Fix the number of Dart sass transpiler instances spun up

server/app/boot_levels.go

@@ -1,54 +1,53 @@
 package app
 
 import (
-	"context"
-	"crypto/tls"
-	"fmt"
-	"github.com/cortezaproject/corteza/server/pkg/sass"
-	"net/url"
-	"os"
-	"regexp"
-	"strings"
-	"time"
+    "context"
+    "crypto/tls"
+    "fmt"
+    "net/url"
+    "os"
+    "regexp"
+    "strings"
+    "time"
 
-	authService "github.com/cortezaproject/corteza/server/auth"
-	"github.com/cortezaproject/corteza/server/auth/saml"
-	authSettings "github.com/cortezaproject/corteza/server/auth/settings"
-	autService "github.com/cortezaproject/corteza/server/automation/service"
-	cmpService "github.com/cortezaproject/corteza/server/compose/service"
-	cmpEvent "github.com/cortezaproject/corteza/server/compose/service/event"
-	discoveryService "github.com/cortezaproject/corteza/server/discovery/service"
-	fedService "github.com/cortezaproject/corteza/server/federation/service"
-	"github.com/cortezaproject/corteza/server/pkg/actionlog"
-	"github.com/cortezaproject/corteza/server/pkg/apigw"
-	apigwTypes "github.com/cortezaproject/corteza/server/pkg/apigw/types"
-	"github.com/cortezaproject/corteza/server/pkg/auth"
-	"github.com/cortezaproject/corteza/server/pkg/corredor"
-	"github.com/cortezaproject/corteza/server/pkg/eventbus"
-	"github.com/cortezaproject/corteza/server/pkg/healthcheck"
-	"github.com/cortezaproject/corteza/server/pkg/http"
-	"github.com/cortezaproject/corteza/server/pkg/id"
-	"github.com/cortezaproject/corteza/server/pkg/locale"
-	"github.com/cortezaproject/corteza/server/pkg/logger"
-	"github.com/cortezaproject/corteza/server/pkg/mail"
-	"github.com/cortezaproject/corteza/server/pkg/messagebus"
-	"github.com/cortezaproject/corteza/server/pkg/monitor"
-	"github.com/cortezaproject/corteza/server/pkg/options"
-	"github.com/cortezaproject/corteza/server/pkg/provision"
-	"github.com/cortezaproject/corteza/server/pkg/rbac"
-	"github.com/cortezaproject/corteza/server/pkg/scheduler"
-	"github.com/cortezaproject/corteza/server/pkg/sentry"
-	"github.com/cortezaproject/corteza/server/pkg/valuestore"
-	"github.com/cortezaproject/corteza/server/pkg/version"
-	"github.com/cortezaproject/corteza/server/pkg/websocket"
-	"github.com/cortezaproject/corteza/server/store"
-	"github.com/cortezaproject/corteza/server/system/service"
-	sysService "github.com/cortezaproject/corteza/server/system/service"
-	sysEvent "github.com/cortezaproject/corteza/server/system/service/event"
-	"github.com/cortezaproject/corteza/server/system/types"
-	"github.com/lestrrat-go/jwx/jwt"
-	"go.uber.org/zap"
-	gomail "gopkg.in/mail.v2"
+    authService "github.com/cortezaproject/corteza/server/auth"
+    "github.com/cortezaproject/corteza/server/auth/saml"
+    authSettings "github.com/cortezaproject/corteza/server/auth/settings"
+    autService "github.com/cortezaproject/corteza/server/automation/service"
+    cmpService "github.com/cortezaproject/corteza/server/compose/service"
+    cmpEvent "github.com/cortezaproject/corteza/server/compose/service/event"
+    discoveryService "github.com/cortezaproject/corteza/server/discovery/service"
+    fedService "github.com/cortezaproject/corteza/server/federation/service"
+    "github.com/cortezaproject/corteza/server/pkg/actionlog"
+    "github.com/cortezaproject/corteza/server/pkg/apigw"
+    apigwTypes "github.com/cortezaproject/corteza/server/pkg/apigw/types"
+    "github.com/cortezaproject/corteza/server/pkg/auth"
+    "github.com/cortezaproject/corteza/server/pkg/corredor"
+    "github.com/cortezaproject/corteza/server/pkg/eventbus"
+    "github.com/cortezaproject/corteza/server/pkg/healthcheck"
+    "github.com/cortezaproject/corteza/server/pkg/http"
+    "github.com/cortezaproject/corteza/server/pkg/id"
+    "github.com/cortezaproject/corteza/server/pkg/locale"
+    "github.com/cortezaproject/corteza/server/pkg/logger"
+    "github.com/cortezaproject/corteza/server/pkg/mail"
+    "github.com/cortezaproject/corteza/server/pkg/messagebus"
+    "github.com/cortezaproject/corteza/server/pkg/monitor"
+    "github.com/cortezaproject/corteza/server/pkg/options"
+    "github.com/cortezaproject/corteza/server/pkg/provision"
+    "github.com/cortezaproject/corteza/server/pkg/rbac"
+    "github.com/cortezaproject/corteza/server/pkg/scheduler"
+    "github.com/cortezaproject/corteza/server/pkg/sentry"
+    "github.com/cortezaproject/corteza/server/pkg/valuestore"
+    "github.com/cortezaproject/corteza/server/pkg/version"
+    "github.com/cortezaproject/corteza/server/pkg/websocket"
+    "github.com/cortezaproject/corteza/server/store"
+    "github.com/cortezaproject/corteza/server/system/service"
+    sysService "github.com/cortezaproject/corteza/server/system/service"
+    sysEvent "github.com/cortezaproject/corteza/server/system/service/event"
+    "github.com/cortezaproject/corteza/server/system/types"
+    "github.com/lestrrat-go/jwx/jwt"
+    "go.uber.org/zap"
+    gomail "gopkg.in/mail.v2"
 )
 
 const (
@@ -561,12 +560,11 @@ func (app *CortezaApp) Activate(ctx context.Context) (err error) {
 	updateDiscoverySettings(app.Opt.Discovery, service.CurrentSettings)
 	updateLocaleSettings(app.Opt.Locale)
 
-	updateSassInstallSettings(ctx, app.Log)
-
 	app.AuthService.Watch(ctx)
 
+    updateSassInstallSettings(ctx, sysService.DefaultStylesheet.SassInstalled(), app.Log)
 	//Generate CSS for webapps
-	if err = service.GenerateCSS(sysService.CurrentSettings, app.Opt.Webapp.ScssDirPath, app.Log); err != nil {
+    if err = sysService.DefaultStylesheet.GenerateCSS(sysService.CurrentSettings, app.Opt.Webapp.ScssDirPath, app.Log); err != nil {
 		return fmt.Errorf("could not generate css for webapps: %w", err)
 	}
 
@@ -970,9 +968,7 @@ func updateSmtpSettings(log *zap.Logger, current *types.AppSettings) {
 	setupSmtpDialer(log, current.SMTP.Servers...)
 }
 
-func updateSassInstallSettings(ctx context.Context, log *zap.Logger) {
-	sassInstalled := sass.DartSassTranspiler(log) != nil
-
+func updateSassInstallSettings(ctx context.Context, sassInstalled bool, log *zap.Logger) {
 	// update dart-sass installed setting
 	err := updateSetting(ctx, "ui.studio.sass-installed", sassInstalled)
 	if err != nil {

server/system/service/service.go

@@ -1,28 +1,29 @@
 package service
 
 import (
-	"context"
-	"errors"
-	"time"
+    "context"
+    "errors"
+    "github.com/bep/godartsass/v2"
+    "time"
 
-	automationService "github.com/cortezaproject/corteza/server/automation/service"
-	discoveryService "github.com/cortezaproject/corteza/server/discovery/service"
-	"github.com/cortezaproject/corteza/server/pkg/actionlog"
-	"github.com/cortezaproject/corteza/server/pkg/dal"
-	"github.com/cortezaproject/corteza/server/pkg/eventbus"
-	"github.com/cortezaproject/corteza/server/pkg/healthcheck"
-	"github.com/cortezaproject/corteza/server/pkg/id"
-	"github.com/cortezaproject/corteza/server/pkg/logger"
-	"github.com/cortezaproject/corteza/server/pkg/objstore"
-	"github.com/cortezaproject/corteza/server/pkg/objstore/minio"
-	"github.com/cortezaproject/corteza/server/pkg/objstore/plain"
-	"github.com/cortezaproject/corteza/server/pkg/options"
-	"github.com/cortezaproject/corteza/server/pkg/rbac"
-	"github.com/cortezaproject/corteza/server/pkg/valuestore"
-	"github.com/cortezaproject/corteza/server/store"
-	"github.com/cortezaproject/corteza/server/system/automation"
-	"github.com/cortezaproject/corteza/server/system/types"
-	"go.uber.org/zap"
+    automationService "github.com/cortezaproject/corteza/server/automation/service"
+    discoveryService "github.com/cortezaproject/corteza/server/discovery/service"
+    "github.com/cortezaproject/corteza/server/pkg/actionlog"
+    "github.com/cortezaproject/corteza/server/pkg/dal"
+    "github.com/cortezaproject/corteza/server/pkg/eventbus"
+    "github.com/cortezaproject/corteza/server/pkg/healthcheck"
+    "github.com/cortezaproject/corteza/server/pkg/id"
+    "github.com/cortezaproject/corteza/server/pkg/logger"
+    "github.com/cortezaproject/corteza/server/pkg/objstore"
+    "github.com/cortezaproject/corteza/server/pkg/objstore/minio"
+    "github.com/cortezaproject/corteza/server/pkg/objstore/plain"
+    "github.com/cortezaproject/corteza/server/pkg/options"
+    "github.com/cortezaproject/corteza/server/pkg/rbac"
+    "github.com/cortezaproject/corteza/server/pkg/valuestore"
+    "github.com/cortezaproject/corteza/server/store"
+    "github.com/cortezaproject/corteza/server/system/automation"
+    "github.com/cortezaproject/corteza/server/system/types"
+    "go.uber.org/zap"
 )
 
 type (
@@ -62,6 +63,8 @@ var (
 	// DefaultSettings controls system's settings
 	DefaultSettings *settings
 
+    DefaultStylesheet *stylesheet
+
 	// DefaultAccessControl Access control checking
 	DefaultAccessControl *accessControl
 
@@ -152,9 +155,12 @@ func Initialize(ctx context.Context, log *zap.Logger, s store.Storer, ws websock
 		}
 	}
 
+    sassTranspiler := dartSassTranspiler(log)
+
 	DefaultAccessControl = AccessControl(s)
 
 	DefaultSettings = Settings(ctx, DefaultStore, DefaultLogger, DefaultAccessControl, DefaultActionlog, CurrentSettings, c.Webapps)
+    DefaultStylesheet = Stylesheet(sassTranspiler, log)
 
 	DefaultDalConnection = Connection(ctx, dal.Service(), c.DB)
 
@@ -344,3 +350,16 @@ func isStale(new *time.Time, updatedAt *time.Time, createdAt time.Time) bool {
 
 	return new.Equal(createdAt)
 }
+
+func dartSassTranspiler(log *zap.Logger) *godartsass.Transpiler {
+    transpiler, err := godartsass.Start(godartsass.Options{
+        DartSassEmbeddedFilename: "sass",
+    })
+
+    if err != nil {
+        log.Warn("dart sass is not installed in your system", zap.Error(err))
+        return nil
+    }
+
+    return transpiler
+}

server/system/service/settings.go

@@ -256,7 +256,7 @@ func (svc *settings) BulkSet(ctx context.Context, vv types.SettingValueSet) (err
 				compStyles = current.FindByName("ui.studio.themes")
 			}
 
-			updateCSS(v, current.FindByName(v.Name), compStyles, v.Name, svc.webappsConf.ScssDirPath, svc.logger)
+            DefaultStylesheet.updateCSS(v, current.FindByName(v.Name), compStyles, v.Name, svc.webappsConf.ScssDirPath, svc.logger)
 		}
 
 		svc.logChange(ctx, v)

server/system/service/stylesheet.go

@@ -1,15 +1,29 @@
 package service
 
 import (
-	"fmt"
-	"github.com/cespare/xxhash/v2"
-	"strings"
-
-	"github.com/cortezaproject/corteza/server/pkg/sass"
-	"github.com/cortezaproject/corteza/server/system/types"
-	"go.uber.org/zap"
+    "fmt"
+    "github.com/bep/godartsass/v2"
+    "github.com/cespare/xxhash/v2"
+    "github.com/cortezaproject/corteza/server/pkg/sass"
+    "github.com/cortezaproject/corteza/server/system/types"
+    "go.uber.org/zap"
+    "strings"
 )
 
+type (
+    stylesheet struct {
+        transpiler *godartsass.Transpiler
+        logger     *zap.Logger
+    }
+)
+
+func Stylesheet(transpiler *godartsass.Transpiler, logger *zap.Logger) *stylesheet {
+    return &stylesheet{
+        transpiler: transpiler,
+        logger:     logger,
+    }
+}
+
 // GenerateCSS takes care of creating CSS for webapps by reading SASS content from embedded assets,
 // combining it with different themeSASS and customCSS themes, and then transpiling it using the dart-sass compiler.
 //
@@ -18,7 +32,7 @@ import (
 // If dart isn't installed on the host machine, customCustom css will continue to function, but without sass support.
 //
 // In case of an error, it will return default css and log out the error
-func GenerateCSS(settings *types.AppSettings, sassDirPath string, log *zap.Logger) (err error) {
+func (svc *stylesheet) GenerateCSS(settings *types.AppSettings, sassDirPath string, log *zap.Logger) (err error) {
 	var (
 		studio       = settings.UI.Studio
 		customCSSMap = make(map[string]string)
@@ -39,12 +53,10 @@ func GenerateCSS(settings *types.AppSettings, sassDirPath string, log *zap.Logge
 		return
 	}
 
-	transpiler := sass.DartSassTranspiler(log)
-
 	// transpile sass to css for each theme
 	for _, theme := range studio.Themes {
 		if studio.CustomCSS == nil {
-			err := sass.Transpile(transpiler, log, theme.ID, theme.Values, "", sassDirPath)
+            err := sass.Transpile(svc.transpiler, log, theme.ID, theme.Values, "", sassDirPath)
 			if err != nil {
 				continue
 			}
@@ -52,7 +64,7 @@ func GenerateCSS(settings *types.AppSettings, sassDirPath string, log *zap.Logge
 
 		customCSS := processCustomCSS(theme.ID, customCSSMap)
 		// transpile sass to css
-		err := sass.Transpile(transpiler, log, theme.ID, theme.Values, customCSS, sassDirPath)
+        err := sass.Transpile(svc.transpiler, log, theme.ID, theme.Values, customCSS, sassDirPath)
 		if err != nil {
 			continue
 		}
@@ -61,6 +73,9 @@ func GenerateCSS(settings *types.AppSettings, sassDirPath string, log *zap.Logge
 	return
 }
 
+func (svc *stylesheet) SassInstalled() bool {
+    return svc.transpiler != nil
+}
 // processCustomCSS, processes CustomCSS input and gives priority to theme specific customCSS
 func processCustomCSS(themeID string, customCSSMap map[string]string) (customCSS string) {
 	var stringsBuilder strings.Builder
@@ -82,16 +97,14 @@ func processCustomCSS(themeID string, customCSSMap map[string]string) (customCSS
 }
 
 // updateCSS, updates theme css when ui.studio.themes or ui.studio.custom-css settings are updated
-func updateCSS(current, old, compStyles *types.SettingValue, name, sassDirPath string, log *zap.Logger) {
-	transpiler := sass.DartSassTranspiler(log)
-
+func (svc *stylesheet) updateCSS(current, old, compStyles *types.SettingValue, name, sassDirPath string, log *zap.Logger) {
 	complimentaryStylesMap := themeMap(compStyles)
 	oldThemesMap := themeMap(old)
 	currentThemesMap := themeMap(current)
 
 	transpileSASS := func(themeID, themeSASS string, themeCustomCSS map[string]string) {
 		customCSS := processCustomCSS(themeID, themeCustomCSS)
-		err := sass.Transpile(transpiler, log, themeID, themeSASS, customCSS, sassDirPath)
+        err := sass.Transpile(svc.transpiler, log, themeID, themeSASS, customCSS, sassDirPath)
 		if err != nil {
 			log.Error("failed to transpile sass to css", zap.Error(err))
 		}