python-concurrent-disk-io/http-threaded-simulated-disk-io-server.py at master · openstack-yak/python-concurrent-disk-io · GitHub

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# python threads - simulate occasional problematic (long blocking) requests
# to run: python http-threaded-simulated-disk-io-server.py


import string
import time
import socket
from threading import Thread


READ_TIMEOUT_SECS = 4

SERVER_NAME = 'http-threaded-simulated-disk-io-server.py'
HTTP_STATUS_OK = '200 OK'
HTTP_STATUS_TIMEOUT = '408 TIMEOUT'
HTTP_STATUS_BAD_REQUEST = '400 BAD REQUEST'


def simulated_file_read(elapsed_time_ms):
    time.sleep(elapsed_time_ms / 1000.0)  # seconds


def handle_socket_request(sock, receipt_timestamp):
    reader = sock.makefile('r')
    writer = sock.makefile('w')
    request_text = reader.readline()
    reader.close()
    if request_text:
        request_text = request_text.rstrip()
        start_processing_timestamp = time.time()
        queue_time_ms = start_processing_timestamp - receipt_timestamp
        queue_time_secs = queue_time_ms / 1000

        rc = HTTP_STATUS_OK
        disk_read_time_ms = 0
        file_path = ''

        # has this request already timed out?
        if queue_time_secs >= READ_TIMEOUT_SECS:
            print("timeout (queue)")
            rc = HTTP_STATUS_TIMEOUT
        else:
            line_tokens = string.split(request_text, ' ')
            if len(line_tokens) > 1:
                request_method = line_tokens[0]
                args_text = line_tokens[1]
                fields = string.split(args_text, ',')
                if len(fields) == 3:
                    first_field = fields[0].strip('/')
                    rc = int(first_field)
                    disk_read_time_ms = long(fields[1])
                    file_path = fields[2]
                    simulated_file_read(disk_read_time_ms)
                else:
                    print("len(fields) != 3")
                    rc = HTTP_STATUS_BAD_REQUEST
            else:
                print("len(line_tokens) <= 0")
                rc = HTTP_STATUS_BAD_REQUEST

        # total request time is sum of time spent in queue and the
        # simulated disk read time
        tot_request_time_ms = queue_time_ms + disk_read_time_ms

        # construct response and send back to client
        resp_text = 'HTTP/1.1 %s\n' % rc
        resp_text += "%s\n" % SERVER_NAME
        resp_text += "Connection: close\n\n"
        resp_text += "%d,%s" % \
            (tot_request_time_ms, file_path)
        writer.write(resp_text)
        writer.flush()
    writer.close()
    sock.close()


def main(server_port):
    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    server_socket.bind(('', server_port))
    server_socket.listen(100)
    print("server listening on port %d" % server_port)

    try:
        while True:
            sock, addr = server_socket.accept()
            receipt_timestamp = time.time()
            Thread(target=lambda: handle_socket_request(sock, receipt_timestamp)).start()
    except KeyboardInterrupt:
        pass  # exit


if __name__=='__main__':
    server_port = 7000
    main(server_port)