Optimize template renderer (#1585)

* Add renderMulti

* Batch template rendering

* Update tests

6 files changed, 160 insertions, 9 deletions

diff --git a/ext/js/data/anki-note-builder.js b/ext/js/data/anki-note-builder.js
index 38f1eb16..b84b2eda 100644
--- a/ext/js/data/anki-note-builder.js
+++ b/ext/js/data/anki-note-builder.js
@@ -24,6 +24,8 @@ class AnkiNoteBuilder {
     constructor() {
         this._markerPattern = AnkiUtil.cloneFieldMarkerPattern(true);
         this._templateRenderer = new TemplateRendererProxy();
+        this._batchedRequests = [];
+        this._batchedRequestsQueued = false;
     }
 
     async createNote({
@@ -113,7 +115,7 @@ class AnkiNoteBuilder {
     async _formatField(field, commonData, template, errors=null) {
         return await this._stringReplaceAsync(field, this._markerPattern, async (g0, marker) => {
             try {
-                return await this._renderTemplate(template, marker, commonData);
+                return await this._renderTemplateBatched(template, commonData, marker);
             } catch (e) {
                 if (Array.isArray(errors)) {
                     const error = new Error(`Template render error for {${marker}}`);
@@ -143,4 +145,88 @@ class AnkiNoteBuilder {
     async _renderTemplate(template, marker, commonData) {
         return await this._templateRenderer.render(template, {marker, commonData}, 'ankiNote');
     }
+
+    _getBatchedTemplateGroup(template) {
+        for (const item of this._batchedRequests) {
+            if (item.template === template) {
+                return item;
+            }
+        }
+
+        const result = {template, commonDataRequestsMap: new Map()};
+        this._batchedRequests.push(result);
+        return result;
+    }
+
+    _renderTemplateBatched(template, commonData, marker) {
+        const {promise, resolve, reject} = deferPromise();
+        const {commonDataRequestsMap} = this._getBatchedTemplateGroup(template);
+        let requests = commonDataRequestsMap.get(commonData);
+        if (typeof requests === 'undefined') {
+            requests = [];
+            commonDataRequestsMap.set(commonData, requests);
+        }
+        requests.push({resolve, reject, marker});
+        this._runBatchedRequestsDelayed();
+        return promise;
+    }
+
+    _runBatchedRequestsDelayed() {
+        if (this._batchedRequestsQueued) { return; }
+        this._batchedRequestsQueued = true;
+        Promise.resolve().then(() => {
+            this._batchedRequestsQueued = false;
+            this._runBatchedRequests();
+        });
+    }
+
+    _runBatchedRequests() {
+        if (this._batchedRequests.length === 0) { return; }
+
+        const allRequests = [];
+        const items = [];
+        for (const {template, commonDataRequestsMap} of this._batchedRequests) {
+            const templateItems = [];
+            for (const [commonData, requests] of commonDataRequestsMap.entries()) {
+                const datas = [];
+                for (const {marker} of requests) {
+                    datas.push(marker);
+                }
+                allRequests.push(...requests);
+                templateItems.push({type: 'ankiNote', commonData, datas});
+            }
+            items.push({template, templateItems});
+        }
+
+        this._batchedRequests.length = 0;
+
+        this._resolveBatchedRequests(items, allRequests);
+    }
+
+    async _resolveBatchedRequests(items, requests) {
+        let responses;
+        try {
+            responses = await this._templateRenderer.renderMulti(items);
+        } catch (e) {
+            for (const {reject} of requests) {
+                reject(e);
+            }
+            return;
+        }
+
+        for (let i = 0, ii = requests.length; i < ii; ++i) {
+            const request = requests[i];
+            try {
+                const response = responses[i];
+                const {error} = response;
+                if (typeof error !== 'undefined') {
+                    throw deserializeError(error);
+                } else {
+                    request.resolve(response.result);
+                }
+            } catch (e) {
+                request.reject(e);
+            }
+        }
+    }
 }
diff --git a/ext/js/templates/template-renderer-frame-api.js b/ext/js/templates/template-renderer-frame-api.js
index 104e357b..dd6be517 100644
--- a/ext/js/templates/template-renderer-frame-api.js
+++ b/ext/js/templates/template-renderer-frame-api.js
@@ -20,6 +20,7 @@ class TemplateRendererFrameApi {
         this._templateRenderer = templateRenderer;
         this._windowMessageHandlers = new Map([
             ['render', {async: false, handler: this._onRender.bind(this)}],
+            ['renderMulti', {async: false, handler: this._onRenderMulti.bind(this)}],
             ['getModifiedData', {async: false, handler: this._onGetModifiedData.bind(this)}]
         ]);
     }
@@ -58,6 +59,10 @@ class TemplateRendererFrameApi {
         return this._templateRenderer.render(template, data, type);
     }
 
+    _onRenderMulti({items}) {
+        return this._serializeMulti(this._templateRenderer.renderMulti(items));
+    }
+
     _onGetModifiedData({data, type}) {
         const result = this._templateRenderer.getModifiedData(data, type);
         return this._clone(result);
@@ -82,6 +87,17 @@ class TemplateRendererFrameApi {
         };
     }
 
+    _serializeMulti(array) {
+        for (let i = 0, ii = array.length; i < ii; ++i) {
+            const value = array[i];
+            const {error} = value;
+            if (typeof error !== 'undefined') {
+                value.error = this._serializeError(error);
+            }
+        }
+        return array;
+    }
+
     _clone(value) {
         return JSON.parse(JSON.stringify(value));
     }
diff --git a/ext/js/templates/template-renderer-frame-main.js b/ext/js/templates/template-renderer-frame-main.js
index 40ecf308..3d61295d 100644
--- a/ext/js/templates/template-renderer-frame-main.js
+++ b/ext/js/templates/template-renderer-frame-main.js
@@ -27,7 +27,8 @@
     const templateRenderer = new TemplateRenderer(japaneseUtil);
     const ankiNoteDataCreator = new AnkiNoteDataCreator(japaneseUtil);
     templateRenderer.registerDataType('ankiNote', {
-        modifier: ({marker, commonData}) => ankiNoteDataCreator.create(marker, commonData)
+        modifier: ({marker, commonData}) => ankiNoteDataCreator.create(marker, commonData),
+        composeData: (marker, commonData) => ({marker, commonData})
     });
     const templateRendererFrameApi = new TemplateRendererFrameApi(templateRenderer);
     templateRendererFrameApi.prepare();
diff --git a/ext/js/templates/template-renderer-proxy.js b/ext/js/templates/template-renderer-proxy.js
index aba45e6c..f35239cb 100644
--- a/ext/js/templates/template-renderer-proxy.js
+++ b/ext/js/templates/template-renderer-proxy.js
@@ -30,6 +30,11 @@ class TemplateRendererProxy {
         return await this._invoke('render', {template, data, type});
     }
 
+    async renderMulti(items) {
+        await this._prepareFrame();
+        return await this._invoke('renderMulti', {items});
+    }
+
     async getModifiedData(data, type) {
         await this._prepareFrame();
         return await this._invoke('getModifiedData', {data, type});
diff --git a/ext/js/templates/template-renderer.js b/ext/js/templates/template-renderer.js
index 5441528c..ed9cc41c 100644
--- a/ext/js/templates/template-renderer.js
+++ b/ext/js/templates/template-renderer.js
@@ -29,18 +29,39 @@ class TemplateRenderer {
         this._dataTypes = new Map();
     }
 
-    registerDataType(name, {modifier=null}) {
-        this._dataTypes.set(name, {modifier});
+    registerDataType(name, {modifier=null, composeData=null}) {
+        this._dataTypes.set(name, {modifier, composeData});
     }
 
     render(template, data, type) {
         const instance = this._getTemplateInstance(template);
-        data = this._getModifiedData(data, type);
+        data = this._getModifiedData(data, void 0, type);
         return this._renderTemplate(instance, data);
     }
 
+    renderMulti(items) {
+        const results = [];
+        for (const {template, templateItems} of items) {
+            const instance = this._getTemplateInstance(template);
+            for (const {type, commonData, datas} of templateItems) {
+                for (let data of datas) {
+                    let result;
+                    try {
+                        data = this._getModifiedData(data, commonData, type);
+                        result = this._renderTemplate(instance, data);
+                        result = {result};
+                    } catch (error) {
+                        result = {error};
+                    }
+                    results.push(result);
+                }
+            }
+        }
+        return results;
+    }
+
     getModifiedData(data, type) {
-        return this._getModifiedData(data, type);
+        return this._getModifiedData(data, void 0, type);
     }
 
     // Private
@@ -70,10 +91,16 @@ class TemplateRenderer {
         }
     }
 
-    _getModifiedData(data, type) {
+    _getModifiedData(data, commonData, type) {
         if (typeof type === 'string') {
             const typeInfo = this._dataTypes.get(type);
             if (typeof typeInfo !== 'undefined') {
+                if (typeof commonData !== 'undefined') {
+                    const {composeData} = typeInfo;
+                    if (typeof composeData === 'function') {
+                        data = composeData(data, commonData);
+                    }
+                }
                 const {modifier} = typeInfo;
                 if (typeof modifier === 'function') {
                     data = modifier(data);
diff --git a/test/test-anki-note-builder.js b/test/test-anki-note-builder.js
index b1fffbcd..152a8739 100644
--- a/test/test-anki-note-builder.js
+++ b/test/test-anki-note-builder.js
@@ -55,12 +55,28 @@ async function createVM() {
             const japaneseUtil = new JapaneseUtil(null);
             this._templateRenderer = new TemplateRenderer(japaneseUtil);
             this._templateRenderer.registerDataType('ankiNote', {
-                modifier: ({marker, commonData}) => ankiNoteDataCreator.create(marker, commonData)
+                modifier: ({marker, commonData}) => ankiNoteDataCreator.create(marker, commonData),
+                composeData: (marker, commonData) => ({marker, commonData})
             });
         }
 
         async render(template, data, type) {
-            return await this._templateRenderer.render(template, data, type);
+            return this._templateRenderer.render(template, data, type);
+        }
+
+        async renderMulti(items) {
+            return this._serializeMulti(this._templateRenderer.renderMulti(items));
+        }
+
+        _serializeMulti(array) {
+            for (let i = 0, ii = array.length; i < ii; ++i) {
+                const value = array[i];
+                const {error} = value;
+                if (typeof error !== 'undefined') {
+                    value.error = this._serializeError(error);
+                }
+            }
+            return array;
         }
     }
     vm.set({TemplateRendererProxy});