move list_recordings_by_* logic into raw.rs

I want to start having the db.rs version augment this with the uncommitted
recordings, and it's nice to have the separation of the raw db vs augmented
versions. Also, this fits with the general theme of shrinking db.rs a bit.

I had to put the raw video_sample_entry_id into the rows rather than
the video_sample_entry Arc. In hindsight, this is better anyway: the common
callers don't need to do the btree lookup and arc clone on every row. I think
I'd originally done it that way only because I was quite new to rust and
didn't understand that db could be used from within the row callback given
that both borrows are immutable.

db/raw.rs

@@ -38,6 +38,49 @@ use rusqlite;
 use std::ops::Range;
 use uuid::Uuid;
 
+// Note: the magic number "27000000" below is recording::MAX_RECORDING_DURATION.
+const LIST_RECORDINGS_BY_TIME_SQL: &'static str = r#"
+    select
+        recording.composite_id,
+        recording.run_offset,
+        recording.flags,
+        recording.start_time_90k,
+        recording.duration_90k,
+        recording.sample_file_bytes,
+        recording.video_samples,
+        recording.video_sync_samples,
+        recording.video_sample_entry_id
+    from
+        recording
+    where
+        stream_id = :stream_id and
+        recording.start_time_90k > :start_time_90k - 27000000 and
+        recording.start_time_90k < :end_time_90k and
+        recording.start_time_90k + recording.duration_90k > :start_time_90k
+    order by
+        recording.start_time_90k
+"#;
+
+const LIST_RECORDINGS_BY_ID_SQL: &'static str = r#"
+    select
+        recording.composite_id,
+        recording.run_offset,
+        recording.flags,
+        recording.start_time_90k,
+        recording.duration_90k,
+        recording.sample_file_bytes,
+        recording.video_samples,
+        recording.video_sync_samples,
+        recording.video_sample_entry_id
+    from
+        recording
+    where
+        :start <= composite_id and
+        composite_id < :end
+    order by
+        recording.composite_id
+"#;
+
 const INSERT_RECORDING_SQL: &'static str = r#"
     insert into recording (composite_id, stream_id, open_id, run_offset, flags,
                            sample_file_bytes, start_time_90k, duration_90k,
@@ -90,6 +133,51 @@ const LIST_OLDEST_RECORDINGS_SQL: &'static str = r#"
       composite_id
 "#;
 
+/// Lists the specified recordings in ascending order by start time, passing them to a supplied
+/// function. Given that the function is called with the database lock held, it should be quick.
+pub(crate) fn list_recordings_by_time(
+    conn: &rusqlite::Connection, stream_id: i32, desired_time: Range<recording::Time>,
+    f: &mut FnMut(db::ListRecordingsRow) -> Result<(), Error>) -> Result<(), Error> {
+    let mut stmt = conn.prepare_cached(LIST_RECORDINGS_BY_TIME_SQL)?;
+    let rows = stmt.query_named(&[
+        (":stream_id", &stream_id),
+        (":start_time_90k", &desired_time.start.0),
+        (":end_time_90k", &desired_time.end.0)])?;
+    list_recordings_inner(rows, f)
+}
+
+/// Lists the specified recordings in ascending order by id.
+pub(crate) fn list_recordings_by_id(
+    conn: &rusqlite::Connection, stream_id: i32, desired_ids: Range<i32>,
+    f: &mut FnMut(db::ListRecordingsRow) -> Result<(), Error>) -> Result<(), Error> {
+    let mut stmt = conn.prepare_cached(LIST_RECORDINGS_BY_ID_SQL)?;
+    let rows = stmt.query_named(&[
+        (":start", &CompositeId::new(stream_id, desired_ids.start).0),
+        (":end", &CompositeId::new(stream_id, desired_ids.end).0),
+    ])?;
+    list_recordings_inner(rows, f)
+}
+
+fn list_recordings_inner(mut rows: rusqlite::Rows,
+                         f: &mut FnMut(db::ListRecordingsRow) -> Result<(), Error>)
+                         -> Result<(), Error> {
+    while let Some(row) = rows.next() {
+        let row = row?;
+        f(db::ListRecordingsRow {
+            id: CompositeId(row.get_checked(0)?),
+            run_offset: row.get_checked(1)?,
+            flags: row.get_checked(2)?,
+            start: recording::Time(row.get_checked(3)?),
+            duration_90k: row.get_checked(4)?,
+            sample_file_bytes: row.get_checked(5)?,
+            video_samples: row.get_checked(6)?,
+            video_sync_samples: row.get_checked(7)?,
+            video_sample_entry_id: row.get_checked(8)?,
+        })?;
+    }
+    Ok(())
+}
+
 pub(crate) fn get_db_uuid(conn: &rusqlite::Connection) -> Result<Uuid, Error> {
     conn.query_row("select uuid from meta", &[], |row| -> Result<Uuid, Error> {
         let uuid: FromSqlUuid = row.get_checked(0)?;