ct-cache-lib 0.2.0

A specialized library developed by Credenti for efficient caching in Flask applications.

Ct Cache Lib

A specialized library developed by Credenti for efficient caching in Flask applications.

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Features

• Decorator-based caching for Flask endpoints and functions
• Configurable Valkey connection pooling
• Supports cache key templating with nested attribute access
• Easy integration with Flask app lifecycle

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Installation

pip install ct-cache-lib

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Configuration

Add the following to your Flask app configuration:

app.config['CACHE'] = True              # Enable or disable caching
app.config['CACHE_EXPIRE_TIME'] = 60    # Default cache expiration time in seconds
app.config['CACHE_HOST'] = 'localhost'  # Cache host
app.config['CACHE_PORT'] = 6379         # Cache port
app.config['CACHE_USERNAME'] = 'user'   # Cache username (if required)
app.config['CACHE_PASSWORD'] = 'pass'   # Cache password (if required)
app.config['CACHE_CLIENT_NAME'] = 'my-client' # Cache client name

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Usage

The @ct_cache.cache decorator can be applied to any function to enable caching. It supports both positional and keyword arguments.

You can also set read_only=True to prevent the cache from being updated on a cache miss. This is useful for high-priority reads where you want to avoid writing to the cache.

from flask import Flask
from ct_cache_lib import init_cache
import logging

app = Flask(__name__)
logger = logging.getLogger(__name__)

# Initialize the cache
ct_cache = init_cache(app, logger)

@app.route('/idle_time')
@ct_cache.cache(template_cache_key='idle_time_value:$idle_time', field='$idle_time')
def get_idle_time_value(idle_time: str):
    # Your function logic here
    return {'idle_time': idle_time}

Bypassing the Cache

You can dynamically bypass the cache for any decorated function by passing use_cache=False when you call it. This tells the decorator to ignore the cache and execute the function directly.

# This call will use the cache
get_idle_time_value(idle_time='123')

# This call will bypass the cache and execute the function
get_idle_time_value(idle_time='123', use_cache=False)

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Updating a Cache Entry

Update a cache entry directly:

ct_cache.update(
    cache_key='idle_time_value:123',  # Actual cache key
    field='some_field',
    value={'idle_time': 123},
    is_global=False,                  # or True if the key is global
    expire_time=120                   # optional, in seconds
)

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Deleting a Cache Entry

Delete a cache entry:

ct_cache.delete(
    cache_key='idle_time_value:123',  # Actual cache key, not a template
    field='some_field',
    is_global=False                   # or True if the key is global
)

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Committing and Resetting Cache

Commit cache writes after each request:

@app.after_request
def after_request(response):
    ct_cache.commit(response)
    return response

Reset cache if you need to roll back changes:

ct_cache.reset()

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Cache Key Specification Examples

You can use dynamic cache keys by referencing function arguments or nested data using $.

Basic Example

@ct_cache.cache(template_cache_key='idle_time_value:$idle_time', field='$idle_time')
def get_idle_time_value(idle_time: str):
    return {'idle_time': idle_time}

• If idle_time = 123, the cache key will be idle_time_value:123.

Keyword Argument Example

The decorator also supports keyword arguments, making it flexible for various function signatures.

@ct_cache.cache(template_cache_key='user_cache:$user_id', field='$user_id')
def get_user_by_id(user_id: int):
    # Function logic to fetch user
    return {'user_id': user_id}

• If you call get_user_by_id(user_id=42), the cache key will be user_cache:42.

Nested Dictionary Example

@ct_cache.cache(template_cache_key='user_cache:$user.id', field='$user.id')
def get_user(user: dict):
    return user

• If user = {'id': 01, 'name': 'User1'}, the cache key will be user_cache:01.

Nested Object Example

class User:
    def __init__(self, id, name):
        self.id = id
        self.name = name

@ct_cache.cache(template_cache_key='user_cache:$user.id', field='$user.id')
def get_user_obj(user: User):
    return {'id': user.id, 'name': user.name}

• If user.id = 01, the cache key will be user_cache:01.

Deeply Nested Example

@ct_cache.cache(template_cache_key='deep_cache:$data.profile.info.id', field='$data.profile.info.id')
def get_deep(data: dict):
    return data

• If data = {'profile': {'info': {'id': 01}}}, the cache key will be deep_cache:01.

Static Key Example

@ct_cache.cache(template_cache_key='static_key')
def get_static():
    return {'result': 1}

• The cache key will always be static_key.

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