server-timing-profiler 0.0.2

# HTTP Server-Timing for Python Flask


This is a library including middleware for using
[HTTP Server-Timing](https://www.w3.org/TR/server-timing) with Python. This header
allows a server to send timing information from the backend, such as database
access time, file reads, etc. The timing information can be then be inspected
in the standard browser developer tools:


## Features

* Middleware for injecting the server timing into the request `Context`
and writing the `Server-Timing` header.

* Concurrency-safe structures for easily recording timings of multiple
concurrency tasks.

* Parse `Server-Timing` headers as a client.

* Note: No browser properly supports sending the Server-Timing header as
an [HTTP Trailer](https://tools.ietf.org/html/rfc7230#section-4.4) so
the Middleware only supports a normal header currently.

## Browser Support

Browser support is required to **view** server timings easily. Because server
timings are sent as an HTTP header, there is no negative impact to sending
the header to unsupported browsers.

* **Chrome 65 or higher** is required to properly display server timings
in the devtools.

## Usage

Example usage is shown below. A fully runnable example is available in
the `example/` directory.

```python
from flask import Flask, jsonify
import time
from profiler.profile_manager import ProfileManager

app = Flask(__name__)

profiler = ProfileManager(app, 'debug')


@app.route("/test", methods=["GET"])
def hello():
print 'test start sleep'

profiler.start('App 1')
time.sleep(1)
profiler.stop('App 1')

profiler.start('App 2')
time.sleep(2)
profiler.stop('App 2')

profiler.start('App 3')
time.sleep(3)
profiler.stop('App 3')

profiler.start('App 4')
time.sleep(4)
profiler.stop('App 4')

print 'test stop sleep'
return jsonify({'success':True})

app.run(host="0.0.0.0",port=8080,debug=True)
```