Merge from vscode 52dcb723a39ae75bee1bd56b3312d7fcdc87aeed (#6719)

src/vs/base/node/stream.ts

@@ -4,6 +4,10 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as fs from 'fs';
+import { VSBufferReadableStream, VSBufferReadable, VSBuffer } from 'vs/base/common/buffer';
+import { Readable } from 'stream';
+import { isUndefinedOrNull } from 'vs/base/common/types';
+import { UTF8, UTF8_with_bom, UTF8_BOM, UTF16be, UTF16le_BOM, UTF16be_BOM, UTF16le, UTF_ENCODING } from 'vs/base/node/encoding';
 
 /**
  * Reads a file until a matching string is found.
@@ -66,4 +70,107 @@ export function readToMatchingString(file: string, matchingString: string, chunk
 			readChunk();
 		})
 	);
-}
+}
+
+export function streamToNodeReadable(stream: VSBufferReadableStream): Readable {
+	return new class extends Readable {
+		private listening = false;
+
+		_read(size?: number): void {
+			if (!this.listening) {
+				this.listening = true;
+
+				// Data
+				stream.on('data', data => {
+					try {
+						if (!this.push(data.buffer)) {
+							stream.pause(); // pause the stream if we should not push anymore
+						}
+					} catch (error) {
+						this.emit(error);
+					}
+				});
+
+				// End
+				stream.on('end', () => {
+					try {
+						this.push(null); // signal EOS
+					} catch (error) {
+						this.emit(error);
+					}
+				});
+
+				// Error
+				stream.on('error', error => this.emit('error', error));
+			}
+
+			// ensure the stream is flowing
+			stream.resume();
+		}
+
+		_destroy(error: Error | null, callback: (error: Error | null) => void): void {
+			stream.destroy();
+
+			callback(null);
+		}
+	};
+}
+
+export function nodeReadableToString(stream: NodeJS.ReadableStream): Promise<string> {
+	return new Promise((resolve, reject) => {
+		let result = '';
+
+		stream.on('data', chunk => result += chunk);
+		stream.on('error', reject);
+		stream.on('end', () => resolve(result));
+	});
+}
+
+export function nodeStreamToVSBufferReadable(stream: NodeJS.ReadWriteStream, addBOM?: { encoding: UTF_ENCODING }): VSBufferReadable {
+	let bytesRead = 0;
+	let done = false;
+
+	return {
+		read(): VSBuffer | null {
+			if (done) {
+				return null;
+			}
+
+			const res = stream.read();
+			if (isUndefinedOrNull(res)) {
+				done = true;
+
+				// If we are instructed to add a BOM but we detect that no
+				// bytes have been read, we must ensure to return the BOM
+				// ourselves so that we comply with the contract.
+				if (bytesRead === 0 && addBOM) {
+					switch (addBOM.encoding) {
+						case UTF8:
+						case UTF8_with_bom:
+							return VSBuffer.wrap(Buffer.from(UTF8_BOM));
+						case UTF16be:
+							return VSBuffer.wrap(Buffer.from(UTF16be_BOM));
+						case UTF16le:
+							return VSBuffer.wrap(Buffer.from(UTF16le_BOM));
+					}
+				}
+
+				return null;
+			}
+
+			// Handle String
+			if (typeof res === 'string') {
+				bytesRead += res.length;
+
+				return VSBuffer.fromString(res);
+			}
+
+			// Handle Buffer
+			else {
+				bytesRead += res.byteLength;
+
+				return VSBuffer.wrap(res);
+			}
+		}
+	};
+}