Switch to global database pointer

Passing the database pointer around is a lot of text and has no benefit.

5 files changed, 62 insertions, 85 deletions

diff --git a/database.go b/database.go
index d19572a..1efd22e 100644
--- a/database.go
+++ b/database.go
@@ -20,17 +20,26 @@ import (
 const databaseSchemaVersion int = 2  // this defines the needed version for the
                                      // executable
 
-type Database struct {
-	target string
-	Backend *sql.DB
-}
+func setupDatabase() *sql.DB {
+
+	u,err := user.Current()
+	if err != nil {
+		log.Fatal(err)
+	}
+	target := fmt.Sprintf("%s@unix(%s)/%s", u.Username, config.Database.Socket,
+	                      config.Database.Database)
+
+	db,err := sql.Open("mysql", target)
+	if err != nil {
+		log.Fatal(err)
+	}
 
-func InitDatabase() Database {
+	err = db.Ping()
+	if err != nil {
+		log.Fatal(err)
+	}
 
-	db := NewDatabase()
-	db.Connect()
-	db.Ping()
-	db.Migrate()
+	migrate(db)
 
 	// allow graceful shutdown
 	var listener = make(chan os.Signal)
@@ -39,53 +48,19 @@ func InitDatabase() Database {
 	go func() {
 		signal := <-listener
 		log.Printf("\nGot signal '%+v'. Shutting down ...\n", signal)
-		db.Cleanup()
+		dbCleanup(db)
 		os.Exit(0)  // TODO this does not belong to a database - write utils file 'shutdown.go'
 	}()
 
 	return db
 }
 
-func NewDatabase() Database {
-
-	db := Database{}
-
-	var username string
-	user_ptr,err := user.Current()
-	if err != nil {
-		log.Fatal(err)
-	}
-	username = user_ptr.Username
-	db.target = fmt.Sprintf("%s@unix(%s)/%s", username, config.Database.Socket,
-	                        config.Database.Database)
-
-	return db
-}
-
-func (db *Database) Connect() {
-	var err error
-	db.Backend,err = sql.Open("mysql", db.target)
-	if err != nil {
-		log.Fatal(err)
-	}
-	log.Printf("Connected to database '%s'\n", db.target)
-}
-
-func (db *Database) Ping() {
-	err := db.Backend.Ping()
-	if err != nil {
-		log.Fatal(err)
-	} else {
-		log.Println("Database is responding")
-	}
-}
-
-func (db *Database) Migrate() {
+func migrate(db *sql.DB) {
 
 	const t = databaseSchemaVersion  // targeted database schema version
 
 	for {
-		v := db.SchemaVersion()  // read schema version from DB table
+		v := schemaVersion(db)  // read schema version from DB table
 
 		// handle current database schema which is newer than targeted one
 		if v > t {
@@ -102,12 +77,12 @@ func (db *Database) Migrate() {
 		log.Printf("Starting database schema migration to version %d.\n", v+1)
 		path := filepath.Join(config.Database.Migrations,
 		                      fmt.Sprintf("%04d_migration.sql", v+1))
-		RunSql(path)
+		RunSqlScript(path)
 		log.Printf("Finished database schema migration to version %d.\n", v+1)
 	}
 }
 
-func RunSql(path string) {
+func RunSqlScript(path string) {
 
 	script, err := os.Open(path)
 	if err != nil {
@@ -133,11 +108,11 @@ func RunSql(path string) {
 	}
 }
 
-func (db *Database) SchemaVersion() int {
+func schemaVersion(db *sql.DB) int {
 
 	// ask database for schema version
 	cmd := "SELECT value FROM meta WHERE (identifier='version');"
-	rows, err := db.Backend.Query(cmd)
+	rows, err := db.Query(cmd)
 
 	// handle missing meta table
 	if err != nil {
@@ -165,8 +140,8 @@ func (db *Database) SchemaVersion() int {
 	return v
 }
 
-func (db *Database) Cleanup() {
-	err := db.Backend.Close()
+func dbCleanup(db *sql.DB) {
+	err := db.Close()
 	if err != nil {
 		log.Println("Could not close database connection")
 	} else {
diff --git a/handler.go b/handler.go
index b6c57c4..0899797 100644
--- a/handler.go
+++ b/handler.go
@@ -17,12 +17,12 @@ const (
 	VALID_ID_REGEX = `^[0-9]+$`
 )
 
-func indexGet(w http.ResponseWriter, r *http.Request, db *Database) {
+func indexGet(w http.ResponseWriter, r *http.Request) {
 
 	// get data from database
 	cmd := "SELECT id,title FROM recipes ORDER BY title;"
 	log.Printf("Query: %s", cmd)
-	rows, err := db.Backend.Query(cmd)
+	rows, err := db.Query(cmd)
 	if err != nil {
 		http.Error(w, "Failed to load recipes from database.", 500)
 		return
@@ -53,7 +53,7 @@ func indexGet(w http.ResponseWriter, r *http.Request, db *Database) {
 	ServeTemplate(w, "index", path, elements)
 }
 
-func recipeGet(w http.ResponseWriter, r *http.Request, db *Database) {
+func recipeGet(w http.ResponseWriter, r *http.Request) {
 
 	// get id from URL parameters
 	ids := r.URL.Query()["id"]
@@ -74,7 +74,7 @@ func recipeGet(w http.ResponseWriter, r *http.Request, db *Database) {
 	// get data from database
 	cmd := fmt.Sprintf("SELECT title,upstream_url,description_markdown FROM recipes WHERE (id='%s');", idStr)
 	log.Printf("Query: %s", cmd)
-	rows, err := db.Backend.Query(cmd)
+	rows, err := db.Query(cmd)
 	if err != nil {
 		http.Error(w, "Database returned error: " + err.Error(), 500)
 		return
@@ -120,7 +120,7 @@ func recipeGet(w http.ResponseWriter, r *http.Request, db *Database) {
 	ServeTemplate(w, "recipe", path, elements[0])
 }
 
-func recipePost(w http.ResponseWriter, r *http.Request, db *Database) {
+func recipePost(w http.ResponseWriter, r *http.Request) {
 
 	// get id from URL parameters
 	ids := r.URL.Query()["id"]
@@ -141,10 +141,10 @@ func recipePost(w http.ResponseWriter, r *http.Request, db *Database) {
 	// read request body
 	buffer,_ := ioutil.ReadAll(r.Body)  // FIXME error handling
 	body := string(buffer)
-	updateRecipe(db, body, idStr)
+	updateRecipe(body, idStr)
 }
 
-func recipeEditGet(w http.ResponseWriter, r *http.Request, db *Database) {
+func recipeEditGet(w http.ResponseWriter, r *http.Request) {
 
 	// get id from URL parameters
 	ids := r.URL.Query()["id"]
@@ -164,7 +164,7 @@ func recipeEditGet(w http.ResponseWriter, r *http.Request, db *Database) {
 	// get data from database
 	cmd := fmt.Sprintf("SELECT title,upstream_url,description_markdown FROM recipes WHERE (id='%s');", idStr)
 	log.Printf("Query: %s", cmd)
-	rows, err := db.Backend.Query(cmd)
+	rows, err := db.Query(cmd)
 	if err != nil {
 		http.Error(w, "Got error from database: " + err.Error(), 500)
 		return
@@ -205,7 +205,7 @@ func recipeEditGet(w http.ResponseWriter, r *http.Request, db *Database) {
 	ServeTemplate(w, "recipe", path, elements[0])
 }
 
-func recipeEditPost(w http.ResponseWriter, r *http.Request, db *Database) {
+func recipeEditPost(w http.ResponseWriter, r *http.Request) {
 
 	// get id from URL parameters
 	ids := r.URL.Query()["id"]
@@ -225,13 +225,13 @@ func recipeEditPost(w http.ResponseWriter, r *http.Request, db *Database) {
 	// read request body
 	buffer,_ := ioutil.ReadAll(r.Body)  // FIXME error handling
 	body := string(buffer)
-	updateRecipe(db, body, idStr)
+	updateRecipe(body, idStr)
 }
 
-func updateRecipe(db *Database, body string, idStr string) {
+func updateRecipe(body string, idStr string) {
 
 	// execute SQL UPDATE
-	_,_ = db.Backend.Exec(`
+	_,_ = db.Exec(`
 		UPDATE
 			recipes
 		SET
@@ -275,14 +275,14 @@ func addRecipesGet(w http.ResponseWriter, r *http.Request) {
 	http.ServeFile(w, r, path)
 }
 
-func addRecipesPost(w http.ResponseWriter, r *http.Request, db *Database) {
+func addRecipesPost(w http.ResponseWriter, r *http.Request) {
 
 	url := r.FormValue("url")
 	title := r.FormValue("title")
 
 	cmd := fmt.Sprintf("INSERT INTO recipes (title,upstream_url) VALUES ('%s', '%s')", title, url)
 	log.Println(cmd)
-	res,err := db.Backend.Exec(cmd)
+	res,err := db.Exec(cmd)
 	if err != nil {
 		http.Error(w, "Could not add recipe.", 500)
 		return
diff --git a/main.go b/main.go
index 0473231..3afdf49 100644
--- a/main.go
+++ b/main.go
@@ -3,13 +3,15 @@ package main
 
 import (
 	"log"
+	"database/sql"
 )
 
 var config RuntimeConfig
+var db *sql.DB
 
 func main() {
 	config = GetRuntimeConfig()
 	log.Printf("Starting ceres with config file '%s'\n", config.Path)
-	db := InitDatabase()
-	runServer(&db)
+	db = setupDatabase()
+	runServer()
 }
diff --git a/mux.go b/mux.go
index 3aed42d..2b37286 100644
--- a/mux.go
+++ b/mux.go
@@ -5,37 +5,37 @@ import (
 	"net/http"
 )
 
-func indexMux(db *Database) func(http.ResponseWriter, *http.Request) {
+func indexMux() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case "GET":
-			indexGet(w, r, db)
+			indexGet(w, r)
 		default:
 			http.Error(w, "Bad Request", 400)
 		}
 	}
 }
 
-func recipeMux(db *Database) func(http.ResponseWriter, *http.Request) {
+func recipeMux() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case "GET":
-			recipeGet(w, r, db)
+			recipeGet(w, r)
 		case "POST":
-			recipePost(w, r, db)
+			recipePost(w, r)
 		default:
 			http.Error(w, "Bad Request", 400)
 		}
 	}
 }
 
-func recipeEditMux(db *Database) func(http.ResponseWriter, *http.Request) {
+func recipeEditMux() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case "GET":
-			recipeEditGet(w, r, db)
+			recipeEditGet(w, r)
 		case "POST":
-			recipeEditPost(w, r, db)
+			recipeEditPost(w, r)
 		default:
 			http.Error(w, "Bad Request", 400)
 		}
@@ -53,13 +53,13 @@ func recipeImageMux() func(http.ResponseWriter, *http.Request) {
 	}
 }
 
-func addRecipesMux(db *Database) func(http.ResponseWriter, *http.Request) {
+func addRecipesMux() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case "GET":
 			addRecipesGet(w, r)
 		case "POST":
-			addRecipesPost(w, r, db)
+			addRecipesPost(w, r)
 		default:
 			http.Error(w, "Bad Request", 400)
 		}
diff --git a/server.go b/server.go
index f7f67f4..d70373b 100644
--- a/server.go
+++ b/server.go
@@ -6,20 +6,20 @@ import (
 	"net/http"
 )
 
-func setupRoutes(db *Database) {
+func setupRoutes() {
 
-	http.HandleFunc("/", indexMux(db))
-	http.HandleFunc("/recipe", recipeMux(db))
-	http.HandleFunc("/recipe/edit", recipeEditMux(db))
+	http.HandleFunc("/", indexMux())
+	http.HandleFunc("/recipe", recipeMux())
+	http.HandleFunc("/recipe/edit", recipeEditMux())
 	http.HandleFunc("/recipe/image", recipeImageMux())
-	http.HandleFunc("/add_recipes", addRecipesMux(db))
+	http.HandleFunc("/add_recipes", addRecipesMux())
 	http.HandleFunc("/static/style.css", staticStyleMux())
 	http.HandleFunc("/favicon.ico", faviconMux())
 }
 
-func runServer(db *Database) {
+func runServer() {
 
-	setupRoutes(db)
+	setupRoutes()
 	address := config.Http.Host + ":" + config.Http.Port
 	log.Println("Binding to 'http://" + address)
 	log.Fatal(http.ListenAndServe(address, nil))