Parse messages on arrival

Rather than queuing inbound messages, the HubController now saves
pending promises/rejects for each pending request. Each inbound packet
is checked at the time of arrival, and if the ID matches a pending
response, the corresponding promise is called.

This fixes a problem where the longer the time between reads, the more
garbage responses queue up that are guaranteed to get thrown away the
next time the next response was gathered.

src/commands.ts

@@ -246,7 +246,7 @@ let hub: HubManager | null;
 async function connectHub(): Promise<void> {
   if (hub) {
     vscode.window.showWarningMessage('LEGO Hub is already connected, reconnecting...');
-    hub.close();
+    disconnectHub();
   }
   const config = vscode.workspace.getConfiguration();
 
@@ -283,7 +283,7 @@ async function connectHub(): Promise<void> {
 }
 
 async function disconnectHub(): Promise<void> {
-  if (!hub) {
+  if (!hub || !hub.isOpen()) {
     vscode.window.showErrorMessage('LEGO Hub is not connected');
     return;
   }
@@ -294,7 +294,7 @@ async function disconnectHub(): Promise<void> {
 }
 
 async function uploadCurrentFile(): Promise<void> {
-  if (!hub) {
+  if (!hub || !hub.isOpen()) {
     vscode.window.showErrorMessage('LEGO Hub is not connected!');
     return;
   }
@@ -327,7 +327,7 @@ async function uploadCurrentFile(): Promise<void> {
 
 // TODO: find empty slots
 async function runProgram(): Promise<void> {
-  if (!hub) {
+  if (!hub || !hub.isOpen()) {
     vscode.window.showErrorMessage('LEGO Hub is not connected!');
     return;
   }
@@ -348,7 +348,7 @@ async function runProgram(): Promise<void> {
 }
 
 async function stopExecution(): Promise<void> {
-  if (!hub) {
+  if (!hub || !hub.isOpen()) {
     vscode.window.showErrorMessage('LEGO Hub is not connected!');
     return;
   }
@@ -359,7 +359,7 @@ async function stopExecution(): Promise<void> {
 
 // TODO: find slots from status
 async function deleteProgram(): Promise<void> {
-  if (!hub) {
+  if (!hub || !hub.isOpen()) {
     vscode.window.showErrorMessage('LEGO Hub is not connected!');
     return;
   }

src/extension.ts

@@ -5,6 +5,14 @@ import commands from './commands';
 
 import AccessNodeProvider from './accessNodeProvider';
 
+// create output channel
+const outputChannel = vscode.window.createOutputChannel("SPIKE Prime Output");
+
+export function MindReaderOutput(line: string) {
+  outputChannel.show();
+  outputChannel.appendLine(line);
+}
+
 let parser: pl.Parser = new pl.Parser();
 
 export function activate(context: vscode.ExtensionContext) {

src/hubManager.ts

@@ -2,6 +2,7 @@ import * as vscode from 'vscode';
 import * as SerialPort from 'serialport';
 import * as fs from 'fs';
 import { performance } from 'perf_hooks';
+import { MindReaderOutput } from './extension';
 
 /**
  * @type RPCRequest an RPC request message
@@ -48,8 +49,8 @@ type HubOptions = {
  */
 export default class HubManager {
   private port: SerialPort;
-  private receiveQueue: string[] = []; // queue of received messages to handle
+  private receiveBuffer: string = ''; // buffer for in-flight messages
-  public responses: RPCResponse[] = []; // list of messages returned to the user
+  private pendingRequests = new Map<string, [(result: any) => void, (error: string) => void]>();
 
   // ======================== INSTANCE METHODS ========================
 
@@ -58,6 +59,65 @@ export default class HubManager {
    */
   private constructor(public options: HubOptions) { }
 
+  public isOpen(): boolean {
+    return this.port.isOpen;
+  }
+
+  /**
+   * Handle a received data chunk from the serial port
+   *
+   * @param `data` Data received from serial port
+   */
+  private async receiveData(data: string) {
+    // add data to buffer
+    this.receiveBuffer += data;
+
+    // get full lines in buffer
+
+    let msgs = this.receiveBuffer.split(/\r/); // split by newline
+    this.receiveBuffer = msgs.pop()!; // store unhandled data
+
+    msgs = msgs.filter(x => !x.startsWith('{"m":0,"p":')); // drop sensor broadcast response spam
+
+    for (const msg of msgs) {
+      // check if this msg is a response to a pending request
+      try {
+        let json: { [key: string]: any };
+
+        json = JSON.parse(msg);
+
+        let id = json['i'];
+        if (id && this.pendingRequests.has(id)) {
+          // a request is waiting on this response
+          let [resolve, reject] = this.pendingRequests.get(id) ?? [];
+
+          if (json['e'] && reject) {
+            // error
+            reject(Buffer.from(json['e'], 'base64').toString());
+          } else if (resolve) {
+            resolve(json['r']);
+          }
+
+          this.pendingRequests.delete(id);
+        } else if (json['m']) {
+          // Print errors
+          const params = json['p'];
+          switch (json['m']) {
+            case 'user_program_error':
+              MindReaderOutput(Buffer.from(params[3], 'base64').toString());
+              MindReaderOutput(Buffer.from(params[4], 'base64').toString());
+              break;
+            case 'runtime_error':
+              MindReaderOutput(Buffer.from(params[3], 'base64').toString());
+              break;
+          }
+        }
+      } catch (err) {
+        console.log('Could not parse JSON:', msg);
+      }
+    }
+  }
+
   /**
    * Initializes a created HubManager with the current option settings
    */
@@ -79,8 +139,10 @@ export default class HubManager {
 
     // push lines received to data queue
 
-    let rl = this.port.pipe(new SerialPort.parsers.Readline({delimiter: '\r'}));
+    let mgr = this;
-    rl.on('data', data => this.receiveQueue.push(data));
+    this.port.on('data', data => {
+      mgr.receiveData(data)
+    });
   }
 
   public async close(): Promise<void> {
@@ -97,99 +159,18 @@ export default class HubManager {
    */
   // TODO: make send take a single RPCRequest argument, made inline in each function
   public async send(request: RPCRequest): Promise<RPCResponse> {
-    return new Promise(resolve => {
+    return new Promise((resolve, reject) => {
       if (request['i'] === undefined) {
         // generate an ID
         request['i'] = 'mind-reader-' + HubManager.randomID();
       }
 
       // write JSON to port
+
+      this.pendingRequests.set(request['i'], [resolve, reject]);
       this.port.write(JSON.stringify(request));
-      this.port.write('\r', async () => {
+      this.port.write('\r');
-        if (request['i']) {
+      this.port.drain();
-          // expecting a response
-          let response = await this.recv(request['i']);
-          resolve(response);
-        }
-      });
-    });
-  }
-
-  /**
-   * Receive an RPC message.
-   *
-   * @param `id` The id to match received messages against. Use `null` to match *all* messages
-   */
-  public async recv(id: string | null): Promise<RPCResponse> {
-    let index = 0; // index into receive qeueue
-    let startTime = performance.now();
-
-    return new Promise(async (resolve) => {
-      // used for non-blocking "wait-until" behavior
-      let rcv = () => {
-        let elapsedTime = performance.now() - startTime;
-        if (this.options.timeout !== null && elapsedTime >= this.options.timeout!) {
-          return resolve({
-            'e': 'Timed out while receiving message',
-            'i': id
-          });
-        }
-
-        // check that there is more data in the queue
-        if (index < this.receiveQueue.length) {
-          // get next message in queue
-          let r = this.receiveQueue[index];
-          index++;
-
-          try {
-            let j = JSON.parse(r);
-
-
-            // check for matching id
-            if (id === null || 'i' in j && j['i'] === id) {
-              let response: RPCResponse;
-              // is response an error?
-              if ('e' in j) {
-                // decode error from base64
-                let error = JSON.parse(Buffer.from(j['e'], 'base64').toString('ascii'));
-
-                response = {
-                  'i': id,
-                  'e': error
-                };
-
-                this.responses.push(response);
-                return resolve(response);
-              } else {
-                response = j;
-              }
-
-              // trim start of queue (just processed)
-              this.receiveQueue = this.receiveQueue.slice(index);
-
-              // return response object
-              this.responses.push(response);
-              return resolve(response);
-            } else {
-              // not at end of queue, eager retry
-              setTimeout(rcv, 0);
-            }
-          } catch (err) {
-            // TODO: parse print statements somehow
-            //console.debug('Could not parse json response: "' + r + '"');
-
-            // not at end of queue, eager retry
-            setTimeout(rcv, 0);
-          }
-        } else {
-          // no more data in queue, wait
-          // before attempting again
-          setTimeout(rcv, 1000);
-        }
-
-      };
-
-      rcv();
     });
   }
 
@@ -199,9 +180,9 @@ export default class HubManager {
     name = name || file;
     const now = performance.now();
 
-    const ack = await this.startWriteProgram(name, size, slotid, now, now);
+    const ack: {[key: string]: any} = await this.startWriteProgram(name, size, slotid, now, now);
-    const blockSize = ack['r'].blocksize;
+    const blockSize = ack.blocksize;
-    const transferid = ack['r'].transferid;
+    const transferid = ack.transferid;
 
     const numBlocks = Math.ceil(size / blockSize);
 
@@ -226,14 +207,17 @@ export default class HubManager {
    * @param `slotid` Slot ID of the program to run
    */
   public async programExecute(slotid: number): Promise<RPCResponse> {
-    return Promise.resolve(
+    return new Promise(async (resolve) => {
-      await this.send({
+        let response = await this.send({
-        'm': 'program_execute',
+          'm': 'program_execute',
-        'p': {
+          'p': {
-          'slotid': slotid
+            'slotid': slotid
-        }
+          }
-      })
+        });
-    );
+
+
+        resolve(response);
+      });
   }
 
   /**
@@ -285,7 +269,7 @@ export default class HubManager {
       'name': name,
       'type': 'python', // always python
       // eslint-disable-next-line @typescript-eslint/naming-convention
-      'project_id': '50uN1ZaRpHj2', // TODO: check this
+      'project_id': HubManager.randomID(16),
     };
 
     return Promise.resolve(