WIP: FS to DB sync

2 files changed, 35 insertions, 8 deletions

diff --git a/main.go b/main.go
index 8b70dec..64cf26c 100644
--- a/main.go
+++ b/main.go
@@ -1166,6 +1166,8 @@ func syncDirectory(c *syncContext, dbParent int64, fsPath string) error {
 	for iDB < len(db) && iFS < len(fs) {
 		if db[iDB].dbName == fs[iFS].fsName {
 			pairs = append(pairs, syncPair{&db[iDB], &fs[iFS]})
+			iDB++
+			iFS++
 		} else if db[iDB].dbName < fs[iFS].fsName {
 			pairs = append(pairs, syncPair{&db[iDB], nil})
 			iDB++
@@ -1220,7 +1222,37 @@ func syncRoot(c *syncContext, fsPath string) error {
 	for i := 0; i < cap(taskSemaphore); i++ {
 		taskSemaphore.release()
 	}
-	return nil
+
+	// Delete empty directories, from the bottom of the tree up to,
+	// but not including, the inserted root.
+	//
+	// We need to do this at the end due to our recursive handling,
+	// as well as because of asynchronous file filtering.
+	stmt, err := c.tx.Prepare(`
+		WITH RECURSIVE subtree(id, parent, sha1, level) AS (
+			SELECT id, parent, sha1, 1 FROM node WHERE id = ?
+			UNION ALL
+			SELECT n.id, n.parent, n.sha1, s.level + 1
+			FROM node AS n JOIN subtree AS s ON n.parent = s.id
+		) DELETE FROM node WHERE id IN (
+			SELECT id FROM subtree WHERE level <> 1 AND sha1 IS NULL
+			-- No idea why one can't put the "node" table in the subselect.
+			-- The whole query then matches nothing.
+			AND id NOT IN (SELECT parent FROM subtree)
+		)`)
+	if err != nil {
+		return err
+	}
+
+	for {
+		if result, err := stmt.Exec(dbParent); err != nil {
+			return err
+		} else if n, err := result.RowsAffected(); err != nil {
+			return err
+		} else if n == 0 {
+			return nil
+		}
+	}
 }
 
 const disposeCTE = `WITH RECURSIVE
@@ -1296,12 +1328,6 @@ func syncRun(ctx context.Context, tx *sql.Tx, roots []string) error {
 			return err
 		}
 	}
-
-	// TODO: Garbage collect empty directories, recursively.
-	// Ideally, stop at the affected DB roots (assuming we go bottom-up).
-	//
-	// We need to do this at the end, due to our recursive handling,
-	// as well as because of asynchronous file filtering.
 	return nil
 }
 
diff --git a/test.sh b/test.sh
index c51841a..3609de4 100755
--- a/test.sh
+++ b/test.sh
@@ -7,7 +7,8 @@ mkdir -p $target
 cp -ra $HOME/Pictures/Anime $input
 
 ./gallery init $target
-./gallery import $target $input
+#./gallery import $target $input
+./gallery sync $target $input
 ./gallery thumbnail $target
 ./gallery dhash $target $HOME/Projects/fiv/build/hash
 ./gallery tag $target autotagger "DanBooru autotagger" \