chat: store disk sessions using an 'append log'

src/vs/base/common/buffer.ts

@@ -213,7 +213,7 @@ export function binaryIndexOf(haystack: Uint8Array, needle: Uint8Array, offset =
 	}
 
 	if (needleLen === 1) {
-		return haystack.indexOf(needle[0]);
+		return haystack.indexOf(needle[0], offset);
 	}
 
 	if (needleLen > haystackLen - offset) {

src/vs/platform/files/browser/indexedDBFileSystemProvider.ts

@@ -11,7 +11,7 @@ import { ExtUri } from '../../../base/common/resources.js';
 import { isString } from '../../../base/common/types.js';
 import { URI, UriDto } from '../../../base/common/uri.js';
 import { localize } from '../../../nls.js';
-import { createFileSystemProviderError, FileChangeType, IFileDeleteOptions, IFileOverwriteOptions, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, IFileWriteOptions, IFileChange, IFileSystemProviderWithFileReadWriteCapability, IStat, IWatchOptions } from '../common/files.js';
+import { createFileSystemProviderError, FileChangeType, IFileDeleteOptions, IFileOverwriteOptions, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, IFileWriteOptions, IFileChange, IFileSystemProviderWithFileAppendCapability, IFileSystemProviderWithFileReadWriteCapability, IStat, IWatchOptions } from '../common/files.js';
 import { IndexedDB } from '../../../base/browser/indexedDB.js';
 import { BroadcastDataChannel } from '../../../base/browser/broadcast.js';
 
@@ -152,10 +152,11 @@ class IndexedDBFileSystemNode {
 	}
 }
 
-export class IndexedDBFileSystemProvider extends Disposable implements IFileSystemProviderWithFileReadWriteCapability {
+export class IndexedDBFileSystemProvider extends Disposable implements IFileSystemProviderWithFileReadWriteCapability, IFileSystemProviderWithFileAppendCapability {
 
 	readonly capabilities: FileSystemProviderCapabilities =
 		FileSystemProviderCapabilities.FileReadWrite
+		| FileSystemProviderCapabilities.FileAppend
 		| FileSystemProviderCapabilities.PathCaseSensitive;
 	readonly onDidChangeCapabilities: Event<void> = Event.None;
 
@@ -263,6 +264,30 @@ export class IndexedDBFileSystemProvider extends Disposable implements IFileSyst
 		await this.bulkWrite([[resource, content]]);
 	}
 
+	async appendFile(resource: URI, content: Uint8Array, opts: IFileWriteOptions): Promise<void> {
+		const existing = await this.stat(resource).catch(() => undefined);
+		if (existing?.type === FileType.Directory) {
+			throw ERR_FILE_IS_DIR;
+		}
+
+		// Read existing content and append
+		let existingContent: Uint8Array;
+		try {
+			existingContent = await this.readFile(resource);
+		} catch (error) {
+			if (!opts.create) {
+				throw error;
+			}
+			existingContent = new Uint8Array(0);
+		}
+
+		const newContent = new Uint8Array(existingContent.byteLength + content.byteLength);
+		newContent.set(existingContent, 0);
+		newContent.set(content, existingContent.byteLength);
+
+		await this.bulkWrite([[resource, newContent]]);
+	}
+
 	async rename(from: URI, to: URI, opts: IFileOverwriteOptions): Promise<void> {
 		const fileTree = await this.getFiletree();
 		const fromEntry = fileTree.read(from.path);

src/vs/platform/files/common/diskFileSystemProviderClient.ts

@@ -13,7 +13,7 @@ import { newWriteableStream, ReadableStreamEventPayload, ReadableStreamEvents }
 import { URI } from '../../../base/common/uri.js';
 import { generateUuid } from '../../../base/common/uuid.js';
 import { IChannel } from '../../../base/parts/ipc/common/ipc.js';
-import { createFileSystemProviderError, IFileAtomicReadOptions, IFileDeleteOptions, IFileOpenOptions, IFileOverwriteOptions, IFileReadStreamOptions, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, IFileWriteOptions, IFileChange, IFileSystemProviderWithFileAtomicReadCapability, IFileSystemProviderWithFileCloneCapability, IFileSystemProviderWithFileFolderCopyCapability, IFileSystemProviderWithFileReadStreamCapability, IFileSystemProviderWithFileReadWriteCapability, IFileSystemProviderWithOpenReadWriteCloseCapability, IStat, IWatchOptions, IFileSystemProviderError } from './files.js';
+import { createFileSystemProviderError, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, IFileAtomicReadOptions, IFileChange, IFileDeleteOptions, IFileOpenOptions, IFileOverwriteOptions, IFileReadStreamOptions, IFileSystemProviderError, IFileSystemProviderWithFileAppendCapability, IFileSystemProviderWithFileAtomicReadCapability, IFileSystemProviderWithFileCloneCapability, IFileSystemProviderWithFileFolderCopyCapability, IFileSystemProviderWithFileReadStreamCapability, IFileSystemProviderWithFileReadWriteCapability, IFileSystemProviderWithOpenReadWriteCloseCapability, IFileWriteOptions, IStat, IWatchOptions } from './files.js';
 import { reviveFileChanges } from './watcher.js';
 
 export const LOCAL_FILE_SYSTEM_CHANNEL_NAME = 'localFilesystem';
@@ -29,6 +29,7 @@ export class DiskFileSystemProviderClient extends Disposable implements
 	IFileSystemProviderWithFileReadStreamCapability,
 	IFileSystemProviderWithFileFolderCopyCapability,
 	IFileSystemProviderWithFileAtomicReadCapability,
+	IFileSystemProviderWithFileAppendCapability,
 	IFileSystemProviderWithFileCloneCapability {
 
 	constructor(
@@ -56,6 +57,7 @@ export class DiskFileSystemProviderClient extends Disposable implements
 				FileSystemProviderCapabilities.FileAtomicRead |
 				FileSystemProviderCapabilities.FileAtomicWrite |
 				FileSystemProviderCapabilities.FileAtomicDelete |
+				FileSystemProviderCapabilities.FileAppend |
 				FileSystemProviderCapabilities.FileClone |
 				FileSystemProviderCapabilities.FileRealpath;
 
@@ -160,6 +162,10 @@ export class DiskFileSystemProviderClient extends Disposable implements
 		return this.channel.call('writeFile', [resource, VSBuffer.wrap(content), opts]);
 	}
 
+	appendFile(resource: URI, content: Uint8Array, opts: IFileWriteOptions): Promise<void> {
+		return this.channel.call('appendFile', [resource, VSBuffer.wrap(content), opts]);
+	}
+
 	open(resource: URI, opts: IFileOpenOptions): Promise<number> {
 		return this.channel.call('open', [resource, opts]);
 	}

src/vs/platform/files/common/fileService.ts

@@ -18,7 +18,7 @@ import { extUri, extUriIgnorePathCase, IExtUri, isAbsolutePath } from '../../../
 import { consumeStream, isReadableBufferedStream, isReadableStream, listenStream, newWriteableStream, peekReadable, peekStream, transform } from '../../../base/common/stream.js';
 import { URI } from '../../../base/common/uri.js';
 import { localize } from '../../../nls.js';
-import { ensureFileSystemProviderError, etag, ETAG_DISABLED, FileChangesEvent, IFileDeleteOptions, FileOperation, FileOperationError, FileOperationEvent, FileOperationResult, FilePermission, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, hasFileAtomicReadCapability, hasFileFolderCopyCapability, hasFileReadStreamCapability, hasOpenReadWriteCloseCapability, hasReadWriteCapability, ICreateFileOptions, IFileContent, IFileService, IFileStat, IFileStatWithMetadata, IFileStreamContent, IFileSystemProvider, IFileSystemProviderActivationEvent, IFileSystemProviderCapabilitiesChangeEvent, IFileSystemProviderRegistrationEvent, IFileSystemProviderWithFileAtomicReadCapability, IFileSystemProviderWithFileReadStreamCapability, IFileSystemProviderWithFileReadWriteCapability, IFileSystemProviderWithOpenReadWriteCloseCapability, IReadFileOptions, IReadFileStreamOptions, IResolveFileOptions, IFileStatResult, IFileStatResultWithMetadata, IResolveMetadataFileOptions, IStat, IFileStatWithPartialMetadata, IWatchOptions, IWriteFileOptions, NotModifiedSinceFileOperationError, toFileOperationResult, toFileSystemProviderErrorCode, hasFileCloneCapability, TooLargeFileOperationError, hasFileAtomicDeleteCapability, hasFileAtomicWriteCapability, IWatchOptionsWithCorrelation, IFileSystemWatcher, IWatchOptionsWithoutCorrelation, hasFileRealpathCapability } from './files.js';
+import { ensureFileSystemProviderError, etag, ETAG_DISABLED, FileChangesEvent, IFileDeleteOptions, FileOperation, FileOperationError, FileOperationEvent, FileOperationResult, FilePermission, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, hasFileAppendCapability, hasFileAtomicReadCapability, hasFileFolderCopyCapability, hasFileReadStreamCapability, hasOpenReadWriteCloseCapability, hasReadWriteCapability, ICreateFileOptions, IFileContent, IFileService, IFileStat, IFileStatWithMetadata, IFileStreamContent, IFileSystemProvider, IFileSystemProviderActivationEvent, IFileSystemProviderCapabilitiesChangeEvent, IFileSystemProviderRegistrationEvent, IFileSystemProviderWithFileAtomicReadCapability, IFileSystemProviderWithFileReadStreamCapability, IFileSystemProviderWithFileReadWriteCapability, IFileSystemProviderWithOpenReadWriteCloseCapability, IFileWriteOptions, IReadFileOptions, IReadFileStreamOptions, IResolveFileOptions, IFileStatResult, IFileStatResultWithMetadata, IResolveMetadataFileOptions, IStat, IFileStatWithPartialMetadata, IWatchOptions, IWriteFileOptions, NotModifiedSinceFileOperationError, toFileOperationResult, toFileSystemProviderErrorCode, hasFileCloneCapability, TooLargeFileOperationError, hasFileAtomicDeleteCapability, hasFileAtomicWriteCapability, IWatchOptionsWithCorrelation, IFileSystemWatcher, IWatchOptionsWithoutCorrelation, hasFileRealpathCapability } from './files.js';
 import { readFileIntoStream } from './io.js';
 import { ILogService } from '../../log/common/log.js';
 import { ErrorNoTelemetry } from '../../../base/common/errors.js';
@@ -431,6 +431,60 @@ export class FileService extends Disposable implements IFileService {
 		return this.resolve(resource, { resolveMetadata: true });
 	}
 
+	async appendFile(resource: URI, bufferOrReadableOrStream: VSBuffer | VSBufferReadable | VSBufferReadableStream, options?: IWriteFileOptions): Promise<IFileStatWithMetadata> {
+		const provider = this.throwIfFileSystemIsReadonly(await this.withWriteProvider(resource), resource);
+
+		try {
+			// if provider supports append, use it directly
+			if (hasFileAppendCapability(provider)) {
+				const buffer = bufferOrReadableOrStream instanceof VSBuffer
+					? bufferOrReadableOrStream
+					: isReadableStream(bufferOrReadableOrStream)
+						? await streamToBuffer(bufferOrReadableOrStream)
+						: readableToBuffer(bufferOrReadableOrStream);
+
+				const writeOptions: IFileWriteOptions = {
+					create: true,
+					overwrite: false,
+					unlock: options?.unlock ?? false,
+					atomic: options?.atomic ?? false
+				};
+
+				await provider.appendFile(resource, buffer.buffer, writeOptions);
+
+				// events
+				this._onDidRunOperation.fire(new FileOperationEvent(resource, FileOperation.WRITE));
+			} else {
+				// fallback: read existing content and write combined content
+				let existingContent: VSBuffer;
+				try {
+					const fileContent = await this.readFile(resource);
+					existingContent = fileContent.value;
+				} catch (error) {
+					// if file doesn't exist, start with empty content
+					if (toFileOperationResult(error) === FileOperationResult.FILE_NOT_FOUND) {
+						existingContent = VSBuffer.fromString('');
+					} else {
+						throw error;
+					}
+				}
+
+				const newContent = bufferOrReadableOrStream instanceof VSBuffer
+					? bufferOrReadableOrStream
+					: isReadableStream(bufferOrReadableOrStream)
+						? await streamToBuffer(bufferOrReadableOrStream)
+						: readableToBuffer(bufferOrReadableOrStream);
+
+				const combinedContent = VSBuffer.concat([existingContent, newContent]);
+				await this.writeFile(resource, combinedContent, options);
+			}
+		} catch (error) {
+			throw new FileOperationError(localize('err.append', "Unable to append to file '{0}' ({1})", this.resourceForError(resource), ensureFileSystemProviderError(error).toString()), toFileOperationResult(error), options);
+		}
+
+		return this.resolve(resource, { resolveMetadata: true });
+	}
+
 
 	private async peekBufferForWriting(provider: IFileSystemProviderWithFileReadWriteCapability | IFileSystemProviderWithOpenReadWriteCloseCapability, bufferOrReadableOrStream: VSBuffer | VSBufferReadable | VSBufferReadableStream): Promise<VSBuffer | VSBufferReadable | VSBufferReadableStream | VSBufferReadableBufferedStream> {
 		let peekResult: VSBuffer | VSBufferReadable | VSBufferReadableStream | VSBufferReadableBufferedStream;

src/vs/platform/files/common/files.ts

@@ -163,6 +163,13 @@ export interface IFileService {
 	 */
 	writeFile(resource: URI, bufferOrReadableOrStream: VSBuffer | VSBufferReadable | VSBufferReadableStream, options?: IWriteFileOptions): Promise<IFileStatWithMetadata>;
 
+	/**
+	 * Appends content to the end of the file.
+	 *
+	 * Emits a `FileOperation.WRITE` file operation event when successful.
+	 */
+	appendFile(resource: URI, bufferOrReadableOrStream: VSBuffer | VSBufferReadable | VSBufferReadableStream, options?: IWriteFileOptions): Promise<IFileStatWithMetadata>;
+
 	/**
 	 * Moves the file/folder to a new path identified by the resource.
 	 *
@@ -654,7 +661,12 @@ export const enum FileSystemProviderCapabilities {
 	/**
 	 * Provider support to resolve real paths.
 	 */
-	FileRealpath = 1 << 18
+	FileRealpath = 1 << 18,
+
+	/**
+	 * Provider support to append to files.
+	 */
+	FileAppend = 1 << 19
 }
 
 export interface IFileSystemProvider {
@@ -676,6 +688,7 @@ export interface IFileSystemProvider {
 
 	readFile?(resource: URI): Promise<Uint8Array>;
 	writeFile?(resource: URI, content: Uint8Array, opts: IFileWriteOptions): Promise<void>;
+	appendFile?(resource: URI, content: Uint8Array, opts: IFileWriteOptions): Promise<void>;
 
 	readFileStream?(resource: URI, opts: IFileReadStreamOptions, token: CancellationToken): ReadableStreamEvents<Uint8Array>;
 
@@ -696,6 +709,14 @@ export function hasReadWriteCapability(provider: IFileSystemProvider): provider
 	return !!(provider.capabilities & FileSystemProviderCapabilities.FileReadWrite);
 }
 
+export interface IFileSystemProviderWithFileAppendCapability extends IFileSystemProvider {
+	appendFile(resource: URI, content: Uint8Array, opts: IFileWriteOptions): Promise<void>;
+}
+
+export function hasFileAppendCapability(provider: IFileSystemProvider): provider is IFileSystemProviderWithFileAppendCapability {
+	return !!(provider.capabilities & FileSystemProviderCapabilities.FileAppend);
+}
+
 export interface IFileSystemProviderWithFileFolderCopyCapability extends IFileSystemProvider {
 	copy(from: URI, to: URI, opts: IFileOverwriteOptions): Promise<void>;
 }

src/vs/platform/files/common/inMemoryFilesystemProvider.ts

@@ -9,7 +9,7 @@ import { Disposable, IDisposable } from '../../../base/common/lifecycle.js';
 import * as resources from '../../../base/common/resources.js';
 import { ReadableStreamEvents, newWriteableStream } from '../../../base/common/stream.js';
 import { URI } from '../../../base/common/uri.js';
-import { FileChangeType, IFileDeleteOptions, IFileOverwriteOptions, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, IFileWriteOptions, IFileChange, IFileSystemProviderWithFileReadWriteCapability, IStat, IWatchOptions, createFileSystemProviderError, IFileSystemProviderWithOpenReadWriteCloseCapability, IFileOpenOptions, IFileSystemProviderWithFileAtomicDeleteCapability, IFileSystemProviderWithFileAtomicReadCapability, IFileSystemProviderWithFileAtomicWriteCapability, IFileSystemProviderWithFileReadStreamCapability } from './files.js';
+import { FileChangeType, IFileDeleteOptions, IFileOverwriteOptions, FileSystemProviderCapabilities, FileSystemProviderErrorCode, FileType, IFileWriteOptions, IFileChange, IFileSystemProviderWithFileAppendCapability, IFileSystemProviderWithFileReadWriteCapability, IStat, IWatchOptions, createFileSystemProviderError, IFileSystemProviderWithOpenReadWriteCloseCapability, IFileOpenOptions, IFileSystemProviderWithFileAtomicDeleteCapability, IFileSystemProviderWithFileAtomicReadCapability, IFileSystemProviderWithFileAtomicWriteCapability, IFileSystemProviderWithFileReadStreamCapability } from './files.js';
 
 class File implements IStat {
 
@@ -56,6 +56,7 @@ export class InMemoryFileSystemProvider extends Disposable implements
 	IFileSystemProviderWithFileReadWriteCapability,
 	IFileSystemProviderWithOpenReadWriteCloseCapability,
 	IFileSystemProviderWithFileReadStreamCapability,
+	IFileSystemProviderWithFileAppendCapability,
 	IFileSystemProviderWithFileAtomicReadCapability,
 	IFileSystemProviderWithFileAtomicWriteCapability,
 	IFileSystemProviderWithFileAtomicDeleteCapability {
@@ -65,14 +66,14 @@ export class InMemoryFileSystemProvider extends Disposable implements
 	private _onDidChangeCapabilities = this._register(new Emitter<void>());
 	readonly onDidChangeCapabilities = this._onDidChangeCapabilities.event;
 
-	private _capabilities = FileSystemProviderCapabilities.FileReadWrite | FileSystemProviderCapabilities.PathCaseSensitive;
+	private _capabilities = FileSystemProviderCapabilities.FileReadWrite | FileSystemProviderCapabilities.FileAppend | FileSystemProviderCapabilities.PathCaseSensitive;
 	get capabilities(): FileSystemProviderCapabilities { return this._capabilities; }
 
 	setReadOnly(readonly: boolean) {
 		const isReadonly = !!(this._capabilities & FileSystemProviderCapabilities.Readonly);
 		if (readonly !== isReadonly) {
-			this._capabilities = readonly ? FileSystemProviderCapabilities.Readonly | FileSystemProviderCapabilities.PathCaseSensitive | FileSystemProviderCapabilities.FileReadWrite
-				: FileSystemProviderCapabilities.FileReadWrite | FileSystemProviderCapabilities.PathCaseSensitive;
+			this._capabilities = readonly ? FileSystemProviderCapabilities.Readonly | FileSystemProviderCapabilities.PathCaseSensitive | FileSystemProviderCapabilities.FileReadWrite | FileSystemProviderCapabilities.FileAppend
+				: FileSystemProviderCapabilities.FileReadWrite | FileSystemProviderCapabilities.FileAppend | FileSystemProviderCapabilities.PathCaseSensitive;
 			this._onDidChangeCapabilities.fire();
 		}
 	}
@@ -136,6 +137,35 @@ export class InMemoryFileSystemProvider extends Disposable implements
 		this._fireSoon({ type: FileChangeType.UPDATED, resource });
 	}
 
+	async appendFile(resource: URI, content: Uint8Array, opts: IFileWriteOptions): Promise<void> {
+		const basename = resources.basename(resource);
+		const parent = this._lookupParentDirectory(resource);
+		let entry = parent.entries.get(basename);
+		if (entry instanceof Directory) {
+			throw createFileSystemProviderError('file is directory', FileSystemProviderErrorCode.FileIsADirectory);
+		}
+		if (!entry && !opts.create) {
+			throw createFileSystemProviderError('file not found', FileSystemProviderErrorCode.FileNotFound);
+		}
+		if (!entry) {
+			entry = new File(basename);
+			parent.entries.set(basename, entry);
+			this._fireSoon({ type: FileChangeType.ADDED, resource });
+		}
+
+		// Append to existing data
+		const existingData = entry.data || new Uint8Array(0);
+		const newData = new Uint8Array(existingData.byteLength + content.byteLength);
+		newData.set(existingData, 0);
+		newData.set(content, existingData.byteLength);
+
+		entry.mtime = Date.now();
+		entry.size = newData.byteLength;
+		entry.data = newData;
+
+		this._fireSoon({ type: FileChangeType.UPDATED, resource });
+	}
+
 	// file open/read/write/close
 	open(resource: URI, opts: IFileOpenOptions): Promise<number> {
 		const data = this._lookupAsFile(resource, false).data;