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  1. @invalid-email-address Anonymous created this gist Jun 27, 2012.
    1,087 changes: 1,087 additions & 0 deletions fcgi.py
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,1087 @@
    # encoding: utf-8

    # FastCGI-to-WSGI bridge for files/pipes transport (not socket)
    #
    # Copyright (c) 2002, 2003, 2005, 2006 Allan Saddi <[email protected]>
    # Copyright (c) 2011 Ruslan Keba <[email protected]>
    # Copyright (c) 2012 Antoine Martin <[email protected]>
    # All rights reserved.
    #
    # Redistribution and use in source and binary forms, with or without
    # modification, are permitted provided that the following conditions
    # are met:
    # 1. Redistributions of source code must retain the above copyright
    # notice, this list of conditions and the following disclaimer.
    # 2. Redistributions in binary form must reproduce the above copyright
    # notice, this list of conditions and the following disclaimer in the
    # documentation and/or other materials provided with the distribution.
    #
    # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
    # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
    # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    # SUCH DAMAGE.
    #

    __author__ = 'Allan Saddi <[email protected]>, Ruslan Keba <[email protected]>, Antoine Martin <[email protected]>'

    import msvcrt
    import struct
    import os
    import os.path
    import logging
    import sys
    import traceback
    import datetime
    import urllib
    from optparse import OptionParser
    from django.core.management.base import BaseCommand
    from django.conf import settings


    # Constants from the spec.

    FCGI_LISTENSOCK_FILENO = 0
    FCGI_HEADER_LEN = 8
    FCGI_VERSION_1 = 1
    FCGI_BEGIN_REQUEST = 1
    FCGI_ABORT_REQUEST = 2
    FCGI_END_REQUEST = 3
    FCGI_PARAMS = 4
    FCGI_STDIN = 5
    FCGI_STDOUT = 6
    FCGI_STDERR = 7
    FCGI_DATA = 8
    FCGI_GET_VALUES = 9
    FCGI_GET_VALUES_RESULT = 10
    FCGI_UNKNOWN_TYPE = 11
    FCGI_MAXTYPE = FCGI_UNKNOWN_TYPE
    FCGI_NULL_REQUEST_ID = 0
    FCGI_KEEP_CONN = 1
    FCGI_RESPONDER = 1
    FCGI_AUTHORIZER = 2
    FCGI_FILTER = 3
    FCGI_REQUEST_COMPLETE = 0
    FCGI_CANT_MPX_CONN = 1
    FCGI_OVERLOADED = 2
    FCGI_UNKNOWN_ROLE = 3

    FCGI_MAX_CONNS = 'FCGI_MAX_CONNS'
    FCGI_MAX_REQS = 'FCGI_MAX_REQS'
    FCGI_MPXS_CONNS = 'FCGI_MPXS_CONNS'

    FCGI_Header = '!BBHHBx'
    FCGI_BeginRequestBody = '!HB5x'
    FCGI_EndRequestBody = '!LB3x'
    FCGI_UnknownTypeBody = '!B7x'

    FCGI_EndRequestBody_LEN = struct.calcsize(FCGI_EndRequestBody)
    FCGI_UnknownTypeBody_LEN = struct.calcsize(FCGI_UnknownTypeBody)

    FCGI_HEADER_NAMES = (
    'ERROR TYPE: 0',
    'BEGIN_REQUEST',
    'ABORT_REQUEST',
    'END_REQUEST',
    'PARAMS',
    'STDIN',
    'STDOUT',
    'STDERR',
    'DATA',
    'GET_VALUES',
    'GET_VALUES_RESULT',
    'UNKNOWN_TYPE',
    )

    FCGI_DEBUG = getattr(settings, 'FCGI_DEBUG', settings.DEBUG)
    FCGI_LOG = getattr(settings, 'FCGI_LOG', FCGI_DEBUG)
    FCGI_LOG_PATH = getattr(settings, 'FCGI_LOG_PATH', os.path.dirname(os.path.abspath(sys.argv[0])))

    class InputStream(object):
    """
    File-like object representing FastCGI input streams (FCGI_STDIN and
    FCGI_DATA). Supports the minimum methods required by WSGI spec.
    """

    def __init__(self, conn):
    self._conn = conn

    # See Server.
    self._shrinkThreshold = conn.server.inputStreamShrinkThreshold

    self._buf = ''
    self._bufList = []
    self._pos = 0 # Current read position.
    self._avail = 0 # Number of bytes currently available.

    self._eof = False # True when server has sent EOF notification.

    def _shrinkBuffer(self):
    """Gets rid of already read data (since we can't rewind)."""
    if self._pos >= self._shrinkThreshold:
    self._buf = self._buf[self._pos:]
    self._avail -= self._pos
    self._pos = 0

    assert self._avail >= 0

    def _waitForData(self):
    """Waits for more data to become available."""
    self._conn.process_input()

    def read(self, n=-1):
    if self._pos == self._avail and self._eof:
    return ''
    while True:
    if n < 0 or (self._avail - self._pos) < n:
    # Not enough data available.
    if self._eof:
    # And there's no more coming.
    newPos = self._avail
    break
    else:
    # Wait for more data.
    self._waitForData()
    continue
    else:
    newPos = self._pos + n
    break
    # Merge buffer list, if necessary.
    if self._bufList:
    self._buf += ''.join(self._bufList)
    self._bufList = []
    r = self._buf[self._pos:newPos]
    self._pos = newPos
    self._shrinkBuffer()
    return r

    def readline(self, length=None):
    if self._pos == self._avail and self._eof:
    return ''
    while True:
    # Unfortunately, we need to merge the buffer list early.
    if self._bufList:
    self._buf += ''.join(self._bufList)
    self._bufList = []
    # Find newline.
    i = self._buf.find('\n', self._pos)
    if i < 0:
    # Not found?
    if self._eof:
    # No more data coming.
    newPos = self._avail
    break
    else:
    if length is not None and len(self._buf) >= length + self._pos:
    newPos = self._pos + length
    break
    # Wait for more to come.
    self._waitForData()
    continue
    else:
    newPos = i + 1
    break
    r = self._buf[self._pos:newPos]
    self._pos = newPos
    self._shrinkBuffer()
    return r

    def readlines(self, sizehint=0):
    total = 0
    lines = []
    line = self.readline()
    while line:
    lines.append(line)
    total += len(line)
    if 0 < sizehint <= total:
    break
    line = self.readline()
    return lines

    def __iter__(self):
    return self

    def next(self):
    r = self.readline()
    if not r:
    raise StopIteration
    return r

    def add_data(self, data):
    if not data:
    self._eof = True
    else:
    self._bufList.append(data)
    self._avail += len(data)


    class OutputStream(object):
    """
    FastCGI output stream (FCGI_STDOUT/FCGI_STDERR). By default, calls to
    write() or writelines() immediately result in Records being sent back
    to the server. Buffering should be done in a higher level!
    """

    def __init__(self, conn, req, type, buffered=False):
    self._conn = conn
    self._req = req
    self._type = type
    self._buffered = buffered
    self._bufList = [] # Used if buffered is True
    self.dataWritten = False
    self.closed = False

    def _write(self, data):
    length = len(data)
    while length:
    to_write = min(length, self._req.server.maxwrite - FCGI_HEADER_LEN)

    rec = Record(self._type, self._req.requestId)
    rec.contentLength = to_write
    rec.contentData = data[:to_write]
    self._conn.writeRecord(rec)

    data = data[to_write:]
    length -= to_write

    def write(self, data):
    assert not self.closed

    if not data:
    return

    self.dataWritten = True

    if self._buffered:
    self._bufList.append(data)
    else:
    self._write(data)

    def writelines(self, lines):
    assert not self.closed

    for line in lines:
    self.write(line)

    def flush(self):
    # Only need to flush if this OutputStream is actually buffered.
    if self._buffered:
    data = ''.join(self._bufList)
    self._bufList = []
    self._write(data)

    # Though available, the following should NOT be called by WSGI apps.
    def close(self):
    """Sends end-of-stream notification, if necessary."""
    if not self.closed and self.dataWritten:
    self.flush()
    rec = Record(self._type, self._req.requestId)
    self._conn.writeRecord(rec)
    self.closed = True


    class TeeOutputStream(object):
    """
    Simple wrapper around two or more output file-like objects that copies
    written data to all streams.
    """

    def __init__(self, streamList):
    self._streamList = streamList

    def write(self, data):
    for f in self._streamList:
    f.write(data)

    def writelines(self, lines):
    for line in lines:
    self.write(line)

    def flush(self):
    for f in self._streamList:
    f.flush()


    class StdoutWrapper(object):
    """
    Wrapper for sys.stdout so we know if data has actually been written.
    """

    def __init__(self, stdout):
    self._file = stdout
    self.dataWritten = False

    def write(self, data):
    if data:
    self.dataWritten = True
    self._file.write(data)

    def writelines(self, lines):
    for line in lines:
    self.write(line)

    def __getattr__(self, name):
    return getattr(self._file, name)


    def decode_pair(s, pos=0):
    """
    Decodes a name/value pair.
    The number of bytes decoded as well as the name/value pair
    are returned.
    """
    nameLength = ord(s[pos])
    if nameLength & 128:
    nameLength = struct.unpack('!L', s[pos:pos + 4])[0] & 0x7fffffff
    pos += 4
    else:
    pos += 1

    valueLength = ord(s[pos])
    if valueLength & 128:
    valueLength = struct.unpack('!L', s[pos:pos + 4])[0] & 0x7fffffff
    pos += 4
    else:
    pos += 1

    name = s[pos:pos + nameLength]
    pos += nameLength
    value = s[pos:pos + valueLength]
    pos += valueLength

    return pos, (name, value)


    def encode_pair(name, value):
    """
    Encodes a name/value pair.
    The encoded string is returned.
    """
    nameLength = len(name)
    if nameLength < 128:
    s = chr(nameLength)
    else:
    s = struct.pack('!L', nameLength | 0x80000000L)

    valueLength = len(value)
    if valueLength < 128:
    s += chr(valueLength)
    else:
    s += struct.pack('!L', valueLength | 0x80000000L)

    return s + name + value


    class Record(object):
    """
    A FastCGI Record.
    Used for encoding/decoding records.
    """

    def __init__(self, type=FCGI_UNKNOWN_TYPE, requestId=FCGI_NULL_REQUEST_ID):
    self.version = FCGI_VERSION_1
    self.type = type
    self.requestId = requestId
    self.contentLength = 0
    self.paddingLength = 0
    self.contentData = ''


    def _recvall(stream, length):
    """
    Attempts to receive length bytes from a socket, blocking if necessary.
    (Socket may be blocking or non-blocking.)
    """

    if FCGI_DEBUG: logging.debug('_recvall (%d)' % (length))

    dataList = []
    recvLen = 0

    while length:
    data = stream.read(length)
    if not data: # EOF
    break
    dataList.append(data)
    dataLen = len(data)
    recvLen += dataLen
    length -= dataLen

    #if FCGI_DEBUG: logging.debug('recived length = %d' % (recvLen))

    return ''.join(dataList), recvLen

    _recvall = staticmethod(_recvall)


    def read(self, stream):
    """Read and decode a Record from a socket."""
    try:
    header, length = self._recvall(stream, FCGI_HEADER_LEN)
    except:
    raise
    raise EOFError

    if length < FCGI_HEADER_LEN:
    raise EOFError

    if FCGI_DEBUG:
    hex = ''
    for s in header:
    hex += '%x|' % (ord(s))

    self.version, self.type, self.requestId, self.contentLength,\
    self.paddingLength = struct.unpack(FCGI_Header, header)

    if FCGI_DEBUG: logging.debug('recv fcgi header: %s %s len: %d' % (FCGI_HEADER_NAMES[self.type] if self.type is not None and self.type < FCGI_MAXTYPE else FCGI_HEADER_NAMES[FCGI_MAXTYPE], hex, len(header)))

    if self.contentLength:
    try:
    self.contentData, length = self._recvall(stream, self.contentLength)
    except:
    raise EOFError

    if length < self.contentLength:
    raise EOFError

    if self.paddingLength:
    try:
    self._recvall(stream, self.paddingLength)
    except:
    raise EOFError

    def _sendall(stream, data):
    """
    Writes data to a socket and does not return until all the data is sent.
    """
    if FCGI_DEBUG: logging.debug('_sendall: len=%d' % len(data))
    stream.write(data)

    _sendall = staticmethod(_sendall)


    def write(self, stream):
    """Encode and write a Record to a socket."""
    if not self.contentLength:
    self.paddingLength = 8
    else:
    self.paddingLength = -self.contentLength & 7

    header = struct.pack(FCGI_Header, self.version, self.type,
    self.requestId, self.contentLength,
    self.paddingLength)

    if FCGI_DEBUG: logging.debug('send fcgi header: %s' % FCGI_HEADER_NAMES[self.type] if self.type is not None and self.type < FCGI_MAXTYPE else FCGI_HEADER_NAMES[FCGI_MAXTYPE])

    self._sendall(stream, header)

    if self.contentLength:
    if FCGI_DEBUG: logging.debug('send CONTENT')
    self._sendall(stream, self.contentData)
    if self.paddingLength:
    if FCGI_DEBUG: logging.debug('send PADDING')
    self._sendall(stream, '\x00' * self.paddingLength)



    class Request(object):
    """
    Represents a single FastCGI request.
    These objects are passed to your handler and is the main interface
    between your handler and the fcgi module. The methods should not
    be called by your handler. However, server, params, stdin, stdout,
    stderr, and data are free for your handler's use.
    """

    def __init__(self, conn, inputStreamClass):
    self._conn = conn

    self.server = conn.server
    self.params = {}
    self.stdin = inputStreamClass(conn)
    self.stdout = OutputStream(conn, self, FCGI_STDOUT)
    self.stderr = OutputStream(conn, self, FCGI_STDERR)
    self.data = inputStreamClass(conn)


    def run(self):
    """Runs the handler, flushes the streams, and ends the request."""

    try:
    protocolStatus, appStatus = self.server.handler(self)
    except Exception, instance:
    if FCGI_DEBUG:
    logging.error(traceback.format_exc())
    raise
    # TODO: fix it
    #self.stderr.flush()
    #if not self.stdout.dataWritten:
    # self.server.error(self)
    #protocolStatus, appStatus = FCGI_REQUEST_COMPLETE, 0

    if FCGI_DEBUG: logging.debug('protocolStatus = %d, appStatus = %d' % (protocolStatus, appStatus))

    self._flush()
    self._end(appStatus, protocolStatus)


    def _end(self, appStatus=0L, protocolStatus=FCGI_REQUEST_COMPLETE):
    self._conn.end_request(self, appStatus, protocolStatus)


    def _flush(self):
    self.stdout.flush()
    self.stderr.flush()


    class Connection(object):
    """
    A Connection with the web server.
    Each Connection is associated with a single socket (which is
    connected to the web server) and is responsible for handling all
    the FastCGI message processing for that socket.
    """

    _multiplexed = False
    _inputStreamClass = InputStream

    def __init__(self, stdin, stdout, server):
    self._stdin = stdin
    self._stdout = stdout
    self.server = server

    # Active Requests for this Connection, mapped by request ID.
    self._requests = {}


    def run(self):
    """Begin processing data from the socket."""

    self._keepGoing = True
    while self._keepGoing:
    try:
    self.process_input()
    except KeyboardInterrupt:
    break
    #except EOFError, inst:
    # raise
    # if FCGI_DEBUG: logging.error(str(inst))
    # break


    def process_input(self):
    """Attempt to read a single Record from the socket and process it."""
    # Currently, any children Request threads notify this Connection
    # that it is no longer needed by closing the Connection's socket.
    # We need to put a timeout on select, otherwise we might get
    # stuck in it indefinitely... (I don't like this solution.)

    if not self._keepGoing:
    return

    rec = Record()
    rec.read(self._stdin)

    if rec.type == FCGI_GET_VALUES:
    self._do_get_values(rec)
    elif rec.type == FCGI_BEGIN_REQUEST:
    self._do_begin_request(rec)
    elif rec.type == FCGI_ABORT_REQUEST:
    self._do_abort_request(rec)
    elif rec.type == FCGI_PARAMS:
    self._do_params(rec)
    elif rec.type == FCGI_STDIN:
    self._do_stdin(rec)
    elif rec.type == FCGI_DATA:
    self._do_data(rec)
    elif rec.requestId == FCGI_NULL_REQUEST_ID:
    self._do_unknown_type(rec)
    else:
    # Need to complain about this.
    pass


    def writeRecord(self, rec):
    """
    Write a Record to the socket.
    """
    rec.write(self._stdout)


    def end_request(self, req, appStatus=0L, protocolStatus=FCGI_REQUEST_COMPLETE, remove=True):
    """
    End a Request.
    Called by Request objects. An FCGI_END_REQUEST Record is
    sent to the web server. If the web server no longer requires
    the connection, the socket is closed, thereby ending this
    Connection (run() returns).
    """

    # write empty packet to stdin
    rec = Record(FCGI_STDOUT, req.requestId)
    rec.contentData = ''
    rec.contentLength = 0
    self.writeRecord(rec)

    # write end request
    rec = Record(FCGI_END_REQUEST, req.requestId)
    rec.contentData = struct.pack(FCGI_EndRequestBody, appStatus,
    protocolStatus)
    rec.contentLength = FCGI_EndRequestBody_LEN
    self.writeRecord(rec)

    if remove:
    if FCGI_DEBUG: logging.debug('end_request: removing request from list')
    del self._requests[req.requestId]

    if FCGI_DEBUG: logging.debug('end_request: flags = %d' % req.flags)

    if not (req.flags & FCGI_KEEP_CONN) and not self._requests:
    if FCGI_DEBUG: logging.debug('end_request: set _keepGoing = False')
    self._keepGoing = False


    def _do_get_values(self, inrec):
    """Handle an FCGI_GET_VALUES request from the web server."""

    outrec = Record(FCGI_GET_VALUES_RESULT)

    pos = 0
    while pos < inrec.contentLength:
    pos, (name, value) = decode_pair(inrec.contentData, pos)
    cap = self.server.capability.get(name)
    if cap is not None:
    outrec.contentData += encode_pair(name, str(cap))

    outrec.contentLength = len(outrec.contentData)
    self.writeRecord(outrec)


    def _do_begin_request(self, inrec):
    """Handle an FCGI_BEGIN_REQUEST from the web server."""
    role, flags = struct.unpack(FCGI_BeginRequestBody, inrec.contentData)

    req = self.server.request_class(self, self._inputStreamClass)
    req.requestId, req.role, req.flags = inrec.requestId, role, flags
    req.aborted = False

    if not self._multiplexed and self._requests:
    # Can't multiplex requests.
    self.end_request(req, 0L, FCGI_CANT_MPX_CONN, remove=False)
    else:
    self._requests[inrec.requestId] = req


    def _do_abort_request(self, inrec):
    """
    Handle an FCGI_ABORT_REQUEST from the web server.
    We just mark a flag in the associated Request.
    """
    req = self._requests.get(inrec.requestId)
    if req is not None:
    req.aborted = True


    def _start_request(self, req):
    """Run the request."""
    # Not multiplexed, so run it inline.
    req.run()


    def _do_params(self, inrec):
    """
    Handle an FCGI_PARAMS Record.
    If the last FCGI_PARAMS Record is received, start the request.
    """

    req = self._requests.get(inrec.requestId)
    if req is not None:
    if inrec.contentLength:
    pos = 0
    while pos < inrec.contentLength:
    pos, (name, value) = decode_pair(inrec.contentData, pos)
    req.params[name] = value


    def _do_stdin(self, inrec):
    """Handle the FCGI_STDIN stream."""
    req = self._requests.get(inrec.requestId)

    if inrec.contentLength:
    if req is not None:
    req.stdin.add_data(inrec.contentData)
    else:
    self._start_request(req)


    def _do_data(self, inrec):
    """Handle the FCGI_DATA stream."""
    req = self._requests.get(inrec.requestId)
    if req is not None:
    req.data.add_data(inrec.contentData)


    def _do_unknown_type(self, inrec):
    """Handle an unknown request type. Respond accordingly."""
    outrec = Record(FCGI_UNKNOWN_TYPE)
    outrec.contentData = struct.pack(FCGI_UnknownTypeBody, inrec.type)
    outrec.contentLength = FCGI_UnknownTypeBody_LEN
    self.writeRecord(outrec)


    class FCGIServer(object):
    request_class = Request
    maxwrite = 8192
    inputStreamShrinkThreshold = 102400 - 8192

    def __init__(self, application, environ=None,
    multithreaded=False, multiprocess=False,
    debug=False, roles=(FCGI_RESPONDER,),
    app_root=None):
    if environ is None:
    environ = {}

    self.application = application
    self.environ = environ
    self.multithreaded = multithreaded
    self.multiprocess = multiprocess
    self.debug = debug
    self.roles = roles
    self._connectionClass = Connection
    self.capability = {
    # If threads aren't available, these are pretty much correct.
    FCGI_MAX_CONNS: 1,
    FCGI_MAX_REQS: 1,
    FCGI_MPXS_CONNS: 0
    }
    self.app_root = app_root


    def run(self):
    msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
    stdin = sys.stdin
    stdout = os.fdopen(sys.stdin.fileno(), 'w', 0)

    conn = Connection(stdin, stdout, self)
    conn.run()


    def handler(self, req):
    """Special handler for WSGI."""
    if req.role not in self.roles:
    return FCGI_UNKNOWN_ROLE, 0

    # Mostly taken from example CGI gateway.
    environ = req.params
    environ.update(self.environ)

    environ['wsgi.version'] = (1, 0)
    environ['wsgi.input'] = req.stdin
    stderr = TeeOutputStream((sys.stderr, req.stderr))
    environ['wsgi.errors'] = stderr
    environ['wsgi.multithread'] = False
    environ['wsgi.multiprocess'] = False
    environ['wsgi.run_once'] = False

    if environ.get('HTTPS', 'off') in ('on', '1'):
    environ['wsgi.url_scheme'] = 'https'
    else:
    environ['wsgi.url_scheme'] = 'http'

    self._sanitizeEnv(environ)

    headers_set = []
    headers_sent = []
    result = None

    def write(data):
    assert type(data) is str, 'write() argument must be string'
    assert headers_set, 'write() before start_response()'

    if not headers_sent:
    status, responseHeaders = headers_sent[:] = headers_set
    found = False
    for header, value in responseHeaders:
    if header.lower() == 'content-length':
    found = True
    break
    if not found and result is not None:
    try:
    if len(result) == 1:
    responseHeaders.append(('Content-Length',
    str(len(data))))
    except:
    pass
    s = 'Status: %s\r\n' % status
    for header in responseHeaders:
    s += '%s: %s\r\n' % header
    s += '\r\n'
    req.stdout.write(s)

    req.stdout.write(data)
    req.stdout.flush()

    def start_response(status, response_headers, exc_info=None):
    if exc_info:
    try:
    if headers_sent:
    # Re-raise if too late
    raise exc_info[0], exc_info[1], exc_info[2]
    finally:
    exc_info = None # avoid dangling circular ref
    else:
    assert not headers_set, 'Headers already set!'

    assert type(status) is str, 'Status must be a string'
    assert len(status) >= 4, 'Status must be at least 4 characters'
    assert int(status[:3]), 'Status must begin with 3-digit code'
    assert status[3] == ' ', 'Status must have a space after code'
    assert type(response_headers) is list, 'Headers must be a list'
    if FCGI_DEBUG:
    logging.debug('response headers:')
    for name, val in response_headers:
    assert type(name) is str, 'Header name "%s" must be a string' % name
    assert type(val) is str, 'Value of header "%s" must be a string' % name
    logging.debug('%s: %s' % (name, val))

    headers_set[:] = [status, response_headers]
    return write

    try:
    try:
    result = self.application(environ, start_response)
    try:
    for data in result:
    if data:
    write(data)
    if not headers_sent:
    write('') # in case body was empty
    finally:
    #if hasattr(result, 'close'):
    # result.close()
    pass
    #except socket.error, e:
    # if e[0] != errno.EPIPE:
    # raise # Don't let EPIPE propagate beyond server
    except:
    raise
    finally:
    pass

    return FCGI_REQUEST_COMPLETE, 0


    def _sanitizeEnv(self, environ):
    """Ensure certain values are present, if required by WSGI."""

    if FCGI_DEBUG:
    logging.debug('raw envs: {0}'.format(environ))

    #if not environ.has_key('SCRIPT_NAME'):
    # environ['SCRIPT_NAME'] = ''
    # TODO: fix for django
    environ['SCRIPT_NAME'] = ''

    reqUri = None
    if environ.has_key('REQUEST_URI'):
    reqUri = environ['REQUEST_URI'].split('?', 1)

    if not environ.has_key('PATH_INFO') or not environ['PATH_INFO']:
    if reqUri is not None:
    environ['PATH_INFO'] = reqUri[0]
    else:
    environ['PATH_INFO'] = ''

    # convert %XX to python unicode
    environ['PATH_INFO'] = urllib.unquote(environ['PATH_INFO'])

    # process app_root
    if self.app_root and environ['PATH_INFO'].startswith(self.app_root):
    environ['PATH_INFO'] = environ['PATH_INFO'][len(self.app_root):]

    if not environ.has_key('QUERY_STRING') or not environ['QUERY_STRING']:
    if reqUri is not None and len(reqUri) > 1:
    environ['QUERY_STRING'] = reqUri[1]
    else:
    environ['QUERY_STRING'] = ''

    # If any of these are missing, it probably signifies a broken
    # server...
    for name, default in [('REQUEST_METHOD', 'GET'),
    ('SERVER_NAME', 'localhost'),
    ('SERVER_PORT', '80'),
    ('SERVER_PROTOCOL', 'HTTP/1.0')]:
    if not environ.has_key(name):
    environ['wsgi.errors'].write('%s: missing FastCGI param %s '
    'required by WSGI!\n' %
    (self.__class__.__name__, name))
    environ[name] = default


    def error(self, req):
    """
    Called by Request if an exception occurs within the handler. May and
    should be overridden.
    """
    if self.debug:
    import cgitb

    req.stdout.write('Status: 500 Internal Server Error\r\n' +
    'Content-Type: text/html\r\n\r\n' +
    cgitb.html(sys.exc_info()))
    else:
    errorpage = """<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
    <html><head>
    <title>Unhandled Exception</title>
    </head><body>
    <h1>Unhandled Exception</h1>
    <p>An unhandled exception was thrown by the application.</p>
    </body></html>
    """
    req.stdout.write('Status: 500 Internal Server Error\r\n' +
    'Content-Type: text/html\r\n\r\n' +
    errorpage)


    def example_application(environ, start_response):
    '''example wsgi app which outputs wsgi environment'''
    logging.debug('wsgi app started')
    data = ''
    env_keys = environ.keys()
    env_keys.sort()
    for e in env_keys:
    data += '%s: %s\n' % (e, environ[e])
    data += 'sys.version: '+sys.version+'\n'
    start_response('200 OK', [('Content-Type', 'text/plain'), ('Content-Length', str(len(data)))])
    yield data


    def run_example_app():
    if FCGI_DEBUG: logging.info('run_fcgi: STARTED')
    FCGIServer(example_application).run()
    if FCGI_DEBUG: logging.info('run_fcgi: EXITED')


    def run_django_app(django_settings_module, django_root):
    '''run django app by django_settings_module,
    django_settings_module can be python path or physical path
    '''
    if os.path.exists(django_settings_module):
    # this is physical path
    app_path, app_settings = os.path.split(django_settings_module)

    # add diretory to PYTHONPATH
    app_dir = os.path.dirname(app_path)
    if app_dir not in sys.path:
    sys.path.append(app_dir)
    if FCGI_DEBUG: logging.debug('%s added to PYTHONPATH' % app_dir)

    # cut .py extension in module
    if app_settings.endswith('.py'):
    app_settings = app_settings[:-3]

    # get python path to settings
    settings_module = '%s.%s' % (os.path.basename(app_path), app_settings)
    else:
    #consider that django_settings_module is valid python path
    settings_module = django_settings_module

    os.environ['DJANGO_SETTINGS_MODULE'] = settings_module
    if FCGI_DEBUG: logging.info('DJANGO_SETTINGS_MODULE set to %s' % settings_module)

    try:
    from django.core.handlers.wsgi import WSGIHandler
    except ImportError:
    if FCGI_DEBUG: logging.error('Could not import django.core.handlers.wsgi module. Check that django is installed and in PYTHONPATH.')
    raise



    FCGIServer(WSGIHandler(), app_root=django_root).run()

    class Command(BaseCommand):
    args = '[root_path]'
    help = '''Run as a fcgi server'''
    def handle(self, *args, **options):
    django_root=args[0] if args else None
    if FCGI_LOG:
    logging.basicConfig(
    filename=os.path.join(FCGI_LOG_PATH, 'fcgi_%s_%d.log' %(datetime.datetime.now().strftime('%y%m%d_%H%M%S'), os.getpid())),
    filemode='w',
    format='%(asctime)s [%(levelname)-5s] %(message)s',
    level=logging.DEBUG)
    try:
    from django.core.handlers.wsgi import WSGIHandler
    except ImportError:
    if FCGI_DEBUG: logging.error('Could not import django.core.handlers.wsgi module. Check that django is installed and in PYTHONPATH.')
    raise



    FCGIServer(WSGIHandler(), app_root=django_root).run()


    if __name__ == '__main__':

    # compile self
    compiled = os.path.split(__file__)[-1].replace('.py', '.pyc' if FCGI_DEBUG else '.pyo')
    if not os.path.exists(compiled):
    import py_compile
    try:
    py_compile.compile(__file__)
    except:
    pass

    # enable logging
    if FCGI_DEBUG:
    logging.basicConfig(
    filename=os.path.join(FCGI_LOG_PATH, 'fcgi_%s_%d.log' %(datetime.datetime.now().strftime('%y%m%d_%H%M%S'), os.getpid())),
    filemode='w',
    format='%(asctime)s [%(levelname)-5s] %(message)s',
    level=logging.DEBUG)

    # If we are inside a subdirectory of a django app, set the default Djan
    default_django_settings_module=None
    parent_settings_file = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'settings.py')
    if os.path.exists(parent_settings_file):
    default_django_settings_module = os.path.abspath(parent_settings_file)
    if FCGI_DEBUG:
    logging.info('default DJANGO_SETTINGS_MODULE set to %s' % default_django_settings_module)


    # parse options
    usage = "usage: %prog [options]"
    parser = OptionParser(usage)
    parser.add_option("", "--django-settings-module", dest="django_settings_module", help="python or physical path to Django settings module")
    parser.add_option("", "--django-root", dest="django_root", help="strip this string from the front of any URLs before matching them against your URLconf patterns.")
    parser.set_defaults(
    django_settings_module = os.environ.get('DJANGO_SETTINGS_MODULE', default_django_settings_module),
    django_root = os.environ.get('django.root', None)
    )

    (options, args) = parser.parse_args()

    # check django
    if options.django_settings_module:
    run_django_app(options.django_settings_module, options.django_root)
    else:
    # run example app
    run_example_app()