cache data.js (#153)

* cache data.js

* fix etag check

* use an md5 hash of the data for the etag

main.py

@@ -5,6 +5,7 @@ from admin import *
 from crons import *
 from tests import *
 from tasks import *
+import hashlib
 
 @ndb.toplevel
 @app.route('/comm')
@@ -157,17 +158,37 @@ def serve_codejs():
 	else: request.response.set_data("game_log('load_code: Code not found',colors.code_error)")
 	return request.response
 
+# Cache when data is prepared
+cached_data = None
+cached_data_hash = None
+
 @app.route('/data.js',methods=['GET','POST'])
 @ndb.toplevel
 def serve_datajs():
-	domain=gdi(request); additional=""
+	global cached_data
+	global cached_data_hash
+	
+	init_request(request)
+
+	additional=""
+
+	if request.values.get("reload"):
+		additional="add_log('Game data reloaded','#32A3B0');\napply_backup()\n"
+	elif cached_data_hash != None and request.headers.get('If-None-Match') == cached_data_hash:
+		# The ETag matches
+		request.response.status_code = 304
+		return request.response
+
+	if cached_data == None or cached_data_hash == None:
 		geometry={}
+
 		for name in maps:
 			key=maps[name]["key"]
 			if maps[name].get("ignore"): continue
 			#if name=="test" and not is_sdk: key="test"
 			#logging.info(key)
 			geometry[name]=get_by_iid("map|%s"%key).info.data
+
 		data={
 			"version":game_version,
 			"achievements":achievements,
@@ -202,8 +223,15 @@ def serve_datajs():
 			"docs":docs,
 			"drops":drops,
 		}
-	if request.values.get("reload"): additional="add_log('Game data reloaded','#32A3B0');\napply_backup()\n"
+
-	request.response.set_data("var G=%s;\n%s"%(json.dumps(data),additional))
+		cached_data = json.dumps(data)
+		cached_data_hash = hashlib.md5(cached_data).hexdigest()
+
+	# The browser should cache this
+	request.response.headers['ETag'] = cached_data_hash
+	request.response.headers['Cache-Control'] = "max-age=31536000" # 1 Year
+
+	request.response.set_data("var G=%s;\n%s"%(cached_data,additional))
 	return request.response