From cf03e0e33859b213f1d7e55b300a074eea107100 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Guillot?= <fred@miniflux.net>
Date: Wed, 1 Aug 2018 20:28:45 -0700
Subject: [PATCH] Create database package (refactoring)

---
 cli/cli.go                                  | 16 ++++++++-----
 config/config.go                            | 10 ++++++--
 daemon/daemon.go                            |  1 -
 database/database.go                        | 25 ++++++++++++++++++++
 {storage => database}/migration.go          | 26 ++++++++++-----------
 {sql => database}/sql.go                    |  2 +-
 {sql => database/sql}/schema_version_1.sql  |  0
 {sql => database/sql}/schema_version_10.sql |  0
 {sql => database/sql}/schema_version_11.sql |  0
 {sql => database/sql}/schema_version_12.sql |  0
 {sql => database/sql}/schema_version_13.sql |  0
 {sql => database/sql}/schema_version_14.sql |  0
 {sql => database/sql}/schema_version_15.sql |  0
 {sql => database/sql}/schema_version_16.sql |  0
 {sql => database/sql}/schema_version_17.sql |  0
 {sql => database/sql}/schema_version_18.sql |  0
 {sql => database/sql}/schema_version_19.sql |  0
 {sql => database/sql}/schema_version_2.sql  |  0
 {sql => database/sql}/schema_version_20.sql |  0
 {sql => database/sql}/schema_version_3.sql  |  0
 {sql => database/sql}/schema_version_4.sql  |  0
 {sql => database/sql}/schema_version_5.sql  |  0
 {sql => database/sql}/schema_version_6.sql  |  0
 {sql => database/sql}/schema_version_7.sql  |  0
 {sql => database/sql}/schema_version_8.sql  |  0
 {sql => database/sql}/schema_version_9.sql  |  0
 generate.go                                 |  2 +-
 main.go                                     |  2 +-
 sql/doc.go                                  | 10 --------
 storage/storage.go                          | 21 ++---------------
 30 files changed, 61 insertions(+), 54 deletions(-)
 create mode 100644 database/database.go
 rename {storage => database}/migration.go (59%)
 rename {sql => database}/sql.go (99%)
 rename {sql => database/sql}/schema_version_1.sql (100%)
 rename {sql => database/sql}/schema_version_10.sql (100%)
 rename {sql => database/sql}/schema_version_11.sql (100%)
 rename {sql => database/sql}/schema_version_12.sql (100%)
 rename {sql => database/sql}/schema_version_13.sql (100%)
 rename {sql => database/sql}/schema_version_14.sql (100%)
 rename {sql => database/sql}/schema_version_15.sql (100%)
 rename {sql => database/sql}/schema_version_16.sql (100%)
 rename {sql => database/sql}/schema_version_17.sql (100%)
 rename {sql => database/sql}/schema_version_18.sql (100%)
 rename {sql => database/sql}/schema_version_19.sql (100%)
 rename {sql => database/sql}/schema_version_2.sql (100%)
 rename {sql => database/sql}/schema_version_20.sql (100%)
 rename {sql => database/sql}/schema_version_3.sql (100%)
 rename {sql => database/sql}/schema_version_4.sql (100%)
 rename {sql => database/sql}/schema_version_5.sql (100%)
 rename {sql => database/sql}/schema_version_6.sql (100%)
 rename {sql => database/sql}/schema_version_7.sql (100%)
 rename {sql => database/sql}/schema_version_8.sql (100%)
 rename {sql => database/sql}/schema_version_9.sql (100%)
 delete mode 100644 sql/doc.go

diff --git a/cli/cli.go b/cli/cli.go
index 4f5417ca..f4014db3 100644
--- a/cli/cli.go
+++ b/cli/cli.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/miniflux/miniflux/config"
 	"github.com/miniflux/miniflux/daemon"
+	"github.com/miniflux/miniflux/database"
 	"github.com/miniflux/miniflux/logger"
 	"github.com/miniflux/miniflux/storage"
 	"github.com/miniflux/miniflux/version"
@@ -33,10 +34,13 @@ func Parse() {
 		logger.EnableDebug()
 	}
 
-	store := storage.NewStorage(
-		cfg.DatabaseURL(),
-		cfg.DatabaseMaxConnections(),
-	)
+	db, err := database.NewConnectionPool(cfg.DatabaseURL(), cfg.DatabaseMinConns(), cfg.DatabaseMaxConns())
+	if err != nil {
+		logger.Fatal("Unable to connect to the database: %v", err)
+	}
+	defer db.Close()
+
+	store := storage.NewStorage(db)
 
 	if *flagInfo {
 		info()
@@ -49,7 +53,7 @@ func Parse() {
 	}
 
 	if *flagMigrate {
-		store.Migrate()
+		database.Migrate(db)
 		return
 	}
 
@@ -75,7 +79,7 @@ func Parse() {
 
 	// Run migrations and start the deamon.
 	if cfg.RunMigrations() {
-		store.Migrate()
+		database.Migrate(db)
 	}
 
 	// Create admin user and start the deamon.
diff --git a/config/config.go b/config/config.go
index 4cba7895..580f01d6 100644
--- a/config/config.go
+++ b/config/config.go
@@ -20,6 +20,7 @@ const (
 	defaultPollingFrequency = 60
 	defaultBatchSize        = 10
 	defaultDatabaseMaxConns = 20
+	defaultDatabaseMinConns = 1
 	defaultListenAddr       = "127.0.0.1:8080"
 	defaultCertFile         = ""
 	defaultKeyFile          = ""
@@ -119,11 +120,16 @@ func (c *Config) DatabaseURL() string {
 	return value
 }
 
-// DatabaseMaxConnections returns the number of maximum database connections.
-func (c *Config) DatabaseMaxConnections() int {
+// DatabaseMaxConns returns the maximum number of database connections.
+func (c *Config) DatabaseMaxConns() int {
 	return c.getInt("DATABASE_MAX_CONNS", defaultDatabaseMaxConns)
 }
 
+// DatabaseMinConns returns the minimum number of database connections.
+func (c *Config) DatabaseMinConns() int {
+	return c.getInt("DATABASE_MIN_CONNS", defaultDatabaseMinConns)
+}
+
 // ListenAddr returns the listen address for the HTTP server.
 func (c *Config) ListenAddr() string {
 	if port := os.Getenv("PORT"); port != "" {
diff --git a/daemon/daemon.go b/daemon/daemon.go
index cdd81ef1..de91d71a 100644
--- a/daemon/daemon.go
+++ b/daemon/daemon.go
@@ -59,6 +59,5 @@ func Run(cfg *config.Config, store *storage.Storage) {
 	defer cancel()
 
 	server.Shutdown(ctx)
-	store.Close()
 	logger.Info("Server gracefully stopped")
 }
diff --git a/database/database.go b/database/database.go
new file mode 100644
index 00000000..42f22925
--- /dev/null
+++ b/database/database.go
@@ -0,0 +1,25 @@
+// Copyright 2018 Frédéric Guillot. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package database
+
+import (
+	"database/sql"
+
+	// Postgresql driver import
+	_ "github.com/lib/pq"
+)
+
+// NewConnectionPool configures the database connection pool.
+func NewConnectionPool(dsn string, minConnections, maxConnections int) (*sql.DB, error) {
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		return nil, err
+	}
+
+	db.SetMaxOpenConns(maxConnections)
+	db.SetMaxIdleConns(minConnections)
+
+	return db, nil
+}
diff --git a/storage/migration.go b/database/migration.go
similarity index 59%
rename from storage/migration.go
rename to database/migration.go
index e78f1d55..e348e40c 100644
--- a/storage/migration.go
+++ b/database/migration.go
@@ -1,23 +1,23 @@
-// Copyright 2017 Frédéric Guillot. All rights reserved.
+// Copyright 2018 Frédéric Guillot. All rights reserved.
 // Use of this source code is governed by the Apache 2.0
 // license that can be found in the LICENSE file.
 
-package storage
+package database
 
 import (
+	"database/sql"
 	"fmt"
 	"strconv"
 
 	"github.com/miniflux/miniflux/logger"
-	"github.com/miniflux/miniflux/sql"
 )
 
 const schemaVersion = 20
 
-// Migrate run database migrations.
-func (s *Storage) Migrate() {
+// Migrate executes database migrations.
+func Migrate(db *sql.DB) {
 	var currentVersion int
-	s.db.QueryRow(`select version from schema_version`).Scan(&currentVersion)
+	db.QueryRow(`select version from schema_version`).Scan(&currentVersion)
 
 	fmt.Println("Current schema version:", currentVersion)
 	fmt.Println("Latest schema version:", schemaVersion)
@@ -25,31 +25,31 @@ func (s *Storage) Migrate() {
 	for version := currentVersion + 1; version <= schemaVersion; version++ {
 		fmt.Println("Migrating to version:", version)
 
-		tx, err := s.db.Begin()
+		tx, err := db.Begin()
 		if err != nil {
-			logger.Fatal("[Storage:Migrate] %v", err)
+			logger.Fatal("[Migrate] %v", err)
 		}
 
-		rawSQL := sql.SqlMap["schema_version_"+strconv.Itoa(version)]
+		rawSQL := SqlMap["schema_version_"+strconv.Itoa(version)]
 		// fmt.Println(rawSQL)
 		_, err = tx.Exec(rawSQL)
 		if err != nil {
 			tx.Rollback()
-			logger.Fatal("[Storage:Migrate] %v", err)
+			logger.Fatal("[Migrate] %v", err)
 		}
 
 		if _, err := tx.Exec(`delete from schema_version`); err != nil {
 			tx.Rollback()
-			logger.Fatal("[Storage:Migrate] %v", err)
+			logger.Fatal("[Migrate] %v", err)
 		}
 
 		if _, err := tx.Exec(`insert into schema_version (version) values($1)`, version); err != nil {
 			tx.Rollback()
-			logger.Fatal("[Storage:Migrate] %v", err)
+			logger.Fatal("[Migrate] %v", err)
 		}
 
 		if err := tx.Commit(); err != nil {
-			logger.Fatal("[Storage:Migrate] %v", err)
+			logger.Fatal("[Migrate] %v", err)
 		}
 	}
 }
diff --git a/sql/sql.go b/database/sql.go
similarity index 99%
rename from sql/sql.go
rename to database/sql.go
index 60af4c5b..a9468ecb 100644
--- a/sql/sql.go
+++ b/database/sql.go
@@ -1,6 +1,6 @@
 // Code generated by go generate; DO NOT EDIT.
 
-package sql
+package database
 
 var SqlMap = map[string]string{
 	"schema_version_1": `create table schema_version (
diff --git a/sql/schema_version_1.sql b/database/sql/schema_version_1.sql
similarity index 100%
rename from sql/schema_version_1.sql
rename to database/sql/schema_version_1.sql
diff --git a/sql/schema_version_10.sql b/database/sql/schema_version_10.sql
similarity index 100%
rename from sql/schema_version_10.sql
rename to database/sql/schema_version_10.sql
diff --git a/sql/schema_version_11.sql b/database/sql/schema_version_11.sql
similarity index 100%
rename from sql/schema_version_11.sql
rename to database/sql/schema_version_11.sql
diff --git a/sql/schema_version_12.sql b/database/sql/schema_version_12.sql
similarity index 100%
rename from sql/schema_version_12.sql
rename to database/sql/schema_version_12.sql
diff --git a/sql/schema_version_13.sql b/database/sql/schema_version_13.sql
similarity index 100%
rename from sql/schema_version_13.sql
rename to database/sql/schema_version_13.sql
diff --git a/sql/schema_version_14.sql b/database/sql/schema_version_14.sql
similarity index 100%
rename from sql/schema_version_14.sql
rename to database/sql/schema_version_14.sql
diff --git a/sql/schema_version_15.sql b/database/sql/schema_version_15.sql
similarity index 100%
rename from sql/schema_version_15.sql
rename to database/sql/schema_version_15.sql
diff --git a/sql/schema_version_16.sql b/database/sql/schema_version_16.sql
similarity index 100%
rename from sql/schema_version_16.sql
rename to database/sql/schema_version_16.sql
diff --git a/sql/schema_version_17.sql b/database/sql/schema_version_17.sql
similarity index 100%
rename from sql/schema_version_17.sql
rename to database/sql/schema_version_17.sql
diff --git a/sql/schema_version_18.sql b/database/sql/schema_version_18.sql
similarity index 100%
rename from sql/schema_version_18.sql
rename to database/sql/schema_version_18.sql
diff --git a/sql/schema_version_19.sql b/database/sql/schema_version_19.sql
similarity index 100%
rename from sql/schema_version_19.sql
rename to database/sql/schema_version_19.sql
diff --git a/sql/schema_version_2.sql b/database/sql/schema_version_2.sql
similarity index 100%
rename from sql/schema_version_2.sql
rename to database/sql/schema_version_2.sql
diff --git a/sql/schema_version_20.sql b/database/sql/schema_version_20.sql
similarity index 100%
rename from sql/schema_version_20.sql
rename to database/sql/schema_version_20.sql
diff --git a/sql/schema_version_3.sql b/database/sql/schema_version_3.sql
similarity index 100%
rename from sql/schema_version_3.sql
rename to database/sql/schema_version_3.sql
diff --git a/sql/schema_version_4.sql b/database/sql/schema_version_4.sql
similarity index 100%
rename from sql/schema_version_4.sql
rename to database/sql/schema_version_4.sql
diff --git a/sql/schema_version_5.sql b/database/sql/schema_version_5.sql
similarity index 100%
rename from sql/schema_version_5.sql
rename to database/sql/schema_version_5.sql
diff --git a/sql/schema_version_6.sql b/database/sql/schema_version_6.sql
similarity index 100%
rename from sql/schema_version_6.sql
rename to database/sql/schema_version_6.sql
diff --git a/sql/schema_version_7.sql b/database/sql/schema_version_7.sql
similarity index 100%
rename from sql/schema_version_7.sql
rename to database/sql/schema_version_7.sql
diff --git a/sql/schema_version_8.sql b/database/sql/schema_version_8.sql
similarity index 100%
rename from sql/schema_version_8.sql
rename to database/sql/schema_version_8.sql
diff --git a/sql/schema_version_9.sql b/database/sql/schema_version_9.sql
similarity index 100%
rename from sql/schema_version_9.sql
rename to database/sql/schema_version_9.sql
diff --git a/generate.go b/generate.go
index 7b845aa9..cba64e31 100644
--- a/generate.go
+++ b/generate.go
@@ -209,7 +209,7 @@ func main() {
 
 	generateBinaryBundle("ui/static/bin.go", glob("ui/static/bin/*"))
 
-	generateBundle("sql/sql.go", "sql", "SqlMap", glob("sql/*.sql"))
+	generateBundle("database/sql.go", "database", "SqlMap", glob("database/sql/*.sql"))
 	generateBundle("template/views.go", "template", "templateViewsMap", glob("template/html/*.html"))
 	generateBundle("template/common.go", "template", "templateCommonMap", glob("template/html/common/*.html"))
 	generateBundle("locale/translations.go", "locale", "translations", glob("locale/translations/*.json"))
diff --git a/main.go b/main.go
index 951329a8..44f38dbb 100644
--- a/main.go
+++ b/main.go
@@ -5,7 +5,7 @@
 package main
 
 //go:generate go run generate.go
-//go:generate gofmt -s -w sql/sql.go
+//go:generate gofmt -s -w database/sql.go
 //go:generate gofmt -s -w ui/static/css.go
 //go:generate gofmt -s -w ui/static/bin.go
 //go:generate gofmt -s -w ui/static/js.go
diff --git a/sql/doc.go b/sql/doc.go
deleted file mode 100644
index 2096efc6..00000000
--- a/sql/doc.go
+++ /dev/null
@@ -1,10 +0,0 @@
-// Copyright 2018 Frédéric Guillot. All rights reserved.
-// Use of this source code is governed by the MIT license
-// that can be found in the LICENSE file.
-
-/*
-
-Package sql contains all SQL queries or database schema instructions.
-
-*/
-package sql
diff --git a/storage/storage.go b/storage/storage.go
index f7a06b4d..19372f07 100644
--- a/storage/storage.go
+++ b/storage/storage.go
@@ -6,10 +6,6 @@ package storage
 
 import (
 	"database/sql"
-
-	// Postgresql driver import
-	_ "github.com/lib/pq"
-	"github.com/miniflux/miniflux/logger"
 )
 
 // Storage handles all operations related to the database.
@@ -17,20 +13,7 @@ type Storage struct {
 	db *sql.DB
 }
 
-// Close closes all database connections.
-func (s *Storage) Close() {
-	s.db.Close()
-}
-
 // NewStorage returns a new Storage.
-func NewStorage(databaseURL string, maxOpenConns int) *Storage {
-	db, err := sql.Open("postgres", databaseURL)
-	if err != nil {
-		logger.Fatal("[Storage] Unable to connect to the database: %v", err)
-	}
-
-	db.SetMaxOpenConns(maxOpenConns)
-	db.SetMaxIdleConns(2)
-
-	return &Storage{db: db}
+func NewStorage(db *sql.DB) *Storage {
+	return &Storage{db}
 }