Release v0.1.0

vendor/github.com/btcsuite/btcd/database/driver.go

@@ -0,0 +1,89 @@
+// Copyright (c) 2015-2016 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package database
+
+import (
+	"fmt"
+
+	"github.com/btcsuite/btclog"
+)
+
+// Driver defines a structure for backend drivers to use when they registered
+// themselves as a backend which implements the DB interface.
+type Driver struct {
+	// DbType is the identifier used to uniquely identify a specific
+	// database driver.  There can be only one driver with the same name.
+	DbType string
+
+	// Create is the function that will be invoked with all user-specified
+	// arguments to create the database.  This function must return
+	// ErrDbExists if the database already exists.
+	Create func(args ...interface{}) (DB, error)
+
+	// Open is the function that will be invoked with all user-specified
+	// arguments to open the database.  This function must return
+	// ErrDbDoesNotExist if the database has not already been created.
+	Open func(args ...interface{}) (DB, error)
+
+	// UseLogger uses a specified Logger to output package logging info.
+	UseLogger func(logger btclog.Logger)
+}
+
+// driverList holds all of the registered database backends.
+var drivers = make(map[string]*Driver)
+
+// RegisterDriver adds a backend database driver to available interfaces.
+// ErrDbTypeRegistered will be returned if the database type for the driver has
+// already been registered.
+func RegisterDriver(driver Driver) error {
+	if _, exists := drivers[driver.DbType]; exists {
+		str := fmt.Sprintf("driver %q is already registered",
+			driver.DbType)
+		return makeError(ErrDbTypeRegistered, str, nil)
+	}
+
+	drivers[driver.DbType] = &driver
+	return nil
+}
+
+// SupportedDrivers returns a slice of strings that represent the database
+// drivers that have been registered and are therefore supported.
+func SupportedDrivers() []string {
+	supportedDBs := make([]string, 0, len(drivers))
+	for _, drv := range drivers {
+		supportedDBs = append(supportedDBs, drv.DbType)
+	}
+	return supportedDBs
+}
+
+// Create initializes and opens a database for the specified type.  The
+// arguments are specific to the database type driver.  See the documentation
+// for the database driver for further details.
+//
+// ErrDbUnknownType will be returned if the the database type is not registered.
+func Create(dbType string, args ...interface{}) (DB, error) {
+	drv, exists := drivers[dbType]
+	if !exists {
+		str := fmt.Sprintf("driver %q is not registered", dbType)
+		return nil, makeError(ErrDbUnknownType, str, nil)
+	}
+
+	return drv.Create(args...)
+}
+
+// Open opens an existing database for the specified type.  The arguments are
+// specific to the database type driver.  See the documentation for the database
+// driver for further details.
+//
+// ErrDbUnknownType will be returned if the the database type is not registered.
+func Open(dbType string, args ...interface{}) (DB, error) {
+	drv, exists := drivers[dbType]
+	if !exists {
+		str := fmt.Sprintf("driver %q is not registered", dbType)
+		return nil, makeError(ErrDbUnknownType, str, nil)
+	}
+
+	return drv.Open(args...)
+}