add config options and graph.Handle

config/config.go

@@ -29,6 +29,8 @@ type Config struct {
 	DatabaseType       string
 	DatabasePath       string
 	DatabaseOptions    map[string]interface{}
+	ReplicationType    string
+	ReplicationOptions map[string]interface{}
 	ListenHost         string
 	ListenPort         string
 	ReadOnly           bool
@@ -40,6 +42,8 @@ type config struct {
 	DatabaseType       string                 `json:"database"`
 	DatabasePath       string                 `json:"db_path"`
 	DatabaseOptions    map[string]interface{} `json:"db_options"`
+	ReplicationType    string                 `json:"replication"`
+	ReplicationOptions map[string]interface{} `json:"replication_options"`
 	ListenHost         string                 `json:"listen_host"`
 	ListenPort         string                 `json:"listen_port"`
 	ReadOnly           bool                   `json:"read_only"`
@@ -57,6 +61,8 @@ func (c *Config) UnmarshalJSON(data []byte) error {
 		DatabaseType:       t.DatabaseType,
 		DatabasePath:       t.DatabasePath,
 		DatabaseOptions:    t.DatabaseOptions,
+		ReplicationType:    t.ReplicationType,
+		ReplicationOptions: t.ReplicationOptions,
 		ListenHost:         t.ListenHost,
 		ListenPort:         t.ListenPort,
 		ReadOnly:           t.ReadOnly,
@@ -71,6 +77,8 @@ func (c *Config) MarshalJSON() ([]byte, error) {
 		DatabaseType:       c.DatabaseType,
 		DatabasePath:       c.DatabasePath,
 		DatabaseOptions:    c.DatabaseOptions,
+		ReplicationType:    c.ReplicationType,
+		ReplicationOptions: c.ReplicationOptions,
 		ListenHost:         c.ListenHost,
 		ListenPort:         c.ListenPort,
 		ReadOnly:           c.ReadOnly,
@@ -117,6 +125,7 @@ func (d *duration) MarshalJSON() ([]byte, error) {
 var (
 	databasePath       = flag.String("dbpath", "/tmp/testdb", "Path to the database.")
 	databaseBackend    = flag.String("db", "memstore", "Database Backend.")
+	replicationBackend = flag.String("replication", "single", "Replication method.")
 	host               = flag.String("host", "0.0.0.0", "Host to listen on (defaults to all).")
 	loadSize           = flag.Int("load_size", 10000, "Size of triplesets to load")
 	port               = flag.String("port", "64210", "Port to listen on.")
@@ -175,6 +184,10 @@ func ParseConfigFromFlagsAndFile(fileFlag string) *Config {
 		config.DatabaseType = *databaseBackend
 	}
 
+	if config.ReplicationType == "" {
+		config.ReplicationType = *replicationBackend
+	}
+
 	if config.ListenHost == "" {
 		config.ListenHost = *host
 	}

db/db.go

@@ -36,8 +36,20 @@ func Init(cfg *config.Config) error {
 	return graph.InitTripleStore(cfg.DatabaseType, cfg.DatabasePath, cfg.DatabaseOptions)
 }
 
-func Open(cfg *config.Config) (graph.TripleStore, error) {
-	glog.Infof("Opening database %q at %s", cfg.DatabaseType, cfg.DatabasePath)
+func Open(cfg *config.Config) (*graph.Handle, error) {
+	qs, err := OpenQuadStore(cfg)
+	if err != nil {
+		return nil, err
+	}
+	qw, err := OpenQuadWriter(qs, cfg)
+	if err != nil {
+		return nil, err
+	}
+	return &graph.Handle{QuadStore: qs, QuadWriter: qw}, nil
+}
+
+func OpenQuadStore(cfg *config.Config) (graph.TripleStore, error) {
+	glog.Infof("Opening quad store %q at %s", cfg.DatabaseType, cfg.DatabasePath)
 	ts, err := graph.NewTripleStore(cfg.DatabaseType, cfg.DatabasePath, cfg.DatabaseOptions)
 	if err != nil {
 		return nil, err
@@ -46,6 +58,16 @@ func Open(cfg *config.Config) (graph.TripleStore, error) {
 	return ts, nil
 }
 
+func OpenQuadWriter(qs graph.TripleStore, cfg *config.Config) (graph.QuadWriter, error) {
+	glog.Infof("Opening replication method %q", cfg.ReplicationType)
+	w, err := graph.NewQuadWriter(cfg.ReplicationType, qs, cfg.ReplicationOptions)
+	if err != nil {
+		return nil, err
+	}
+
+	return w, nil
+}
+
 func Load(ts graph.TripleStore, cfg *config.Config, dec quad.Unmarshaler) error {
 	bulker, canBulk := ts.(graph.BulkLoader)
 	if canBulk {

graph/quadwriter.go

@@ -43,6 +43,11 @@ type Delta struct {
 	Timestamp time.Time
 }
 
+type Handle struct {
+	QuadStore  TripleStore
+	QuadWriter QuadWriter
+}
+
 var ErrQuadExists = errors.New("Quad exists")
 var ErrQuadNotExist = errors.New("Quad doesn't exist")