From 2518bfa8d35ab6c546660aef506b8e2cef265f31 Mon Sep 17 00:00:00 2001
From: Dmitry Gozman <dgozman@gmail.com>
Date: Thu, 16 Mar 2023 11:15:57 -0700
Subject: [PATCH] Revert "feat(tracing): throttle trace event writes (#21694)"
 (#21718)

This reverts commit 3f20602735ed102bc0158ba492de5f4ff7a31225.
---
 .../src/server/trace/recorder/tracing.ts      | 23 ++++---------------
 1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/packages/playwright-core/src/server/trace/recorder/tracing.ts b/packages/playwright-core/src/server/trace/recorder/tracing.ts
index 285e366c93..37fe87836f 100644
--- a/packages/playwright-core/src/server/trace/recorder/tracing.ts
+++ b/packages/playwright-core/src/server/trace/recorder/tracing.ts
@@ -61,9 +61,7 @@ type RecordingState = {
   filesCount: number,
   networkSha1s: Set<string>,
   traceSha1s: Set<string>,
-  recording: boolean,
-  pendingTraceEvents: trace.TraceEvent[],
-  flushPendingTraceEventsTimer: NodeJS.Timer | undefined,
+  recording: boolean;
 };
 
 const kScreencastOptions = { width: 800, height: 600, quality: 90 };
@@ -134,7 +132,7 @@ export class Tracing extends SdkObject implements InstrumentationListener, Snaps
     // and conflict.
     const traceName = options.name || createGuid();
     // Init the state synchronously.
-    this._state = { options, traceName, traceFile: '', networkFile: '', tracesDir: '', resourcesDir: '', filesCount: 0, traceSha1s: new Set(), networkSha1s: new Set(), recording: false, pendingTraceEvents: [], flushPendingTraceEventsTimer: undefined };
+    this._state = { options, traceName, traceFile: '', networkFile: '', tracesDir: '', resourcesDir: '', filesCount: 0, traceSha1s: new Set(), networkSha1s: new Set(), recording: false };
     const state = this._state;
 
     state.tracesDir = await this._createTracesDirIfNeeded();
@@ -160,7 +158,6 @@ export class Tracing extends SdkObject implements InstrumentationListener, Snaps
     state.filesCount++;
     state.traceFile = path.join(state.tracesDir, `${state.traceName}${suffix}.trace`);
     state.recording = true;
-    state.flushPendingTraceEventsTimer = setInterval(() => this._flushTraceEvents(state), 100);
 
     if (options.name && options.name !== this._state.traceName)
       this._changeTraceName(this._state, options.name);
@@ -231,8 +228,6 @@ export class Tracing extends SdkObject implements InstrumentationListener, Snaps
   async dispose() {
     this._snapshotter?.dispose();
     this._harTracer.stop();
-    if (this._state?.flushPendingTraceEventsTimer)
-      clearInterval(this._state.flushPendingTraceEventsTimer);
     await this._writeChain;
   }
 
@@ -256,9 +251,6 @@ export class Tracing extends SdkObject implements InstrumentationListener, Snaps
     if (state.options.snapshots)
       await this._snapshotter?.stop();
 
-    clearInterval(state.flushPendingTraceEventsTimer);
-    this._flushTraceEvents(state);
-
     // Chain the export operation against write operations,
     // so that neither trace files nor sha1s change during the export.
     return await this._appendTraceOperation(async () => {
@@ -413,16 +405,9 @@ export class Tracing extends SdkObject implements InstrumentationListener, Snaps
   }
 
   private _appendTraceEvent(event: trace.TraceEvent) {
-    this._state!.pendingTraceEvents.push(event);
-  }
-
-  private _flushTraceEvents(state: RecordingState) {
-    if (!state.pendingTraceEvents.length)
-      return;
-    const lines = state.pendingTraceEvents.map(event => JSON.stringify(visitTraceEvent(event, state.traceSha1s)) + '\n');
-    state.pendingTraceEvents = [];
     this._appendTraceOperation(async () => {
-      await fs.promises.appendFile(state.traceFile, lines.join(''));
+      const visited = visitTraceEvent(event, this._state!.traceSha1s);
+      await fs.promises.appendFile(this._state!.traceFile, JSON.stringify(visited) + '\n');
     });
   }