Import wsgiref into the stdlib, as of the external version 0.1-r2181.

6 files changed, 1559 insertions, 0 deletions

diff --git a/Lib/wsgiref/__init__.py b/Lib/wsgiref/__init__.py
new file mode 100644
index 0000000..46c579f
--- /dev/null
+++ b/Lib/wsgiref/__init__.py
@@ -0,0 +1,23 @@
+"""wsgiref -- a WSGI (PEP 333) Reference Library
+
+Current Contents:
+
+* util -- Miscellaneous useful functions and wrappers
+
+* headers -- Manage response headers
+
+* handlers -- base classes for server/gateway implementations
+
+* simple_server -- a simple BaseHTTPServer that supports WSGI
+
+* validate -- validation wrapper that sits between an app and a server
+  to detect errors in either
+
+To-Do:
+
+* cgi_gateway -- Run WSGI apps under CGI (pending a deployment standard)
+
+* cgi_wrapper -- Run CGI apps under WSGI
+
+* router -- a simple middleware component that handles URL traversal
+"""
diff --git a/Lib/wsgiref/handlers.py b/Lib/wsgiref/handlers.py
new file mode 100644
index 0000000..52771a2
--- /dev/null
+++ b/Lib/wsgiref/handlers.py
@@ -0,0 +1,492 @@
+"""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
+
+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 Dude, this is whack!"
+    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.
+        """
+        if not self.result_is_file() or not self.sendfile():
+            for data in self.result:
+                self.write(data)
+            self.finish_content()
+        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 not self.headers.has_key('Content-Length'):
+            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 not self.headers.has_key('Date'):
+                    self._write(
+                        'Date: %s\r\n' % format_date_time(time.time())
+                    )
+                if self.server_software and not self.headers.has_key('Server'):
+                    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:
+            self.headers['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
+
+    def __init__(self):
+        BaseCGIHandler.__init__(
+            self, sys.stdin, sys.stdout, sys.stderr, dict(os.environ.items()),
+            multithread=False, multiprocess=True
+        )
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/Lib/wsgiref/headers.py b/Lib/wsgiref/headers.py
new file mode 100644
index 0000000..fa9b829
--- /dev/null
+++ b/Lib/wsgiref/headers.py
@@ -0,0 +1,205 @@
+"""Manage HTTP Response Headers
+
+Much of this module is red-handedly pilfered from email.Message in the stdlib,
+so portions are Copyright (C) 2001,2002 Python Software Foundation, and were
+written by Barry Warsaw.
+"""
+
+from types import ListType, TupleType
+
+# Regular expression that matches `special' characters in parameters, the
+# existance of which force quoting of the parameter value.
+import re
+tspecials = re.compile(r'[ \(\)<>@,;:\\"/\[\]\?=]')
+
+def _formatparam(param, value=None, quote=1):
+    """Convenience function to format and return a key=value pair.
+
+    This will quote the value if needed or if quote is true.
+    """
+    if value is not None and len(value) > 0:
+        if quote or tspecials.search(value):
+            value = value.replace('\\', '\\\\').replace('"', r'\"')
+            return '%s="%s"' % (param, value)
+        else:
+            return '%s=%s' % (param, value)
+    else:
+        return param
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+class Headers:
+
+    """Manage a collection of HTTP response headers"""
+
+    def __init__(self,headers):
+        if type(headers) is not ListType:
+            raise TypeError("Headers must be a list of name/value tuples")
+        self._headers = headers
+
+    def __len__(self):
+        """Return the total number of headers, including duplicates."""
+        return len(self._headers)
+
+    def __setitem__(self, name, val):
+        """Set the value of a header."""
+        del self[name]
+        self._headers.append((name, val))
+
+    def __delitem__(self,name):
+        """Delete all occurrences of a header, if present.
+
+        Does *not* raise an exception if the header is missing.
+        """
+        name = name.lower()
+        self._headers[:] = [kv for kv in self._headers if kv[0].lower()<>name]
+
+    def __getitem__(self,name):
+        """Get the first header value for 'name'
+
+        Return None if the header is missing instead of raising an exception.
+
+        Note that if the header appeared multiple times, the first exactly which
+        occurrance gets returned is undefined.  Use getall() to get all
+        the values matching a header field name.
+        """
+        return self.get(name)
+
+
+
+
+
+    def has_key(self, name):
+        """Return true if the message contains the header."""
+        return self.get(name) is not None
+
+    __contains__ = has_key
+
+
+    def get_all(self, name):
+        """Return a list of all the values for the named field.
+
+        These will be sorted in the order they appeared in the original header
+        list or were added to this instance, and may contain duplicates.  Any
+        fields deleted and re-inserted are always appended to the header list.
+        If no fields exist with the given name, returns an empty list.
+        """
+        name = name.lower()
+        return [kv[1] for kv in self._headers if kv[0].lower()==name]
+
+
+    def get(self,name,default=None):
+        """Get the first header value for 'name', or return 'default'"""
+        name = name.lower()
+        for k,v in self._headers:
+            if k.lower()==name:
+                return v
+        return default
+
+
+    def keys(self):
+        """Return a list of all the header field names.
+
+        These will be sorted in the order they appeared in the original header
+        list, or were added to this instance, and may contain duplicates.
+        Any fields deleted and re-inserted are always appended to the header
+        list.
+        """
+        return [k for k, v in self._headers]
+
+
+
+
+    def values(self):
+        """Return a list of all header values.
+
+        These will be sorted in the order they appeared in the original header
+        list, or were added to this instance, and may contain duplicates.
+        Any fields deleted and re-inserted are always appended to the header
+        list.
+        """
+        return [v for k, v in self._headers]
+
+    def items(self):
+        """Get all the header fields and values.
+
+        These will be sorted in the order they were in the original header
+        list, or were added to this instance, and may contain duplicates.
+        Any fields deleted and re-inserted are always appended to the header
+        list.
+        """
+        return self._headers[:]
+
+    def __repr__(self):
+        return "Headers(%s)" % `self._headers`
+
+    def __str__(self):
+        """str() returns the formatted headers, complete with end line,
+        suitable for direct HTTP transmission."""
+        return '\r\n'.join(["%s: %s" % kv for kv in self._headers]+['',''])
+
+    def setdefault(self,name,value):
+        """Return first matching header value for 'name', or 'value'
+
+        If there is no header named 'name', add a new header with name 'name'
+        and value 'value'."""
+        result = self.get(name)
+        if result is None:
+            self._headers.append((name,value))
+            return value
+        else:
+            return result
+
+
+    def add_header(self, _name, _value, **_params):
+        """Extended header setting.
+
+        _name is the header field to add.  keyword arguments can be used to set
+        additional parameters for the header field, with underscores converted
+        to dashes.  Normally the parameter will be added as key="value" unless
+        value is None, in which case only the key will be added.
+
+        Example:
+
+        h.add_header('content-disposition', 'attachment', filename='bud.gif')
+
+        Note that unlike the corresponding 'email.Message' method, this does
+        *not* handle '(charset, language, value)' tuples: all values must be
+        strings or None.
+        """
+        parts = []
+        if _value is not None:
+            parts.append(_value)
+        for k, v in _params.items():
+            if v is None:
+                parts.append(k.replace('_', '-'))
+            else:
+                parts.append(_formatparam(k.replace('_', '-'), v))
+        self._headers.append((_name, "; ".join(parts)))
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/Lib/wsgiref/simple_server.py b/Lib/wsgiref/simple_server.py
new file mode 100644
index 0000000..e171686
--- /dev/null
+++ b/Lib/wsgiref/simple_server.py
@@ -0,0 +1,205 @@
+"""BaseHTTPServer that implements the Python WSGI protocol (PEP 333, rev 1.21)
+
+This is both an example of how WSGI can be implemented, and a basis for running
+simple web applications on a local machine, such as might be done when testing
+or debugging an application.  It has not been reviewed for security issues,
+however, and we strongly recommend that you use a "real" web server for
+production use.
+
+For example usage, see the 'if __name__=="__main__"' block at the end of the
+module.  See also the BaseHTTPServer module docs for other API information.
+"""
+
+from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
+import urllib, sys
+from wsgiref.handlers import SimpleHandler
+
+__version__ = "0.1"
+__all__ = ['WSGIServer', 'WSGIRequestHandler', 'demo_app', 'make_server']
+
+
+server_version = "WSGIServer/" + __version__
+sys_version = "Python/" + sys.version.split()[0]
+software_version = server_version + ' ' + sys_version
+
+
+class ServerHandler(SimpleHandler):
+
+    server_software = software_version
+
+    def close(self):
+        try:
+            self.request_handler.log_request(
+                self.status.split(' ',1)[0], self.bytes_sent
+            )
+        finally:
+            SimpleHandler.close(self)
+
+
+
+
+
+class WSGIServer(HTTPServer):
+
+    """BaseHTTPServer that implements the Python WSGI protocol"""
+
+    application = None
+
+    def server_bind(self):
+        """Override server_bind to store the server name."""
+        HTTPServer.server_bind(self)
+        self.setup_environ()
+
+    def setup_environ(self):
+        # Set up base environment
+        env = self.base_environ = {}
+        env['SERVER_NAME'] = self.server_name
+        env['GATEWAY_INTERFACE'] = 'CGI/1.1'
+        env['SERVER_PORT'] = str(self.server_port)
+        env['REMOTE_HOST']=''
+        env['CONTENT_LENGTH']=''
+        env['SCRIPT_NAME'] = ''
+
+    def get_app(self):
+        return self.application
+
+    def set_app(self,application):
+        self.application = application
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+class WSGIRequestHandler(BaseHTTPRequestHandler):
+
+    server_version = "WSGIServer/" + __version__
+
+    def get_environ(self):
+        env = self.server.base_environ.copy()
+        env['SERVER_PROTOCOL'] = self.request_version
+        env['REQUEST_METHOD'] = self.command
+        if '?' in self.path:
+            path,query = self.path.split('?',1)
+        else:
+            path,query = self.path,''
+
+        env['PATH_INFO'] = urllib.unquote(path)
+        env['QUERY_STRING'] = query
+
+        host = self.address_string()
+        if host != self.client_address[0]:
+            env['REMOTE_HOST'] = host
+        env['REMOTE_ADDR'] = self.client_address[0]
+
+        if self.headers.typeheader is None:
+            env['CONTENT_TYPE'] = self.headers.type
+        else:
+            env['CONTENT_TYPE'] = self.headers.typeheader
+
+        length = self.headers.getheader('content-length')
+        if length:
+            env['CONTENT_LENGTH'] = length
+
+        for h in self.headers.headers:
+            k,v = h.split(':',1)
+            k=k.replace('-','_').upper(); v=v.strip()
+            if k in env:
+                continue                    # skip content length, type,etc.
+            if 'HTTP_'+k in env:
+                env['HTTP_'+k] += ','+v     # comma-separate multiple headers
+            else:
+                env['HTTP_'+k] = v
+        return env
+
+    def get_stderr(self):
+        return sys.stderr
+
+    def handle(self):
+        """Handle a single HTTP request"""
+
+        self.raw_requestline = self.rfile.readline()
+        if not self.parse_request(): # An error code has been sent, just exit
+            return
+
+        handler = ServerHandler(
+            self.rfile, self.wfile, self.get_stderr(), self.get_environ()
+        )
+        handler.request_handler = self      # backpointer for logging
+        handler.run(self.server.get_app())
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+def demo_app(environ,start_response):
+    from StringIO import StringIO
+    stdout = StringIO()
+    print >>stdout, "Hello world!"
+    print >>stdout
+    h = environ.items(); h.sort()
+    for k,v in h:
+        print >>stdout, k,'=',`v`
+    start_response("200 OK", [('Content-Type','text/plain')])
+    return [stdout.getvalue()]
+
+
+def make_server(
+    host, port, app, server_class=WSGIServer, handler_class=WSGIRequestHandler
+):
+    """Create a new WSGI server listening on `host` and `port` for `app`"""
+    server = server_class((host, port), handler_class)
+    server.set_app(app)
+    return server
+
+
+if __name__ == '__main__':
+    server_address = ('', 8000)
+    httpd = make_server('', 8000, demo_app)
+    sa = httpd.socket.getsockname()
+    print "Serving HTTP on", sa[0], "port", sa[1], "..."
+    import webbrowser
+    webbrowser.open('http://localhost:8000/xyz?abc')
+    httpd.handle_request()  # serve one request, then exit
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/Lib/wsgiref/util.py b/Lib/wsgiref/util.py
new file mode 100644
index 0000000..78ebb3b
--- /dev/null
+++ b/Lib/wsgiref/util.py
@@ -0,0 +1,205 @@
+"""Miscellaneous WSGI-related Utilities"""
+
+import posixpath
+
+__all__ = [
+    'FileWrapper', 'guess_scheme', 'application_uri', 'request_uri',
+    'shift_path_info', 'setup_testing_defaults',
+]
+
+
+class FileWrapper:
+    """Wrapper to convert file-like objects to iterables"""
+
+    def __init__(self, filelike, blksize=8192):
+        self.filelike = filelike
+        self.blksize = blksize
+        if hasattr(filelike,'close'):
+            self.close = filelike.close
+
+    def __getitem__(self,key):
+        data = self.filelike.read(self.blksize)
+        if data:
+            return data
+        raise IndexError
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        data = self.filelike.read(self.blksize)
+        if data:
+            return data
+        raise StopIteration
+
+
+
+
+
+
+
+
+def guess_scheme(environ):
+    """Return a guess for whether 'wsgi.url_scheme' should be 'http' or 'https'
+    """
+    if environ.get("HTTPS") in ('yes','on','1'):
+        return 'https'
+    else:
+        return 'http'
+
+def application_uri(environ):
+    """Return the application's base URI (no PATH_INFO or QUERY_STRING)"""
+    url = environ['wsgi.url_scheme']+'://'
+    from urllib import quote
+
+    if environ.get('HTTP_HOST'):
+        url += environ['HTTP_HOST']
+    else:
+        url += environ['SERVER_NAME']
+
+        if environ['wsgi.url_scheme'] == 'https':
+            if environ['SERVER_PORT'] != '443':
+               url += ':' + environ['SERVER_PORT']
+        else:
+            if environ['SERVER_PORT'] != '80':
+               url += ':' + environ['SERVER_PORT']
+
+    url += quote(environ.get('SCRIPT_NAME') or '/')
+    return url
+
+def request_uri(environ, include_query=1):
+    """Return the full request URI, optionally including the query string"""
+    url = application_uri(environ)
+    from urllib import quote
+    path_info = quote(environ.get('PATH_INFO',''))
+    if not environ.get('SCRIPT_NAME'):
+        url += path_info[1:]
+    else:
+        url += path_info
+    if include_query and environ.get('QUERY_STRING'):
+        url += '?' + environ['QUERY_STRING']
+    return url
+
+def shift_path_info(environ):
+    """Shift a name from PATH_INFO to SCRIPT_NAME, returning it
+
+    If there are no remaining path segments in PATH_INFO, return None.
+    Note: 'environ' is modified in-place; use a copy if you need to keep
+    the original PATH_INFO or SCRIPT_NAME.
+
+    Note: when PATH_INFO is just a '/', this returns '' and appends a trailing
+    '/' to SCRIPT_NAME, even though empty path segments are normally ignored,
+    and SCRIPT_NAME doesn't normally end in a '/'.  This is intentional
+    behavior, to ensure that an application can tell the difference between
+    '/x' and '/x/' when traversing to objects.
+    """
+    path_info = environ.get('PATH_INFO','')
+    if not path_info:
+        return None
+
+    path_parts = path_info.split('/')
+    path_parts[1:-1] = [p for p in path_parts[1:-1] if p and p<>'.']
+    name = path_parts[1]
+    del path_parts[1]
+
+    script_name = environ.get('SCRIPT_NAME','')
+    script_name = posixpath.normpath(script_name+'/'+name)
+    if script_name.endswith('/'):
+        script_name = script_name[:-1]
+    if not name and not script_name.endswith('/'):
+        script_name += '/'
+
+    environ['SCRIPT_NAME'] = script_name
+    environ['PATH_INFO']   = '/'.join(path_parts)
+
+    # Special case: '/.' on PATH_INFO doesn't get stripped,
+    # because we don't strip the last element of PATH_INFO
+    # if there's only one path part left.  Instead of fixing this
+    # above, we fix it here so that PATH_INFO gets normalized to
+    # an empty string in the environ.
+    if name=='.':
+        name = None
+    return name
+
+def setup_testing_defaults(environ):
+    """Update 'environ' with trivial defaults for testing purposes
+
+    This adds various parameters required for WSGI, including HTTP_HOST,
+    SERVER_NAME, SERVER_PORT, REQUEST_METHOD, SCRIPT_NAME, PATH_INFO,
+    and all of the wsgi.* variables.  It only supplies default values,
+    and does not replace any existing settings for these variables.
+
+    This routine is intended to make it easier for unit tests of WSGI
+    servers and applications to set up dummy environments.  It should *not*
+    be used by actual WSGI servers or applications, since the data is fake!
+    """
+
+    environ.setdefault('SERVER_NAME','127.0.0.1')
+    environ.setdefault('SERVER_PROTOCOL','HTTP/1.0')
+
+    environ.setdefault('HTTP_HOST',environ['SERVER_NAME'])
+    environ.setdefault('REQUEST_METHOD','GET')
+
+    if 'SCRIPT_NAME' not in environ and 'PATH_INFO' not in environ:
+        environ.setdefault('SCRIPT_NAME','')
+        environ.setdefault('PATH_INFO','/')
+
+    environ.setdefault('wsgi.version', (1,0))
+    environ.setdefault('wsgi.run_once', 0)
+    environ.setdefault('wsgi.multithread', 0)
+    environ.setdefault('wsgi.multiprocess', 0)
+
+    from StringIO import StringIO
+    environ.setdefault('wsgi.input', StringIO(""))
+    environ.setdefault('wsgi.errors', StringIO())
+    environ.setdefault('wsgi.url_scheme',guess_scheme(environ))
+
+    if environ['wsgi.url_scheme']=='http':
+        environ.setdefault('SERVER_PORT', '80')
+    elif environ['wsgi.url_scheme']=='https':
+        environ.setdefault('SERVER_PORT', '443')
+
+
+
+
+_hoppish = {
+    'connection':1, 'keep-alive':1, 'proxy-authenticate':1,
+    'proxy-authorization':1, 'te':1, 'trailers':1, 'transfer-encoding':1,
+    'upgrade':1
+}.has_key
+
+def is_hop_by_hop(header_name):
+    """Return true if 'header_name' is an HTTP/1.1 "Hop-by-Hop" header"""
+    return _hoppish(header_name.lower())
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/Lib/wsgiref/validate.py b/Lib/wsgiref/validate.py
new file mode 100644
index 0000000..e72c507
--- /dev/null
+++ b/Lib/wsgiref/validate.py
@@ -0,0 +1,429 @@
+# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org)
+# Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
+# Also licenced under the Apache License, 2.0: http://opensource.org/licenses/apache2.0.php
+# Licensed to PSF under a Contributor Agreement
+"""
+Middleware to check for obedience to the WSGI specification.
+
+Some of the things this checks:
+
+* Signature of the application and start_response (including that
+  keyword arguments are not used).
+
+* Environment checks:
+
+  - Environment is a dictionary (and not a subclass).
+
+  - That all the required keys are in the environment: REQUEST_METHOD,
+    SERVER_NAME, SERVER_PORT, wsgi.version, wsgi.input, wsgi.errors,
+    wsgi.multithread, wsgi.multiprocess, wsgi.run_once
+
+  - That HTTP_CONTENT_TYPE and HTTP_CONTENT_LENGTH are not in the
+    environment (these headers should appear as CONTENT_LENGTH and
+    CONTENT_TYPE).
+
+  - Warns if QUERY_STRING is missing, as the cgi module acts
+    unpredictably in that case.
+
+  - That CGI-style variables (that don't contain a .) have
+    (non-unicode) string values
+
+  - That wsgi.version is a tuple
+
+  - That wsgi.url_scheme is 'http' or 'https' (@@: is this too
+    restrictive?)
+
+  - Warns if the REQUEST_METHOD is not known (@@: probably too
+    restrictive).
+
+  - That SCRIPT_NAME and PATH_INFO are empty or start with /
+
+  - That at least one of SCRIPT_NAME or PATH_INFO are set.
+
+  - That CONTENT_LENGTH is a positive integer.
+
+  - That SCRIPT_NAME is not '/' (it should be '', and PATH_INFO should
+    be '/').
+
+  - That wsgi.input has the methods read, readline, readlines, and
+    __iter__
+
+  - That wsgi.errors has the methods flush, write, writelines
+
+* The status is a string, contains a space, starts with an integer,
+  and that integer is in range (> 100).
+
+* That the headers is a list (not a subclass, not another kind of
+  sequence).
+
+* That the items of the headers are tuples of strings.
+
+* That there is no 'status' header (that is used in CGI, but not in
+  WSGI).
+
+* That the headers don't contain newlines or colons, end in _ or -, or
+  contain characters codes below 037.
+
+* That Content-Type is given if there is content (CGI often has a
+  default content type, but WSGI does not).
+
+* That no Content-Type is given when there is no content (@@: is this
+  too restrictive?)
+
+* That the exc_info argument to start_response is a tuple or None.
+
+* That all calls to the writer are with strings, and no other methods
+  on the writer are accessed.
+
+* That wsgi.input is used properly:
+
+  - .read() is called with zero or one argument
+
+  - That it returns a string
+
+  - That readline, readlines, and __iter__ return strings
+
+  - That .close() is not called
+
+  - No other methods are provided
+
+* That wsgi.errors is used properly:
+
+  - .write() and .writelines() is called with a string
+
+  - That .close() is not called, and no other methods are provided.
+
+* The response iterator:
+
+  - That it is not a string (it should be a list of a single string; a
+    string will work, but perform horribly).
+
+  - That .next() returns a string
+
+  - That the iterator is not iterated over until start_response has
+    been called (that can signal either a server or application
+    error).
+
+  - That .close() is called (doesn't raise exception, only prints to
+    sys.stderr, because we only know it isn't called when the object
+    is garbage collected).
+"""
+__all__ = ['validator']
+
+
+import re
+import sys
+from types import DictType, StringType, TupleType, ListType
+import warnings
+
+header_re = re.compile(r'^[a-zA-Z][a-zA-Z0-9\-_]*$')
+bad_header_value_re = re.compile(r'[\000-\037]')
+
+class WSGIWarning(Warning):
+    """
+    Raised in response to WSGI-spec-related warnings
+    """
+
+def validator(application):
+
+    """
+    When applied between a WSGI server and a WSGI application, this
+    middleware will check for WSGI compliancy on a number of levels.
+    This middleware does not modify the request or response in any
+    way, but will throw an AssertionError if anything seems off
+    (except for a failure to close the application iterator, which
+    will be printed to stderr -- there's no way to throw an exception
+    at that point).
+    """
+
+    def lint_app(*args, **kw):
+        assert len(args) == 2, "Two arguments required"
+        assert not kw, "No keyword arguments allowed"
+        environ, start_response = args
+
+        check_environ(environ)
+
+        # We use this to check if the application returns without
+        # calling start_response:
+        start_response_started = []
+
+        def start_response_wrapper(*args, **kw):
+            assert len(args) == 2 or len(args) == 3, (
+                "Invalid number of arguments: %s" % args)
+            assert not kw, "No keyword arguments allowed"
+            status = args[0]
+            headers = args[1]
+            if len(args) == 3:
+                exc_info = args[2]
+            else:
+                exc_info = None
+
+            check_status(status)
+            check_headers(headers)
+            check_content_type(status, headers)
+            check_exc_info(exc_info)
+
+            start_response_started.append(None)
+            return WriteWrapper(start_response(*args))
+
+        environ['wsgi.input'] = InputWrapper(environ['wsgi.input'])
+        environ['wsgi.errors'] = ErrorWrapper(environ['wsgi.errors'])
+
+        iterator = application(environ, start_response_wrapper)
+        assert iterator is not None and iterator != False, (
+            "The application must return an iterator, if only an empty list")
+
+        check_iterator(iterator)
+
+        return IteratorWrapper(iterator, start_response_started)
+
+    return lint_app
+
+class InputWrapper:
+
+    def __init__(self, wsgi_input):
+        self.input = wsgi_input
+
+    def read(self, *args):
+        assert len(args) <= 1
+        v = self.input.read(*args)
+        assert type(v) is type("")
+        return v
+
+    def readline(self):
+        v = self.input.readline()
+        assert type(v) is type("")
+        return v
+
+    def readlines(self, *args):
+        assert len(args) <= 1
+        lines = self.input.readlines(*args)
+        assert type(lines) is type([])
+        for line in lines:
+            assert type(line) is type("")
+        return lines
+
+    def __iter__(self):
+        while 1:
+            line = self.readline()
+            if not line:
+                return
+            yield line
+
+    def close(self):
+        assert 0, "input.close() must not be called"
+
+class ErrorWrapper:
+
+    def __init__(self, wsgi_errors):
+        self.errors = wsgi_errors
+
+    def write(self, s):
+        assert type(s) is type("")
+        self.errors.write(s)
+
+    def flush(self):
+        self.errors.flush()
+
+    def writelines(self, seq):
+        for line in seq:
+            self.write(line)
+
+    def close(self):
+        assert 0, "errors.close() must not be called"
+
+class WriteWrapper:
+
+    def __init__(self, wsgi_writer):
+        self.writer = wsgi_writer
+
+    def __call__(self, s):
+        assert type(s) is type("")
+        self.writer(s)
+
+class PartialIteratorWrapper:
+
+    def __init__(self, wsgi_iterator):
+        self.iterator = wsgi_iterator
+
+    def __iter__(self):
+        # We want to make sure __iter__ is called
+        return IteratorWrapper(self.iterator)
+
+class IteratorWrapper:
+
+    def __init__(self, wsgi_iterator, check_start_response):
+        self.original_iterator = wsgi_iterator
+        self.iterator = iter(wsgi_iterator)
+        self.closed = False
+        self.check_start_response = check_start_response
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        assert not self.closed, (
+            "Iterator read after closed")
+        v = self.iterator.next()
+        if self.check_start_response is not None:
+            assert self.check_start_response, (
+                "The application returns and we started iterating over its body, but start_response has not yet been called")
+            self.check_start_response = None
+        return v
+
+    def close(self):
+        self.closed = True
+        if hasattr(self.original_iterator, 'close'):
+            self.original_iterator.close()
+
+    def __del__(self):
+        if not self.closed:
+            sys.stderr.write(
+                "Iterator garbage collected without being closed")
+        assert self.closed, (
+            "Iterator garbage collected without being closed")
+
+def check_environ(environ):
+    assert type(environ) is DictType, (
+        "Environment is not of the right type: %r (environment: %r)"
+        % (type(environ), environ))
+
+    for key in ['REQUEST_METHOD', 'SERVER_NAME', 'SERVER_PORT',
+                'wsgi.version', 'wsgi.input', 'wsgi.errors',
+                'wsgi.multithread', 'wsgi.multiprocess',
+                'wsgi.run_once']:
+        assert key in environ, (
+            "Environment missing required key: %r" % key)
+
+    for key in ['HTTP_CONTENT_TYPE', 'HTTP_CONTENT_LENGTH']:
+        assert key not in environ, (
+            "Environment should not have the key: %s "
+            "(use %s instead)" % (key, key[5:]))
+
+    if 'QUERY_STRING' not in environ:
+        warnings.warn(
+            'QUERY_STRING is not in the WSGI environment; the cgi '
+            'module will use sys.argv when this variable is missing, '
+            'so application errors are more likely',
+            WSGIWarning)
+
+    for key in environ.keys():
+        if '.' in key:
+            # Extension, we don't care about its type
+            continue
+        assert type(environ[key]) is StringType, (
+            "Environmental variable %s is not a string: %r (value: %r)"
+            % (type(environ[key]), environ[key]))
+
+    assert type(environ['wsgi.version']) is TupleType, (
+        "wsgi.version should be a tuple (%r)" % environ['wsgi.version'])
+    assert environ['wsgi.url_scheme'] in ('http', 'https'), (
+        "wsgi.url_scheme unknown: %r" % environ['wsgi.url_scheme'])
+
+    check_input(environ['wsgi.input'])
+    check_errors(environ['wsgi.errors'])
+
+    # @@: these need filling out:
+    if environ['REQUEST_METHOD'] not in (
+        'GET', 'HEAD', 'POST', 'OPTIONS','PUT','DELETE','TRACE'):
+        warnings.warn(
+            "Unknown REQUEST_METHOD: %r" % environ['REQUEST_METHOD'],
+            WSGIWarning)
+
+    assert (not environ.get('SCRIPT_NAME')
+            or environ['SCRIPT_NAME'].startswith('/')), (
+        "SCRIPT_NAME doesn't start with /: %r" % environ['SCRIPT_NAME'])
+    assert (not environ.get('PATH_INFO')
+            or environ['PATH_INFO'].startswith('/')), (
+        "PATH_INFO doesn't start with /: %r" % environ['PATH_INFO'])
+    if environ.get('CONTENT_LENGTH'):
+        assert int(environ['CONTENT_LENGTH']) >= 0, (
+            "Invalid CONTENT_LENGTH: %r" % environ['CONTENT_LENGTH'])
+
+    if not environ.get('SCRIPT_NAME'):
+        assert environ.has_key('PATH_INFO'), (
+            "One of SCRIPT_NAME or PATH_INFO are required (PATH_INFO "
+            "should at least be '/' if SCRIPT_NAME is empty)")
+    assert environ.get('SCRIPT_NAME') != '/', (
+        "SCRIPT_NAME cannot be '/'; it should instead be '', and "
+        "PATH_INFO should be '/'")
+
+def check_input(wsgi_input):
+    for attr in ['read', 'readline', 'readlines', '__iter__']:
+        assert hasattr(wsgi_input, attr), (
+            "wsgi.input (%r) doesn't have the attribute %s"
+            % (wsgi_input, attr))
+
+def check_errors(wsgi_errors):
+    for attr in ['flush', 'write', 'writelines']:
+        assert hasattr(wsgi_errors, attr), (
+            "wsgi.errors (%r) doesn't have the attribute %s"
+            % (wsgi_errors, attr))
+
+def check_status(status):
+    assert type(status) is StringType, (
+        "Status must be a string (not %r)" % status)
+    # Implicitly check that we can turn it into an integer:
+    status_code = status.split(None, 1)[0]
+    assert len(status_code) == 3, (
+        "Status codes must be three characters: %r" % status_code)
+    status_int = int(status_code)
+    assert status_int >= 100, "Status code is invalid: %r" % status_int
+    if len(status) < 4 or status[3] != ' ':
+        warnings.warn(
+            "The status string (%r) should be a three-digit integer "
+            "followed by a single space and a status explanation"
+            % status, WSGIWarning)
+
+def check_headers(headers):
+    assert type(headers) is ListType, (
+        "Headers (%r) must be of type list: %r"
+        % (headers, type(headers)))
+    header_names = {}
+    for item in headers:
+        assert type(item) is TupleType, (
+            "Individual headers (%r) must be of type tuple: %r"
+            % (item, type(item)))
+        assert len(item) == 2
+        name, value = item
+        assert name.lower() != 'status', (
+            "The Status header cannot be used; it conflicts with CGI "
+            "script, and HTTP status is not given through headers "
+            "(value: %r)." % value)
+        header_names[name.lower()] = None
+        assert '\n' not in name and ':' not in name, (
+            "Header names may not contain ':' or '\\n': %r" % name)
+        assert header_re.search(name), "Bad header name: %r" % name
+        assert not name.endswith('-') and not name.endswith('_'), (
+            "Names may not end in '-' or '_': %r" % name)
+        assert not bad_header_value_re.search(value), (
+            "Bad header value: %r (bad char: %r)"
+            % (value, bad_header_value_re.search(value).group(0)))
+
+def check_content_type(status, headers):
+    code = int(status.split(None, 1)[0])
+    # @@: need one more person to verify this interpretation of RFC 2616
+    #     http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
+    NO_MESSAGE_BODY = (204, 304)
+    for name, value in headers:
+        if name.lower() == 'content-type':
+            if code not in NO_MESSAGE_BODY:
+                return
+            assert 0, (("Content-Type header found in a %s response, "
+                        "which must not return content.") % code)
+    if code not in NO_MESSAGE_BODY:
+        assert 0, "No Content-Type header found in headers (%s)" % headers
+
+def check_exc_info(exc_info):
+    assert exc_info is None or type(exc_info) is type(()), (
+        "exc_info (%r) is not a tuple: %r" % (exc_info, type(exc_info)))
+    # More exc_info checks?
+
+def check_iterator(iterator):
+    # Technically a string is legal, which is why it's a really bad
+    # idea, because it may cause the response to be returned
+    # character-by-character
+    assert not isinstance(iterator, str), (
+        "You should not return a string as your application iterator, "
+        "instead return a single-item list containing that string.")
+