39 lines
1.5 KiB
Python
Executable file
39 lines
1.5 KiB
Python
Executable file
#!/usr/bin/python
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import time
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# The amount of internal buffering a WebSocket connection has is not
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# standardised, and varies depending upon the OS. Setting this number too small
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# will result in false negatives, as the entire message gets buffered. Setting
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# this number too large will result in false positives, when it takes more than
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# 2 seconds to transmit the message anyway. This number was arrived at by
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# trial-and-error.
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MESSAGE_SIZE = 1024 * 1024
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# With Windows 10 and Python 3, the OS will buffer an entire message in memory
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# and return from send() immediately, even if it is very large. To work around
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# this problem, send multiple messages.
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MESSAGE_COUNT = 16
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def web_socket_do_extra_handshake(request):
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# Turn off permessage-deflate, otherwise it shrinks our big message to a
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# tiny message.
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request.ws_extension_processors = []
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def web_socket_transfer_data(request):
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# Send empty message to fill the ReadableStream queue
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request.ws_stream.send_message(b'', binary=True)
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# TODO(ricea@chromium.org): Use time.perf_counter() when migration to python
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# 3 is complete. time.time() can go backwards.
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start_time = time.time()
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# The large messages that will be blocked by backpressure.
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for i in range(MESSAGE_COUNT):
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request.ws_stream.send_message(b' ' * MESSAGE_SIZE, binary=True)
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# Report the time taken to send the large message.
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request.ws_stream.send_message(str(time.time() - start_time),
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binary=False)
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