Fixes microsoft#188060 (microsoft#188219)

Author: hediet

src/vs/editor/common/diff/algorithms/joinSequenceDiffs.ts

@@ -5,6 +5,7 @@
 
 import { OffsetRange } from 'vs/editor/common/core/offsetRange';
 import { ISequence, SequenceDiff } from 'vs/editor/common/diff/algorithms/diffAlgorithm';
+import { LinesSliceCharSequence } from 'vs/editor/common/diff/standardLinesDiffComputer';
 
 export function optimizeSequenceDiffs(sequence1: ISequence, sequence2: ISequence, sequenceDiffs: SequenceDiff[]): SequenceDiff[] {
 	let result = sequenceDiffs;
@@ -32,6 +33,74 @@ export function smoothenSequenceDiffs(sequence1: ISequence, sequence2: ISequence
 	return result;
 }
 
+export function randomRandomMatches(sequence1: LinesSliceCharSequence, sequence2: LinesSliceCharSequence, sequenceDiffs: SequenceDiff[]): SequenceDiff[] {
+	let diffs = sequenceDiffs;
+
+	let counter = 0;
+	let shouldRepeat: boolean;
+	do {
+		shouldRepeat = false;
+
+		const result: SequenceDiff[] = [
+			diffs[0]
+		];
+
+		for (let i = 1; i < diffs.length; i++) {
+			const cur = diffs[i];
+			const lastResult = result[result.length - 1];
+
+			function shouldJoinDiffs(before: SequenceDiff, after: SequenceDiff): boolean {
+				const unchangedRange = new OffsetRange(lastResult.seq1Range.endExclusive, cur.seq1Range.start);
+
+				const unchangedLineCount = sequence1.countLinesIn(unchangedRange);
+				if (unchangedLineCount > 5 || unchangedRange.length > 500) {
+					return false;
+				}
+
+				const unchangedText = sequence1.getText(unchangedRange).trim();
+				if (unchangedText.length > 20 || unchangedText.split(/\r\n|\r|\n/).length > 1) {
+					return false;
+				}
+
+				const beforeLineCount1 = sequence1.countLinesIn(before.seq1Range);
+				const beforeSeq1Length = before.seq1Range.length;
+				const beforeLineCount2 = sequence2.countLinesIn(before.seq2Range);
+				const beforeSeq2Length = before.seq2Range.length;
+
+				const afterLineCount1 = sequence1.countLinesIn(after.seq1Range);
+				const afterSeq1Length = after.seq1Range.length;
+				const afterLineCount2 = sequence2.countLinesIn(after.seq2Range);
+				const afterSeq2Length = after.seq2Range.length;
+
+				// TODO: Maybe a neural net can be used to derive the result from these numbers
+
+				const max = 2 * 40 + 50;
+				function cap(v: number): number {
+					return Math.min(v, max);
+				}
+
+				if (Math.pow(Math.pow(cap(beforeLineCount1 * 40 + beforeSeq1Length), 1.5) + Math.pow(cap(beforeLineCount2 * 40 + beforeSeq2Length), 1.5), 1.5)
+					+ Math.pow(Math.pow(cap(afterLineCount1 * 40 + afterSeq1Length), 1.5) + Math.pow(cap(afterLineCount2 * 40 + afterSeq2Length), 1.5), 1.5) > ((max ** 1.5) ** 1.5) * 1.3) {
+					return true;
+				}
+				return false;
+			}
+
+			const shouldJoin = shouldJoinDiffs(lastResult, cur);
+			if (shouldJoin) {
+				shouldRepeat = true;
+				result[result.length - 1] = result[result.length - 1].join(cur);
+			} else {
+				result.push(cur);
+			}
+		}
+
+		diffs = result;
+	} while (counter++ < 10 && shouldRepeat);
+
+	return diffs;
+}
+
 /**
  * This function fixes issues like this:
  * ```

src/vs/editor/common/diff/standardLinesDiffComputer.ts

@@ -11,7 +11,7 @@ import { Position } from 'vs/editor/common/core/position';
 import { Range } from 'vs/editor/common/core/range';
 import { DateTimeout, ISequence, ITimeout, InfiniteTimeout, SequenceDiff } from 'vs/editor/common/diff/algorithms/diffAlgorithm';
 import { DynamicProgrammingDiffing } from 'vs/editor/common/diff/algorithms/dynamicProgrammingDiffing';
-import { optimizeSequenceDiffs, smoothenSequenceDiffs } from 'vs/editor/common/diff/algorithms/joinSequenceDiffs';
+import { optimizeSequenceDiffs, randomRandomMatches, smoothenSequenceDiffs } from 'vs/editor/common/diff/algorithms/joinSequenceDiffs';
 import { MyersDiffAlgorithm } from 'vs/editor/common/diff/algorithms/myersDiffAlgorithm';
 import { ILinesDiffComputer, ILinesDiffComputerOptions, LineRangeMapping, LinesDiff, MovedText, RangeMapping, SimpleLineRangeMapping } from 'vs/editor/common/diff/linesDiffComputer';
 
@@ -173,8 +173,8 @@ export class StandardLinesDiffComputer implements ILinesDiffComputer {
 	}
 
 	private refineDiff(originalLines: string[], modifiedLines: string[], diff: SequenceDiff, timeout: ITimeout, considerWhitespaceChanges: boolean): { mappings: RangeMapping[]; hitTimeout: boolean } {
-		const slice1 = new Slice(originalLines, diff.seq1Range, considerWhitespaceChanges);
-		const slice2 = new Slice(modifiedLines, diff.seq2Range, considerWhitespaceChanges);
+		const slice1 = new LinesSliceCharSequence(originalLines, diff.seq1Range, considerWhitespaceChanges);
+		const slice2 = new LinesSliceCharSequence(modifiedLines, diff.seq2Range, considerWhitespaceChanges);
 
 		const diffResult = slice1.length + slice2.length < 500
 			? this.dynamicProgrammingDiffing.compute(slice1, slice2, timeout)
@@ -184,6 +184,7 @@ export class StandardLinesDiffComputer implements ILinesDiffComputer {
 		diffs = optimizeSequenceDiffs(slice1, slice2, diffs);
 		diffs = coverFullWords(slice1, slice2, diffs);
 		diffs = smoothenSequenceDiffs(slice1, slice2, diffs);
+		diffs = randomRandomMatches(slice1, slice2, diffs);
 
 		const result = diffs.map(
 			(d) =>
@@ -202,7 +203,7 @@ export class StandardLinesDiffComputer implements ILinesDiffComputer {
 	}
 }
 
-function coverFullWords(sequence1: Slice, sequence2: Slice, sequenceDiffs: SequenceDiff[]): SequenceDiff[] {
+function coverFullWords(sequence1: LinesSliceCharSequence, sequence2: LinesSliceCharSequence, sequenceDiffs: SequenceDiff[]): SequenceDiff[] {
 	const additional: SequenceDiff[] = [];
 
 	let lastModifiedWord: { added: number; deleted: number; count: number; s1Range: OffsetRange; s2Range: OffsetRange } | undefined = undefined;
@@ -417,7 +418,7 @@ function getIndentation(str: string): number {
 	return i;
 }
 
-class Slice implements ISequence {
+export class LinesSliceCharSequence implements ISequence {
 	private readonly elements: number[] = [];
 	private readonly firstCharOffsetByLineMinusOne: number[] = [];
 	public readonly lineRange: OffsetRange;
@@ -471,7 +472,11 @@ class Slice implements ISequence {
 	}
 
 	get text(): string {
-		return [...this.elements].map(e => String.fromCharCode(e)).join('');
+		return this.getText(new OffsetRange(0, this.length));
+	}
+
+	getText(range: OffsetRange): string {
+		return this.elements.slice(range.start, range.endExclusive).map(e => String.fromCharCode(e)).join('');
 	}
 
 	getElement(offset: number): number {
@@ -559,6 +564,10 @@ class Slice implements ISequence {
 
 		return new OffsetRange(start, end);
 	}
+
+	public countLinesIn(range: OffsetRange): number {
+		return this.translateOffset(range.endExclusive).lineNumber - this.translateOffset(range.start).lineNumber;
+	}
 }
 
 function isWordChar(charCode: number): boolean {

src/vs/editor/test/node/diffing/fixtures/class-replacement/advanced.expected.diff.json

@@ -13,12 +13,8 @@
 			"modifiedRange": "[29,31)",
 			"innerChanges": [
 				{
-					"originalRange": "[29,1 -> 33,1]",
-					"modifiedRange": "[29,1 -> 29,1]"
-				},
-				{
-					"originalRange": "[33,14 -> 33,41]",
-					"modifiedRange": "[29,14 -> 30,54]"
+					"originalRange": "[29,1 -> 33,41]",
+					"modifiedRange": "[29,1 -> 30,54]"
 				}
 			]
 		},
@@ -47,16 +43,8 @@
 			"modifiedRange": "[36,37)",
 			"innerChanges": [
 				{
-					"originalRange": "[41,9 -> 41,18]",
-					"modifiedRange": "[36,9 -> 36,44]"
-				},
-				{
-					"originalRange": "[41,26 -> 42,34]",
-					"modifiedRange": "[36,52 -> 36,64]"
-				},
-				{
-					"originalRange": "[43,1 -> 46,1]",
-					"modifiedRange": "[37,1 -> 37,1]"
+					"originalRange": "[41,9 -> 46,1]",
+					"modifiedRange": "[36,9 -> 37,1]"
 				}
 			]
 		},
@@ -65,12 +53,8 @@
 			"modifiedRange": "[39,40)",
 			"innerChanges": [
 				{
-					"originalRange": "[48,9 -> 63,48]",
-					"modifiedRange": "[39,9 -> 39,43]"
-				},
-				{
-					"originalRange": "[64,1 -> 72,1]",
-					"modifiedRange": "[40,1 -> 40,1]"
+					"originalRange": "[48,9 -> 72,1]",
+					"modifiedRange": "[39,9 -> 40,1]"
 				}
 			]
 		}

src/vs/editor/test/node/diffing/fixtures/difficult-move/advanced.expected.diff.json

@@ -43,60 +43,8 @@
 			"modifiedRange": "[226,234)",
 			"innerChanges": [
 				{
-					"originalRange": "[222,17 -> 222,19]",
-					"modifiedRange": "[226,17 -> 226,17]"
-				},
-				{
-					"originalRange": "[223,4 -> 223,28]",
-					"modifiedRange": "[227,4 -> 227,37]"
-				},
-				{
-					"originalRange": "[223,32 -> 223,49]",
-					"modifiedRange": "[227,41 -> 227,48]"
-				},
-				{
-					"originalRange": "[223,54 -> 223,65]",
-					"modifiedRange": "[227,53 -> 227,62]"
-				},
-				{
-					"originalRange": "[224,4 -> 224,29]",
-					"modifiedRange": "[228,4 -> 228,55]"
-				},
-				{
-					"originalRange": "[224,43 -> 225,63]",
-					"modifiedRange": "[228,69 -> 228,108]"
-				},
-				{
-					"originalRange": "[225,78 -> 226,8]",
-					"modifiedRange": "[228,123 -> 228,152]"
-				},
-				{
-					"originalRange": "[226,22 -> 226,25]",
-					"modifiedRange": "[228,166 -> 228,169]"
-				},
-				{
-					"originalRange": "[227,5 -> 227,93]",
-					"modifiedRange": "[229,5 -> 229,67]"
-				},
-				{
-					"originalRange": "[228,5 -> 228,51]",
-					"modifiedRange": "[230,5 -> 230,30]"
-				},
-				{
-					"originalRange": "[229,6 -> 229,143]",
-					"modifiedRange": "[231,6 -> 231,40]"
-				},
-				{
-					"originalRange": "[230,5 -> 232,42]",
-					"modifiedRange": "[232,5 -> 232,19]"
-				},
-				{
-					"originalRange": "[232,48 -> 232,98]",
-					"modifiedRange": "[232,25 -> 233,58]"
-				},
-				{
-					"originalRange": "[233,1 -> 234,1]",
-					"modifiedRange": "[234,1 -> 234,1]"
+					"originalRange": "[222,17 -> 234,1]",
+					"modifiedRange": "[226,17 -> 234,1]"
 				}
 			]
 		}

src/vs/editor/test/node/diffing/fixtures/method-splitting/advanced.expected.diff.json

@@ -33,16 +33,8 @@
 					"modifiedRange": "[7,9 -> 7,27]"
 				},
 				{
-					"originalRange": "[7,61 -> 7,105]",
-					"modifiedRange": "[7,50 -> 7,85]"
-				},
-				{
-					"originalRange": "[7,112 -> 8,10]",
-					"modifiedRange": "[7,92 -> 7,130]"
-				},
-				{
-					"originalRange": "[8,15 -> 10,1]",
-					"modifiedRange": "[7,135 -> 8,1]"
+					"originalRange": "[7,61 -> 10,1]",
+					"modifiedRange": "[7,50 -> 8,1]"
 				}
 			]
 		},

src/vs/editor/test/node/diffing/fixtures/noise-1/1.tst

@@ -0,0 +1,57 @@
+this._sash = derivedWithStore('sash', (reader, store) => {
+	const showSash = this._options.renderSideBySide.read(reader);
+	this.elements.root.classList.toggle('side-by-side', showSash);
+	if (!showSash) { return undefined; }
+	const result = store.add(new DiffEditorSash(
+		this._options,
+		this.elements.root,
+		{
+			height: this._rootSizeObserver.height,
+			width: this._rootSizeObserver.width.map((w, reader) => w - (this._options.renderOverviewRuler.read(reader) ? OverviewRulerPart.ENTIRE_DIFF_OVERVIEW_WIDTH : 0)),
+		}
+	));
+	store.add(autorun('setBoundarySashes', reader => {
+		const boundarySashes = this._boundarySashes.read(reader);
+		if (boundarySashes) {
+			result.setBoundarySashes(boundarySashes);
+		}
+	}));
+	return result;
+});
+this._register(keepAlive(this._sash, true));
+
+this._register(autorunWithStore2('UnchangedRangesFeature', (reader, store) => {
+	this.unchangedRangesFeature = store.add(new (readHotReloadableExport(UnchangedRangesFeature, reader))(this._editors, this._diffModel, this._options));
+}));
+
+this._register(autorunWithStore2('DiffEditorDecorations', (reader, store) => {
+	store.add(new (readHotReloadableExport(DiffEditorDecorations, reader))(this._editors, this._diffModel, this._options));
+}));
+this._register(autorunWithStore2('ViewZoneManager', (reader, store) => {
+	store.add(this._instantiationService.createInstance(
+		readHotReloadableExport(ViewZoneManager, reader),
+		this._editors,
+		this._diffModel,
+		this._options,
+		this,
+		() => this.unchangedRangesFeature.isUpdatingViewZones,
+	));
+}));
+
+this._register(autorunWithStore2('OverviewRulerPart', (reader, store) => {
+	store.add(this._instantiationService.createInstance(readHotReloadableExport(OverviewRulerPart, reader), this._editors,
+		this.elements.root,
+		this._diffModel,
+		this._rootSizeObserver.width,
+		this._rootSizeObserver.height,
+		this._layoutInfo.map(i => i.modifiedEditor),
+		this._options,
+	));
+}));
+
+this._reviewPane = this._register(this._instantiationService.createInstance(DiffReview2, this));
+this.elements.root.appendChild(this._reviewPane.domNode.domNode);
+this.elements.root.appendChild(this._reviewPane.actionBarContainer.domNode);
+reviewPaneObservable.set(this._reviewPane, undefined);
+
+this._createDiffEditorContributions();