HTTPChannel.py

import asyncore, asynchat
import StringIO, mimetools
import string
import os, sys
import datetime

class push_FileProducer:
    # a producer which reads data from a file object

    def __init__(self, file):
        self.file = open(file, "rb")

    def more(self):
        if self.file:
            data = self.file.read(2048)
            if data:
                return data
            self.file = None
        return ""

class HTTPChannel(asynchat.async_chat):
    def __init__(self, server, sock, addr):
        asynchat.async_chat.__init__(self, sock)
        self.server = server
        self.set_terminator("\r\n\r\n")
        self.header = None
        self.data = ""
        self.shutdown = 0

    def collect_incoming_data(self, data):
        self.data = self.data + data
        if len(self.data) > 16384:
        # limit the header size to prevent attacks
            self.shutdown = 1

    def found_terminator(self):
        if not self.header:
            # parse http header
            fp = StringIO.StringIO(self.data)
            request = string.split(fp.readline(), None, 2)
            if len(request) != 3:
                # badly formed request; just shut down
                self.shutdown = 1
            else:
                # parse message header
                self.header = mimetools.Message(fp)
                self.set_terminator("\r\n")
                self.server.handle_request(
                    self, request[0], request[1], self.header
                    )
                self.close_when_done()
            self.data = ""
        else:
            pass # ignore body data, for now

    def pushstatus(self, status, explanation="OK"):
        self.push("HTTP/1.0 %d %s\r\n" % (status, explanation))

    def pushok(self, content):
        self.pushstatus(200, "OK")
        self.push('Content-type: application/json\r\n')
        self.push('Expires: Sat, 26 Jul 1997 05:00:00 GMT\r\n')
        self.push('Last-Modified: '+ datetime.datetime.now().strftime("%d/%m/%Y %H:%M:%S")+' GMT\r\n')
        self.push('Cache-Control: no-store, no-cache, must-revalidate\r\n' ) 
        self.push('Cache-Control: post-check=0, pre-check=0\r\n') 
        self.push('Pragma: no-cache\r\n' )
        self.push('\r\n')
        self.push(content)

    def pushfile(self, file):
        self.pushstatus(200, "OK")
        extension = os.path.splitext(file)[1]
        if extension == ".html":
            self.push("Content-type: text/html\r\n")
        elif extension == ".js":
            self.push("Content-type: text/javascript\r\n")
        elif extension == ".png":
            self.push("Content-type: image/png\r\n")
        elif extension == ".css":
            self.push("Content-type: text/css\r\n")
        self.push("\r\n")
        self.push_with_producer(push_FileProducer(sys.path[0] + os.sep + 'ext' + os.sep + file))