Dbquerries: add EXIST querries for podcast and episode.

hammond-data/src/dbqueries.rs

@@ -257,6 +257,33 @@ pub fn delete_podcast_episodes(con: &SqliteConnection, parent_id: i32) -> QueryR
     diesel::delete(episode.filter(podcast_id.eq(parent_id))).execute(&*con)
 }
 
+pub fn podcast_exists(source_id_: i32) -> Result<bool> {
+    use schema::podcast::dsl::*;
+    use diesel::select;
+    use diesel::dsl::exists;
+
+    let db = connection();
+    let con = db.get()?;
+
+    select(exists(podcast.filter(source_id.eq(source_id_))))
+        .get_result(&*con)
+        .map_err(From::from)
+}
+
+#[cfg_attr(rustfmt, rustfmt_skip)]
+pub fn episode_exists(title_: &str, podcast_id_: i32) -> Result<bool> {
+    use schema::episode::dsl::*;
+    use diesel::select;
+    use diesel::dsl::exists;
+
+    let db = connection();
+    let con = db.get()?;
+
+    select(exists(episode.filter(podcast_id.eq(podcast_id_)).filter(title.eq(title_))))
+        .get_result(&*con)
+        .map_err(From::from)
+}
+
 pub fn update_none_to_played_now(parent: &Podcast) -> Result<usize> {
     use schema::episode::dsl::*;
 

hammond-data/src/errors.rs

@@ -1,4 +1,4 @@
-use diesel::result;
+use diesel;
 use diesel_migrations::RunMigrationsError;
 use rss;
 use reqwest;
@@ -11,7 +11,7 @@ use std::io;
 error_chain! {
     foreign_links {
         R2D2Error(r2d2::Error);
-        DieselResultError(result::Error);
+        DieselResultError(diesel::result::Error);
         DieselMigrationError(RunMigrationsError);
         RSSError(rss::Error);
         ReqError(reqwest::Error);

hammond-data/src/feed.rs

@@ -93,13 +93,9 @@ impl Feed {
 
     // This could also retrurn a FutureResult<Vec<FutureNewEpisode, Error>>, Error> Instead
     #[allow(dead_code)]
-    fn parse_channel_items_future(
-        &self,
-        pd: &Podcast,
-    ) -> Box<Vec<FutureResult<NewEpisode, Error>>> {
-        let items = self.channel.items();
-
-        let episodes: Vec<_> = items
+    fn parse_episodes_future(&self, pd: &Podcast) -> Box<Vec<FutureResult<NewEpisode, Error>>> {
+        let episodes = self.channel
+            .items()
             .par_iter()
             .map(|item| result(parser::new_episode(item, pd.id())))
             .collect();