Support stdin in server-side execution

Author: davidbrochart

plugins/kernels/fps_kernels/kernel_driver/driver.py

@@ -2,9 +2,10 @@
 import os
 import time
 import uuid
+from functools import partial
 from typing import Any, Dict, List, Optional, cast
 
-from pycrdt import Array, Map
+from pycrdt import Array, Map, Text
 
 from jupyverse_api.yjs import Yjs
 
@@ -46,6 +47,7 @@ def __init__(
         self.execute_requests: Dict[str, Dict[str, asyncio.Queue]] = {}
         self.comm_messages: asyncio.Queue = asyncio.Queue()
         self.tasks: List[asyncio.Task] = []
+        self._background_tasks: set[asyncio.Task] = set()
 
     async def restart(self, startup_timeout: float = float("inf")) -> None:
         for task in self.tasks:
@@ -80,13 +82,23 @@ async def connect(self, startup_timeout: float = float("inf")) -> None:
 
     def connect_channels(self, connection_cfg: Optional[cfg_t] = None):
         connection_cfg = connection_cfg or self.connection_cfg
-        self.shell_channel = connect_channel("shell", connection_cfg)
+        self.shell_channel = connect_channel(
+            "shell",
+            connection_cfg,
+            identity=self.session_id.encode(),
+        )
         self.control_channel = connect_channel("control", connection_cfg)
         self.iopub_channel = connect_channel("iopub", connection_cfg)
+        self.stdin_channel = connect_channel(
+            "stdin",
+            connection_cfg,
+            identity=self.session_id.encode(),
+        )
 
     def listen_channels(self):
         self.tasks.append(asyncio.create_task(self.listen_iopub()))
         self.tasks.append(asyncio.create_task(self.listen_shell()))
+        self.tasks.append(asyncio.create_task(self.listen_stdin()))
 
     async def stop(self) -> None:
         self.kernel_process.kill()
@@ -111,6 +123,13 @@ async def listen_shell(self):
             if msg_id in self.execute_requests.keys():
                 self.execute_requests[msg_id]["shell_msg"].put_nowait(msg)
 
+    async def listen_stdin(self):
+        while True:
+            msg = await receive_message(self.stdin_channel, change_str_to_date=True)
+            msg_id = msg["parent_header"].get("msg_id")
+            if msg_id in self.execute_requests.keys():
+               self.execute_requests[msg_id]["stdin_msg"].put_nowait(msg)
+
     async def execute(
         self,
         ycell: Map,
@@ -121,7 +140,7 @@ async def execute(
         if ycell["cell_type"] != "code":
             return
         ycell["execution_state"] = "busy"
-        content = {"code": str(ycell["source"]), "silent": False}
+        content = {"code": str(ycell["source"]), "silent": False, "allow_stdin": True}
         msg = create_message(
             "execute_request", content, session_id=self.session_id, msg_id=str(self.msg_cnt)
         )
@@ -134,6 +153,7 @@ async def execute(
         self.execute_requests[msg_id] = {
             "iopub_msg": asyncio.Queue(),
             "shell_msg": asyncio.Queue(),
+            "stdin_msg": asyncio.Queue(),
         }
         if wait_for_executed:
             deadline = time.time() + timeout
@@ -165,21 +185,73 @@ async def execute(
                 ycell["execution_state"] = "idle"
             del self.execute_requests[msg_id]
         else:
-            self.tasks.append(asyncio.create_task(self._handle_iopub(msg_id, ycell)))
+            stdin_task = asyncio.create_task(self._handle_stdin(msg_id, ycell))
+            self.tasks.append(stdin_task)
+            self.tasks.append(asyncio.create_task(self._handle_iopub(msg_id, ycell, stdin_task)))
 
-    async def _handle_iopub(self, msg_id: str, ycell: Map) -> None:
+    async def _handle_iopub(self, msg_id: str, ycell: Map, stdin_task: asyncio.Task) -> None:
         while True:
             msg = await self.execute_requests[msg_id]["iopub_msg"].get()
             await self._handle_outputs(ycell["outputs"], msg)
             if (
                 (msg["header"]["msg_type"] == "status"
                 and msg["content"]["execution_state"] == "idle")
             ):
+                stdin_task.cancel()
                 msg = await self.execute_requests[msg_id]["shell_msg"].get()
                 with ycell.doc.transaction():
                     ycell["execution_count"] = msg["content"]["execution_count"]
                     ycell["execution_state"] = "idle"
 
+    async def _handle_stdin(self, msg_id: str, ycell: Map) -> None:
+        while True:
+            msg = await self.execute_requests[msg_id]["stdin_msg"].get()
+            if msg["msg_type"] == "input_request":
+                content = msg["content"]
+                prompt = content["prompt"]
+                password = content["password"]
+                stdin_output = Map(
+                    {
+                        "output_type": "stdin",
+                        "submitted": False,
+                        "password": password,
+                        "prompt": prompt,
+                        "value": Text(),
+                    }
+                )
+                outputs = ycell.get("outputs")
+                stdin_idx = len(outputs)
+                outputs.append(stdin_output)
+                stdin_output.observe(partial(self._handle_stdin_submission, outputs, stdin_idx, password, prompt))
+
+    def _handle_stdin_submission(self, outputs, stdin_idx, password, prompt, event):
+        if event.target["submitted"]:
+            # send input reply to kernel
+            value = str(event.target["value"])
+            content = {"value": value}
+            msg = create_message(
+                "input_reply", content, session_id=self.session_id, msg_id=str(self.msg_cnt)
+            )
+            task0 = asyncio.create_task(
+                    send_message(msg, self.stdin_channel, self.key, change_date_to_str=True)
+            )
+            if password:
+                value = "········"
+            value = f"{prompt} {value}"
+            task1 = asyncio.create_task(self._change_stdin_to_stream(outputs, stdin_idx, value))
+            self._background_tasks.add(task0)
+            self._background_tasks.add(task1)
+            task0.add_done_callback(self._background_tasks.discard)
+            task1.add_done_callback(self._background_tasks.discard)
+
+    async def _change_stdin_to_stream(self, outputs, stdin_idx, value):
+        # replace stdin output with stream output
+        outputs[stdin_idx] = {
+            "output_type": "stream",
+            "name": "stdin",
+            "text": value + '\n',
+        }
+
     async def _handle_comms(self) -> None:
         if self.yjs is None or self.yjs.widgets is None:  # type: ignore
             return

plugins/yjs/fps_yjs/ydocs/ynotebook.py

@@ -49,6 +49,15 @@ def get_cell(self, index: int) -> Dict[str, Any]:
             and not cell["attachments"]
         ):
             del cell["attachments"]
+        outputs = cell.get("outputs", [])
+        del_outputs = []
+        for idx, output in enumerate(outputs):
+            if output["output_type"] == "stdin":
+                del_outputs.append(idx)
+        deleted = 0
+        for idx in del_outputs:
+            del outputs[idx - deleted]
+            deleted += 1
         return cell
 
     def append_cell(self, value: Dict[str, Any]) -> None: