| """Implements a fully blocking kernel client. |
| |
| Useful for test suites and blocking terminal interfaces. |
| """ |
|
|
| import sys |
|
|
| |
| |
| |
| |
| |
| |
| from queue import Empty, Queue |
|
|
| |
| from traitlets import Type |
|
|
| |
| from .channels import InProcessChannel |
| from .client import InProcessKernelClient |
|
|
|
|
| class BlockingInProcessChannel(InProcessChannel): |
| """A blocking in-process channel.""" |
|
|
| def __init__(self, *args, **kwds): |
| """Initialize the channel.""" |
| super().__init__(*args, **kwds) |
| self._in_queue: Queue[object] = Queue() |
|
|
| def call_handlers(self, msg): |
| """Call the handlers for a message.""" |
| self._in_queue.put(msg) |
|
|
| def get_msg(self, block=True, timeout=None): |
| """Gets a message if there is one that is ready.""" |
| if timeout is None: |
| |
| |
| timeout = 604800 |
| return self._in_queue.get(block, timeout) |
|
|
| def get_msgs(self): |
| """Get all messages that are currently ready.""" |
| msgs = [] |
| while True: |
| try: |
| msgs.append(self.get_msg(block=False)) |
| except Empty: |
| break |
| return msgs |
|
|
| def msg_ready(self): |
| """Is there a message that has been received?""" |
| return not self._in_queue.empty() |
|
|
|
|
| class BlockingInProcessStdInChannel(BlockingInProcessChannel): |
| """A blocking in-process stdin channel.""" |
|
|
| def call_handlers(self, msg): |
| """Overridden for the in-process channel. |
| |
| This methods simply calls raw_input directly. |
| """ |
| msg_type = msg["header"]["msg_type"] |
| if msg_type == "input_request": |
| _raw_input = self.client.kernel._sys_raw_input |
| prompt = msg["content"]["prompt"] |
| print(prompt, end="", file=sys.__stdout__) |
| assert sys.__stdout__ is not None |
| sys.__stdout__.flush() |
| self.client.input(_raw_input()) |
|
|
|
|
| class BlockingInProcessKernelClient(InProcessKernelClient): |
| """A blocking in-process kernel client.""" |
|
|
| |
| shell_channel_class = Type(BlockingInProcessChannel) |
| iopub_channel_class = Type(BlockingInProcessChannel) |
| stdin_channel_class = Type(BlockingInProcessStdInChannel) |
|
|
| def wait_for_ready(self): |
| """Wait for kernel info reply on shell channel.""" |
| while True: |
| self.kernel_info() |
| try: |
| msg = self.shell_channel.get_msg(block=True, timeout=1) |
| except Empty: |
| pass |
| else: |
| if msg["msg_type"] == "kernel_info_reply": |
| |
| try: |
| self.iopub_channel.get_msg(block=True, timeout=0.2) |
| except Empty: |
| pass |
| else: |
| self._handle_kernel_info_reply(msg) |
| break |
|
|
| |
| while True: |
| try: |
| msg = self.iopub_channel.get_msg(block=True, timeout=0.2) |
| print(msg["msg_type"]) |
| except Empty: |
| break |
|
|