Introduction to Queuelib

Queuelib is a simple and lightweight Python library designed for managing queues efficiently. It is widely used for applications requiring task management, message handling, or queue-based processing with persistent storage support when needed. If you’re looking for a straightforward queue library that supports both in-memory and disk-based queues, Queuelib is a great choice.

Key Features

• Support for persistent and non-persistent queues
• Simple and minimalistic API
• Ideal for lightweight task management

Installing Queuelib

You can install Queuelib using pip:

  pip install queuelib

Examples of Useful APIs

1. Creating an In-Memory Queue

The `FifoMemoryQueue` class allows you to create a first-in-first-out (FIFO) queue in memory:

  from queuelib.queue import FifoMemoryQueue

  queue = FifoMemoryQueue()
  queue.push(b'Task 1')
  queue.push(b'Task 2')
  print(queue.pop())  # Output: b'Task 1'
  print(queue.pop())  # Output: b'Task 2'

2. Persistent Disk-Based Queue

Use `FifoDiskQueue` for a disk-persistent queue that stores tasks on disk:

  from queuelib.queue import FifoDiskQueue

  queue = FifoDiskQueue('queue_storage')
  queue.push(b'Task 1')
  queue.push(b'Task 2')
  print(queue.pop())  # Output: b'Task 1'
  print(queue.pop())  # Output: b'Task 2'

The stored tasks are maintained even after the application restarts.

3. LIFO Queue with `LifoMemoryQueue`

Queuelib supports a last-in-first-out (LIFO) queue through `LifoMemoryQueue`:

  from queuelib.queue import LifoMemoryQueue

  queue = LifoMemoryQueue()
  queue.push(b'Task 1')
  queue.push(b'Task 2')
  print(queue.pop())  # Output: b'Task 2'
  print(queue.pop())  # Output: b'Task 1'

4. Checking Queue Length

Get the current length of the queue using the `__len__` method:

  queue.push(b'Task 1')
  print(len(queue))  # Output: 1
  queue.pop()
  print(len(queue))  # Output: 0

5. Clearing the Queue

Use `close` and `clear` methods to manage resources and flush the queue:

  queue.close()
  queue.clear()

6. Using Queuelib in a Complex Application

Let’s create a simple task queue processor using Queuelib:

  from queuelib.queue import FifoMemoryQueue

  def process_task(task):
      print(f'Processing: {task}')

  # Create a queue
  queue = FifoMemoryQueue()

  # Add tasks to the queue
  queue.push(b'Task 1')
  queue.push(b'Task 2')
  queue.push(b'Task 3')

  # Process tasks
  while len(queue) > 0:
      task = queue.pop()
      process_task(task)

This script demonstrates how Queuelib can be a building block for task-oriented applications.

Conclusion

Queuelib is a versatile library that simplifies working with both in-memory and persistent queues. Its APIs are intuitive, making it an excellent choice for lightweight task management. Start integrating Queuelib into your Python projects today to streamline your task processing workflows.