Buffer: send and receive binary data over Channel

(also some minor fixes in channel)

tests/channel.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 import threading
 import RNS
 from RNS.Channel import MessageState, ChannelOutletBase, Channel, MessageBase
+import RNS.Buffer
 from RNS.vendor import umsgpack
 from typing import Callable
 import contextlib
@@ -91,17 +92,20 @@ class ChannelOutletTest(ChannelOutletBase):
         self._rtt = rtt
         self._usable = True
         self.packets = []
+        self.lock = threading.RLock()
         self.packet_callback: Callable[[ChannelOutletBase, bytes], None] | None = None
 
     def send(self, raw: bytes) -> Packet:
-        packet = Packet(raw)
-        packet.send()
-        self.packets.append(packet)
-        return packet
+        with self.lock:
+            packet = Packet(raw)
+            packet.send()
+            self.packets.append(packet)
+            return packet
 
     def resend(self, packet: Packet) -> Packet:
-        packet.send()
-        return packet
+        with self.lock:
+            packet.send()
+            return packet
 
     @property
     def mdu(self):
@@ -370,6 +374,105 @@ class TestChannel(unittest.TestCase):
 
         self.eat_own_dog_food(message, check)
 
+    def test_buffer_small_bidirectional(self):
+        data = "Hello\n"
+        with RNS.Buffer.create_bidirectional_buffer(0, 0, self.h.channel) as buffer:
+            count = buffer.write(data.encode("utf-8"))
+            buffer.flush()
+
+            self.assertEqual(len(data), count)
+            self.assertEqual(1, len(self.h.outlet.packets))
+
+            packet = self.h.outlet.packets[0]
+            self.h.channel._receive(packet.raw)
+            result = buffer.readline()
+
+            self.assertIsNotNone(result)
+            self.assertEqual(len(result), len(data))
+
+            decoded = result.decode("utf-8")
+
+            self.assertEqual(data, decoded)
+
+    def test_buffer_big(self):
+        writer = RNS.Buffer.create_writer(15, self.h.channel)
+        reader = RNS.Buffer.create_reader(15, self.h.channel)
+        data = "01234556789"*1024  # 10 KB
+        count = 0
+        write_finished = False
+
+        def write_thread():
+            nonlocal count, write_finished
+            count = writer.write(data.encode("utf-8"))
+            writer.flush()
+            writer.close()
+            write_finished = True
+        threading.Thread(target=write_thread, name="Write Thread", daemon=True).start()
+
+        while not write_finished or next(filter(lambda x: x.state != MessageState.MSGSTATE_DELIVERED,
+                                                self.h.outlet.packets), None) is not None:
+            with self.h.outlet.lock:
+                for packet in self.h.outlet.packets:
+                    if packet.state != MessageState.MSGSTATE_DELIVERED:
+                        self.h.channel._receive(packet.raw)
+                        packet.delivered()
+            time.sleep(0.0001)
+
+        self.assertEqual(len(data), count)
+
+        read_finished = False
+        result = bytes()
+
+        def read_thread():
+            nonlocal read_finished, result
+            result = reader.read()
+            read_finished = True
+        threading.Thread(target=read_thread, name="Read Thread", daemon=True).start()
+
+        timeout_at = time.time() + 7
+        while not read_finished and time.time() < timeout_at:
+            time.sleep(0.001)
+
+        self.assertTrue(read_finished)
+        self.assertEqual(len(data), len(result))
+
+        decoded = result.decode("utf-8")
+
+        self.assertSequenceEqual(data, decoded)
+
+    def test_buffer_small_with_callback(self):
+        callbacks = 0
+        last_cb_value = None
+
+        def callback(ready: int):
+            nonlocal callbacks, last_cb_value
+            callbacks += 1
+            last_cb_value = ready
+
+        data = "Hello\n"
+        with RNS.RawChannelWriter(0, self.h.channel) as writer, RNS.RawChannelReader(0, self.h.channel) as reader:
+            reader.add_ready_callback(callback)
+            count = writer.write(data.encode("utf-8"))
+            writer.flush()
+
+            self.assertEqual(len(data), count)
+            self.assertEqual(1, len(self.h.outlet.packets))
+
+            packet = self.h.outlet.packets[0]
+            self.h.channel._receive(packet.raw)
+
+            self.assertEqual(1, callbacks)
+            self.assertEqual(len(data), last_cb_value)
+
+            result = reader.readline()
+
+            self.assertIsNotNone(result)
+            self.assertEqual(len(result), len(data))
+
+            decoded = result.decode("utf-8")
+
+            self.assertEqual(data, decoded)
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)

tests/link.py

@@ -396,6 +396,48 @@ class TestLink(unittest.TestCase):
         self.assertEqual(l1.status, RNS.Link.CLOSED)
         self.assertEqual(0, len(l1._channel._rx_ring))
 
+    def test_11_buffer_round_trip(self):
+        global c_rns
+        init_rns(self)
+        print("")
+        print("Buffer round trip test")
+
+        # TODO: Load this from public bytes only
+        id1 = RNS.Identity.from_bytes(bytes.fromhex(fixed_keys[0][0]))
+        self.assertEqual(id1.hash, bytes.fromhex(fixed_keys[0][1]))
+
+        dest = RNS.Destination(id1, RNS.Destination.OUT, RNS.Destination.SINGLE, APP_NAME, "link", "establish")
+
+        self.assertEqual(dest.hash, bytes.fromhex("fb48da0e82e6e01ba0c014513f74540d"))
+
+        l1 = RNS.Link(dest)
+        time.sleep(1)
+        self.assertEqual(l1.status, RNS.Link.ACTIVE)
+        buffer = None
+
+        received = []
+        def handle_data(ready_bytes: int):
+            data = buffer.read(ready_bytes)
+            received.append(data)
+
+        channel = l1.get_channel()
+        buffer = RNS.Buffer.create_bidirectional_buffer(0, 0, channel, handle_data)
+
+        buffer.write("Hi there".encode("utf-8"))
+        buffer.flush()
+
+        time.sleep(0.5)
+
+        self.assertEqual(1 , len(received))
+
+        rx_message = received[0].decode("utf-8")
+
+        self.assertEqual("Hi there back at you", rx_message)
+
+        l1.teardown()
+        time.sleep(0.5)
+        self.assertEqual(l1.status, RNS.Link.CLOSED)
+
 
     def size_str(self, num, suffix='B'):
         units = ['','K','M','G','T','P','E','Z']
@@ -462,6 +504,15 @@ def targets(yp=False):
         channel.register_message_type(MessageTest)
         channel.add_message_handler(handle_message)
 
+        buffer = None
+
+        def handle_buffer(ready_bytes: int):
+            data = buffer.read(ready_bytes)
+            buffer.write((data.decode("utf-8") + " back at you").encode("utf-8"))
+            buffer.flush()
+
+        buffer = RNS.Buffer.create_bidirectional_buffer(0, 0, channel, handle_buffer)
+
     m_rns = RNS.Reticulum("./tests/rnsconfig")
     id1 = RNS.Identity.from_bytes(bytes.fromhex(fixed_keys[0][0]))
     d1 = RNS.Destination(id1, RNS.Destination.IN, RNS.Destination.SINGLE, APP_NAME, "link", "establish")