Adding jotblk sample.

A web editor that embeds uEforth.

attic/jotblk/main.py

@@ -0,0 +1,81 @@
+# Copyright 2025 Bradley D. Nelson
+#
+# 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 base64
+from flask import Flask, request, send_from_directory
+from google.cloud import datastore
+
+client = datastore.Client()
+
+root_passwd_key = client.key('passwd', 'root')
+root_passwd_entity = client.get(root_passwd_key)
+if root_passwd_entity is None:
+  root_passwd = 'xyzzy'
+else:
+  root_passwd = root_passwd_entity['secret']
+
+def SaveBlock(index, data):
+  assert index >= 0
+  assert len(data) == 1024, len(data)
+  entity = datastore.Entity(key=client.key('block', index+1))
+  entity.update({'data': data})
+  client.put(entity)
+  return ''
+
+def LoadBlocks(start, end):
+  assert end >= end
+  assert start >= 0
+  assert end - start <= 128
+  query = client.query(kind='block')
+  first_key = client.key('block', start+1)
+  last_key = client.key('block', end+1)
+  query.key_filter(first_key, '>=')
+  query.key_filter(last_key, '<')
+  entities = query.fetch()
+  blks = {}
+  for i in entities:
+    blks[i.key.path[0]['id']-1] = i['data']
+  result = []
+  for i in range(start, end+1):
+    if i in blks:
+      result.append(blks[i])
+    else:
+      result.append(b' ' * 1024)
+  return b''.join(result) 
+
+app = Flask(__name__)
+
+@app.route('/<path:filename>')
+def canned(filename):
+  return send_from_directory('static', filename)
+
+@app.route('/')
+def root():
+  return canned('index.html')
+
+@app.route('/io', methods=['POST'])
+def io():
+  if root_passwd != request.form['passwd']:
+    return 'deny', 403
+  if request.form['command'] == 'read':
+    start = int(request.form['start'])
+    end = int(request.form['end'])
+    return LoadBlocks(start, end)
+  elif request.form['command'] == 'write':
+    index = int(request.form['index'])
+    data = request.files['data'].read()
+    return SaveBlock(index, data)
+
+if __name__ == '__main__':
+  app.run(host='127.0.0.1', port=8080, debug=True)