test for ouput compression

src/vs/workbench/contrib/notebook/common/model/notebookCellOutputTextModel.ts

@@ -96,11 +96,15 @@ export class NotebookCellOutputTextModel extends Disposable implements ICellOutp
 			});
 			this.outputs.length = 0;
 			mimeTypes.forEach(mime => {
-				const compressed = compressOutputItemStreams(mimeOutputs.get(mime)!);
+				const compressionResult = compressOutputItemStreams(mimeOutputs.get(mime)!);
 				this.outputs.push({
 					mime,
-					data: compressed
+					data: compressionResult.data
 				});
+				if (compressionResult.didCompression) {
+					// we can't rely on knowing buffer lengths if we've erased previous lines
+					this.versionedBufferLengths = {};
+				}
 			});
 		}
 	}

src/vs/workbench/contrib/notebook/common/notebookCommon.ts

@@ -996,6 +996,7 @@ const textDecoder = new TextDecoder();
  * Given a stream of individual stdout outputs, this function will return the compressed lines, escaping some of the common terminal escape codes.
  * E.g. some terminal escape codes would result in the previous line getting cleared, such if we had 3 lines and
  * last line contained such a code, then the result string would be just the first two lines.
+ * @returns a single VSBuffer with the concatenated and compressed data, and whether any compression was done.
  */
 export function compressOutputItemStreams(outputs: Uint8Array[]) {
 	const buffers: Uint8Array[] = [];
@@ -1008,13 +1009,17 @@ export function compressOutputItemStreams(outputs: Uint8Array[]) {
 			startAppending = true;
 		}
 	}
-	compressStreamBuffer(buffers);
-	return formatStreamText(VSBuffer.concat(buffers.map(buffer => VSBuffer.wrap(buffer))));
+
+	const didCompression = compressStreamBuffer(buffers);
+	const data = formatStreamText(VSBuffer.concat(buffers.map(buffer => VSBuffer.wrap(buffer))));
+	return { data, didCompression };
 }
-const MOVE_CURSOR_1_LINE_COMMAND = `${String.fromCharCode(27)}[A`;
+
+export const MOVE_CURSOR_1_LINE_COMMAND = `${String.fromCharCode(27)}[A`;
 const MOVE_CURSOR_1_LINE_COMMAND_BYTES = MOVE_CURSOR_1_LINE_COMMAND.split('').map(c => c.charCodeAt(0));
 const LINE_FEED = 10;
 function compressStreamBuffer(streams: Uint8Array[]) {
+	let didCompress = false;
 	streams.forEach((stream, index) => {
 		if (index === 0 || stream.length < MOVE_CURSOR_1_LINE_COMMAND.length) {
 			return;
@@ -1029,10 +1034,13 @@ function compressStreamBuffer(streams: Uint8Array[]) {
 			if (lastIndexOfLineFeed === -1) {
 				return;
 			}
+
+			didCompress = true;
 			streams[index - 1] = previousStream.subarray(0, lastIndexOfLineFeed);
 			streams[index] = stream.subarray(MOVE_CURSOR_1_LINE_COMMAND.length);
 		}
 	});
+	return didCompress;
 }
 
 

src/vs/workbench/contrib/notebook/test/browser/notebookTextModel.test.ts

@@ -11,7 +11,7 @@ import { ILanguageService } from 'vs/editor/common/languages/language';
 import { TestInstantiationService } from 'vs/platform/instantiation/test/common/instantiationServiceMock';
 import { IUndoRedoService } from 'vs/platform/undoRedo/common/undoRedo';
 import { NotebookTextModel } from 'vs/workbench/contrib/notebook/common/model/notebookTextModel';
-import { CellEditType, CellKind, ICellEditOperation, NotebookTextModelChangedEvent, NotebookTextModelWillAddRemoveEvent, SelectionStateType } from 'vs/workbench/contrib/notebook/common/notebookCommon';
+import { CellEditType, CellKind, ICellEditOperation, MOVE_CURSOR_1_LINE_COMMAND, NotebookTextModelChangedEvent, NotebookTextModelWillAddRemoveEvent, SelectionStateType } from 'vs/workbench/contrib/notebook/common/notebookCommon';
 import { setupInstantiationService, TestCell, valueBytesFromString, withTestNotebook } from 'vs/workbench/contrib/notebook/test/browser/testNotebookEditor';
 
 suite('NotebookTextModel', () => {
@@ -436,6 +436,48 @@ suite('NotebookTextModel', () => {
 		);
 	});
 
+	test('appending streaming outputs with compression', async function () {
+
+		await withTestNotebook(
+			[
+				['var a = 1;', 'javascript', CellKind.Code, [], {}],
+			],
+			(editor) => {
+				const textModel = editor.textModel;
+
+				textModel.applyEdits([
+					{
+						index: 0,
+						editType: CellEditType.Output,
+						append: true,
+						outputs: [{
+							outputId: 'append1',
+							outputs: [
+								{ mime: stdOutMime, data: valueBytesFromString('append 1') },
+								{ mime: stdOutMime, data: valueBytesFromString('\nappend 1') }]
+						}]
+					}], true, undefined, () => undefined, undefined, true);
+				const [output] = textModel.cells[0].outputs;
+				assert.strictEqual(output.versionId, 0, 'initial output version should be 0');
+
+				textModel.applyEdits([
+					{
+						editType: CellEditType.OutputItems,
+						append: true,
+						outputId: 'append1',
+						items: [{
+							mime: stdOutMime, data: valueBytesFromString(MOVE_CURSOR_1_LINE_COMMAND + '\nappend 2')
+						}]
+					}], true, undefined, () => undefined, undefined, true);
+				assert.strictEqual(output.versionId, 1, 'version should bump per append');
+
+				assert.strictEqual(output.outputs[0].data.toString(), 'append 1\nappend 2');
+				assert.strictEqual(output.appendedSinceVersion(0, stdOutMime), undefined,
+					'compressing outputs should clear out previous versioned output buffers');
+			}
+		);
+	});
+
 	test('appending multiple different mime streaming outputs', async function () {
 		await withTestNotebook(
 			[