xorm.go

// Copyright 2015 The Xorm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package xorm

import (
	"fmt"
	"reflect"
	"runtime"
	"sync"

	"github.com/lingochamp/core"
)

const (
	// Version show the xorm's version
	Version string = "0.6.4.0910"
)

func regDrvsNDialects() bool {
	providedDrvsNDialects := map[string]struct {
		dbType     core.DbType
		getDriver  func() core.Driver
		getDialect func() core.Dialect
	}{
		"mssql": {"mssql", func() core.Driver { return &odbcDriver{} }, func() core.Dialect { return &mssql{} }},
		"odbc":  {"mssql", func() core.Driver { return &odbcDriver{} }, func() core.Dialect { return &mssql{} }}, // !nashtsai! TODO change this when supporting MS Access
		"mysql": {"mysql", func() core.Driver { return &mysqlDriver{} }, func() core.Dialect { return &mysql{} }},
		// OpenCensus SQL database driver wrapper. https://github.com/opencensus-integrations/ocsql
		"ocmysql":  {"mysql", func() core.Driver { return &mysqlDriver{} }, func() core.Dialect { return &mysql{} }},
		"mymysql":  {"mysql", func() core.Driver { return &mymysqlDriver{} }, func() core.Dialect { return &mysql{} }},
		"postgres": {"postgres", func() core.Driver { return &pqDriver{} }, func() core.Dialect { return &postgres{} }},
		"pgx":      {"postgres", func() core.Driver { return &pqDriver{} }, func() core.Dialect { return &postgres{} }},
		"sqlite3":  {"sqlite3", func() core.Driver { return &sqlite3Driver{} }, func() core.Dialect { return &sqlite3{} }},
		"oci8":     {"oracle", func() core.Driver { return &oci8Driver{} }, func() core.Dialect { return &oracle{} }},
		"goracle":  {"oracle", func() core.Driver { return &goracleDriver{} }, func() core.Dialect { return &oracle{} }},
	}

	for driverName, v := range providedDrvsNDialects {
		if driver := core.QueryDriver(driverName); driver == nil {
			core.RegisterDriver(driverName, v.getDriver())
			core.RegisterDialect(v.dbType, v.getDialect)
		}
	}
	return true
}

func close(engine *Engine) {
	engine.Close()
}

func init() {
	regDrvsNDialects()
}

// NewEngine new a db manager according to the parameter. Currently support four
// drivers
func NewEngine(driverName string, dataSourceName string, opts ...Option) (*Engine, error) {
	driver := core.QueryDriver(driverName)
	if driver == nil {
		return nil, fmt.Errorf("Unsupported driver name: %v", driverName)
	}

	uri, err := driver.Parse(driverName, dataSourceName)
	if err != nil {
		return nil, err
	}

	dialect := core.QueryDialect(uri.DbType)
	if dialect == nil {
		return nil, fmt.Errorf("Unsupported dialect type: %v", uri.DbType)
	}

	db, err := core.Open(driverName, dataSourceName)
	if err != nil {
		return nil, err
	}
	err = dialect.Init(db, uri, driverName, dataSourceName)
	if err != nil {
		return nil, err
	}

	engine := &Engine{
		db:            db,
		dialect:       dialect,
		Tables:        make(map[reflect.Type]*core.Table, 0),
		mutex:         &sync.RWMutex{},
		TagIdentifier: "xorm",
		tagHandlers:   defaultTagHandlers,
		opts:          opts,
	}

	fns := append(defaultOptions(), opts...)
	for _, fn := range fns {
		fn(engine)
	}

	runtime.SetFinalizer(engine, close)

	return engine, nil
}

// Clone clone an engine
func (engine *Engine) Clone() (*Engine, error) {
	return NewEngine(engine.DriverName(), engine.DataSourceName(), engine.opts...)
}