Commit 85e7af4e authored by Erik Nordin's avatar Erik Nordin Committed by enordin@mozilla.com
Browse files

Bug 1820252 - Lazify Full-Page Translations r=translations-reviewers,gregtatum 

This patch introduces IntersectionObservers into the
TranslationsDocument, rewriting the algorithm to allow
translating only node content and attributes that are
within close proximity to the device's viewport.

Differential Revision: https://phabricator.services.mozilla.com/D249983
parent 3facdb37

toolkit/components/translations/actors/TranslationsChild.sys.mjs

+2 −2
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ export class TranslationsChild extends JSWindowActorChild { 


    switch (name) {

      case "Translations:TranslatePage": {

        if (this.#translatedDoc?.translator.engineStatus === "error") {

        if (this.#translatedDoc?.engineStatus === "error") {

          this.#translatedDoc.destroy();

          this.#translatedDoc = null;

        }
@@ -145,7 +145,7 @@ export class TranslationsChild extends JSWindowActorChild { 
      }

      case "Translations:AcquirePort": {

        this.addProfilerMarker("Acquired a port, resuming translations");

        this.#translatedDoc.translator.acquirePort(data.port);

        this.#translatedDoc.acquirePort(data.port);

        return undefined;

      }

      default:

toolkit/components/translations/content/translations-document.sys.mjs

+3027 −610

File changed.

Preview size limit exceeded, changes collapsed.

toolkit/components/translations/content/translations-engine.sys.mjs

+54 −0
Original line number Diff line number Diff line
@@ -614,23 +614,66 @@ function listenForPortMessages(languagePair, innerWindowId, port) { 
        );

        break;

      }

      case "TranslationsPort:Passthrough": {

        const { translationId } = data;



        port.postMessage({

          type: "TranslationsPort:TranslationResponse",

          translationId,

          targetText: null,

        });



        TE_addProfilerMarker({

          innerWindowId,

          type: "Passthrough",

          message: `Handled passthrough translation`,

        });



        break;

      }

      case "TranslationsPort:CachedTranslation": {

        const { cachedTranslation, translationId } = data;

        port.postMessage({

          type: "TranslationsPort:TranslationResponse",

          translationId,

          targetText: cachedTranslation,

        });



        TE_addProfilerMarker({

          innerWindowId,

          type: "Cached",

          message: `Handled cached translation of ${cachedTranslation.length} code units`,

        });



        break;

      }

      case "TranslationsPort:TranslationRequest": {

        const { sourceText, isHTML, translationId } = data;



        const engine = await TranslationsEngine.getOrCreate(

          languagePair,

          innerWindowId

        );



        TE_addProfilerMarker({

          innerWindowId,

          type: "Request",

          message: `Handled translation request of ${sourceText.length} code units`,

        });



        const targetText = await engine.translate(

          sourceText,

          isHTML,

          innerWindowId,

          translationId

        );



        port.postMessage({

          type: "TranslationsPort:TranslationResponse",

          translationId,

          targetText,

        });



        break;

      }

      case "TranslationsPort:CancelSingleTranslation": {
@@ -638,10 +681,21 @@ function listenForPortMessages(languagePair, innerWindowId, port) { 
        TranslationsEngine.withCachedEngine(languagePair, engine => {

          engine.cancelSingleTranslation(innerWindowId, translationId);

        });



        TE_addProfilerMarker({

          innerWindowId,

          type: "Cancel",

          message: `Cancelled request for translationId ${translationId}`,

        });

        break;

      }

      case "TranslationsPort:DiscardTranslations": {

        discardTranslations(innerWindowId);

        TE_addProfilerMarker({

          innerWindowId,

          type: "Discard",

          message: `Discarded all active translation requests`,

        });

        break;

      }

      default:

toolkit/components/translations/translations.d.ts

+19 −8
Original line number Diff line number Diff line
@@ -256,7 +256,7 @@ interface TranslationsEnginePayload { 
/**

 * Nodes that are being translated are given priority according to their visibility.

 */

export type NodeVisibility = "in-viewport" | "out-of-viewport" | "hidden";

export type NodeVisibility = "in-viewport" | "beyond-viewport" | "hidden";



/**

 * Used to decide how to translate a page for full page translations.
@@ -383,7 +383,17 @@ export type RequestTranslationsPort = ( 
  languagePair: LanguagePair

) => Promise<MessagePort>;



export type TranslationsPortMessages = {

export type TranslationsPortMessages =

  // We have determined that the source text is already translated into the target language, so do nothing.

  | { type: "TranslationsPort:Passthrough"; translationId: string }

  // We found translated text for this request in our cache, so send the targetText directly without translating.

  | {

      type: "TranslationsPort:CachedTranslation";

      translationId: string;

      targetText: string;

    }

  // This is a new, uncached request, and it needs to be translated by the TranslationsEngine.

  | {

      type: "TranslationsPort:TranslationRequest";

      translationId: string;

      sourceText: string;
@@ -393,9 +403,10 @@ export type TranslationsPortMessages = { 
export type EngineStatus = "uninitialized" | "ready" | "error" | "closed";



export type PortToPage =

  // The targetText may be null if the TranslationsEngine had an error, or if this is a response to a Passthrough.

  | {

      type: "TranslationsPort:TranslationResponse";

      targetText: string;

      targetText: string | null;

      translationId: number;

    }

  | { type: "TranslationsPort:GetEngineStatusResponse"; status: EngineStatus }