New initial commit with .svn directories and their contents ignored.

appengine/storage.py

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+"""Blockly Demo: Storage
+
+Copyright 2012 Google Inc.
+http://blockly.googlecode.com/
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+"""Store and retrieve XML with App Engine.
+"""
+
+__author__ = "q.neutron@gmail.com (Quynh Neutron)"
+
+import cgi
+from random import randint
+from google.appengine.ext import db
+from google.appengine.api import memcache
+import logging
+
+print "Content-Type: text/plain\n"
+
+def keyGen():
+  # Generate a random string of length KEY_LEN.
+  KEY_LEN = 6
+  CHARS = "abcdefghijkmnopqrstuvwxyz23456789" # Exclude l, 0, 1.
+  max_index = len(CHARS) - 1
+  return "".join([CHARS[randint(0, max_index)] for x in range(KEY_LEN)])
+
+class Xml(db.Model):
+  # A row in the database.
+  xml_hash = db.IntegerProperty()
+  xml_content = db.TextProperty()
+
+forms = cgi.FieldStorage()
+if "xml" in forms:
+  # Store XML and return a generated key.
+  xml_content = forms["xml"].value
+  xml_hash = hash(xml_content)
+  lookup_query = db.Query(Xml)
+  lookup_query.filter("xml_hash =", xml_hash)
+  lookup_result = lookup_query.get()
+  if lookup_result:
+    xml_key = lookup_result.key().name()
+  else:
+    trials = 0
+    result = True
+    while result:
+      trials += 1
+      if trials == 100:
+        raise Exception("Sorry, the generator failed to get a key for you.")
+      xml_key = keyGen()
+      result = db.get(db.Key.from_path("Xml", xml_key))
+    xml = db.Text(xml_content, encoding="utf_8")
+    row = Xml(key_name = xml_key, xml_hash = xml_hash, xml_content = xml)
+    row.put()
+  print xml_key
+
+if "key" in forms:
+  # Retrieve stored XML based on the provided key.
+  key_provided = forms["key"].value
+  # Normalize the string.
+  key_provided = key_provided.lower().strip()
+  # Check memcache for a quick match.
+  xml = memcache.get("XML_" + key_provided)
+  if xml is None:
+    # Check datastore for a definitive match.
+    result = db.get(db.Key.from_path("Xml", key_provided))
+    if not result:
+      xml = ""
+    else:
+      xml = result.xml_content
+    # Save to memcache for next hit.
+    if not memcache.add("XML_" + key_provided, xml, 3600):
+      logging.error("Memcache set failed.")
+  print xml.encode("utf-8")