newforms-admin: Merged to [5571]

git-svn-id: http://code.djangoproject.com/svn/django/branches/newforms-admin@5572 bcc190cf-cafb-0310-a4f2-bffc1f526a37

4 files changed, 252 insertions, 64 deletions

diff --git a/django/core/mail.py b/django/core/mail.py
index 8661d84287..e9d8a150a1 100644
--- a/django/core/mail.py
+++ b/django/core/mail.py
@@ -3,10 +3,13 @@ Tools for sending email.
 """
 
 from django.conf import settings
+from email import Charset, Encoders
 from email.MIMEText import MIMEText
+from email.MIMEMultipart import MIMEMultipart
+from email.MIMEBase import MIMEBase
 from email.Header import Header
 from email.Utils import formatdate
-from email import Charset
+import mimetypes
 import os
 import smtplib
 import socket
@@ -17,6 +20,10 @@ import random
 # some spam filters.
 Charset.add_charset('utf-8', Charset.SHORTEST, Charset.QP, 'utf-8')
 
+# Default MIME type to use on attachments (if it is not explicitly given
+# and cannot be guessed).
+DEFAULT_ATTACHMENT_MIME_TYPE = 'application/octet-stream'
+
 # Cache the hostname, but do it lazily: socket.getfqdn() can take a couple of
 # seconds, which slows down the restart of the server.
 class CachedDnsName(object):
@@ -55,14 +62,22 @@ def make_msgid(idstring=None):
 class BadHeaderError(ValueError):
     pass
 
-class SafeMIMEText(MIMEText):
+class SafeHeaderMixin(object):
     def __setitem__(self, name, val):
         "Forbids multi-line headers, to prevent header injection."
         if '\n' in val or '\r' in val:
             raise BadHeaderError, "Header values can't contain newlines (got %r for header %r)" % (val, name)
         if name == "Subject":
             val = Header(val, settings.DEFAULT_CHARSET)
-        MIMEText.__setitem__(self, name, val)
+        # Note: using super() here is safe; any __setitem__ overrides must use
+        # the same argument signature.
+        super(SafeHeaderMixin, self).__setitem__(name, val)
+
+class SafeMIMEText(MIMEText, SafeHeaderMixin):
+    pass
+
+class SafeMIMEMultipart(MIMEMultipart, SafeHeaderMixin):
+    pass
 
 class SMTPConnection(object):
     """
@@ -154,12 +169,19 @@ class EmailMessage(object):
     """
     A container for email information.
     """
-    def __init__(self, subject='', body='', from_email=None, to=None, bcc=None, connection=None):
+    content_subtype = 'plain'
+    multipart_subtype = 'mixed'
+    encoding = None     # None => use settings default
+
+    def __init__(self, subject='', body='', from_email=None, to=None, bcc=None,
+            connection=None, attachments=None, headers=None):
         self.to = to or []
         self.bcc = bcc or []
         self.from_email = from_email or settings.DEFAULT_FROM_EMAIL
         self.subject = subject
         self.body = body
+        self.attachments = attachments or []
+        self.extra_headers = headers or {}
         self.connection = connection
 
     def get_connection(self, fail_silently=False):
@@ -168,7 +190,18 @@ class EmailMessage(object):
         return self.connection
 
     def message(self):
-        msg = SafeMIMEText(self.body, 'plain', settings.DEFAULT_CHARSET)
+        encoding = self.encoding or settings.DEFAULT_CHARSET
+        msg = SafeMIMEText(self.body, self.content_subtype, encoding)
+        if self.attachments:
+            body_msg = msg
+            msg = SafeMIMEMultipart(_subtype=self.multipart_subtype)
+            if self.body:
+                msg.attach(body_msg)
+            for attachment in self.attachments:
+                if isinstance(attachment, MIMEBase):
+                    msg.attach(attachment)
+                else:
+                    msg.attach(self._create_attachment(*attachment))
         msg['Subject'] = self.subject
         msg['From'] = self.from_email
         msg['To'] = ', '.join(self.to)
@@ -176,6 +209,8 @@ class EmailMessage(object):
         msg['Message-ID'] = make_msgid()
         if self.bcc:
             msg['Bcc'] = ', '.join(self.bcc)
+        for name, value in self.extra_headers.items():
+            msg[name] = value
         return msg
 
     def recipients(self):
@@ -189,6 +224,61 @@ class EmailMessage(object):
         """Send the email message."""
         return self.get_connection(fail_silently).send_messages([self])
 
+    def attach(self, filename=None, content=None, mimetype=None):
+        """
+        Attaches a file with the given filename and content. The filename can
+        be omitted (useful for multipart/alternative messages) and the mimetype
+        is guessed, if not provided.
+
+        If the first parameter is a MIMEBase subclass it is inserted directly
+        into the resulting message attachments.
+        """
+        if isinstance(filename, MIMEBase):
+            assert content == mimetype == None
+            self.attachements.append(filename)
+        else:
+            assert content is not None
+            self.attachments.append((filename, content, mimetype))
+
+    def attach_file(self, path, mimetype=None):
+        """Attaches a file from the filesystem."""
+        filename = os.path.basename(path)
+        content = open(path, 'rb').read()
+        self.attach(filename, content, mimetype)
+
+    def _create_attachment(self, filename, content, mimetype=None):
+        """
+        Convert the filename, content, mimetype triple into a MIME attachment
+        object.
+        """
+        if mimetype is None:
+            mimetype, _ = mimetypes.guess_type(filename)
+            if mimetype is None:
+                mimetype = DEFAULT_ATTACHMENT_MIME_TYPE
+        basetype, subtype = mimetype.split('/', 1)
+        if basetype == 'text':
+            attachment = SafeMIMEText(content, subtype, settings.DEFAULT_CHARSET)
+        else:
+            # Encode non-text attachments with base64.
+            attachment = MIMEBase(basetype, subtype)
+            attachment.set_payload(content)
+            Encoders.encode_base64(attachment)
+        if filename:
+            attachment.add_header('Content-Disposition', 'attachment', filename=filename)
+        return attachment
+
+class EmailMultiAlternatives(EmailMessage):
+    """
+    A version of EmailMessage that makes it easy to send multipart/alternative
+    messages. For example, including text and HTML versions of the text is
+    made easier.
+    """
+    multipart_subtype = 'alternative'
+
+    def attach_alternative(self, content, mimetype=None):
+        """Attach an alternative content representation."""
+        self.attach(content=content, mimetype=mimetype)
+
 def send_mail(subject, message, from_email, recipient_list, fail_silently=False, auth_user=None, auth_password=None):
     """
     Easy wrapper for sending a single message to a recipient list. All members
diff --git a/django/core/management.py b/django/core/management.py
index 29ee9c2f90..1c049a790b 100644
--- a/django/core/management.py
+++ b/django/core/management.py
@@ -7,9 +7,10 @@ from optparse import OptionParser
 from django.utils import termcolors
 import os, re, shutil, sys, textwrap
 
-# For Python 2.3
-if not hasattr(__builtins__, 'set'):
-    from sets import Set as set
+try:
+    set
+except NameError:
+    from sets import Set as set   # Python 2.3 fallback
 
 # For backwards compatibility: get_version() used to be in this module.
 get_version = django.get_version
@@ -58,12 +59,16 @@ def _is_valid_dir_name(s):
 
 def _get_installed_models(table_list):
     "Gets a set of all models that are installed, given a list of existing tables"
-    from django.db import models
+    from django.db import backend, models
     all_models = []
     for app in models.get_apps():
         for model in models.get_models(app):
             all_models.append(model)
-    return set([m for m in all_models if m._meta.db_table in table_list])
+    if backend.uses_case_insensitive_names:
+        converter = str.upper
+    else:
+        converter = lambda x: x
+    return set([m for m in all_models if converter(m._meta.db_table) in map(converter, table_list)])
 
 def _get_table_list():
     "Gets a list of all db tables that are physically installed."
@@ -99,6 +104,7 @@ get_rel_data_type = lambda f: (f.get_internal_type() in ('AutoField', 'PositiveI
 def get_sql_create(app):
     "Returns a list of the CREATE TABLE SQL statements for the given app."
     from django.db import get_creation_module, models
+
     data_types = get_creation_module().DATA_TYPES
 
     if not data_types:
@@ -170,15 +176,20 @@ def _get_sql_model_create(model, known_models=set()):
             rel_field = f
             data_type = f.get_internal_type()
         col_type = data_types[data_type]
+        tablespace = f.db_tablespace or opts.db_tablespace
         if col_type is not None:
             # Make the definition (e.g. 'foo VARCHAR(30)') for this field.
             field_output = [style.SQL_FIELD(backend.quote_name(f.column)),
                 style.SQL_COLTYPE(col_type % rel_field.__dict__)]
             field_output.append(style.SQL_KEYWORD('%sNULL' % (not f.null and 'NOT ' or '')))
-            if f.unique:
+            if f.unique and (not f.primary_key or backend.allows_unique_and_pk):
                 field_output.append(style.SQL_KEYWORD('UNIQUE'))
             if f.primary_key:
                 field_output.append(style.SQL_KEYWORD('PRIMARY KEY'))
+            if tablespace and backend.supports_tablespaces and (f.unique or f.primary_key) and backend.autoindexes_primary_keys:
+                # We must specify the index tablespace inline, because we
+                # won't be generating a CREATE INDEX statement for this field.
+                field_output.append(backend.get_tablespace_sql(tablespace, inline=True))
             if f.rel:
                 if f.rel.to in known_models:
                     field_output.append(style.SQL_KEYWORD('REFERENCES') + ' ' + \
@@ -202,9 +213,19 @@ def _get_sql_model_create(model, known_models=set()):
     full_statement = [style.SQL_KEYWORD('CREATE TABLE') + ' ' + style.SQL_TABLE(backend.quote_name(opts.db_table)) + ' (']
     for i, line in enumerate(table_output): # Combine and add commas.
         full_statement.append('    %s%s' % (line, i < len(table_output)-1 and ',' or ''))
-    full_statement.append(');')
+    full_statement.append(')')
+    if opts.db_tablespace and backend.supports_tablespaces:
+        full_statement.append(backend.get_tablespace_sql(opts.db_tablespace))
+    full_statement.append(';')
     final_output.append('\n'.join(full_statement))
 
+    if opts.has_auto_field and hasattr(backend, 'get_autoinc_sql'):
+        # Add any extra SQL needed to support auto-incrementing primary keys
+        autoinc_sql = backend.get_autoinc_sql(opts.db_table)
+        if autoinc_sql:
+            for stmt in autoinc_sql:
+                final_output.append(stmt)
+
     return final_output, pending_references
 
 def _get_sql_for_pending_references(model, pending_references):
@@ -212,6 +233,7 @@ def _get_sql_for_pending_references(model, pending_references):
     Get any ALTER TABLE statements to add constraints after the fact.
     """
     from django.db import backend, get_creation_module
+    from django.db.backends.util import truncate_name
     data_types = get_creation_module().DATA_TYPES
 
     final_output = []
@@ -228,7 +250,7 @@ def _get_sql_for_pending_references(model, pending_references):
                 # So we are careful with character usage here.
                 r_name = '%s_refs_%s_%x' % (r_col, col, abs(hash((r_table, table))))
                 final_output.append(style.SQL_KEYWORD('ALTER TABLE') + ' %s ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s (%s)%s;' % \
-                    (backend.quote_name(r_table), r_name,
+                    (backend.quote_name(r_table), truncate_name(r_name, backend.get_max_name_length()),
                     backend.quote_name(r_col), backend.quote_name(table), backend.quote_name(col),
                     backend.get_deferrable_sql()))
             del pending_references[model]
@@ -244,12 +266,18 @@ def _get_many_to_many_sql_for_model(model):
     final_output = []
     for f in opts.many_to_many:
         if not isinstance(f.rel, generic.GenericRel):
+            tablespace = f.db_tablespace or opts.db_tablespace
+            if tablespace and backend.supports_tablespaces and backend.autoindexes_primary_keys:
+                tablespace_sql = ' ' + backend.get_tablespace_sql(tablespace, inline=True)
+            else:
+                tablespace_sql = ''
             table_output = [style.SQL_KEYWORD('CREATE TABLE') + ' ' + \
                 style.SQL_TABLE(backend.quote_name(f.m2m_db_table())) + ' (']
-            table_output.append('    %s %s %s,' % \
+            table_output.append('    %s %s %s%s,' % \
                 (style.SQL_FIELD(backend.quote_name('id')),
                 style.SQL_COLTYPE(data_types['AutoField']),
-                style.SQL_KEYWORD('NOT NULL PRIMARY KEY')))
+                style.SQL_KEYWORD('NOT NULL PRIMARY KEY'),
+                tablespace_sql))
             table_output.append('    %s %s %s %s (%s)%s,' % \
                 (style.SQL_FIELD(backend.quote_name(f.m2m_column_name())),
                 style.SQL_COLTYPE(data_types[get_rel_data_type(opts.pk)] % opts.pk.__dict__),
@@ -264,17 +292,30 @@ def _get_many_to_many_sql_for_model(model):
                 style.SQL_TABLE(backend.quote_name(f.rel.to._meta.db_table)),
                 style.SQL_FIELD(backend.quote_name(f.rel.to._meta.pk.column)),
                 backend.get_deferrable_sql()))
-            table_output.append('    %s (%s, %s)' % \
+            table_output.append('    %s (%s, %s)%s' % \
                 (style.SQL_KEYWORD('UNIQUE'),
                 style.SQL_FIELD(backend.quote_name(f.m2m_column_name())),
-                style.SQL_FIELD(backend.quote_name(f.m2m_reverse_name()))))
-            table_output.append(');')
+                style.SQL_FIELD(backend.quote_name(f.m2m_reverse_name())),
+                tablespace_sql))
+            table_output.append(')')
+            if opts.db_tablespace and backend.supports_tablespaces:
+                # f.db_tablespace is only for indices, so ignore its value here.
+                table_output.append(backend.get_tablespace_sql(opts.db_tablespace))
+            table_output.append(';')
             final_output.append('\n'.join(table_output))
+
+            # Add any extra SQL needed to support auto-incrementing PKs
+            autoinc_sql = backend.get_autoinc_sql(f.m2m_db_table())
+            if autoinc_sql:
+                for stmt in autoinc_sql:
+                    final_output.append(stmt)
+
     return final_output
 
 def get_sql_delete(app):
     "Returns a list of the DROP TABLE SQL statements for the given app."
     from django.db import backend, connection, models, get_introspection_module
+    from django.db.backends.util import truncate_name
     introspection = get_introspection_module()
 
     # This should work even if a connection isn't available
@@ -288,6 +329,10 @@ def get_sql_delete(app):
         table_names = introspection.get_table_list(cursor)
     else:
         table_names = []
+    if backend.uses_case_insensitive_names:
+        table_name_converter = str.upper
+    else:
+        table_name_converter = lambda x: x
 
     output = []
 
@@ -297,7 +342,7 @@ def get_sql_delete(app):
     references_to_delete = {}
     app_models = models.get_models(app)
     for model in app_models:
-        if cursor and model._meta.db_table in table_names:
+        if cursor and table_name_converter(model._meta.db_table) in table_names:
             # The table exists, so it needs to be dropped
             opts = model._meta
             for f in opts.fields:
@@ -307,7 +352,7 @@ def get_sql_delete(app):
             to_delete.add(model)
 
     for model in app_models:
-        if cursor and model._meta.db_table in table_names:
+        if cursor and table_name_converter(model._meta.db_table) in table_names:
             # Drop the table now
             output.append('%s %s;' % (style.SQL_KEYWORD('DROP TABLE'),
                 style.SQL_TABLE(backend.quote_name(model._meta.db_table))))
@@ -317,20 +362,26 @@ def get_sql_delete(app):
                     col = f.column
                     r_table = model._meta.db_table
                     r_col = model._meta.get_field(f.rel.field_name).column
+                    r_name = '%s_refs_%s_%x' % (col, r_col, abs(hash((table, r_table))))
                     output.append('%s %s %s %s;' % \
                         (style.SQL_KEYWORD('ALTER TABLE'),
                         style.SQL_TABLE(backend.quote_name(table)),
                         style.SQL_KEYWORD(backend.get_drop_foreignkey_sql()),
-                        style.SQL_FIELD(backend.quote_name('%s_refs_%s_%x' % (col, r_col, abs(hash((table, r_table))))))))
+                        style.SQL_FIELD(truncate_name(r_name, backend.get_max_name_length()))))
                 del references_to_delete[model]
+            if model._meta.has_auto_field and hasattr(backend, 'get_drop_sequence'):
+                output.append(backend.get_drop_sequence(model._meta.db_table))
 
     # Output DROP TABLE statements for many-to-many tables.
     for model in app_models:
         opts = model._meta
         for f in opts.many_to_many:
-            if cursor and f.m2m_db_table() in table_names:
+            if cursor and table_name_converter(f.m2m_db_table()) in table_names:
                 output.append("%s %s;" % (style.SQL_KEYWORD('DROP TABLE'),
                     style.SQL_TABLE(backend.quote_name(f.m2m_db_table()))))
+                if hasattr(backend, 'get_drop_sequence'):
+                    output.append(backend.get_drop_sequence("%s_%s" % (model._meta.db_table, f.column)))
+
 
     app_label = app_models[0]._meta.app_label
 
@@ -429,14 +480,20 @@ def get_sql_indexes_for_model(model):
     output = []
 
     for f in model._meta.fields:
-        if f.db_index:
+        if f.db_index and not ((f.primary_key or f.unique) and backend.autoindexes_primary_keys):
             unique = f.unique and 'UNIQUE ' or ''
+            tablespace = f.db_tablespace or model._meta.db_tablespace
+            if tablespace and backend.supports_tablespaces:
+                tablespace_sql = ' ' + backend.get_tablespace_sql(tablespace)
+            else:
+                tablespace_sql = ''
             output.append(
                 style.SQL_KEYWORD('CREATE %sINDEX' % unique) + ' ' + \
                 style.SQL_TABLE(backend.quote_name('%s_%s' % (model._meta.db_table, f.column))) + ' ' + \
                 style.SQL_KEYWORD('ON') + ' ' + \
                 style.SQL_TABLE(backend.quote_name(model._meta.db_table)) + ' ' + \
-                "(%s);" % style.SQL_FIELD(backend.quote_name(f.column))
+                "(%s)" % style.SQL_FIELD(backend.quote_name(f.column)) + \
+                "%s;" % tablespace_sql
             )
     return output
 
@@ -460,7 +517,7 @@ def _emit_post_sync_signal(created_models, verbosity, interactive):
 
 def syncdb(verbosity=1, interactive=True):
     "Creates the database tables for all apps in INSTALLED_APPS whose tables haven't already been created."
-    from django.db import connection, transaction, models, get_creation_module
+    from django.db import backend, connection, transaction, models, get_creation_module
     from django.conf import settings
 
     disable_termcolors()
@@ -483,6 +540,10 @@ def syncdb(verbosity=1, interactive=True):
     # Get a list of all existing database tables,
     # so we know what needs to be added.
     table_list = _get_table_list()
+    if backend.uses_case_insensitive_names:
+        table_name_converter = str.upper
+    else:
+        table_name_converter = lambda x: x
 
     # Get a list of already installed *models* so that references work right.
     seen_models = _get_installed_models(table_list)
@@ -497,7 +558,7 @@ def syncdb(verbosity=1, interactive=True):
             # Create the model's database table, if it doesn't already exist.
             if verbosity >= 2:
                 print "Processing %s.%s model" % (app_name, model._meta.object_name)
-            if model._meta.db_table in table_list:
+            if table_name_converter(model._meta.db_table) in table_list:
                 continue
             sql, references = _get_sql_model_create(model, seen_models)
             seen_models.add(model)
@@ -509,7 +570,7 @@ def syncdb(verbosity=1, interactive=True):
                 print "Creating table %s" % model._meta.db_table
             for statement in sql:
                 cursor.execute(statement)
-            table_list.append(model._meta.db_table)
+            table_list.append(table_name_converter(model._meta.db_table))
 
     # Create the m2m tables. This must be done after all tables have been created
     # to ensure that all referred tables will exist.
@@ -828,7 +889,7 @@ def inspectdb():
         except NotImplementedError:
             indexes = {}
         for i, row in enumerate(introspection_module.get_table_description(cursor, table_name)):
-            att_name = row[0]
+            att_name = row[0].lower()
             comment_notes = [] # Holds Field notes, to be displayed in a Python comment.
             extra_params = {}  # Holds Field parameters such as 'db_column'.
 
@@ -1324,7 +1385,7 @@ def load_data(fixture_labels, verbosity=1):
     # Keep a count of the installed objects and fixtures
     count = [0,0]
     models = set()
-    
+
     humanize = lambda dirname: dirname and "'%s'" % dirname or 'absolute path'
 
     # Get a cursor (even though we don't need one yet). This has
@@ -1402,7 +1463,7 @@ def load_data(fixture_labels, verbosity=1):
                     if verbosity > 1:
                         print "No %s fixture '%s' in %s." % \
                             (format, fixture_name, humanize(fixture_dir))
-                            
+
     if count[0] > 0:
         sequence_sql = backend.get_sql_sequence_reset(style, models)
         if sequence_sql:
@@ -1410,10 +1471,10 @@ def load_data(fixture_labels, verbosity=1):
                 print "Resetting sequences"
             for line in sequence_sql:
                 cursor.execute(line)
-            
+
     transaction.commit()
     transaction.leave_transaction_management()
-    
+
     if count[0] == 0:
         if verbosity > 0:
             print "No fixtures found."
@@ -1628,7 +1689,9 @@ def execute_from_command_line(action_mapping=DEFAULT_ACTION_MAPPING, argv=None):
         if not mod_list:
             parser.print_usage_and_exit()
         if action not in NO_SQL_TRANSACTION:
-            print style.SQL_KEYWORD("BEGIN;")
+            from django.db import backend
+            if backend.get_start_transaction_sql():
+                print style.SQL_KEYWORD(backend.get_start_transaction_sql())
         for mod in mod_list:
             if action == 'reset':
                 output = action_mapping[action](mod, options.interactive)
diff --git a/django/core/servers/basehttp.py b/django/core/servers/basehttp.py
index 80a0bf6a91..64ed739473 100644
--- a/django/core/servers/basehttp.py
+++ b/django/core/servers/basehttp.py
@@ -9,7 +9,7 @@ been reviewed for security issues. Don't use it for production use.
 
 from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 from types import ListType, StringType
-import os, re, sys, time, urllib
+import os, re, sys, time, urllib, mimetypes
 
 __version__ = "0.1"
 __all__ = ['WSGIServer','WSGIRequestHandler','demo_app']
@@ -630,6 +630,9 @@ class AdminMediaHandler(object):
             else:
                 status = '200 OK'
                 headers = {}
+                mime_type = mimetypes.guess_type(file_path)[0]
+                if mime_type:
+                    headers['Content-Type'] = mime_type
                 output = [fp.read()]
                 fp.close()
         start_response(status, headers.items())
diff --git a/django/core/urlresolvers.py b/django/core/urlresolvers.py
index 38b3263da1..f4c2dc4677 100644
--- a/django/core/urlresolvers.py
+++ b/django/core/urlresolvers.py
@@ -9,8 +9,17 @@ a string) and returns a tuple in this format:
 
 from django.http import Http404
 from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
+from django.utils.functional import memoize
 import re
 
+try:
+    reversed
+except NameError:
+    from django.utils.itercompat import reversed     # Python 2.3 fallback
+
+_resolver_cache = {} # Maps urlconf modules to RegexURLResolver instances.
+_callable_cache = {} # Maps view and url pattern names to their view functions.
+
 class Resolver404(Http404):
     pass
 
@@ -18,6 +27,34 @@ class NoReverseMatch(Exception):
     # Don't make this raise an error when used in a template.
     silent_variable_failure = True
 
+def get_callable(lookup_view, can_fail=False):
+    """
+    Convert a string version of a function name to the callable object.
+
+    If the lookup_view is not an import path, it is assumed to be a URL pattern
+    label and the original string is returned.
+
+    If can_fail is True, lookup_view might be a URL pattern label, so errors
+    during the import fail and the string is returned.
+    """
+    if not callable(lookup_view):
+        mod_name, func_name = get_mod_func(lookup_view)
+        try:
+            if func_name != '':
+                lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
+        except (ImportError, AttributeError):
+            if not can_fail:
+                raise
+    return lookup_view
+get_callable = memoize(get_callable, _callable_cache)
+
+def get_resolver(urlconf):
+    if urlconf is None:
+        from django.conf import settings
+        urlconf = settings.ROOT_URLCONF
+    return RegexURLResolver(r'^/', urlconf)
+get_resolver = memoize(get_resolver, _resolver_cache)
+
 def get_mod_func(callback):
     # Converts 'django.views.news.stories.story_detail' to
     # ['django.views.news.stories', 'story_detail']
@@ -129,12 +166,13 @@ class RegexURLPattern(object):
     def _get_callback(self):
         if self._callback is not None:
             return self._callback
-        mod_name, func_name = get_mod_func(self._callback_str)
         try:
-            self._callback = getattr(__import__(mod_name, {}, {}, ['']), func_name)
+            self._callback = get_callable(self._callback_str)
         except ImportError, e:
+            mod_name, _ = get_mod_func(self._callback_str)
             raise ViewDoesNotExist, "Could not import %s. Error was: %s" % (mod_name, str(e))
         except AttributeError, e:
+            mod_name, func_name = get_mod_func(self._callback_str)
             raise ViewDoesNotExist, "Tried %s in module %s. Error was: %s" % (func_name, mod_name, str(e))
         return self._callback
     callback = property(_get_callback)
@@ -160,6 +198,19 @@ class RegexURLResolver(object):
         self.urlconf_name = urlconf_name
         self.callback = None
         self.default_kwargs = default_kwargs or {}
+        self._reverse_dict = {}
+
+    def _get_reverse_dict(self):
+        if not self._reverse_dict and hasattr(self.urlconf_module, 'urlpatterns'):
+            for pattern in reversed(self.urlconf_module.urlpatterns):
+                if isinstance(pattern, RegexURLResolver):
+                    for key, value in pattern.reverse_dict.iteritems():
+                        self._reverse_dict[key] = (pattern,) + value
+                else:
+                    self._reverse_dict[pattern.callback] = (pattern,)
+                    self._reverse_dict[pattern.name] = (pattern,)
+        return self._reverse_dict
+    reverse_dict = property(_get_reverse_dict)
 
     def resolve(self, path):
         tried = []
@@ -209,24 +260,12 @@ class RegexURLResolver(object):
         return self._resolve_special('500')
 
     def reverse(self, lookup_view, *args, **kwargs):
-        if not callable(lookup_view):
-            mod_name, func_name = get_mod_func(lookup_view)
-            try:
-                lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
-            except (ImportError, AttributeError):
-                if func_name != '':
-                    raise NoReverseMatch
-        for pattern in self.urlconf_module.urlpatterns:
-            if isinstance(pattern, RegexURLResolver):
-                try:
-                    return pattern.reverse_helper(lookup_view, *args, **kwargs)
-                except NoReverseMatch:
-                    continue
-            elif pattern.callback == lookup_view or pattern.name == lookup_view:
-                try:
-                    return pattern.reverse_helper(*args, **kwargs)
-                except NoReverseMatch:
-                    continue
+        try:
+            lookup_view = get_callable(lookup_view, True)
+        except (ImportError, AttributeError):
+            raise NoReverseMatch
+        if lookup_view in self.reverse_dict:
+            return ''.join([reverse_helper(part.regex, *args, **kwargs) for part in self.reverse_dict[lookup_view]])
         raise NoReverseMatch
 
     def reverse_helper(self, lookup_view, *args, **kwargs):
@@ -235,17 +274,10 @@ class RegexURLResolver(object):
         return result + sub_match
 
 def resolve(path, urlconf=None):
-    if urlconf is None:
-        from django.conf import settings
-        urlconf = settings.ROOT_URLCONF
-    resolver = RegexURLResolver(r'^/', urlconf)
-    return resolver.resolve(path)
+    return get_resolver(urlconf).resolve(path)
 
 def reverse(viewname, urlconf=None, args=None, kwargs=None):
     args = args or []
     kwargs = kwargs or {}
-    if urlconf is None:
-        from django.conf import settings
-        urlconf = settings.ROOT_URLCONF
-    resolver = RegexURLResolver(r'^/', urlconf)
-    return '/' + resolver.reverse(viewname, *args, **kwargs)
+    return '/' + get_resolver(urlconf).reverse(viewname, *args, **kwargs)
+