Improve amendment list performance

client/src/app/site/pages/meetings/pages/motions/modules/change-recommendations/services/motion-diff.service/motion-diff.service.ts

@@ -390,6 +390,24 @@ export class MotionDiffService {
         return HtmlDiff.getAmendmentParagraphsLines(paragraphNo, origText, newText, lineLength, changes);
     }
 
+    /**
+     * Returns the index of the first difference between two texts
+     *
+     * @param {string} origText The original text
+     * @param {string} newText The changed text
+     * @return {number | null} Token index of first change, or null if no changes
+     */
+    public getFirstChangedTokenIndex(origText: string, newText: string): number | null {
+        if (origText === newText) return null;
+
+        const minLen = Math.min(origText.length, newText.length);
+        for (let i = 0; i < minLen; i += 1) {
+            if (origText[i] !== newText[i]) return i;
+        }
+
+        return minLen;
+    }
+
     /**
      * Returns the HTML with the changes, optionally with a highlighted line.
      * The original motion needs to be provided.

client/src/app/site/pages/meetings/pages/motions/services/common/motion-controller.service/motion-controller.service.ts

@@ -242,8 +242,19 @@ export class MotionControllerService extends BaseMeetingControllerService<ViewMo
                     includeUnchanged
                 );
             };
+
+            viewModel.getAmendmentFirstChangeIndex = (recoMode: ChangeRecoMode): number | null => {
+                const changeRecos = viewModel.change_recommendations.filter(changeReco => changeReco.showInFinalView());
+                return this.motionLineNumbering.getAmendmentFirstChangeIndex(
+                    viewModel,
+                    this._lineLength,
+                    recoMode,
+                    changeRecos
+                );
+            };
         } else {
             viewModel.getAmendmentParagraphLines = (): DiffLinesInParagraph[] => [];
+            viewModel.getAmendmentFirstChangeIndex = (): number | null => null;
         }
         viewModel.getExtendedStateLabel = (): string => this.getExtendedStateLabel(viewModel);
         viewModel.getExtendedRecommendationLabel = (): string => this.getExtendedRecommendationLabel(viewModel);

client/src/app/site/pages/meetings/pages/motions/services/common/motion-line-numbering.service/motion-line-numbering.service.ts

@@ -121,7 +121,7 @@ export class MotionLineNumberingService {
      * @param {number} lineLength
      * @returns {string[]}
      */
-    public getTextParagraphs(motion: ViewMotion, lineBreaks: boolean, lineLength: number): string[] {
+    public getTextParagraphs(motion: ViewMotion, lineBreaks: boolean, lineLength?: number): string[] {
         if (!motion) {
             return [];
         }
@@ -307,6 +307,56 @@ export class MotionLineNumberingService {
             .filter((para: DiffLinesInParagraph | null) => !!para) as DiffLinesInParagraph[];
     }
 
+    /**
+     * Returns the first token that has a change
+     *
+     * Should only be called for paragraph-based amendments.
+     *
+     * @param {ViewMotion} amendment
+     * @param {number} lineLength
+     * @param {ChangeRecoMode} crMode
+     * @param {ViewMotionChangeRecommendation[]} changeRecommendations
+     * @returns {DiffLinesInParagraph}
+     */
+    public getAmendmentFirstChangeIndex(
+        amendment: ViewMotion,
+        lineLength: number,
+        crMode: ChangeRecoMode,
+        changeRecommendations: ViewMotionChangeRecommendation[]
+    ): number | null {
+        const motion = amendment.lead_motion as ViewMotion;
+        const baseParagraphs = this.getTextParagraphs(motion, false);
+
+        let amendmentParagraphs: string[] = [];
+        if (crMode === ChangeRecoMode.Original || changeRecommendations.length === 0) {
+            amendmentParagraphs = baseParagraphs.map(
+                (_: string, paraNo: number) => amendment.amendment_paragraph_text(paraNo) as string
+            );
+        } else {
+            amendmentParagraphs = this.applyChangesToAmendment(amendment, lineLength, changeRecommendations, true).map(
+                p => (p ? this.lineNumberingService.stripLineNumbers(p) : p)
+            ) as string[];
+        }
+
+        let paragraphStart = 0;
+        for (let paraNo = 0; paraNo < baseParagraphs.length; paraNo++) {
+            const newText = amendmentParagraphs[paraNo];
+            if (baseParagraphs[paraNo] !== undefined) {
+                const origText = baseParagraphs[paraNo].replace(/\n/gm, ``);
+                if (newText !== null) {
+                    const tokenIdx = this.diffService.getFirstChangedTokenIndex(origText, newText);
+                    if (tokenIdx !== null) {
+                        return paragraphStart + tokenIdx;
+                    }
+                }
+
+                paragraphStart += origText.length;
+            }
+        }
+
+        return null;
+    }
+
     public getAmendmentParagraphLinesTitle(paragraph: DiffLinesInParagraph): string {
         if (paragraph.diffLineTo === paragraph.diffLineFrom) {
             return this.translate.instant(`Line`) + ` ` + paragraph.diffLineFrom.toString(10);

client/src/app/site/pages/meetings/pages/motions/services/list/amendment-list-sort.service/amendment-list-sort.service.ts

@@ -15,7 +15,7 @@ export class AmendmentListSortService extends MotionListBaseSortService {
 
     private amendmentSortOptions: OsSortingOption<ViewMotion>[] = [
         {
-            property: `parentAndLineNumber`,
+            property: `parentAndChangeIndex`,
             label: this.translate.instant(`Main motion and line number`),
             baseKeys: [`amendment_paragraphs`],
             foreignBaseKeys: {
@@ -28,7 +28,7 @@ export class AmendmentListSortService extends MotionListBaseSortService {
 
     public constructor() {
         super({
-            sortProperty: `parentAndLineNumber`,
+            sortProperty: `parentAndChangeIndex`,
             sortAscending: true
         });
     }

client/src/app/site/pages/meetings/pages/motions/view-models/view-motion.ts

@@ -217,14 +217,20 @@ export class ViewMotion extends BaseProjectableViewModel<Motion> {
     }
 
     /**
-     * Get the number of the first diff line, in case a motion is an amendment
+     * Get the index of the first diff change, in case a motion is an amendment
      */
-    public get parentAndLineNumber(): string | null {
+    public get parentAndChangeIndex(): string | null {
         if (this.isParagraphBasedAmendment() && this.lead_motion && this.changedAmendmentLines?.length) {
-            return `${this.lead_motion.number} ${this.changedAmendmentLines[0].diffLineFrom}`;
-        } else {
-            return null;
+            if (this._firstChangeIndex === undefined) {
+                this._firstChangeIndex = this.getAmendmentFirstChangeIndex(ChangeRecoMode.Changed);
+            }
+
+            if (this._firstChangeIndex !== null) {
+                return `${this.lead_motion.number} ${this._firstChangeIndex}`;
+            }
         }
+
+        return null;
     }
 
     public get forwardingStatus(): ForwardingStatus {
@@ -249,6 +255,7 @@ export class ViewMotion extends BaseProjectableViewModel<Motion> {
 
     private _changedAmendmentLines: DiffLinesInParagraph[] | null = null;
     private _affectedAmendmentLines: DiffLinesInParagraph[] | null = null;
+    private _firstChangeIndex: number | null | undefined = undefined;
 
     public getVotingText(context: VotingTextContext<ViewMotion>): string {
         const motionTranslation = context.translateFn(`Motion`);
@@ -264,6 +271,8 @@ export class ViewMotion extends BaseProjectableViewModel<Motion> {
         includeUnchanged?: boolean
     ) => DiffLinesInParagraph[] = () => [];
 
+    public getAmendmentFirstChangeIndex: (recoMode: ChangeRecoMode) => number | null = () => null;
+
     public getParagraphTitleByParagraph!: (paragraph: DiffLinesInParagraph) => string | null;
     // This is set by the repository
     public getNumberOrTitle!: () => string;

packages/openslides-motion-diff/src/diff/internal-diff.ts

@@ -1,4 +1,3 @@
-import { splitStringKeepSeperator } from "../utils/utils";
 import { normalizeHtmlForDiff } from "./internal";
 
 /**
@@ -143,6 +142,17 @@ function diffArrays(oldArr: any, newArr: any): any {
     return { o: oldArr, n: newArr };
 }
 
+const TOKENIZE_REGEXES = {
+    prependLt: /(?=<)/g,
+    appendGt: /(.*?>)/g,
+    space: /( )/g,
+    dot: /(\.)/g,
+    comma: /(,)/g,
+    exclaim: /(!)/g,
+    dash: /(-)/g,
+    appendNewline: /(.*?\n)/g,
+};
+
 /**
  * This method splits a string into an array of strings, such as that it can be used by the diff method.
  * Mainly it tries to split it into single words, but prevents HTML tags from being split into different elements.
@@ -151,17 +161,19 @@ function diffArrays(oldArr: any, newArr: any): any {
  * @returns {string[]}
  */
 function tokenizeHtml(str: string): string[] {
+    const splitConfigs = [
+        { by: `<`, regex: TOKENIZE_REGEXES.prependLt, append: false },
+        { by: `>`, regex: TOKENIZE_REGEXES.appendGt, append: true },
+        { by: ` `, regex: TOKENIZE_REGEXES.space, append: false },
+        { by: `.`, regex: TOKENIZE_REGEXES.dot, append: false },
+        { by: `,`, regex: TOKENIZE_REGEXES.comma, append: false },
+        { by: `!`, regex: TOKENIZE_REGEXES.exclaim, append: false },
+        { by: `-`, regex: TOKENIZE_REGEXES.dash, append: false },
+        { by: `\n`, regex: TOKENIZE_REGEXES.appendNewline, append: true },
+    ];
+
     let res = [str];
-    for (const splitConf of [
-        { by: `<`, type: `prepend` },
-        { by: `>`, type: `append` },
-        { by: ` ` },
-        { by: `.` },
-        { by: `,` },
-        { by: `!` },
-        { by: `-` },
-        { by: `\n`, type: `append` }
-    ]) {
+    for (const splitConf of splitConfigs) {
         const newArr = [];
         for (const str of res) {
             // Don't split HTML tags
@@ -170,10 +182,13 @@ function tokenizeHtml(str: string): string[] {
                 continue;
             }
 
-            newArr.push(...splitStringKeepSeperator(str, splitConf.by, splitConf.type));
+            const parts = str.split(splitConf.regex);
+            newArr.push(
+                ...(splitConf.append ? parts.filter((el) => el !== ``) : parts),
+            );
         }
         res = newArr;
     }
 
-    return res.filter(el => el !== ``);
+    return res.filter((el) => el !== ``);
 }