))) {
+ error(0, "scheduled event %s: user %s' has no rights???", id, who);
+ return -1;
+ }
+ if(parse_rights(rights, &r, 1)) {
+ error(0, "scheduled event %s: user %s has invalid rights '%s'",
+ id, who, rights);
+ return -1;
+ }
+ if(!(r & schedule_actions[n].right)) {
+ error(0, "scheduled event %s: user %s lacks rights for action %s",
+ id, who, action);
+ return -1;
+ }
+ return n;
+}
+
+/** @brief Called when an action is due */
+static int schedule_trigger(ev_source *ev,
+ const struct timeval attribute((unused)) *now,
+ void *u) {
+ const char *action, *id = u;
+ struct kvp *actiondata = schedule_get(id);
+ int n;
+
+ if(!actiondata)
+ return 0;
+ /* schedule_get() enforces these being present */
+ action = kvp_get(actiondata, "action");
+ /* Look up the action */
+ n = schedule_lookup(id, actiondata);
+ if(n < 0)
+ goto done;
+ /* Go ahead and do it */
+ schedule_actions[n].callback(ev, id, kvp_get(actiondata, "who"), actiondata);
+done:
+ /* TODO: rewrite recurring events for their next trigger time,
+ * rather than deleting them */
+ schedule_del(id);
+ return 0;
+}
+
+/*
+Local Variables:
+c-basic-offset:2
+comment-column:40
+fill-column:79
+indent-tabs-mode:nil
+End:
+*/
~mdw / disorder / commitdiff