Low level playlist database operations: read, createwrite, list, delete.

[disorder] / lib / trackdb.c

diff --git a/lib/trackdb.c b/lib/trackdb.c
index 08aeac2677b38befc531960c76504abfaeaf0697..a364446c8c23f7461752c589f6ef5cc5c9e9b5b6 100644 (file)
--- a/lib/trackdb.c
+++ b/lib/trackdb.c
@@ -159,6 +159,13 @@ DB *trackdb_scheduledb;
  */
 DB *trackdb_usersdb;
 
+/** @brief The playlists database
+ * - Keys are playlist names
+ * - Values are encoded key-value pairs
+ * - Data is user data and cannot be reconstructed
+ */
+DB *trackdb_playlistsdb;
+
 static pid_t db_deadlock_pid = -1;      /* deadlock manager PID */
 static pid_t rescan_pid = -1;           /* rescanner PID */
 static int initialized, opened;         /* state */
@@ -468,6 +475,7 @@ void trackdb_open(int flags) {
   trackdb_noticeddb = open_db("noticed.db",
                              DB_DUPSORT, DB_BTREE, dbflags, 0666);
   trackdb_scheduledb = open_db("schedule.db", 0, DB_HASH, dbflags, 0666);
+  trackdb_playlistsdb = open_db("playlists.db", 0, DB_HASH, dbflags, 0666);
   if(!trackdb_existing_database) {
     /* Stash the database version */
     char buf[32];
@@ -502,6 +510,8 @@ void trackdb_close(void) {
     fatal(0, "error closing schedule.db: %s", db_strerror(err));
   if((err = trackdb_usersdb->close(trackdb_usersdb, 0)))
     fatal(0, "error closing users.db: %s", db_strerror(err));
+  if((err = trackdb_playlistsdb->close(trackdb_playlistsdb, 0)))
+    fatal(0, "error closing playlists.db: %s", db_strerror(err));
   trackdb_tracksdb = trackdb_searchdb = trackdb_prefsdb = 0;
   trackdb_tagsdb = trackdb_globaldb = 0;
   D(("closed databases"));
@@ -509,8 +519,13 @@ void trackdb_close(void) {
 
 /* generic db routines *******************************************************/
 
-/* fetch and decode a database entry.  Returns 0, DB_NOTFOUND or
- * DB_LOCK_DEADLOCK. */
+/** @brief Fetch and decode a database entry
+ * @param db Database
+ * @param track Track name
+ * @param kp Where to put decoded list (or NULL if you don't care)
+ * @param tid Owning transaction
+ * @return 0, @c DB_NOTFOUND or @c DB_LOCK_DEADLOCK
+ */
 int trackdb_getdata(DB *db,
                     const char *track,
                     struct kvp **kp,
@@ -521,10 +536,12 @@ int trackdb_getdata(DB *db,
   switch(err = db->get(db, tid, make_key(&key, track),
                        prepare_data(&data), 0)) {
   case 0:
-    *kp = kvp_urldecode(data.data, data.size);
+    if(kp)
+      *kp = kvp_urldecode(data.data, data.size);
     return 0;
   case DB_NOTFOUND:
-    *kp = 0;
+    if(kp)
+      *kp = 0;
     return err;
   case DB_LOCK_DEADLOCK:
     error(0, "error querying database: %s", db_strerror(err));
@@ -2407,9 +2424,6 @@ char **trackdb_new(int *ntracksp,
  * @return null-terminated array of track names, or NULL on deadlock
  *
  * The most recently added track is first in the array.
- *
- * TODO: exclude tracks that have been deleted again.
- *
  */
 static char **trackdb_new_tid(int *ntracksp,
                               int maxtracks,
@@ -2418,12 +2432,24 @@ static char **trackdb_new_tid(int *ntracksp,
   DBT k, d;
   int err = 0;
   struct vector tracks[1];
+  hash *h = hash_new(1);
 
   vector_init(tracks);
   c = trackdb_opencursor(trackdb_noticeddb, tid);
   while((maxtracks <= 0 || tracks->nvec < maxtracks)
-        && !(err = c->c_get(c, prepare_data(&k), prepare_data(&d), DB_PREV)))
-    vector_append(tracks, xstrndup(d.data, d.size));
+        && !(err = c->c_get(c, prepare_data(&k), prepare_data(&d), DB_PREV))) {
+    char *const track = xstrndup(d.data, d.size);
+    /* Don't add any track more than once */
+    if(hash_add(h, track, "", HASH_INSERT))
+      continue;
+    /* See if the track still exists */
+    err = trackdb_getdata(trackdb_tracksdb, track, NULL/*kp*/, tid);
+    if(err == DB_NOTFOUND)
+      continue;                         /* It doesn't, skip it */
+    if(err == DB_LOCK_DEADLOCK)
+      break;                            /* Doh */
+    vector_append(tracks, track);
+  }
   switch(err) {
   case 0:                               /* hit maxtracks */
   case DB_NOTFOUND:                     /* ran out of tracks */
@@ -2535,8 +2561,10 @@ static int trusted(const char *user) {
  * Currently we only allow the letters and digits in ASCII.  We could be more
  * liberal than this but it is a nice simple test.  It is critical that
  * semicolons are never allowed.
+ *
+ * NB also used by playlist_parse_name() to validate playlist names!
  */
-static int valid_username(const char *user) {
+int valid_username(const char *user) {
   if(!*user)
     return 0;
   while(*user) {