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Diffstat (limited to 'lib/python2.7/wsgiref/handlers.py')
| -rw-r--r-- | lib/python2.7/wsgiref/handlers.py | 450 |
1 files changed, 0 insertions, 450 deletions
diff --git a/lib/python2.7/wsgiref/handlers.py b/lib/python2.7/wsgiref/handlers.py deleted file mode 100644 index 8cb57e2..0000000 --- a/lib/python2.7/wsgiref/handlers.py +++ /dev/null @@ -1,450 +0,0 @@ -"""Base classes for server/gateway implementations""" - -from types import StringType -from util import FileWrapper, guess_scheme, is_hop_by_hop -from headers import Headers - -import sys, os, time - -__all__ = ['BaseHandler', 'SimpleHandler', 'BaseCGIHandler', 'CGIHandler'] - -try: - dict -except NameError: - def dict(items): - d = {} - for k,v in items: - d[k] = v - return d - -# Uncomment for 2.2 compatibility. -#try: -# True -# False -#except NameError: -# True = not None -# False = not True - - -# Weekday and month names for HTTP date/time formatting; always English! -_weekdayname = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"] -_monthname = [None, # Dummy so we can use 1-based month numbers - "Jan", "Feb", "Mar", "Apr", "May", "Jun", - "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"] - -def format_date_time(timestamp): - year, month, day, hh, mm, ss, wd, y, z = time.gmtime(timestamp) - return "%s, %02d %3s %4d %02d:%02d:%02d GMT" % ( - _weekdayname[wd], day, _monthname[month], year, hh, mm, ss - ) - - -class BaseHandler: - """Manage the invocation of a WSGI application""" - - # Configuration parameters; can override per-subclass or per-instance - wsgi_version = (1,0) - wsgi_multithread = True - wsgi_multiprocess = True - wsgi_run_once = False - - origin_server = True # We are transmitting direct to client - http_version = "1.0" # Version that should be used for response - server_software = None # String name of server software, if any - - # os_environ is used to supply configuration from the OS environment: - # by default it's a copy of 'os.environ' as of import time, but you can - # override this in e.g. your __init__ method. - os_environ = dict(os.environ.items()) - - # Collaborator classes - wsgi_file_wrapper = FileWrapper # set to None to disable - headers_class = Headers # must be a Headers-like class - - # Error handling (also per-subclass or per-instance) - traceback_limit = None # Print entire traceback to self.get_stderr() - error_status = "500 Internal Server Error" - error_headers = [('Content-Type','text/plain')] - error_body = "A server error occurred. Please contact the administrator." - - # State variables (don't mess with these) - status = result = None - headers_sent = False - headers = None - bytes_sent = 0 - - def run(self, application): - """Invoke the application""" - # Note to self: don't move the close()! Asynchronous servers shouldn't - # call close() from finish_response(), so if you close() anywhere but - # the double-error branch here, you'll break asynchronous servers by - # prematurely closing. Async servers must return from 'run()' without - # closing if there might still be output to iterate over. - try: - self.setup_environ() - self.result = application(self.environ, self.start_response) - self.finish_response() - except: - try: - self.handle_error() - except: - # If we get an error handling an error, just give up already! - self.close() - raise # ...and let the actual server figure it out. - - - def setup_environ(self): - """Set up the environment for one request""" - - env = self.environ = self.os_environ.copy() - self.add_cgi_vars() - - env['wsgi.input'] = self.get_stdin() - env['wsgi.errors'] = self.get_stderr() - env['wsgi.version'] = self.wsgi_version - env['wsgi.run_once'] = self.wsgi_run_once - env['wsgi.url_scheme'] = self.get_scheme() - env['wsgi.multithread'] = self.wsgi_multithread - env['wsgi.multiprocess'] = self.wsgi_multiprocess - - if self.wsgi_file_wrapper is not None: - env['wsgi.file_wrapper'] = self.wsgi_file_wrapper - - if self.origin_server and self.server_software: - env.setdefault('SERVER_SOFTWARE',self.server_software) - - - def finish_response(self): - """Send any iterable data, then close self and the iterable - - Subclasses intended for use in asynchronous servers will - want to redefine this method, such that it sets up callbacks - in the event loop to iterate over the data, and to call - 'self.close()' once the response is finished. - """ - try: - if not self.result_is_file() or not self.sendfile(): - for data in self.result: - self.write(data) - self.finish_content() - finally: - self.close() - - - def get_scheme(self): - """Return the URL scheme being used""" - return guess_scheme(self.environ) - - - def set_content_length(self): - """Compute Content-Length or switch to chunked encoding if possible""" - try: - blocks = len(self.result) - except (TypeError,AttributeError,NotImplementedError): - pass - else: - if blocks==1: - self.headers['Content-Length'] = str(self.bytes_sent) - return - # XXX Try for chunked encoding if origin server and client is 1.1 - - - def cleanup_headers(self): - """Make any necessary header changes or defaults - - Subclasses can extend this to add other defaults. - """ - if 'Content-Length' not in self.headers: - self.set_content_length() - - def start_response(self, status, headers,exc_info=None): - """'start_response()' callable as specified by PEP 333""" - - if exc_info: - try: - if self.headers_sent: - # Re-raise original exception if headers sent - raise exc_info[0], exc_info[1], exc_info[2] - finally: - exc_info = None # avoid dangling circular ref - elif self.headers is not None: - raise AssertionError("Headers already set!") - - assert type(status) is StringType,"Status must be a string" - assert len(status)>=4,"Status must be at least 4 characters" - assert int(status[:3]),"Status message must begin w/3-digit code" - assert status[3]==" ", "Status message must have a space after code" - if __debug__: - for name,val in headers: - assert type(name) is StringType,"Header names must be strings" - assert type(val) is StringType,"Header values must be strings" - assert not is_hop_by_hop(name),"Hop-by-hop headers not allowed" - self.status = status - self.headers = self.headers_class(headers) - return self.write - - - def send_preamble(self): - """Transmit version/status/date/server, via self._write()""" - if self.origin_server: - if self.client_is_modern(): - self._write('HTTP/%s %s\r\n' % (self.http_version,self.status)) - if 'Date' not in self.headers: - self._write( - 'Date: %s\r\n' % format_date_time(time.time()) - ) - if self.server_software and 'Server' not in self.headers: - self._write('Server: %s\r\n' % self.server_software) - else: - self._write('Status: %s\r\n' % self.status) - - def write(self, data): - """'write()' callable as specified by PEP 333""" - - assert type(data) is StringType,"write() argument must be string" - - if not self.status: - raise AssertionError("write() before start_response()") - - elif not self.headers_sent: - # Before the first output, send the stored headers - self.bytes_sent = len(data) # make sure we know content-length - self.send_headers() - else: - self.bytes_sent += len(data) - - # XXX check Content-Length and truncate if too many bytes written? - self._write(data) - self._flush() - - - def sendfile(self): - """Platform-specific file transmission - - Override this method in subclasses to support platform-specific - file transmission. It is only called if the application's - return iterable ('self.result') is an instance of - 'self.wsgi_file_wrapper'. - - This method should return a true value if it was able to actually - transmit the wrapped file-like object using a platform-specific - approach. It should return a false value if normal iteration - should be used instead. An exception can be raised to indicate - that transmission was attempted, but failed. - - NOTE: this method should call 'self.send_headers()' if - 'self.headers_sent' is false and it is going to attempt direct - transmission of the file. - """ - return False # No platform-specific transmission by default - - - def finish_content(self): - """Ensure headers and content have both been sent""" - if not self.headers_sent: - # Only zero Content-Length if not set by the application (so - # that HEAD requests can be satisfied properly, see #3839) - self.headers.setdefault('Content-Length', "0") - self.send_headers() - else: - pass # XXX check if content-length was too short? - - def close(self): - """Close the iterable (if needed) and reset all instance vars - - Subclasses may want to also drop the client connection. - """ - try: - if hasattr(self.result,'close'): - self.result.close() - finally: - self.result = self.headers = self.status = self.environ = None - self.bytes_sent = 0; self.headers_sent = False - - - def send_headers(self): - """Transmit headers to the client, via self._write()""" - self.cleanup_headers() - self.headers_sent = True - if not self.origin_server or self.client_is_modern(): - self.send_preamble() - self._write(str(self.headers)) - - - def result_is_file(self): - """True if 'self.result' is an instance of 'self.wsgi_file_wrapper'""" - wrapper = self.wsgi_file_wrapper - return wrapper is not None and isinstance(self.result,wrapper) - - - def client_is_modern(self): - """True if client can accept status and headers""" - return self.environ['SERVER_PROTOCOL'].upper() != 'HTTP/0.9' - - - def log_exception(self,exc_info): - """Log the 'exc_info' tuple in the server log - - Subclasses may override to retarget the output or change its format. - """ - try: - from traceback import print_exception - stderr = self.get_stderr() - print_exception( - exc_info[0], exc_info[1], exc_info[2], - self.traceback_limit, stderr - ) - stderr.flush() - finally: - exc_info = None - - def handle_error(self): - """Log current error, and send error output to client if possible""" - self.log_exception(sys.exc_info()) - if not self.headers_sent: - self.result = self.error_output(self.environ, self.start_response) - self.finish_response() - # XXX else: attempt advanced recovery techniques for HTML or text? - - def error_output(self, environ, start_response): - """WSGI mini-app to create error output - - By default, this just uses the 'error_status', 'error_headers', - and 'error_body' attributes to generate an output page. It can - be overridden in a subclass to dynamically generate diagnostics, - choose an appropriate message for the user's preferred language, etc. - - Note, however, that it's not recommended from a security perspective to - spit out diagnostics to any old user; ideally, you should have to do - something special to enable diagnostic output, which is why we don't - include any here! - """ - start_response(self.error_status,self.error_headers[:],sys.exc_info()) - return [self.error_body] - - - # Pure abstract methods; *must* be overridden in subclasses - - def _write(self,data): - """Override in subclass to buffer data for send to client - - It's okay if this method actually transmits the data; BaseHandler - just separates write and flush operations for greater efficiency - when the underlying system actually has such a distinction. - """ - raise NotImplementedError - - def _flush(self): - """Override in subclass to force sending of recent '_write()' calls - - It's okay if this method is a no-op (i.e., if '_write()' actually - sends the data. - """ - raise NotImplementedError - - def get_stdin(self): - """Override in subclass to return suitable 'wsgi.input'""" - raise NotImplementedError - - def get_stderr(self): - """Override in subclass to return suitable 'wsgi.errors'""" - raise NotImplementedError - - def add_cgi_vars(self): - """Override in subclass to insert CGI variables in 'self.environ'""" - raise NotImplementedError - - -class SimpleHandler(BaseHandler): - """Handler that's just initialized with streams, environment, etc. - - This handler subclass is intended for synchronous HTTP/1.0 origin servers, - and handles sending the entire response output, given the correct inputs. - - Usage:: - - handler = SimpleHandler( - inp,out,err,env, multithread=False, multiprocess=True - ) - handler.run(app)""" - - def __init__(self,stdin,stdout,stderr,environ, - multithread=True, multiprocess=False - ): - self.stdin = stdin - self.stdout = stdout - self.stderr = stderr - self.base_env = environ - self.wsgi_multithread = multithread - self.wsgi_multiprocess = multiprocess - - def get_stdin(self): - return self.stdin - - def get_stderr(self): - return self.stderr - - def add_cgi_vars(self): - self.environ.update(self.base_env) - - def _write(self,data): - self.stdout.write(data) - self._write = self.stdout.write - - def _flush(self): - self.stdout.flush() - self._flush = self.stdout.flush - - -class BaseCGIHandler(SimpleHandler): - - """CGI-like systems using input/output/error streams and environ mapping - - Usage:: - - handler = BaseCGIHandler(inp,out,err,env) - handler.run(app) - - This handler class is useful for gateway protocols like ReadyExec and - FastCGI, that have usable input/output/error streams and an environment - mapping. It's also the base class for CGIHandler, which just uses - sys.stdin, os.environ, and so on. - - The constructor also takes keyword arguments 'multithread' and - 'multiprocess' (defaulting to 'True' and 'False' respectively) to control - the configuration sent to the application. It sets 'origin_server' to - False (to enable CGI-like output), and assumes that 'wsgi.run_once' is - False. - """ - - origin_server = False - - -class CGIHandler(BaseCGIHandler): - - """CGI-based invocation via sys.stdin/stdout/stderr and os.environ - - Usage:: - - CGIHandler().run(app) - - The difference between this class and BaseCGIHandler is that it always - uses 'wsgi.run_once' of 'True', 'wsgi.multithread' of 'False', and - 'wsgi.multiprocess' of 'True'. It does not take any initialization - parameters, but always uses 'sys.stdin', 'os.environ', and friends. - - If you need to override any of these parameters, use BaseCGIHandler - instead. - """ - - wsgi_run_once = True - # Do not allow os.environ to leak between requests in Google App Engine - # and other multi-run CGI use cases. This is not easily testable. - # See http://bugs.python.org/issue7250 - os_environ = {} - - def __init__(self): - BaseCGIHandler.__init__( - self, sys.stdin, sys.stdout, sys.stderr, dict(os.environ.items()), - multithread=False, multiprocess=True - ) |