Reference library

Streaming & messaging

Kafka-style pub/sub, event consumers, async pipelines, and message-driven workflows.

3 matches

Exactly Once Idempotent Consumer Store in Python

A mock key-value store that guarantees exactly-once processing by rejecting duplicate message keys in a message or event stream.

idempotency streaming deduplication

Python

from collections import defaultdict

class ExactlyOnceStore:
    def __init__(self):
        self.processed = defaultdict(set)
        self.data = {}

    def consume(self, key, value):
        if key in self.data:
            return False
        self.data[key] = value
        return True

    def get_processed_count…

15 0 Open

Streaming & messaging easy

How to Build a Materialized View Updater Consumer Mock in Python

A mock consumer that queues change events and triggers refresh callbacks to simulate materialized view updates.

dataclasses deque mocking

Python

import time
from collections import deque
from dataclasses import dataclass, field
from typing import Callable, Deque, Optional


@dataclass
class MaterializedViewUpdater:
    """Mock updater that consumes change events and refreshes a view."""
    refresh: Optional[Callable[[str], None]] = None
    queue: Deque[tuple…

14 0 Open

Streaming & messaging easy

How to Mock RabbitMQ Ack Nack Requeue in Python

A mock RabbitMQ channel and consumer that simulates ack, nack, and requeue handling for testing message processing logic without a broker.

rabbitmq testing mock

Python

import json
from collections import deque


class MockChannel:
    def __init__(self):
        self.acked = []
        self.nacked = []
        self.requeued = []

    def basic_ack(self, delivery_tag):
        self.acked.append(delivery_tag)

    def basic_nack(self, delivery_tag, requeue=False):
        self.nacked.…

15 0 Open

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