aiothrottle package

Module contents

Providing classes for limiting data rates of asyncio sockets

class aiothrottle.Throttle(limit, loop=None)

Bases: object

Throttle for IO operations

As soon as an IO action is registered using add_io(), time_left() returns the seconds to wail until [byte count] / [time passed] = [rate limit]. After that, reset_io() has to be called to measure the new rate.

Parameters:limit (int) – the limit in bytes to read/write per second Raises:ValueError: invalid rate given

add_io(byte_count)

registers a number of bytes read/written

Parameters:byte_count (int) – number of bytes to add to the current rate

current_rate()

returns the current rate, measured since reset_io()

In case the time since the last reset is too short, this returns -1.

Returns:the current rate in bytes per second Return type:float

limit

Returns:the limit in bytes to read/write per second Return type:int

reset_io()

resets the registered IO actions

time_left()

returns the number of seconds left until the rate limit is reached

Returns:seconds left until the rate limit is reached Return type:float

wait_remaining()

waits until the rate limit is reached

within_limit()

returns the current limitation state

Returns:True if the current rate is equal or below the limit rate Return type:bool

class aiothrottle.ThrottledStreamReader(stream, rate_limit, buffer_limit=65536, loop=None, *args, **kwargs)

Bases: aiohttp.streams.StreamReader

Throttling, flow controlling aiohttp.streams.StreamReader for aiohttp.request()

Usage:

>>> import functools
>>> import aiohttp
>>> import aiothrottle
>>> kbps = 200
>>> partial = functools.partial(
>>>     aiothrottle.ThrottledStreamReader, rate_limit=kbps * 1024)
>>> aiohttp.client_reqrep.ClientResponse.flow_control_class = partial

Parameters:

• stream (aiohttp.parsers.StreamParser) – the base stream
• rate_limit (int) – the rate limit in bytes per second
• buffer_limit (int) – the internal buffer limit in bytes
• loop (asyncio.BaseEventLoop) – the asyncio event loop
• args (tuple) – arguments passed through to StreamReader
• kwargs (dict) – keyword arguments passed through to StreamReader

feed_data(data, _=0)

Feeds data into the internal buffer

limit_rate(limit)

Sets the rate limit of this response

Parameters:limit – the limit in bytes to read/write per second

New in version 0.1.1.

rate_limit

Returns:the current rate limit Return type:int

New in version 0.1.2.

read(byte_count=-1)

Reads at most the requested number of bytes from the internal buffer

Parameters:byte_count (int) – the number of bytes to read Returns:the data Return type:bytes

readany()

Reads the bytes next received from the internal buffer

Returns:the data Return type:bytes

readexactly(byte_count)

Reads the requested number of bytes from the internal buffer

This raises asyncio.IncompleteReadError if the stream ended before enough bytes were received

Parameters:byte_count (int) – the number of bytes to read Returns:the data Return type:bytes

readline()

Reads bytes from the internal buffer until \n is found

Returns:the data Return type:bytes

throttling

Returns:wether the connection is being throttled Return type:bool

New in version 0.1.2.

unlimit_rate()

Unlimits the rate of this response

New in version 0.1.1.

aiothrottle.limit_rate(limit)

Limits the rate of all subsequent aiohttp requests

Parameters:limit – the limit in bytes to read/write per second

New in version 0.1.1.

aiothrottle.unlimit_rate()

Unlimits the rate of all subsequent aiohttp requests

New in version 0.1.1.