store: added StringStore

server/store/string_store.go

@@ -0,0 +1,49 @@
+// Copyright 2016 The Chihaya Authors. All rights reserved.
+// Use of this source code is governed by the BSD 2-Clause license,
+// which can be found in the LICENSE file.
+
+package store
+
+import "fmt"
+
+// PrefixInfohash is the prefix to be used for infohashes.
+const PrefixInfohash = "ih-"
+
+var stringStoreDrivers = make(map[string]StringStoreDriver)
+
+// StringStore represents an interface for manipulating strings.
+type StringStore interface {
+	PutString(s string) error
+	HasString(s string) (bool, error)
+	RemoveString(s string) error
+}
+
+// StringStoreDriver represents an interface for creating a handle to the
+// storage of swarms.
+type StringStoreDriver interface {
+	New(*Config) (StringStore, error)
+}
+
+// RegisterStringStoreDriver makes a driver available by the provided name.
+//
+// If this function is called twice with the same name or if the driver is nil,
+// it panics.
+func RegisterStringStoreDriver(name string, driver StringStoreDriver) {
+	if driver == nil {
+		panic("store: could not register nil StringStoreDriver")
+	}
+	if _, dup := stringStoreDrivers[name]; dup {
+		panic("store: could not register duplicate StringStoreDriver: " + name)
+	}
+	stringStoreDrivers[name] = driver
+}
+
+// OpenStringStore returns a StringStore specified by a configuration.
+func OpenStringStore(cfg *Config) (StringStore, error) {
+	driver, ok := stringStoreDrivers[cfg.StringStore]
+	if !ok {
+		return nil, fmt.Errorf("store: unknown driver %q (forgotten import?)", cfg.StringStore)
+	}
+
+	return driver.New(cfg)
+}