Move to explicit checkpoint type

db/db.go

@@ -43,12 +43,39 @@ const (
 	numETx               = "execute_transactions"
 	numQTx               = "query_transactions"
 	numRTx               = "request_transactions"
-
-	CheckpointQuery = "PRAGMA wal_checkpoint(TRUNCATE)" // rqlite WAL compaction requires truncation
 )
 
 var (
+	// ErrWALReplayDirectoryMismatch is returned when the WAL file(s) are not in the same
+	// directory as the database file.
 	ErrWALReplayDirectoryMismatch = errors.New("WAL file(s) not in same directory as database file")
+
+	// ErrCheckpointTimeout is returned when a checkpoint does not complete within the
+	// given duration.
+	ErrCheckpointTimeout = errors.New("checkpoint timeout")
+)
+
+// CheckpointMode is the mode in which a checkpoint runs.
+type CheckpointMode int
+
+const (
+	// CheckpointPassive instructs the checkpoint to run in passive mode.
+	CheckpointPassive CheckpointMode = iota
+	// CheckpointFull instructs the checkpoint to run in full mode.
+	CheckpointFull
+	// CheckpointRestart instructs the checkpoint to run in restart mode.
+	CheckpointRestart
+	// CheckpointTruncate instructs the checkpoint to run in truncate mode.
+	CheckpointTruncate
+)
+
+var (
+	checkpointPRAGMAs = map[CheckpointMode]string{
+		CheckpointPassive:  "PRAGMA wal_checkpoint(PASSIVE)",
+		CheckpointFull:     "PRAGMA wal_checkpoint(FULL)",
+		CheckpointRestart:  "PRAGMA wal_checkpoint(RESTART)",
+		CheckpointTruncate: "PRAGMA wal_checkpoint(TRUNCATE)",
+	}
 )
 
 // DBVersion is the SQLite version.
@@ -302,14 +329,14 @@ func (db *DB) WALSize() (int64, error) {
 
 // Checkpoint checkpoints the WAL file. If the WAL file is not enabled, this
 // function is a no-op.
-func (db *DB) Checkpoint() error {
+func (db *DB) Checkpoint(mode CheckpointMode) error {
-	return db.CheckpointWithTimeout(0)
+	return db.CheckpointWithTimeout(mode, 0)
 }
 
 // CheckpointWithTimeout performs a WAL checkpoint. If the checkpoint does not
 // complete within the given duration, an error is returned. If the duration is 0,
 // the checkpoint will be attempted only once.
-func (db *DB) CheckpointWithTimeout(dur time.Duration) (err error) {
+func (db *DB) CheckpointWithTimeout(mode CheckpointMode, dur time.Duration) (err error) {
 	start := time.Now()
 	defer func() {
 		if err != nil {
@@ -325,7 +352,7 @@ func (db *DB) CheckpointWithTimeout(dur time.Duration) (err error) {
 	var nMoved int
 
 	f := func() error {
-		err := db.rwDB.QueryRow(CheckpointQuery).Scan(&ok, &nPages, &nMoved)
+		err := db.rwDB.QueryRow(checkpointPRAGMAs[mode]).Scan(&ok, &nPages, &nMoved)
 		stats.Add(numCheckpointedPages, int64(nPages))
 		stats.Add(numCheckpointedMoves, int64(nMoved))
 		if err != nil {

db/db_test.go

@@ -132,7 +132,7 @@ func Test_TableCreation(t *testing.T) {
 	testQ()
 
 	// Confirm checkpoint works without error.
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointRestart); err != nil {
 		t.Fatalf("failed to checkpoint database: %s", err.Error())
 	}
 	testQ()
@@ -176,7 +176,7 @@ func Test_DBSums(t *testing.T) {
 		t.Fatalf("WAL sum did not change after insertion")
 	}
 
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointRestart); err != nil {
 		t.Fatalf("failed to checkpoint database: %s", err.Error())
 	}
 
@@ -234,7 +234,7 @@ func Test_DBLastModified(t *testing.T) {
 	// Checkpoint, and check time is later. On some platforms the time resolution isn't that
 	// high, so we sleep so the test won't suffer a false failure.
 	time.Sleep(1 * time.Second)
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointRestart); err != nil {
 		t.Fatalf("failed to checkpoint database: %s", err.Error())
 	}
 	lm3, err := db.LastModified()
@@ -669,14 +669,14 @@ func Test_WALDatabaseCreatedOK(t *testing.T) {
 		t.Fatalf("WAL file exists but is empty")
 	}
 
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 	}
 	if mustFileSize(walPath) != 0 {
 		t.Fatalf("WAL file exists but is non-empty")
 	}
 	// Checkpoint a second time, to ensure it's idempotent.
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 	}
 }
@@ -698,7 +698,7 @@ func Test_WALDatabaseCheckpointOKNoWAL(t *testing.T) {
 		t.Fatalf("WAL file exists when no writes have happened")
 	}
 	defer db.Close()
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode with non-existent WAL: %s", err.Error())
 	}
 }
@@ -717,7 +717,7 @@ func Test_WALDatabaseCheckpointOKDelete(t *testing.T) {
 		t.Fatalf("WAL mode enabled")
 	}
 	defer db.Close()
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in DELETE mode: %s", err.Error())
 	}
 }
@@ -839,7 +839,7 @@ func test_FileCreationOnDisk(t *testing.T, db *DB) {
 
 	// Confirm checkpoint works on all types of on-disk databases. Worst case, this
 	// should be ignored.
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(CheckpointRestart); err != nil {
 		t.Fatalf("failed to checkpoint database in DELETE mode: %s", err.Error())
 	}
 }

db/state.go

@@ -223,7 +223,7 @@ func ReplayWAL(path string, wals []string, deleteMode bool) error {
 		if err != nil {
 			return err
 		}
-		if err := db.Checkpoint(); err != nil {
+		if err := db.Checkpoint(CheckpointTruncate); err != nil {
 			return fmt.Errorf("checkpoint WAL %s: %s", wal, err.Error())
 		}
 

db/state_test.go

@@ -220,7 +220,7 @@ func Test_WALReplayOK(t *testing.T) {
 		}
 		mustCopyFile(replayDBPath, dbPath)
 		mustCopyFile(filepath.Join(replayDir, walFile+"_001"), walPath)
-		if err := db.Checkpoint(); err != nil {
+		if err := db.Checkpoint(CheckpointTruncate); err != nil {
 			t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 		}
 
@@ -233,7 +233,7 @@ func Test_WALReplayOK(t *testing.T) {
 			t.Fatalf("WAL file at %s does not exist", walPath)
 		}
 		mustCopyFile(filepath.Join(replayDir, walFile+"_002"), walPath)
-		if err := db.Checkpoint(); err != nil {
+		if err := db.Checkpoint(CheckpointTruncate); err != nil {
 			t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 		}
 
@@ -321,7 +321,7 @@ func Test_WALReplayOK_Complex(t *testing.T) {
 	if _, err := srcDB.ExecuteStringStmt("CREATE TABLE foo (id INTEGER NOT NULL PRIMARY KEY, name TEXT)"); err != nil {
 		t.Fatalf("failed to create table: %s", err.Error())
 	}
-	if err := srcDB.Checkpoint(); err != nil {
+	if err := srcDB.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 	}
 	mustCopyFile(dstPath, srcPath)
@@ -353,7 +353,7 @@ func Test_WALReplayOK_Complex(t *testing.T) {
 		dstWALPath := fmt.Sprintf("%s-%d", dstPath, i)
 		mustCopyFile(dstWALPath, srcWALPath)
 		dstWALs = append(dstWALs, dstWALPath)
-		if err := srcDB.Checkpoint(); err != nil {
+		if err := srcDB.Checkpoint(CheckpointTruncate); err != nil {
 			t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 		}
 	}
@@ -369,7 +369,7 @@ func Test_WALReplayOK_Complex(t *testing.T) {
 	dstWALPath := fmt.Sprintf("%s-postdelete", dstPath)
 	mustCopyFile(dstWALPath, srcWALPath)
 	dstWALs = append(dstWALs, dstWALPath)
-	if err := srcDB.Checkpoint(); err != nil {
+	if err := srcDB.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 	}
 
@@ -379,7 +379,7 @@ func Test_WALReplayOK_Complex(t *testing.T) {
 	dstWALPath = fmt.Sprintf("%s-postupdate", dstPath)
 	mustCopyFile(dstWALPath, srcWALPath)
 	dstWALs = append(dstWALs, dstWALPath)
-	if err := srcDB.Checkpoint(); err != nil {
+	if err := srcDB.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 	}
 
@@ -394,7 +394,7 @@ func Test_WALReplayOK_Complex(t *testing.T) {
 	dstWALPath = fmt.Sprintf("%s-create-tables", dstPath)
 	mustCopyFile(dstWALPath, srcWALPath)
 	dstWALs = append(dstWALs, dstWALPath)
-	if err := srcDB.Checkpoint(); err != nil {
+	if err := srcDB.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 	}
 
@@ -407,7 +407,7 @@ func Test_WALReplayOK_Complex(t *testing.T) {
 	dstWALPath = fmt.Sprintf("%s-post-create-tables", dstPath)
 	mustCopyFile(dstWALPath, srcWALPath)
 	dstWALs = append(dstWALs, dstWALPath)
-	if err := srcDB.Checkpoint(); err != nil {
+	if err := srcDB.Checkpoint(CheckpointTruncate); err != nil {
 		t.Fatalf("failed to checkpoint database in WAL mode: %s", err.Error())
 	}
 

db/swappable_db.go

@@ -124,10 +124,10 @@ func (s *SwappableDB) StmtReadOnly(sql string) (bool, error) {
 }
 
 // Checkpoint calls Checkpoint on the underlying database.
-func (s *SwappableDB) Checkpoint() error {
+func (s *SwappableDB) Checkpoint(mode CheckpointMode) error {
 	s.dbMu.RLock()
 	defer s.dbMu.RUnlock()
-	return s.db.Checkpoint()
+	return s.db.Checkpoint(mode)
 }
 
 // Path calls Path on the underlying database.

store/state.go

@@ -143,7 +143,7 @@ func RecoverNode(dataDir string, logger *log.Logger, logs raft.LogStore, stable
 
 	// Create a new snapshot, placing the configuration in as if it was
 	// committed at index 1.
-	if err := db.Checkpoint(); err != nil {
+	if err := db.Checkpoint(sql.CheckpointTruncate); err != nil {
 		return fmt.Errorf("failed to checkpoint database: %s", err)
 	}
 	tmpDBFD, err := os.Open(tmpDBPath)

store/store.go

@@ -1903,7 +1903,7 @@ func (s *Store) fsmSnapshot() (fSnap raft.FSMSnapshot, retErr error) {
 
 	var fsmSnapshot raft.FSMSnapshot
 	if fullNeeded {
-		if err := s.db.Checkpoint(); err != nil {
+		if err := s.db.Checkpoint(sql.CheckpointTruncate); err != nil {
 			stats.Add(numFullCheckpointFailed, 1)
 			return nil, err
 		}
@@ -1942,7 +1942,7 @@ func (s *Store) fsmSnapshot() (fSnap raft.FSMSnapshot, retErr error) {
 			}
 			stats.Get(snapshotWALSize).(*expvar.Int).Set(int64(compactedBuf.Len()))
 			stats.Get(snapshotPrecompactWALSize).(*expvar.Int).Set(walSz)
-			if err := s.db.Checkpoint(); err != nil {
+			if err := s.db.Checkpoint(sql.CheckpointTruncate); err != nil {
 				stats.Add(numWALCheckpointFailed, 1)
 				// Failing to checkpoint the WAL leaves the main database in an inconsistent
 				// state (if a WAL file was partially checkpointed, then the next WAL file will not