React recently introduced an experimental profiler API. This page gives instructions on how to use this API in a production release of your app.
Table of Contents
- Profiling in production
React recently introduced an experimental profiler API. After discussing this API with several teams at Facebook, one common piece of feedback was that the performance information would be more useful if it could be associated with the events that caused the application to render (e.g. button click, XHR response). Tracing these events (or "interactions") would enable more powerful tooling to be built around the timing information, capable of answering questions like "What caused this really slow commit?" or "How long does it typically take for this interaction to update the DOM?".
With version 16.4.3, React added experimental support for this tracing by way of a new NPM package, scheduler. However the public API for this package is not yet finalized and will likely change with upcoming minor releases, so it should be used with caution.
This Gist provides some high-level docum
This is the second part of a series about Algebraic Effects and Handlers.
Note: initially I planned a 3-part series, but since the current post on undelimited continuations ended up taking
When this guide is more complete, the plan is to move it into Prepack documentation.
For now I put it out as a gist to gather initial feedback.
None of the string methods modify
this – they always return fresh strings.
charAt(pos: number): string ES1
Returns the character at index
str[i] is equivalent to
str.charAt(i) and more concise (caveat: may not work on old engines).
|script to kill apache 1.3 / 2.x prefork httpd processes serving preconnect connections, in an attempt to prevent chrome from causing a DoS against the httpd|
|This is version 2 of https://gist.github.com/eqhmcow/4774549|
|The major change is the use of two processes instead of one:|
|One process makes server-status requests, the other kills idle prefork processes.|
|This allows the kill script to continue killing idle processes even when Chrome has effectively DoS'd the apache server. When this happens, the check script can't get an updated status response back immediately, but the kill script can hopefully free up a slot by killing some processes. Having an uninterrupted request in the socket queue allows us to get an updated response after killing the Chrome preconnections are killed.|
|<meta charset="utf-8" />|
|<title>Test case for bug in Firefox where a background image in a SVG isn't rendered to the canvas unless a workaround is applied</title>|
|<canvas id="canvas" style="border:1px solid black;" width="200" height="200"></canvas>|
|var canvas = document.getElementById("canvas"),|