From 8a9b95300af2e86e650c6c8d622a3cca728af5b4 Mon Sep 17 00:00:00 2001
From: "Bora M. Alper" <bora@boramalper.org>
Date: Fri, 27 Nov 2020 17:55:57 +0000
Subject: [PATCH] pkg/persistence refactoring

---
 pkg/persistence/interface.go |  6 ++++--
 pkg/persistence/postgres.go  |  8 ++------
 pkg/persistence/stdout.go    | 12 +++++-------
 3 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/pkg/persistence/interface.go b/pkg/persistence/interface.go
index 26fd623..330c9ff 100644
--- a/pkg/persistence/interface.go
+++ b/pkg/persistence/interface.go
@@ -10,6 +10,8 @@ import (
 	"go.uber.org/zap"
 )
 
+var NotImplementedError = errors.New("Function not implemented")
+
 type Database interface {
 	Engine() databaseEngine
 	DoesTorrentExist(infoHash []byte) (bool, error)
@@ -59,8 +61,8 @@ const (
 type databaseEngine uint8
 
 const (
-	Sqlite3  databaseEngine = 1
-	Postgres databaseEngine = 2
+	Sqlite3 databaseEngine = iota + 1
+	Postgres
 	Stdout
 )
 
diff --git a/pkg/persistence/postgres.go b/pkg/persistence/postgres.go
index edfdd71..7a98278 100644
--- a/pkg/persistence/postgres.go
+++ b/pkg/persistence/postgres.go
@@ -197,11 +197,7 @@ func (db *postgresDatabase) QueryTorrents(
 	lastOrderedValue *float64,
 	lastID *uint64,
 ) ([]TorrentMetadata, error) {
-	err := fmt.Errorf("QueryTorrents is not supported yet by PostgreSQL backend")
-
-	torrents := make([]TorrentMetadata, 0)
-
-	return torrents, err
+	return nil, NotImplementedError
 }
 
 func (db *postgresDatabase) GetTorrent(infoHash []byte) (*TorrentMetadata, error) {
@@ -259,7 +255,7 @@ func (db *postgresDatabase) GetFiles(infoHash []byte) ([]File, error) {
 }
 
 func (db *postgresDatabase) GetStatistics(from string, n uint) (*Statistics, error) {
-	panic("Not implemented yet for PostgreSQL")
+	return nil, NotImplementedError
 }
 
 func (db *postgresDatabase) setupDatabase() error {
diff --git a/pkg/persistence/stdout.go b/pkg/persistence/stdout.go
index 814e4ac..a6228c8 100644
--- a/pkg/persistence/stdout.go
+++ b/pkg/persistence/stdout.go
@@ -15,8 +15,6 @@ type out struct {
 	Files    []File `json:"files"`
 }
 
-var notSupportedError = errors.New("This dummy database engine (\"stdout\") does not support any sort of queries")
-
 func makeStdoutDatabase(_ *url.URL) (Database, error) {
 	s := new(stdout)
 	s.encoder = json.NewEncoder(os.Stdout)
@@ -58,7 +56,7 @@ func (s *stdout) Close() error {
 }
 
 func (s *stdout) GetNumberOfTorrents() (uint, error) {
-	return 0, notSupportedError
+	return 0, NotImplementedError
 }
 
 func (s *stdout) QueryTorrents(
@@ -70,17 +68,17 @@ func (s *stdout) QueryTorrents(
 	lastOrderedValue *float64,
 	lastID *uint64,
 ) ([]TorrentMetadata, error) {
-	return nil, notSupportedError
+	return nil, NotImplementedError
 }
 
 func (s *stdout) GetTorrent(infoHash []byte) (*TorrentMetadata, error) {
-	return nil, notSupportedError
+	return nil, NotImplementedError
 }
 
 func (s *stdout) GetFiles(infoHash []byte) ([]File, error) {
-	return nil, notSupportedError
+	return nil, NotImplementedError
 }
 
 func (s *stdout) GetStatistics(from string, n uint) (*Statistics, error) {
-	return nil, notSupportedError
+	return nil, NotImplementedError
 }