Doc commit tag conventions

packages/stack/src/utils/encrypter.ts

@@ -1,7 +1,7 @@
 // TODO: Consider whether we should shuffle this to Stack Util (as opposed to Primitive).
 //       It is async which breaks from our Primitive patterns.
 
-import { utf8ToBin } from '@bitauth/libauth';
+import { generateRandomBytes, utf8ToBin } from '@bitauth/libauth';
 
 // NOTE: We need to provide a default salt otherwise we would be deriving a key per each operation.
 //       This would be far too computationally expensive.
@@ -74,6 +74,12 @@ export class Encrypter {
     return this.fromBytes(key, opts);
   }
 
+  static async generateRandom(opts: Partial<EncrypterOpts> = {}) {
+    const key = generateRandomBytes(32);
+
+    return this.fromBytes(key, opts);
+  }
+
   async encrypt(payload: Uint8Array | string): Promise<Uint8Array> {
     // Convert string payload to Uint8Array if needed
     const data = typeof payload === 'string' ? utf8ToBin(payload) : payload;

packages/stack/src/utils/index.ts

@@ -2,6 +2,8 @@ export * from './encrypter.js';
 export * from './event-emitter.js';
 export * from './ext-error.js';
 export * from './hasher.js';
+export * from './inverse-bloom-filter.js';
 export * from './memoizer.js';
 export * from './misc.js';
+export * from './sse-client.js';
 export * from './uuid.js';

packages/stack/src/utils/inverse-bloom-filter.ts

@@ -15,7 +15,11 @@ interface Cell {
   hashSum: bigint;
 }
 
-class InverseBloomFilter {
+export class InverseBloomFilter {
+  static from(items: string[], expectedDiffSize?: number) {
+    return new this(items, expectedDiffSize);
+  }
+
   private size: number;
   private cells: Cell[];
   private items: Set<string>;
@@ -36,6 +40,41 @@ class InverseBloomFilter {
     }
   }
 
+  findMaybeMissing(otherFilterBytes: Uint8Array): string[] {
+    const diffCells = this.subtractFilter(otherFilterBytes);
+    const missing: string[] = [];
+
+    for (const item of this.items) {
+      const idx = this.hashToIndex(item);
+      const itemId = this.hashToId(item);
+      const cell = diffCells[idx];
+
+      if (cell.count === 1 && cell.idSum === itemId) {
+        missing.push(item);
+      }
+    }
+
+    return missing;
+  }
+
+  toBytes(): Uint8Array {
+    const cellSize = 4 + 8 + 8;
+    const bytes = new Uint8Array(8 + this.size * cellSize);
+    const view = new DataView(bytes.buffer);
+
+    view.setBigInt64(0, BigInt(this.size), true);
+
+    let offset = 8;
+    for (const cell of this.cells) {
+      view.setInt32(offset, cell.count, true);
+      view.setBigInt64(offset + 4, cell.idSum, true);
+      view.setBigInt64(offset + 12, cell.hashSum, true);
+      offset += cellSize;
+    }
+
+    return bytes;
+  }
+
   private hashToIndex(value: string): number {
     let hash = 2166136261;
     for (let i = 0; i < value.length; i++) {
@@ -68,24 +107,6 @@ class InverseBloomFilter {
     cell.hashSum ^= itemId;
   }
 
-  toBytes(): Uint8Array {
-    const cellSize = 4 + 8 + 8;
-    const bytes = new Uint8Array(8 + this.size * cellSize);
-    const view = new DataView(bytes.buffer);
-
-    view.setBigInt64(0, BigInt(this.size), true);
-
-    let offset = 8;
-    for (const cell of this.cells) {
-      view.setInt32(offset, cell.count, true);
-      view.setBigInt64(offset + 4, cell.idSum, true);
-      view.setBigInt64(offset + 12, cell.hashSum, true);
-      offset += cellSize;
-    }
-
-    return bytes;
-  }
-
   private subtractFilter(otherBytes: Uint8Array): Cell[] {
     const view = new DataView(otherBytes.buffer);
     const otherSize = Number(view.getBigInt64(0, true));
@@ -114,21 +135,4 @@ class InverseBloomFilter {
 
     return result;
   }
-
-  findMaybeMissing(otherFilterBytes: Uint8Array): string[] {
-    const diffCells = this.subtractFilter(otherFilterBytes);
-    const missing: string[] = [];
-
-    for (const item of this.items) {
-      const idx = this.hashToIndex(item);
-      const itemId = this.hashToId(item);
-      const cell = diffCells[idx];
-
-      if (cell.count === 1 && cell.idSum === itemId) {
-        missing.push(item);
-      }
-    }
-
-    return missing;
-  }
 }

packages/stack/src/utils/sse-client.ts

@@ -1,205 +1,286 @@
-// TODO: This probably needs some work.
-//       The reason this exists is that Browser's native EventSource is rubbish:
-//       1. It does not allow passing of headers.
-//       2. It is browser-only (this implementation aims to work for Node also)
-//       3. It does not handle disconnects/reconnects gracefully
-//       4. It does not handle last-event-id (important for history).
-//       5. It does not allow a custom fetch function (probably not necessary, but there's a reason I'd rather support this which I'll explain some other time).
-//       This might eventually be shifted out of XO/stack package and into its own.
-//       Q: "Why not just leverage an existing package?"
-//       A: They're all bad - the "go to" is a Microsoft (@azure/fetch-event-soruce) that is no longer maintained.
-//          It does not support NodeJS (or Workers) and we cannot depend upon forks of it.
-
-export interface SSEOptions {
-  fetch?: typeof fetch;
-  headers?: Record<string, string>;
-  onMessage?: (event: SSEMessageEvent) => void;
-  onError?: (error: Error) => void;
-  onOpen?: () => void;
-  onClose?: () => void;
-  maxRetries?: number;
-  retryDelay?: number;
-}
-
-export interface SSEMessageEvent {
-  data: string;
-  type: string;
-  id: string | null;
-  lastEventId: string;
-  origin: string;
-}
-
-export interface SSEEvent {
-  data: string;
-  event: string;
-  id: string | null;
-}
+// TODO: 1. Handle reconnection logic.
+//       2. Allow specifying custom
+//       3. Try to make it so that connect DOES NOT resolve until connection is actually establish.
+//          There's a very slim chance of a race-condition otherwise where we might miss an event.
+//          Note that this IS NOT trivial. Claude will probably NOT be able to do this for you!
 
+/**
+ * A Server-Sent Events client implementation using fetch API.
+ * Supports custom headers, POST requests, and is non-blocking.
+ */
 export class SSEClient {
-  private url: string;
-  private options: Required<Omit<SSEOptions, 'headers'>> & {
-    headers: Record<string, string>;
-  };
-  private abortController: AbortController | null;
-  private retryCount: number;
-  private lastEventId: string;
-  private connected: boolean;
+  /**
+   * Creates and connects a new SSEClient instance.
+   * @param url The URL to connect to
+   * @param options Configuration options
+   * @returns A new connected SSEClient instance
+   */
+  public static async from(
+    url: string,
+    options: SSEClientOptions,
+  ): Promise<SSEClient> {
+    const client = new SSEClient(url, options);
+    await client.connect();
+    return client;
+  }
 
-  constructor(url: string, options: SSEOptions = {}) {
+  // State.
+  private url: string;
+  private options: SSEClientOptions;
+  private controller: AbortController;
+  private connected: boolean = false;
+
+  /**
+   * Creates a new SSEClient instance.
+   * @param url The URL to connect to
+   * @param options Configuration options
+   */
+  constructor(url: string, options: SSEClientOptions) {
     this.url = url;
     this.options = {
-      fetch: globalThis.fetch,
-      headers: {},
-      onMessage: () => {},
-      onError: () => {},
+      method: 'GET',
+      headers: {
+        Accept: 'text/event-stream',
+        'Cache-Control': 'no-cache',
+      },
       onOpen: () => {},
+      onMessage: () => {},
+      onError: (error) => console.error('SSEClient error:', error),
       onClose: () => {},
-      maxRetries: 5,
-      retryDelay: 3000,
       ...options,
     };
-
-    this.abortController = null;
-    this.retryCount = 0;
-    this.lastEventId = '';
-    this.connected = false;
+    this.controller = new AbortController();
   }
 
+  /**
+   * Connects to the SSE endpoint.
+   *
+   * @remarks
+   *
+   * This currently does not await properly and has a chance of introducing a race-condition.
+   * We want to wait for the connection to ESTABLISH before resolving.
+   * Otherwise, there is a slight possibility of missing events during the connection phase.
+   * If you try to fix this, be cautious about using a while(true) loop: JS is single threaded and you may block.
+   * Try to use the Streams event features instead.
+   */
   public async connect(): Promise<void> {
-    if (this.connected) {
-      return;
-    }
+    if (this.connected) return;
 
-    this.abortController = new AbortController();
+    this.connected = true;
+    const { method, headers, body } = this.options;
 
-    try {
-      const response = await this.options.fetch(this.url, {
-        headers: {
-          Accept: 'text/event-stream',
-          'Cache-Control': 'no-cache',
-          'Last-Event-ID': this.lastEventId,
-          ...this.options.headers,
-        },
-        signal: this.abortController.signal,
-      });
-
-      if (!response.ok) {
-        throw new Error(`HTTP error! status: ${response.status}`);
-      }
-
-      if (!response.body) {
-        throw new Error('ReadableStream not supported');
-      }
-
-      this.connected = true;
-      this.options.onOpen();
-
-      const reader = response.body.getReader();
-      const decoder = new TextDecoder();
-      let buffer = '';
-
-      while (true) {
-        const { value, done } = await reader.read();
-
-        if (done) {
-          this.handleDisconnect();
-          break;
-        }
-
-        buffer += decoder.decode(value, { stream: true });
-        const lines = buffer.split(/\r\n|\r|\n/);
-
-        buffer = this.processEventStream(lines);
-      }
-    } catch (error) {
-      if (error instanceof Error && error.name === 'AbortError') {
-        return;
-      }
-
-      this.options.onError(
-        error instanceof Error ? error : new Error(String(error)),
-      );
-      this.handleDisconnect();
-
-      if (this.retryCount < this.options.maxRetries) {
-        this.retryCount++;
-        setTimeout(() => this.connect(), this.options.retryDelay);
-      }
-    }
-  }
-
-  private processEventStream(lines: string[]): string {
-    let event: SSEEvent = {
-      data: '',
-      event: 'message',
-      id: null,
+    const fetchOptions: RequestInit = {
+      method,
+      headers,
+      body,
+      signal: this.controller.signal,
+      cache: 'no-store',
     };
 
-    for (let i = 0; i < lines.length - 1; i++) {
+    // Using an async IIFE to handle the connection without blocking
+    (async () => {
+      try {
+        // TODO: We want to resolve only AFTER we handle connection.
+        //       But this is not trivial!
+        const response = await fetch(this.url, fetchOptions);
+
+        if (!response.ok) {
+          throw new Error(`HTTP error! Status: ${response.status}`);
+        }
+
+        if (!response.body) {
+          throw new Error('Response body is null');
+        }
+
+        // Notify that the connection has been established
+        if (this.options.onOpen) {
+          this.options.onOpen();
+        }
+
+        const reader = response.body.getReader();
+        const decoder = new TextDecoder();
+        let buffer = '';
+
+        while (true) {
+          const { done, value } = await reader.read();
+
+          if (done) {
+            this.connected = false;
+            if (this.options.onClose) {
+              this.options.onClose();
+            }
+            break;
+          }
+
+          // Decode the received chunk and add it to the buffer
+          const chunk = decoder.decode(value, { stream: true });
+          buffer += chunk;
+
+          // Process any complete events in the buffer
+          const events = this.parseEvents(buffer);
+          buffer = events.remainder;
+
+          // Handle each complete event
+          for (const event of events.parsed) {
+            if (this.options.onMessage) {
+              this.options.onMessage(event);
+            }
+          }
+        }
+      } catch (error) {
+        this.connected = false;
+
+        if (this.options.onError) {
+          this.options.onError(error);
+        }
+
+        if (this.options.onClose) {
+          this.options.onClose();
+        }
+      }
+    })();
+  }
+
+  /**
+   * Parses SSE events from a text buffer.
+   * @param buffer The buffer to parse
+   * @returns Parsed events and the remaining buffer
+   */
+  private parseEvents(buffer: string): {
+    parsed: SSEvent[];
+    remainder: string;
+  } {
+    const events: SSEvent[] = [];
+    const lines = buffer.split(/\r\n|\r|\n/);
+
+    let currentEvent: Partial<SSEvent> = {};
+    let completeEventCount = 0;
+
+    for (let i = 0; i < lines.length; i++) {
       const line = lines[i];
 
-      if (line.length === 0) {
-        // Empty line means dispatch the event
-        if (event.data.length > 0) {
-          this.dispatchEvent(event);
-          event = {
-            data: '',
-            event: 'message',
-            id: null,
-          };
+      // Empty line signals the end of an event
+      if (line === '') {
+        if (currentEvent.data) {
+          // Remove trailing newline if present
+          currentEvent.data = currentEvent.data.replace(/\n$/, '');
+          events.push(currentEvent as SSEvent);
+          currentEvent = {};
+          completeEventCount = i + 1;
         }
         continue;
       }
 
-      const [fieldName, ...fieldValue] = line.split(':');
-      const value = fieldValue.join(':').trim();
+      // Parse field: value format
+      const colonIndex = line.indexOf(':');
+      if (colonIndex === -1) continue;
 
-      switch (fieldName) {
-        case 'event':
-          event.event = value;
-          break;
-        case 'data':
-          event.data += value + '\n';
-          break;
-        case 'id':
-          event.id = value;
-          this.lastEventId = value;
-          break;
-        case 'retry': {
-          const retryInt = parseInt(value, 10);
-          if (!isNaN(retryInt)) {
-            this.options.retryDelay = retryInt;
-          }
-          break;
+      const field = line.slice(0, colonIndex);
+      // Skip initial space after colon if present
+      const valueStartIndex =
+        colonIndex + 1 + (line[colonIndex + 1] === ' ' ? 1 : 0);
+      const value = line.slice(valueStartIndex);
+
+      if (field === 'data') {
+        currentEvent.data = currentEvent.data
+          ? currentEvent.data + '\n' + value
+          : value;
+      } else if (field === 'event') {
+        currentEvent.event = value;
+      } else if (field === 'id') {
+        currentEvent.id = value;
+      } else if (field === 'retry') {
+        const retryMs = parseInt(value, 10);
+        if (!isNaN(retryMs)) {
+          currentEvent.retry = retryMs;
         }
       }
     }
 
-    // Return the last incomplete line as the new buffer
-    return lines[lines.length - 1];
-  }
-
-  private dispatchEvent(event: SSEEvent): void {
-    const messageEvent: SSEMessageEvent = {
-      data: event.data.slice(0, -1), // Remove trailing newline
-      type: event.event,
-      id: event.id,
-      lastEventId: this.lastEventId,
-      origin: this.url,
-    };
-
-    this.options.onMessage(messageEvent);
-  }
-
-  private handleDisconnect(): void {
-    this.connected = false;
-    this.options.onClose();
+    const remainder = lines.slice(completeEventCount).join('\n');
+    return { parsed: events, remainder };
   }
 
+  /**
+   * Closes the SSE connection.
+   */
   public close(): void {
-    if (this.abortController) {
-      this.abortController.abort();
-      this.handleDisconnect();
-    }
+    if (!this.connected) return;
+
+    this.controller.abort();
+    this.connected = false;
+  }
+
+  /**
+   * Checks if the client is currently connected.
+   * @returns Whether the client is connected
+   */
+  public isConnected(): boolean {
+    return this.connected;
   }
 }
+
+/**
+ * Configuration options for the SSEClient.
+ */
+export interface SSEClientOptions {
+  /**
+   * HTTP method to use (GET or POST).
+   */
+  method?: 'GET' | 'POST';
+
+  /**
+   * HTTP headers to send with the request.
+   */
+  headers?: Record<string, string>;
+
+  /**
+   * Body to send with POST requests.
+   */
+  body?: string | FormData | URLSearchParams;
+
+  /**
+   * Called when the connection is established.
+   */
+  onOpen?: () => void;
+
+  /**
+   * Called when a message is received.
+   */
+  onMessage?: (event: SSEvent) => void;
+
+  /**
+   * Called when an error occurs.
+   */
+  onError?: (error: unknown) => void;
+
+  /**
+   * Called when the connection is closed.
+   */
+  onClose?: () => void;
+}
+
+/**
+ * Represents a Server-Sent Event.
+ */
+export interface SSEvent {
+  /**
+   * Event data.
+   */
+  data: string;
+
+  /**
+   * Event type.
+   */
+  event?: string;
+
+  /**
+   * Event ID.
+   */
+  id?: string;
+
+  /**
+   * Reconnection time in milliseconds.
+   */
+  retry?: number;
+}