btcd/database/ffldb/driver.go

// 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 ffldb

import (
	"fmt"

	"github.com/btcsuite/btcd/database"
	"github.com/btcsuite/btcd/wire"
	"github.com/btcsuite/btclog"
)

var log = btclog.Disabled

const (
	LevelDB  = "ffldb"
	PebbleDB = "pebbledb"
)

// parseArgs parses the arguments from the database Open/Create methods.
func parseArgs(dbType, funcName string, args ...interface{}) (string, wire.BitcoinNet, error) {
	if len(args) != 2 {
		return "", 0, fmt.Errorf("invalid arguments to %s.%s -- "+
			"expected database path and block network", dbType,
			funcName)
	}

	dbPath, ok := args[0].(string)
	if !ok {
		return "", 0, fmt.Errorf("first argument to %s.%s is invalid -- "+
			"expected database path string", dbType, funcName)
	}

	network, ok := args[1].(wire.BitcoinNet)
	if !ok {
		return "", 0, fmt.Errorf("second argument to %s.%s is invalid -- "+
			"expected block network", dbType, funcName)
	}

	return dbPath, network, nil
}

// openDBDriver is the callback provided during driver registration that opens
// an existing database for use.
func openDBDriver(dbType string, args ...interface{}) (database.DB, error) {
	dbPath, network, err := parseArgs(dbType, "Open", args...)
	if err != nil {
		return nil, err
	}

	return openDB(dbType, dbPath, network, false)
}

// createDBDriver is the callback provided during driver registration that
// creates, initializes, and opens a database for use.
func createDBDriver(dbType string, args ...interface{}) (database.DB, error) {
	dbPath, network, err := parseArgs(dbType, "Create", args...)
	if err != nil {
		return nil, err
	}

	return openDB(dbType, dbPath, network, true)
}

// useLogger is the callback provided during driver registration that sets the
// current logger to the provided one.
func useLogger(logger btclog.Logger) {
	log = logger
}

func init() {
	// Register the drivers.
	drivers := []database.Driver{
		{
			DbType:    LevelDB,
			Create:    createDBDriver,
			Open:      openDBDriver,
			UseLogger: useLogger,
		},
		{
			DbType:    PebbleDB,
			Create:    createDBDriver,
			Open:      openDBDriver,
			UseLogger: useLogger,
		},
	}
	for _, driver := range drivers {
		if err := database.RegisterDriver(driver); err != nil {
			panic(fmt.Sprintf("Failed to register database driver '%s': %v",
				driver.DbType, err))
		}
	}
}