larry babby and threejs for glsl

webGl/my-threejs-test/node_modules/@parcel/reporter-tracer/src/TracerReporter.js

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+// @flow
+import invariant from 'assert';
+import nullthrows from 'nullthrows';
+import path from 'path';
+import {Reporter} from '@parcel/plugin';
+import {Tracer} from 'chrome-trace-event';
+
+// We need to maintain some state here to ensure we write to the same output, there should only be one
+// instance of this reporter (this gets asserted below)
+let tracer;
+let writeStream = null;
+
+function millisecondsToMicroseconds(milliseconds: number) {
+  return Math.floor(milliseconds * 1000);
+}
+
+// TODO: extract this to utils as it's also used in packages/core/workers/src/WorkerFarm.js
+function getTimeId() {
+  let now = new Date();
+  return (
+    String(now.getFullYear()) +
+    String(now.getMonth() + 1).padStart(2, '0') +
+    String(now.getDate()).padStart(2, '0') +
+    '-' +
+    String(now.getHours()).padStart(2, '0') +
+    String(now.getMinutes()).padStart(2, '0') +
+    String(now.getSeconds()).padStart(2, '0')
+  );
+}
+
+export default (new Reporter({
+  report({event, options, logger}) {
+    let filename;
+    let filePath;
+    switch (event.type) {
+      case 'buildStart':
+        invariant(tracer == null, 'Tracer multiple initialisation');
+        tracer = new Tracer();
+        filename = `parcel-trace-${getTimeId()}.json`;
+        filePath = path.join(options.projectRoot, filename);
+        invariant(
+          writeStream == null,
+          'Trace write stream multiple initialisation',
+        );
+        logger.info({
+          message: `Writing trace to ${filename}. See https://parceljs.org/features/profiling/#analysing-traces for more information on working with traces.`,
+        });
+        writeStream = options.outputFS.createWriteStream(filePath);
+        nullthrows(tracer).pipe(nullthrows(writeStream));
+        break;
+      case 'trace':
+        // Due to potential race conditions at the end of the build, we ignore any trace events that occur
+        // after we've closed the write stream.
+        if (tracer === null) return;
+
+        tracer.completeEvent({
+          name: event.name,
+          cat: event.categories,
+          args: event.args,
+          ts: millisecondsToMicroseconds(event.ts),
+          dur: millisecondsToMicroseconds(event.duration),
+          tid: event.tid,
+          pid: event.pid,
+        });
+        break;
+      case 'buildSuccess':
+      case 'buildFailure':
+        nullthrows(tracer).flush();
+        // We explicitly trigger `end` on the writeStream for the trace, then we need to wait for
+        // the `close` event before resolving the promise this report function returns to ensure
+        // that the file has been properly closed and moved from it's temp location before Parcel
+        // shuts down.
+        return new Promise((resolve, reject) => {
+          nullthrows(writeStream).once('close', err => {
+            writeStream = null;
+            tracer = null;
+            if (err) {
+              reject(err);
+            } else {
+              resolve();
+            }
+          });
+          nullthrows(writeStream).end();
+        });
+    }
+  },
+}): Reporter);