Refine data piping to PassThrough for stream and optimize highWaterMa…

…rk for client streams #47

src/server/common.ts

@@ -1,9 +1 @@
-// import { dirname } from 'path';
-// import { fileURLToPath } from 'url';
-
-// // TODO To start the server with ts-node (ts-node-esm, we have to use the import.meta.url)
-// // For webpack we have to use __dirname, else the path is bundled into the server.js file.
-// // For esbuild we have to define the format to esm with other problems.
-// export const curDirName = dirname(fileURLToPath(import.meta.url));
-
 export const curDirName = __dirname;

src/server/control.ts

@@ -31,7 +31,7 @@ export const createRaspiControl = (settingsHelper: SettingsHelper): RaspiControl
   const actionProcess = spawnProcess();
   const streamProcess = spawnProcess({
     stdioOptions: ['ignore', 'pipe', 'inherit'],
-    resolveOnData: true,
+    stream: true,
   });
 
   streamProcess.stream.on('data', (chunk: unknown) =>
@@ -59,7 +59,9 @@ export const createRaspiControl = (settingsHelper: SettingsHelper): RaspiControl
   };
 
   const getStream = () => {
-    const clientStream: ClientStream = { stream: new PassThrough() };
+    // TODO adjustable highwatermark
+    const clientStream: ClientStream = { stream: new PassThrough({ highWaterMark: 128 * 1024 }) };
+
     clientStream.stream.once('close', () => {
       streams = streams.filter((x) => x != clientStream);
     });

src/server/process.ts

@@ -33,7 +33,7 @@ export interface SpawnProcess {
  */
 export const spawnProcess = (options?: {
   stdioOptions?: StdioOptions;
-  resolveOnData?: boolean;
+  stream?: boolean;
 }): SpawnProcess => {
   let process: ChildProcess | undefined;
   const stream = new PassThrough();
@@ -54,14 +54,20 @@ export const spawnProcess = (options?: {
       logger.log(command, spawnArgs.join(' '));
 
       process = spawn(command, spawnArgs, { stdio: options?.stdioOptions });
-      if (options?.resolveOnData) {
-        process.stdout?.once('data', () => resolve());
-      }
       process.on('error', (e) => reject(e));
       process.on('exit', () => resolve());
 
-      process.stdout?.pipe(stream, { end: false });
+      process.stderr?.on('data', (d) => logger.log(removeNewlines(d)));
+
+      if (options?.stream) {
+        process.stdout?.once('data', () => resolve());
+        process.stdout?.pipe(stream, { end: false });
+      } else {
+        process.stdout?.on('data', logger.info);
+      }
     });
 
   return { start, stop, running, stream };
 };
+
+const removeNewlines = (data: unknown) => String(data).replace(/^\s+|\s+$/g, '');