Share HTML template renderers and create a watcher framework (#20218)

The recovery, API, Web and package frameworks all create their own HTML
Renderers. This increases the memory requirements of Gitea
unnecessarily with duplicate templates being kept in memory.

Further the reloading framework in dev mode for these involves locking
and recompiling all of the templates on each load. This will potentially
hide concurrency issues and it is inefficient.

This PR stores the templates renderer in the context and stores this
context in the NormalRoutes, it then creates a fsnotify.Watcher
framework to watch files.

The watching framework is then extended to the mailer templates which
were previously not being reloaded in dev.

Then the locales are simplified to a similar structure.

Fix #20210 
Fix #20211
Fix #20217

Signed-off-by: Andrew Thornton <art27@cantab.net>

services/auth/group.go

@@ -5,6 +5,7 @@
 package auth
 
 import (
+	"context"
 	"net/http"
 	"reflect"
 	"strings"
@@ -51,14 +52,14 @@ func (b *Group) Name() string {
 }
 
 // Init does nothing as the Basic implementation does not need to allocate any resources
-func (b *Group) Init() error {
+func (b *Group) Init(ctx context.Context) error {
 	for _, method := range b.methods {
 		initializable, ok := method.(Initializable)
 		if !ok {
 			continue
 		}
 
-		if err := initializable.Init(); err != nil {
+		if err := initializable.Init(ctx); err != nil {
 			return err
 		}
 	}

services/auth/interface.go

@@ -34,7 +34,7 @@ type Method interface {
 type Initializable interface {
 	// Init should be called exactly once before using any of the other methods,
 	// in order to allow the plugin to allocate necessary resources
-	Init() error
+	Init(ctx context.Context) error
 }
 
 // Named represents a named thing

services/auth/sspi_windows.go

@@ -5,6 +5,7 @@
 package auth
 
 import (
+	"context"
 	"errors"
 	"net/http"
 	"strings"
@@ -52,21 +53,14 @@ type SSPI struct {
 }
 
 // Init creates a new global websspi.Authenticator object
-func (s *SSPI) Init() error {
+func (s *SSPI) Init(ctx context.Context) error {
 	config := websspi.NewConfig()
 	var err error
 	sspiAuth, err = websspi.New(config)
 	if err != nil {
 		return err
 	}
-	s.rnd = render.New(render.Options{
-		Extensions:    []string{".tmpl"},
-		Directory:     "templates",
-		Funcs:         templates.NewFuncMap(),
-		Asset:         templates.GetAsset,
-		AssetNames:    templates.GetAssetNames,
-		IsDevelopment: !setting.IsProd,
-	})
+	_, s.rnd = templates.HTMLRenderer(ctx)
 	return nil
 }
 

services/mailer/mailer.go

@@ -7,6 +7,7 @@ package mailer
 
 import (
 	"bytes"
+	"context"
 	"crypto/tls"
 	"fmt"
 	"hash/fnv"
@@ -348,7 +349,7 @@ var mailQueue queue.Queue
 var Sender gomail.Sender
 
 // NewContext start mail queue service
-func NewContext() {
+func NewContext(ctx context.Context) {
 	// Need to check if mailQueue is nil because in during reinstall (user had installed
 	// before but switched install lock off), this function will be called again
 	// while mail queue is already processing tasks, and produces a race condition.
@@ -381,7 +382,7 @@ func NewContext() {
 
 	go graceful.GetManager().RunWithShutdownFns(mailQueue.Run)
 
-	subjectTemplates, bodyTemplates = templates.Mailer()
+	subjectTemplates, bodyTemplates = templates.Mailer(ctx)
 }
 
 // SendAsync send mail asynchronously