smoothcache 1.1.0

Simple, in-memory, thread-safe caching system for python programs.

smoothcache

smoothcache is a simple, in-memory, thread-safe caching system for your python programs.

Installation

pip install smoothcache

Usage

Interacting with the cache is done using a CacheController object:

from smoothcache import CacheController

Cache = CacheController()

Cache.set("cache key", "cache value")

Interacting with the cache object

The cache object exposes 4 methods for interacting with the cache:

• set
• get
• clear
• remove

Set

Cache.set(key, value, ttl=None)

The set method adds an entry to the cache.

The key parameter is how you can access the cached value.

The ttl parameter is the Time-to-Live value (in seconds) that the cache entry will remain valid.

After ttl seconds has passed, the cache will no longer return the value. The default ttl value is set at 3600 seconds (1 hour) and can be modified in the cache settings.

If a key is passed to set that already exists, the entry gets overridden. This behavior can be changed in the cache settings to instead raise a KeyAlreadyExistsError when a duplicate key is passed.

Get

Cache.get(key, default=None)

The get method retrieves an entry from the cache.

The key parameter is the value of the entries key set with the set method.

The default parameter is the value that will be returned if the entry is no longer valid, or doesn't exist.

get can also be configured in the cache settings to raise an EntryNotFoundError when the specified key doesn't exist or an EntryExpiredError when the specified cache entry has expired.

get returns a CacheResult object with two attributes (key and value) when the entry is found. Otherwise, get returns default.

Clear

Cache.clear()

The clear method removes all entries from the cache

Remove

Cache.remove(key)

The remove method removes the specified key from the cache.

By default, if the key doesn't exist in the cache, the function silently returns and doesn't fail. This behavior can be changed in the cache settings to instead raise an EntryNotFoundError.

Cache Settings

The Cache object's behavior can be modified with it's settings. Settings are accessed within the object's settings property.

# Cache.settings.<setting name> = <setting value>
# For example:
Cache.settings.error_on_dup_key = False

error_on_dup_key:

Default: False

If true, raise a KeyAlreadyExistsError when set is called with a key that is already set in the cache. If false, the cache entry with key is overwritten if the key is already set.

error_on_invalid_key:

Default: False

If true, raise an EntryNotFoundError when get or remove is called with a key that is not set in the cache. If false, the get call will return it's default and the remove call silently returns.

error_on_expired_entry:

Default: False

If true, raise an EntryExpiredError when the entry returned from a get call has gone past it's TTL. If false, the get call will return it's default.

default_ttl:

Default: 3600 (1 hour)

The TTL value (in seconds) set on any entry that does not explicitly have a TTL value.