95 lines
2.3 KiB
Go
95 lines
2.3 KiB
Go
// Copyright (c) 2012-2016 The Revel Framework Authors, All rights reserved.
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// Revel Framework source code and usage is governed by a MIT style
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// license that can be found in the LICENSE file.
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// Package db module configures a database connection for the application.
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//
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// Developers use this module by importing and calling db.Init().
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// A "Transactional" controller type is provided as a way to import interceptors
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// that manage the transaction
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//
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// In particular, a transaction is begun before each request and committed on
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// success. If a panic occurred during the request, the transaction is rolled
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// back. (The application may also roll the transaction back itself.)
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package db
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import (
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"database/sql"
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"github.com/revel/revel"
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)
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// Database connection variables
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var (
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Db *sql.DB
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Driver string
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Spec string
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)
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// Init method used to initialize DB module on `OnAppStart`
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func Init() {
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// Read configuration.
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var found bool
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if Driver, found = revel.Config.String("db.driver"); !found {
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revel.RevelLog.Fatal("db.driver not configured")
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}
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if Spec, found = revel.Config.String("db.spec"); !found {
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revel.RevelLog.Fatal("db.spec not configured")
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}
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// Open a connection.
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var err error
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Db, err = sql.Open(Driver, Spec)
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if err != nil {
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revel.RevelLog.Fatal("Open database connection error", "error", err, "driver", Driver, "spec", Spec)
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}
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}
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// Transactional definition for database transaction
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type Transactional struct {
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*revel.Controller
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Txn *sql.Tx
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}
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// Begin a transaction
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func (c *Transactional) Begin() revel.Result {
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txn, err := Db.Begin()
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if err != nil {
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panic(err)
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}
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c.Txn = txn
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return nil
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}
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// Rollback if it's still going (must have panicked).
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func (c *Transactional) Rollback() revel.Result {
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if c.Txn != nil {
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if err := c.Txn.Rollback(); err != nil {
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if err != sql.ErrTxDone {
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panic(err)
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}
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}
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c.Txn = nil
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}
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return nil
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}
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// Commit the transaction.
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func (c *Transactional) Commit() revel.Result {
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if c.Txn != nil {
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if err := c.Txn.Commit(); err != nil {
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if err != sql.ErrTxDone {
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panic(err)
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}
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}
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c.Txn = nil
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}
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return nil
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}
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func init() {
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revel.InterceptMethod((*Transactional).Begin, revel.BEFORE)
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revel.InterceptMethod((*Transactional).Commit, revel.AFTER)
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revel.InterceptMethod((*Transactional).Rollback, revel.FINALLY)
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}
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