Added boto/ to depot_tools/third_party

third_party/boto/gs/cors.py

+# Copyright 2012 Google Inc.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish, dis-
+# tribute, sublicense, and/or sell copies of the Software, and to permit
+# persons to whom the Software is furnished to do so, subject to the fol-
+# lowing conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
+# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+import types
+from boto.gs.user import User
+from boto.exception import InvalidCorsError
+from xml.sax import handler
+
+# Relevant tags for the CORS XML document.
+CORS_CONFIG = 'CorsConfig'
+CORS        = 'Cors'
+ORIGINS     = 'Origins'
+ORIGIN      = 'Origin'
+METHODS     = 'Methods'
+METHOD      = 'Method'
+HEADERS     = 'ResponseHeaders'
+HEADER      = 'ResponseHeader'
+MAXAGESEC   = 'MaxAgeSec'
+
+class Cors(handler.ContentHandler):
+    """Encapsulates the CORS configuration XML document"""
+    def __init__(self):
+        # List of CORS elements found within a CorsConfig element.
+        self.cors = []
+        # List of collections (e.g. Methods, ResponseHeaders, Origins)
+        # found within a CORS element. We use a list of lists here
+        # instead of a dictionary because the collections need to be
+        # preserved in the order in which they appear in the input XML
+        # document (and Python dictionary keys are inherently unordered).
+        # The elements on this list are two element tuples of the form
+        # (collection name, [list of collection contents]).
+        self.collections = []
+        # Lists of elements within a collection. Again a list is needed to
+        # preserve ordering but also because the same element may appear
+        # multiple times within a collection.
+        self.elements = []
+        # Dictionary mapping supported collection names to element types
+        # which may be contained within each.
+        self.legal_collections = {
+            ORIGINS : [ORIGIN],
+            METHODS : [METHOD],
+            HEADERS : [HEADER],
+            MAXAGESEC: []
+        }
+        # List of supported element types within any collection, used for
+        # checking validadity of a parsed element name.
+        self.legal_elements = [ORIGIN, METHOD, HEADER]
+
+        self.parse_level = 0
+        self.collection = None
+        self.element = None
+
+    def validateParseLevel(self, tag, level):
+        """Verify parse level for a given tag."""
+        if self.parse_level != level:
+            raise InvalidCorsError('Invalid tag %s at parse level %d: ' %
+                                   (tag, self.parse_level))
+
+    def startElement(self, name, attrs, connection):
+        """SAX XML logic for parsing new element found."""
+        if name == CORS_CONFIG:
+            self.validateParseLevel(name, 0)
+            self.parse_level += 1;
+        elif name == CORS:
+            self.validateParseLevel(name, 1)
+            self.parse_level += 1;
+        elif name in self.legal_collections:
+            self.validateParseLevel(name, 2)
+            self.parse_level += 1;
+            self.collection = name
+        elif name in self.legal_elements:
+            self.validateParseLevel(name, 3)
+            # Make sure this tag is found inside a collection tag.
+            if self.collection is None:
+                raise InvalidCorsError('Tag %s found outside collection' % name)
+            # Make sure this tag is allowed for the current collection tag.
+            if name not in self.legal_collections[self.collection]:
+                raise InvalidCorsError('Tag %s not allowed in %s collection' %
+                                       (name, self.collection))
+            self.element = name
+        else:
+            raise InvalidCorsError('Unsupported tag ' + name)
+
+    def endElement(self, name, value, connection):
+        """SAX XML logic for parsing new element found."""
+        if name == CORS_CONFIG:
+            self.validateParseLevel(name, 1)
+            self.parse_level -= 1;
+        elif name == CORS:
+            self.validateParseLevel(name, 2)
+            self.parse_level -= 1;
+            # Terminating a CORS element, save any collections we found
+            # and re-initialize collections list.
+            self.cors.append(self.collections)
+            self.collections = []
+        elif name in self.legal_collections:
+            self.validateParseLevel(name, 3)
+            if name != self.collection:
+              raise InvalidCorsError('Mismatched start and end tags (%s/%s)' %
+                                     (self.collection, name))
+            self.parse_level -= 1;
+            if not self.legal_collections[name]:
+              # If this collection doesn't contain any sub-elements, store
+              # a tuple of name and this tag's element value.
+              self.collections.append((name, value.strip()))
+            else:
+              # Otherwise, we're terminating a collection of sub-elements,
+              # so store a tuple of name and list of contained elements.
+              self.collections.append((name, self.elements))
+            self.elements = []
+            self.collection = None
+        elif name in self.legal_elements:
+            self.validateParseLevel(name, 3)
+            # Make sure this tag is found inside a collection tag.
+            if self.collection is None:
+                raise InvalidCorsError('Tag %s found outside collection' % name)
+            # Make sure this end tag is allowed for the current collection tag.
+            if name not in self.legal_collections[self.collection]:
+                raise InvalidCorsError('Tag %s not allowed in %s collection' %
+                                       (name, self.collection))
+            if name != self.element:
+              raise InvalidCorsError('Mismatched start and end tags (%s/%s)' %
+                                     (self.element, name))
+            # Terminating an element tag, add it to the list of elements
+            # for the current collection.
+            self.elements.append((name, value.strip()))
+            self.element = None
+        else:
+            raise InvalidCorsError('Unsupported end tag ' + name)
+
+    def to_xml(self):
+        """Convert CORS object into XML string representation."""
+        s = '<' + CORS_CONFIG + '>'
+        for collections in self.cors:
+          s += '<' + CORS + '>'
+          for (collection, elements_or_value) in collections:
+            assert collection is not None
+            s += '<' + collection + '>'
+            # If collection elements has type string, append atomic value,
+            # otherwise, append sequence of values in named tags.
+            if isinstance(elements_or_value, types.StringTypes):
+              s += elements_or_value
+            else:
+              for (name, value) in elements_or_value:
+                assert name is not None
+                assert value is not None
+                s += '<' + name + '>' + value + '</' + name + '>'
+            s += '</' + collection + '>'
+          s += '</' + CORS + '>'
+        s += '</' + CORS_CONFIG + '>'
+        return s