SimpleAsyncHTTP.py

import asyncore
import string, socket
import StringIO
import mimetools, urlparse
class AsyncHTTP(asyncore.dispatcher_with_send):
    # HTTP requester
    def __init__(self, uri, consumer):
        asyncore.dispatcher_with_send.__init__(self)
        self.uri = uri
        self.consumer = consumer
        # turn the uri into a valid request
        scheme, host, path, params, query, fragment = urlparse.urlparse(uri)
        assert scheme == "http", "only supports HTTP requests"
        try:
            host, port = string.split(host, ":", 1)
            port = int(port)
        except (TypeError, ValueError):
            port = 80 # default port
        if not path:
            path = "/"
        if params:
            path = path + ";" + params
        if query:
            path = path + "?" + query
        self.request = "GET %s HTTP/1.0\r\nHost: %s\r\n\r\n" % (path,
host)
        self.host = host
        self.port = port
        self.status = None
        self.header = None
        self.data = ""
        # get things going!
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.connect((host, port))
    def handle_connect(self):
        # connection succeeded
        self.send(self.request)
    def handle_expt(self):
    # connection failed; notify consumer (status is None)
        self.close()
        try:
            http_header = self.consumer.http_header
        except AttributeError:
            pass
        else:
            http_header(self)

    def handle_read(self):
        data = self.recv(2048)
        if not self.header:
            self.data = self.data + data
        try:
            i = string.index(self.data, "\r\n\r\n")
        except ValueError:
            return # continue
        else:
            # parse header
            fp = StringIO.StringIO(self.data[:i+4])
            # status line is "HTTP/version status message"
            status = fp.readline()
            self.status = string.split(status, " ", 2)
            # followed by a rfc822-style message header
            self.header = mimetools.Message(fp)
            # followed by a newline, and the payload (if any)
            data = self.data[i+4:]
            self.data = ""
            # notify consumer (status is non-zero)
            try:
                http_header = self.consumer.http_header
            except AttributeError:
                pass
            else:
                http_header(self)
            if not self.connected:
                return # channel was closed by consumer
        self.consumer.feed(data)

    def handle_close(self):
        self.consumer.close()
        self.close()