Import channel implementations from Python SDK v0.9.0

.darglint

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+# -*- mode: ini -*-
+
+[darglint]
+docstring_style=google
+
+# DAR402: The docstring describes an exception not explicitly raised.
+#
+# Ignoring DAR402 because there are cases where public methods
+# document exceptions raised by underlying functions.
+ignore=DAR402

.github/workflows/ci.yaml

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+name: frequenz-channels-python
+
+on:
+  push:
+    branches: [ v0.x.x ]
+
+  pull_request:
+
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-20.04
+
+    steps:
+    - name: Fetch sources
+      uses: actions/checkout@v2
+      with:
+        submodules: true
+
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: "3.8"
+
+    - uses: actions/cache@v2
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('**/setup.cfg') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+
+    - name: Install required Python packages
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install nox
+
+    - name: run nox
+      run: nox
+      timeout-minutes: 10

.gitignore

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+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+.python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/

README.md

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+# Frequenz channels
+
+This repository contains channel implementations for python.

benchmarks/benchmark_anycast.py

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+"""Benchmark for Anycast channels.
+
+Copyright
+Copyright © 2022 Frequenz Energy-as-a-Service GmbH
+
+License
+MIT
+"""
+
+import asyncio
+import csv
+import timeit
+from typing import Any, Coroutine, Dict, List, Tuple
+
+from frequenz.channels import Anycast, Receiver, Sender
+
+
+async def send_msg(num_messages: int, chan: Sender[int]) -> None:
+    """Send messages to the channel continuously.
+
+    Args:
+        num_messages (int): Number of messages to send.
+        chan (Sender[int]): Channel sender to send the messages to.
+    """
+    # send one message for each receiver
+    for ctr in range(num_messages):
+        await chan.send(ctr + 1)
+
+
+async def benchmark_anycast(
+    num_channels: int,
+    num_messages: int,
+    num_receivers: int,
+    buffer_size: int,
+) -> int:
+    """Ensure sent messages are received by one receiver.
+
+    Args:
+        num_channels (int): Number of channels to create.
+        num_messages (int): Number of messages to send per channel.
+        num_receivers (int): Number of broadcast receivers per channel.
+        buffer_size (int): Buffer size of each channel.
+
+    Returns:
+        int: Total number of messages received by all channels.
+    """
+    channels: List[Anycast[int]] = [Anycast(buffer_size) for _ in range(num_channels)]
+    senders = [
+        asyncio.create_task(send_msg(num_messages, bcast.get_sender()))
+        for bcast in channels
+    ]
+
+    # Even though we want just a single int, use a list, so that it can be
+    # updated from other methods.
+    recv_trackers = [0]
+
+    async def update_tracker_on_receive(chan: Receiver[int]) -> None:
+        while True:
+            msg = await chan.receive()
+            if msg is None:
+                return
+            recv_trackers[0] += 1
+
+    receivers = []
+    for acast in channels:
+        for _ in range(num_receivers):
+            receivers.append(update_tracker_on_receive(acast.get_receiver()))
+
+    receivers_runs = asyncio.gather(*receivers)
+
+    await asyncio.gather(*senders)
+    for bcast in channels:
+        await bcast.close()
+    await receivers_runs
+    return recv_trackers[0]
+
+
+def time_async_task(task: Coroutine[Any, Any, int]) -> Tuple[float, Any]:
+    """Run a task and return the time taken and the result.
+
+    Args:
+        task (asyncio.Task): Task to run.
+
+    Returns:
+        (float, Any): Run time in fractional seconds, task return value.
+    """
+    start = timeit.default_timer()
+    ret = asyncio.run(task)
+    return timeit.default_timer() - start, ret
+
+
+def run_one(
+    num_channels: int,
+    num_messages: int,
+    num_receivers: int,
+    buffer_size: int,
+) -> Dict[str, Any]:
+    """Run a single benchmark."""
+    runtime, total_msgs = time_async_task(
+        benchmark_anycast(num_channels, num_messages, num_receivers, buffer_size)
+    )
+    ret = {
+        "channels": num_channels,
+        "messages_per_channel": num_messages,
+        "receivers": num_receivers,
+        "buffer_size": buffer_size,
+        "total_messages": total_msgs,
+        "runtime": f"{runtime:.3f}",
+    }
+
+    return ret
+
+
+def run() -> None:
+    """Run all benchmarks."""
+    with open("/dev/stdout", "w", encoding="utf-8") as csvfile:
+        fields = run_one(1, 0, 1, 1)
+        out = csv.DictWriter(csvfile, fields.keys())
+        out.writeheader()
+        out.writerow(run_one(1, 1000000, 1, 100))
+        out.writerow(run_one(1, 1000000, 1, 1000))
+        out.writerow(run_one(1, 1000000, 10, 100))
+        out.writerow(run_one(1, 1000000, 10, 1000))
+        out.writerow(run_one(1000, 1000, 1, 100))
+        out.writerow(run_one(1000, 1000, 1, 1000))
+        out.writerow(run_one(1000, 1000, 10, 100))
+        out.writerow(run_one(1000, 1000, 10, 1000))
+
+
+if __name__ == "__main__":
+    run()