From d7bc16968aed6a77df3f07abf990b93203a7e811 Mon Sep 17 00:00:00 2001
From: Mark Sujew <mark.sujew@typefox.io>
Date: Tue, 24 Dec 2024 16:31:12 +0100
Subject: [PATCH] Fix file data streaming for long polling (#14659)

---
 .../src/common/remote-file-system-provider.ts | 66 +++++++++----------
 1 file changed, 32 insertions(+), 34 deletions(-)

diff --git a/packages/filesystem/src/common/remote-file-system-provider.ts b/packages/filesystem/src/common/remote-file-system-provider.ts
index 7035bc5460056..fa6704d0b2e7c 100644
--- a/packages/filesystem/src/common/remote-file-system-provider.ts
+++ b/packages/filesystem/src/common/remote-file-system-provider.ts
@@ -46,7 +46,7 @@ export interface RemoteFileSystemServer extends RpcServer<RemoteFileSystemClient
     open(resource: string, opts: FileOpenOptions): Promise<number>;
     close(fd: number): Promise<void>;
     read(fd: number, pos: number, length: number): Promise<{ bytes: Uint8Array; bytesRead: number; }>;
-    readFileStream(resource: string, opts: FileReadStreamOptions, token: CancellationToken): Promise<number>;
+    readFileStream(resource: string, handle: number, opts: FileReadStreamOptions, token: CancellationToken): Promise<void>;
     readFile(resource: string): Promise<Uint8Array>;
     write(fd: number, pos: number, data: Uint8Array, offset: number, length: number): Promise<number>;
     writeFile(resource: string, content: Uint8Array, opts: FileWriteOptions): Promise<void>;
@@ -162,6 +162,8 @@ export class RemoteFileSystemProvider implements Required<FileSystemProvider>, D
     protected readonly readyDeferred = new Deferred<void>();
     readonly ready = this.readyDeferred.promise;
 
+    protected streamHandleSeq = 0;
+
     /**
      * Wrapped remote filesystem.
      */
@@ -251,36 +253,35 @@ export class RemoteFileSystemProvider implements Required<FileSystemProvider>, D
 
     readFileStream(resource: URI, opts: FileReadStreamOptions, token: CancellationToken): ReadableStreamEvents<Uint8Array> {
         const capturedError = new Error();
-        // eslint-disable-next-line @typescript-eslint/no-shadow
-        const stream = newWriteableStream<Uint8Array>(data => BinaryBuffer.concat(data.map(data => BinaryBuffer.wrap(data))).buffer);
-        this.server.readFileStream(resource.toString(), opts, token).then(streamHandle => {
+        const stream = newWriteableStream<Uint8Array>(data => BinaryBuffer.concat(data.map(item => BinaryBuffer.wrap(item))).buffer);
+        const streamHandle = this.streamHandleSeq++;
+        const toDispose = new DisposableCollection(
+            token.onCancellationRequested(() => stream.end(cancelled())),
+            this.onFileStreamData(([handle, data]) => {
+                if (streamHandle === handle) {
+                    stream.write(data);
+                }
+            }),
+            this.onFileStreamEnd(([handle, error]) => {
+                if (streamHandle === handle) {
+                    if (error) {
+                        const code = ('code' in error && error.code) || FileSystemProviderErrorCode.Unknown;
+                        const fileOperationError = new FileSystemProviderError(error.message, code);
+                        fileOperationError.name = error.name;
+                        const capturedStack = capturedError.stack || '';
+                        fileOperationError.stack = `${capturedStack}\nCaused by: ${error.stack}`;
+                        stream.end(fileOperationError);
+                    } else {
+                        stream.end();
+                    }
+                }
+            })
+        );
+        stream.on('end', () => toDispose.dispose());
+        this.server.readFileStream(resource.toString(), streamHandle, opts, token).then(() => {
             if (token.isCancellationRequested) {
                 stream.end(cancelled());
-                return;
             }
-            const toDispose = new DisposableCollection(
-                token.onCancellationRequested(() => stream.end(cancelled())),
-                this.onFileStreamData(([handle, data]) => {
-                    if (streamHandle === handle) {
-                        stream.write(data);
-                    }
-                }),
-                this.onFileStreamEnd(([handle, error]) => {
-                    if (streamHandle === handle) {
-                        if (error) {
-                            const code = ('code' in error && error.code) || FileSystemProviderErrorCode.Unknown;
-                            const fileOperationError = new FileSystemProviderError(error.message, code);
-                            fileOperationError.name = error.name;
-                            const capturedStack = capturedError.stack || '';
-                            fileOperationError.stack = `${capturedStack}\nCaused by: ${error.stack}`;
-                            stream.end(fileOperationError);
-                        } else {
-                            stream.end();
-                        }
-                    }
-                })
-            );
-            stream.on('end', () => toDispose.dispose());
         }, error => stream.end(error));
         return stream;
     }
@@ -528,11 +529,8 @@ export class FileSystemProviderServer implements RemoteFileSystemServer {
         }
     }
 
-    protected readFileStreamSeq = 0;
-
-    async readFileStream(resource: string, opts: FileReadStreamOptions, token: CancellationToken): Promise<number> {
+    async readFileStream(resource: string, handle: number, opts: FileReadStreamOptions, token: CancellationToken): Promise<void> {
         if (hasFileReadStreamCapability(this.provider)) {
-            const handle = this.readFileStreamSeq++;
             const stream = this.provider.readFileStream(new URI(resource), opts, token);
             stream.on('data', data => this.client?.onFileStreamData(handle, data));
             stream.on('error', error => {
@@ -541,9 +539,9 @@ export class FileSystemProviderServer implements RemoteFileSystemServer {
                 this.client?.onFileStreamEnd(handle, { code, name, message, stack });
             });
             stream.on('end', () => this.client?.onFileStreamEnd(handle, undefined));
-            return handle;
+        } else {
+            throw new Error('not supported');
         }
-        throw new Error('not supported');
     }
 
 }