poc blsi with hapic

poc.py

 import aiohttp
 import json
 from aiohttp import web
+import marshmallow
+from hapic import async as hapic
+from hapic.ext.aiohttp.context import AiohttpContext
 
 
-async def uptime_handler(request):
-    resp = web.StreamResponse(
-        status=200,
-        reason='OK',
-        headers={
-            'Content-Type': 'text/csv',
-            'Content-Disposition': 'attachment; filename="filename.csv"',
-        }
-    )
-    await resp.prepare(request)
+class UptimeHandlerStreamItem(marshmallow.Schema):
+    datetime = marshmallow.fields.String(required=True)
+    a_bool = marshmallow.fields.Boolean(required=True)
+    a_float = marshmallow.fields.Number(required=True)
+    an_int = marshmallow.fields.Integer(required=True)
+    text = marshmallow.fields.String(required=True)
+    server = marshmallow.fields.String(required=True)
+    zone = marshmallow.fields.String(required=True)
+
+
+class LineModel(object):
+    def __init__(
+        self,
+        *column_values
+    ):
+        self.datetime = column_values[0]
+        self.a_bool = column_values[1]
+        self.a_float = column_values[2]
+        self.an_int = column_values[3]
+        self.text = column_values[4]
+        self.server = column_values[5]
+        self.zone = column_values[6]
+
+
+class AsyncGenerator:
+    def __init__(self, session):
+        self._session = session
+        self._url = 'http://localhost:8086/query?chunk_size=1000&chunked=true'\
+                    '&db=resourceAux' \
+                    '&q=SELECT+%2A+FROM+resource_aux'
+        self._buffer = []
+        self._buffer_iter = iter(self._buffer)
+
+    async def __aiter__(self):
+        response = await self._session.get(self._url)
+        self._stream_reader = response.content
+        return self
+
+    async def __anext__(self):
+        try:
+            try:
+                # First, send next item
+                return next(self._buffer_iter)
+            # If no more item in buffer, or not started
+            except StopIteration:
+                # Read from incoming data
+                line = await self._stream_reader.readline()
+                # If end of received lines
+                if not line:
+                    # Break the iteration
+                    raise StopAsyncIteration()
 
+            # load values from received package of incomming data
+            data = json.loads(line.decode('utf-8'))
+            values = data['results'][0]['series'][0]['values']
+
+            # Prepare new buffer
+            self._buffer = [LineModel(*value) for value in values]
+            self._buffer_iter = iter(self._buffer)
+
+            # Send an item
+            return next(self._buffer_iter)
+
+        except StopAsyncIteration:
+            await self._session.close()
+            raise
+
+
+@hapic.with_api_doc()
+@hapic.output_stream(item_schema=UptimeHandlerStreamItem())
+async def uptime_handler(request):
     try:
-        async with aiohttp.ClientSession(loop=loop) as session:
-            url = 'http://localhost:8086/query?chunk_size=1000&chunked=true&db=resourceAux&q=SELECT+%2A+FROM+resource_aux'  # nopep8
-            async with session.get(url) as response:
-                async for chunk in response.content:
-                    bytes_to_str = chunk.decode('utf-8')
-                    result = json.loads(bytes_to_str)['results'][0]['series'][0]['values']  # nopep8
-                    for r in result:
-                        await resp.write(str.encode(str(r)+'\n'))
+        # NOTE: This session is currently closed in AsyncGenerator code
+        # it should be made otherwise in real code
+        session = aiohttp.ClientSession(loop=loop)
+        return AsyncGenerator(session)
 
     except Exception as e:
         # So you can observe on disconnects and such.
         print(repr(e))
         raise
 
-    return resp
-
 
 async def build_server(loop, address, port):
     app = web.Application(loop=loop)
     app.router.add_route('GET', "/uptime", uptime_handler)
+    hapic.set_context(AiohttpContext(app))
 
     return await loop.create_server(app.make_handler(), address, port)