From 40dba845fd91d5e477f8bb3177aa7e4c27bd6575 Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Thu, 26 Mar 2020 12:32:01 +0100
Subject: [PATCH] Working on server

---
 src/server.py | 82 +++++++++++++++++++++++++++++++++++----------------
 1 file changed, 57 insertions(+), 25 deletions(-)

diff --git a/src/server.py b/src/server.py
index feb3810..1b12282 100644
--- a/src/server.py
+++ b/src/server.py
@@ -1,27 +1,32 @@
 import asyncio
+import collections
 import logging
+import signal
 
 
 class Server:
-    def __init__(self, host='localhost', input_port=None, output_port=None):
+    def __init__(self, host='localhost', input_port=3001, output_port=3002,
+                 buffer_chunk_size=10**4, buffer_length_limit=10**4):
         self._host = host
         self._input_port = input_port
         self._output_port = output_port
         self._reader = None
         self._writer = None
         self._stopping = False
-        self.buffer = []  # Shared list
+        self.buffer = collections.deque()  # Shared queue of bytes
+        self._buffer_chunk_size = buffer_chunk_size   # How many bytes per chunk
+        self._buffer_length_limit = buffer_length_limit  # How many chunks in buffer
 
     @property
-    def host(self):
+    def host(self) -> str:
         return self._host
 
     @property
-    def input_port(self):
+    def input_port(self) -> int:
         return self._input_port
 
     @property
-    def output_port(self):
+    def output_port(self) -> int:
         return self._output_port
 
     @property
@@ -29,45 +34,72 @@ class Server:
         return self._reader
 
     @property
-    def writer(self) -> asyncio.StreamReader:
+    def writer(self) -> asyncio.StreamWriter:
         return self._writer
 
     @property
     def stopping(self) -> bool:
         return self._stopping
 
-    async def setup_reader(self):
-        reader, _ = await asyncio.open_connection(self.host, self.input_port)
-        self._reader = reader
+    @property
+    def buffer_length_limit(self) -> int:
+        return self._buffer_length_limit
 
-    async def setup_writer(self):
-        _, writer = await asyncio.open_connection(self.host, self.output_port)
-        self._writer = writer
+    @property
+    def buffer_chunk_size(self) -> int:
+        return self._buffer_chunk_size
 
     async def run_server(self):
-        await self.setup_reader()
+        logging.info("===== Started server...")
+        await asyncio.gather(
+            self.run_reader(),
+            self.run_writer()
+        )
+        logging.info("... stopped server. =====")
+        return
+
+    async def run_reader(self):
+        reader, _ = await asyncio.open_connection(self.host, self.input_port)
+        self._reader = reader
         while not self.stopping:
             try:
-                while len(self.buffer) >= 10**4:
+                # Stop if buffer is full
+                while len(self.buffer) >= self.buffer_length_limit:
                     await asyncio.sleep(1)
+                    continue
                 try:
-                    input_data = await self.reader.readexactly(10**4)
+                    input_data = await self.reader.readexactly(self.buffer_chunk_size)
                 except asyncio.IncompleteReadError as e:
                     input_data = e.partial
                 self.buffer.append(input_data)
             except Exception as e:
                 logging.error(e)
 
+    async def run_writer(self):
+        _, writer = await asyncio.open_connection(self.host, self.output_port)
+        self._writer = writer
+        while not self.stopping:
+            try:
+                # Slow down if buffer is short
+                if len(self.buffer) < 3:
+                    await asyncio.sleep(.1)
+                try:
+                    input_data = self.buffer.popleft()
+                except IndexError:
+                    continue
+                self.writer.write(input_data)
+            except Exception as e:
+                logging.error(e)
+
+    def stop(self):
+        self._stopping = True
+
 
 if __name__ == '__main__':
     loop = asyncio.get_event_loop()
-    try:
-        logging.info("Starting file bridging server...")
-        # loop.run_until_complete(
-        #     asyncio.gather(
-        #         read_input_socket,
-        #         write_on_output_socket
-        #     )
-        # )
-    except KeyboardInterrupt():
-        logging.info("Received KeyboardInterrupt, stopping...")
+    server = Server()
+    loop.add_signal_handler(signal.SIGINT, server.stop, loop)
+    logging.info("Starting file bridging server...")
+    loop.run_until_complete(server.run_server())
+    logging.info("Received KeyboardInterrupt, stopping...")
+    loop.close()