############################################################################## # # Copyright (c) 2002 Zope Foundation and Contributors. # # This software is subject to the provisions of the Zope Public License, # Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution. # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS # FOR A PARTICULAR PURPOSE # ############################################################################## """ ZServer HTTPResponse The HTTPResponse class takes care of server headers, response munging and logging duties. """ import asyncore from cStringIO import StringIO import re import tempfile import thread import time from zope.event import notify from ZPublisher.HTTPResponse import HTTPResponse # XXX WTF? from ZPublisher.Iterators import IStreamIterator # XXX WTF? from ZPublisher.pubevents import PubBeforeStreaming # XXX WTF? from ZServer.medusa.http_date import build_http_date from ZServer.PubCore.ZEvent import Wakeup from ZServer.medusa import http_server from ZServer.Producers import ShutdownProducer from ZServer.Producers import LoggingProducer from ZServer.Producers import CallbackProducer from ZServer.Producers import file_part_producer from ZServer.Producers import file_close_producer from ZServer.Producers import iterator_producer from ZServer.DebugLogger import log class ZServerHTTPResponse(HTTPResponse): "Used to push data into a channel's producer fifo" # Set this value to 1 if streaming output in # HTTP/1.1 should use chunked encoding http_chunk = 1 http_chunk_size = 1024 # defaults _http_version = '1.0' _http_connection = 'close' _server_version = 'Zope/2.0 ZServer/2.0' # using streaming response _streaming = 0 # using chunking transfer-encoding _chunking = 0 _bodyproducer = None def __str__(self): if self._wrote: if self._chunking: return '0\r\n\r\n' else: return '' headers = self.headers body = self.body # set 204 (no content) status if 200 and response is empty # and not streaming if ('content-type' not in headers and 'content-length' not in headers and not self._streaming and self.status == 200): self.setStatus('nocontent') if self.status in (100, 101, 102, 204, 304): # These responses should not have any body or Content-Length. # See RFC 2616 4.4 "Message Length". body = '' if 'content-length' in headers: del headers['content-length'] if 'content-type' in headers: del headers['content-type'] elif not headers.has_key('content-length') and not self._streaming: self.setHeader('content-length', len(body)) chunks = [] append = chunks.append # status header must come first. append("HTTP/%s %d %s" % (self._http_version or '1.0', self.status, self.errmsg)) # add zserver headers append('Server: %s' % self._server_version) append('Date: %s' % build_http_date(time.time())) if self._http_version == '1.0': if self._http_connection == 'keep-alive': self.setHeader('Connection','Keep-Alive') else: self.setHeader('Connection','close') # Close the connection if we have been asked to. # Use chunking if streaming output. if self._http_version == '1.1': if self._http_connection == 'close': self.setHeader('Connection','close') elif (not self.headers.has_key('content-length') and self.http_chunk and self._streaming): self.setHeader('Transfer-Encoding','chunked') self._chunking = 1 headers = headers.items() headers.extend(self.accumulated_headers) for key, val in headers: if key.lower() == key: # only change non-literal header names key = "%s%s" % (key[:1].upper(), key[1:]) start = 0 l = key.find('-',start) while l >= start: key = "%s-%s%s" % (key[:l], key[l+1:l+2].upper(), key[l+2:]) start = l + 1 l = key.find('-', start) val = val.replace('\n\t', '\r\n\t') append("%s: %s" % (key, val)) if self.cookies: chunks.extend(['%s: %s' % x for x in self._cookie_list()]) append('') append(body) return "\r\n".join(chunks) _tempfile = None _templock = None _tempstart = 0 def write(self,data): """\ Return data as a stream HTML data may be returned using a stream-oriented interface. This allows the browser to display partial results while computation of a response to proceed. The published object should first set any output headers or cookies on the response object. Note that published objects must not generate any errors after beginning stream-oriented output. """ if type(data) is not str: raise TypeError('Value must be a string') stdout = self.stdout if not self._wrote: notify(PubBeforeStreaming(self)) l = self.headers.get('content-length', None) if l is not None: try: if type(l) is str: l = int(l) if l > 128000: self._tempfile = tempfile.TemporaryFile() self._templock = thread.allocate_lock() except: pass self._streaming = 1 stdout.write(str(self)) self._wrote = 1 if not data: return if self._chunking: data = '%x\r\n%s\r\n' % (len(data),data) l = len(data) t = self._tempfile if t is None or l<200: stdout.write(data) else: b = self._tempstart e = b + l self._templock.acquire() try: t.seek(b) t.write(data) finally: self._templock.release() self._tempstart = e stdout.write(file_part_producer(t,self._templock,b,e), l) _retried_response = None def _finish(self): if self._retried_response: try: self._retried_response._finish() finally: self._retried_response = None return stdout = self.stdout t = self._tempfile if t is not None: stdout.write(file_close_producer(t), 0) self._tempfile = None stdout.finish(self) stdout.close() self.stdout = None # need to break cycle? self._request = None def retry(self): """Return a request object to be used in a retry attempt """ # This implementation is a bit lame, because it assumes that # only stdout stderr were passed to the constructor. OTOH, I # think that that's all that is ever passed. response = self.__class__(stdout=self.stdout, stderr=self.stderr) response.headers = self.headers response._http_version = self._http_version response._http_connection = self._http_connection response._server_version = self._server_version self._retried_response = response return response def outputBody(self): """Output the response body""" self.stdout.write(str(self)) if self._bodyproducer: self.stdout.write(self._bodyproducer, 0) # we assign None to self._bodyproducer below to ensure that even # if self is part of a cycle which causes a leak that we # don't leak the bodyproducer (which often holds a reference to # an open file descriptor, and leaking file descriptors can have # particularly bad ramifications for a long-running process) self._bodyproducer = None def setBody(self, body, title='', is_error=0, **kw): """ Accept either a stream iterator or a string as the body """ if IStreamIterator.providedBy(body): assert(self.headers.has_key('content-length')) # wrap the iterator up in a producer that medusa can understand self._bodyproducer = iterator_producer(body) HTTPResponse.setBody(self, '', title, is_error, **kw) return self else: HTTPResponse.setBody(self, body, title, is_error, **kw) class ChannelPipe: """Experimental pipe from ZPublisher to a ZServer Channel. Should only be used by one thread at a time. Note also that the channel will be being handled by another thread, thus restrict access to channel to the push method only.""" def __init__(self, request): self._channel = request.channel self._request = request self._shutdown = 0 self._close = 0 self._bytes = 0 def write(self, text, l=None): if self._channel.closed: return if l is None: l = len(text) self._bytes = self._bytes + l self._channel.push(text,0) Wakeup() def close(self): log('A', id(self._request), '%s %s' % (self._request.reply_code, self._bytes)) if not self._channel.closed: self._channel.push(LoggingProducer(self._request, self._bytes), 0) self._channel.push(CallbackProducer(self._channel.done), 0) self._channel.push(CallbackProducer( lambda t=('E', id(self._request)): apply(log, t)), 0) if self._shutdown: self._channel.push(ShutdownProducer(), 0) Wakeup() else: if self._close: self._channel.push(None, 0) Wakeup() else: # channel closed too soon self._request.log(self._bytes) log('E', id(self._request)) if self._shutdown: Wakeup(lambda: asyncore.close_all()) else: Wakeup() self._channel = None #need to break cycles? self._request = None def flush(self): pass # yeah, whatever def finish(self, response): if response._shutdownRequested(): self._shutdown = 1 if response.headers.get('connection','') == 'close' or \ response.headers.get('Connection','') == 'close': self._close = 1 self._request.reply_code = response.status def start_response(self, status, headers, exc_info=None): # Used for WSGI self._request.reply_code = int(status.split(' ')[0]) status = 'HTTP/%s %s\r\n' % (self._request.version, status) self.write(status) headers = '\r\n'.join([': '.join(x) for x in headers]) self.write(headers) self.write('\r\n\r\n') return self.write is_proxying_match = re.compile(r'[^ ]* [^ \\]*:').match proxying_connection_re = re.compile ('Proxy-Connection: (.*)', re.IGNORECASE) def make_response(request, headers): "Simple http response factory" # should this be integrated into the HTTPResponse constructor? response = ZServerHTTPResponse(stdout=ChannelPipe(request), stderr=StringIO()) response._http_version = request.version if request.version == '1.0' and is_proxying_match(request.request): # a request that was made as if this zope was an http 1.0 proxy. # that means we have to use some slightly different http # headers to manage persistent connections. connection_re = proxying_connection_re else: # a normal http request connection_re = http_server.CONNECTION response._http_connection = http_server.get_header(connection_re, request.header).lower() response._server_version = request.channel.server.SERVER_IDENT return response