Server push: Download segments while client requests for manifest. Ad…

…apt playback and decode according to it as well

- TODO: Currently, server sends a fake request to itself to announce server push. We need to the create and capture the response for that fake request and retrieve the data in the client. While right now, the server tells the client to blindly believe that the server pushed data is readily available for the client in cache or other location

clients/dash_client.py

@@ -137,7 +137,7 @@ async def fetchNextSegment(self, segment_list, bitrate = 0):
 
 		for fname in sorted(glob(segment_list)):
 			_, self.segment_baseName = fname.rsplit('/', 1)
-			self.args.urls[0] = self.baseUrl + '/' + str(os.stat(fname).st_size)
+			self.args.urls[0] = self.baseUrl.rstrip('manifest') + str(os.stat(fname).st_size)
 			start = time.time()
 
 			res = await perform_http_request(client=self.protocol,
@@ -179,10 +179,12 @@ async def fetchNextSegment(self, segment_list, bitrate = 0):
 	async def download_segment(self) -> None:
 		if config.NUM_SERVER_PUSHED_FRAMES is not None:
 			self.currentSegment = config.NUM_SERVER_PUSHED_FRAMES + 1
+			for i in range(1, config.NUM_SERVER_PUSHED_FRAMES + 1):
+				await self.segmentQueue.put("Frame-pushed-" + str(i) + ".ppm")
 		else:
 			self.currentSegment += 1
 
-		while self.currentSegment < self.totalSegments:
+		while self.currentSegment <= self.totalSegments:
 			async with self.lock:
 				currBuff = self.currBuffer
 

config.py

@@ -1,7 +1,7 @@
 # Can provide a list of manifest to download via HTTP/3
 URLS = ['https://localhost:4433/']
 
-NUM_SERVER_PUSHED_FRAMES = 10
+NUM_SERVER_PUSHED_FRAMES = 3
 
 MANIFEST_FILE = "/home/aniketh/devel/src/abr-over-quic/htdocs/bbb_m.json"
 CA_CERTS = "tests/pycacert.pem"

demo.py

@@ -4,24 +4,27 @@
 
 import datetime
 import os
+import json
 from urllib.parse import urlencode
 
 import httpbin
 from asgiref.wsgi import WsgiToAsgi
 from starlette.applications import Starlette
-from starlette.responses import PlainTextResponse, Response
+from starlette.responses import PlainTextResponse, Response, JSONResponse
 from starlette.staticfiles import StaticFiles
 from starlette.templating import Jinja2Templates
 from starlette.websockets import WebSocketDisconnect
 
+import config
+
 ROOT = os.path.dirname(__file__)
 STATIC_ROOT = os.environ.get("STATIC_ROOT", os.path.join(ROOT, "htdocs"))
 STATIC_URL = "/"
 LOGS_PATH = os.path.join(STATIC_ROOT, "logs")
 QVIS_URL = "https://qvis.edm.uhasselt.be/"
 
 templates = Jinja2Templates(directory=os.path.join(STATIC_ROOT, "templates"))
-app = Starlette()
+app = Starlette(debug=True)
 
 
 @app.route("/")
@@ -32,6 +35,21 @@ async def homepage(request):
     await request.send_push_promise("/style.css")
     return templates.TemplateResponse("index.html", {"request": request})
 
+@app.route("/manifest/{filename:str}")
+async def manifest(request):
+    server_pushed = 0
+
+    filename = request.path_params['filename']
+    manifest = json.load(open(STATIC_ROOT + "/" + filename))
+    segment = manifest['segment_size_bytes'][0][2]
+
+    if config.NUM_SERVER_PUSHED_FRAMES is not None:
+        while server_pushed < config.NUM_SERVER_PUSHED_FRAMES:
+            await request.send_push_promise(str(segment))
+            server_pushed += 1
+
+    return JSONResponse(manifest)
+
 
 @app.route("/echo", methods=["POST"])
 async def echo(request):