‘Upgrade’ from Python 2.7 to Python 3.7

Python is a non-issue.  But App Engine took the opportunity to change everything.

appengine/.gcloudignore

@@ -0,0 +1,23 @@
+# Do not upload these files.
+.*
+deploy
+*.soy
+static/appengine/
+static/closure/
+static/demos/plane/soy/*.jar
+static/demos/plane/xlf/
+static/externs/
+static/i18n/
+static/msg/json/
+static/node_modules/
+static/package/
+static/theme_scripts/
+static/typings/
+
+static/build.py
+static/gulpfile.js
+static/jsconfig.json
+static/LICENSE
+static/package-lock.json
+static/package.json
+static/README.md

appengine/app.yaml

@@ -1,8 +1,4 @@
-application: blockly-demo
+runtime: python37
-version: 20200123
-runtime: python27
-api_version: 1
-threadsafe: no
 
 handlers:
 # Redirect obsolete URLs.
@@ -19,29 +15,15 @@ handlers:
   static_files: redirect.html
   upload: redirect.html
 
-
-# Storage API.
-- url: /storage
-  script: storage.py
-  secure: always
-- url: /storage\.js
-  static_files: storage.js
-  upload: storage\.js
-  secure: always
-
 # Blockly files.
 - url: /static
   static_dir: static
   secure: always
 
-# Closure library for uncompressed Blockly.
+# Storage API.
-- url: /closure-library
+- url: /storage\.js
-  static_dir: closure-library
+  static_files: storage.js
-  secure: always
+  upload: storage\.js
-
-# Redirect for root directory.
-- url: /
-  script: index_redirect.py
   secure: always
 
 # Favicon.
@@ -64,24 +46,8 @@ handlers:
   upload: robots\.txt
   secure: always
 
-
+# Dynamic content.
-skip_files:
+- url: /.*
-# App Engine default patterns.
+  script: auto
-- ^(.*/)?#.*#$
+  secure: always
-- ^(.*/)?.*~$
+  
-- ^(.*/)?.*\.py[co]$
-- ^(.*/)?.*/RCS/.*$
-- ^(.*/)?\..*$
-# Custom skip patterns.
-- ^static/appengine/.*$
-- ^static/demos/plane/soy/.+\.jar$
-- ^static/demos/plane/template.soy$
-- ^static/demos/plane/xlf/.*$
-- ^static/i18n/.*$
-- ^static/msg/json/.*$
-- ^.+\.soy$
-- ^closure-library/.*_test.html$
-- ^closure-library/.*_test.js$
-- ^closure-library/closure/bin/.*$
-- ^closure-library/doc/.*$
-- ^closure-library/scripts/.*$

appengine/deploy

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+# Script to deploy on GAE.
+
+APP=./app.yaml
+if ! [ -f $APP ] ; then
+   echo $APP not found 1>&2
+   exit 1
+fi
+
+PROJECT=blockly-demo
+VERSION=37
+
+echo 'Beginning deployment...'
+gcloud app deploy --project $PROJECT --version $VERSION --no-promote
+echo 'Deployment finished.'

appengine/index_redirect.py

@@ -1,3 +0,0 @@
-print("Status: 301")
-print("Location: /static/demos/index.html")
-print("")

appengine/main.py

@@ -0,0 +1,43 @@
+"""
+Copyright 2020 Google LLC
+
+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.
+"""
+
+import cgi
+import storage
+from google.cloud import ndb
+
+
+# Datastore model.
+class Grid(ndb.Model):
+  data = ndb.StringProperty(required=True)
+
+
+# Route to requested handler.
+def app(environ, start_response):
+  if environ["PATH_INFO"] == "/":
+    return redirect(environ, start_response)
+  if environ["PATH_INFO"] == "/storage.py":
+    return storage.app(environ, start_response)
+  start_response("404 Not Found", [])
+  return [b"Page not found."]
+
+
+# Redirect for root directory.
+def redirect(environ, start_response):
+  headers = [
+    ("Location", "static/demos/index.html")
+  ]
+  start_response("301 Found", headers)
+  return []

appengine/requirements.txt

@@ -0,0 +1 @@
+google-cloud-ndb

appengine/storage.py

@@ -23,8 +23,7 @@ __author__ = "q.neutron@gmail.com (Quynh Neutron)"
 import cgi
 import hashlib
 from random import randint
-from google.appengine.api import memcache
+from google.cloud import ndb
-from google.appengine.ext import ndb
 
 
 def keyGen():
@@ -41,46 +40,52 @@ class Xml(ndb.Model):
 
 def xmlToKey(xml_content):
   # Store XML and return a generated key.
-  xml_hash = long(hashlib.sha1(xml_content).hexdigest(), 16)
+  xml_hash = int(hashlib.sha1(xml_content.encode("utf-8")).hexdigest(), 16)
   xml_hash = int(xml_hash % (2 ** 64) - (2 ** 63))
   lookup_query = Xml.query(Xml.xml_hash == xml_hash)
-  lookup_result = lookup_query.get()
+  client = ndb.Client()
-  if lookup_result:
+  with client.context():
-    xml_key = lookup_result.key.string_id()
+    lookup_result = lookup_query.get()
-  else:
+    if lookup_result:
-    trials = 0
+      xml_key = lookup_result.key.string_id()
-    result = True
+    else:
-    while result:
+      trials = 0
-      trials += 1
+      result = True
-      if trials == 100:
+      while result:
-        raise Exception("Sorry, the generator failed to get a key for you.")
+        trials += 1
-      xml_key = keyGen()
+        if trials == 100:
-      result = Xml.get_by_id(xml_key)
+          raise Exception("Sorry, the generator failed to get a key for you.")
-    row = Xml(id = xml_key, xml_hash = xml_hash, xml_content = xml_content)
+        xml_key = keyGen()
-    row.put()
+        result = Xml.get_by_id(xml_key)
+      row = Xml(id = xml_key, xml_hash = xml_hash, xml_content = xml_content)
+      row.put()
   return xml_key
 
 def keyToXml(key_provided):
   # Retrieve stored XML based on the provided key.
   # Normalize the string.
   key_provided = key_provided.lower().strip()
-  # Check memcache for a quick match.
+  # Check datastore for a match.
-  xml = memcache.get("XML_" + key_provided)
+  client = ndb.Client()
-  if xml is None:
+  with client.context():
-    # Check datastore for a definitive match.
     result = Xml.get_by_id(key_provided)
-    if not result:
+  if not result:
-      xml = ""
+    xml = ""
-    else:
+  else:
-      xml = result.xml_content
+    xml = result.xml_content
-    # Save to memcache for next hit.
+  return xml
-    memcache.add("XML_" + key_provided, xml, 3600)
-  return xml.encode("utf-8")
 
-if __name__ == "__main__":
+def app(environ, start_response):
-  print("Content-Type: text/plain\n")
+  forms = cgi.FieldStorage(fp=environ['wsgi.input'], environ=environ)
-  forms = cgi.FieldStorage()
   if "xml" in forms:
-    print(xmlToKey(forms["xml"].value))
+    out = xmlToKey(forms["xml"].value)
-  if "key" in forms:
+  elif "key" in forms:
-    print(keyToXml(forms["key"].value))
+    out = keyToXml(forms["key"].value)
+  else:
+    out = ""
+
+  headers = [
+    ("Content-Type", "text/plain")
+  ]
+  start_response("200 OK", headers)
+  return [out.encode("utf-8")]