Merge pull request #389 from jumpstarter-dev/pyserial

Implement async pyserial driver

Author: mangelajo

packages/jumpstarter-driver-pyserial/jumpstarter_driver_pyserial/driver.py

@@ -1,29 +1,37 @@
 from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
 
+from anyio import (
+    create_memory_object_stream,
+)
+from anyio._backends._asyncio import StreamReaderWrapper, StreamWriterWrapper
 from anyio.abc import ObjectStream
-from anyio.to_thread import run_sync
-from serial import Serial, serial_for_url
+from anyio.streams.stapled import StapledObjectStream
+from serial import serial_for_url
+from serial_asyncio import open_serial_connection
 
 from jumpstarter.driver import Driver, exportstream
 
+LOOP = "loop://"
+
 
 @dataclass(kw_only=True)
 class AsyncSerial(ObjectStream):
-    device: Serial
+    reader: StreamReaderWrapper
+    writer: StreamWriterWrapper
 
     async def send(self, item):
-        await run_sync(self.device.write, item)
+        await self.writer.send(item)
 
     async def receive(self):
-        size = max(self.device.in_waiting, 1)
-        return await run_sync(self.device.read, size)
+        return await self.reader.receive()
 
     async def send_eof(self):
-        await run_sync(self.device.close)
+        pass
 
     async def aclose(self):
-        await run_sync(self.device.close)
+        await self.writer.aclose()
+        await self.reader.aclose()
 
 
 @dataclass(kw_only=True)
@@ -35,7 +43,7 @@ class PySerial(Driver):
     def __post_init__(self):
         if hasattr(super(), "__post_init__"):
             super().__post_init__()
-        if self.check_present:
+        if self.check_present and self.url != LOOP:
             serial_for_url(self.url, baudrate=self.baudrate)
 
     @classmethod
@@ -46,7 +54,16 @@ def client(cls) -> str:
     @asynccontextmanager
     async def connect(self):
         self.logger.info("Connecting to %s, baudrate: %d", self.url, self.baudrate)
-        device = await run_sync(serial_for_url, self.url, self.baudrate)
-        async with AsyncSerial(device=device) as stream:
-            yield stream
-        self.logger.info("Disconnected from %s", self.url)
+        if self.url != LOOP:
+            reader, writer = await open_serial_connection(url=self.url, baudrate=self.baudrate, limit=1)
+            writer.transport.set_write_buffer_limits(high=4096, low=0)
+            async with AsyncSerial(
+                reader=StreamReaderWrapper(reader),
+                writer=StreamWriterWrapper(writer),
+            ) as stream:
+                yield stream
+            self.logger.info("Disconnected from %s", self.url)
+        else:
+            tx, rx = create_memory_object_stream[bytes](32)
+            async with StapledObjectStream(tx, rx) as stream:
+                yield stream

packages/jumpstarter-driver-pyserial/pyproject.toml

@@ -13,7 +13,8 @@ dependencies = [
     "jumpstarter",
     "jumpstarter-driver-network",
     "pyserial>=3.5",
-    "asyncclick>=8.1.7.2"
+    "asyncclick>=8.1.7.2",
+    "pyserial-asyncio>=0.6",
 ]
 
 [dependency-groups]