From f0e17cff9a96af73591dce8f72dd81fb2a55a1d4 Mon Sep 17 00:00:00 2001
From: Jack Robison <jackrobison@lbry.io>
Date: Sat, 30 Mar 2019 21:08:34 -0400
Subject: [PATCH] support streaming downloads / range requests

---
 lbrynet/extras/daemon/Daemon.py | 55 ++++++++++++++++++++++++++++++++-
 1 file changed, 54 insertions(+), 1 deletion(-)

diff --git a/lbrynet/extras/daemon/Daemon.py b/lbrynet/extras/daemon/Daemon.py
index 22b184b2b..7af1ad21f 100644
--- a/lbrynet/extras/daemon/Daemon.py
+++ b/lbrynet/extras/daemon/Daemon.py
@@ -272,6 +272,8 @@ class Daemon(metaclass=JSONRPCServerType):
         app = web.Application()
         app.router.add_get('/lbryapi', self.handle_old_jsonrpc)
         app.router.add_post('/lbryapi', self.handle_old_jsonrpc)
+        app.router.add_get('/streams', self.handle_streams_index)
+        app.router.add_get('/stream/{sd_hash}', self.handle_stream_range_request)
         app.router.add_post('/', self.handle_old_jsonrpc)
         self.runner = web.AppRunner(app)
 
@@ -452,6 +454,57 @@ class Daemon(metaclass=JSONRPCServerType):
             content_type='application/json'
         )
 
+    async def handle_streams_index(self, request: web.Request):
+        return web.Response(
+            body="<ul>" + "".join([
+                f'<li><a href="/stream/{sd_hash}">lbry://{stream.claim_name}</a></li>'
+                for sd_hash, stream in self.stream_manager.streams.items()
+            ]) + "</ul>",
+            content_type='text/html'
+        )
+
+    async def handle_stream_range_request(self, request: web.Request):
+        sd_hash = request.path.split("/stream/")[1]
+        if sd_hash not in self.stream_manager.streams:
+            return web.HTTPNotFound()
+        stream = self.stream_manager.streams[sd_hash]
+
+        get_range = request.headers.get('range', 'bytes=0-')
+        if '=' in get_range:
+            get_range = get_range.split('=')[1]
+        start, end = get_range.split('-')
+        size = 0
+        await self.stream_manager.start_stream(stream)
+        for blob in stream.descriptor.blobs[:-1]:
+            size += 2097152 - 1 if blob.length == 2097152 else blob.length
+        size -= 15  # last padding is unguessable
+
+        start = int(start)
+        end = int(end) if end else size - 1
+        skip_blobs = start // 2097150
+        skip = skip_blobs * 2097151
+        start = skip
+        final_size = end - start + 1
+
+        headers = {
+            'Accept-Ranges': 'bytes',
+            'Content-Range': f'bytes {start}-{end}/{size}',
+            'Content-Length': str(final_size),
+            'Content-Type': stream.mime_type
+        }
+
+        if stream.delayed_stop:
+            stream.delayed_stop.cancel()
+        response = web.StreamResponse(
+            status=206,
+            headers=headers
+        )
+        await response.prepare(request)
+        async for blob_info, decrypted in stream.aiter_read_stream(skip_blobs):
+            await response.write(decrypted)
+            log.info("sent browser blob %i/%i", blob_info.blob_num + 1, len(stream.descriptor.blobs) - 1)
+        return response
+
     async def _process_rpc_call(self, data):
         args = data.get('params', {})
 
@@ -844,7 +897,7 @@ class Daemon(metaclass=JSONRPCServerType):
         """
         try:
             stream = await self.stream_manager.download_stream_from_uri(
-                uri, self.exchange_rate_manager, file_name, timeout
+                uri, timeout, self.exchange_rate_manager, file_name
             )
             if not stream:
                 raise DownloadSDTimeout(uri)