Class: Merb::Cache::AbstractStrategyStore

Class | Merb::Cache::AbstractStrategyStore
In: | lib/merb-cache/stores/strategy/abstract_strategy_store.rb
Parent: | AbstractStore

A strategy store wraps one or more fundamental stores, acting as a middle man between caching requests.

For example, if you need to save memory on your Memcache server, you could wrap your MemcachedStore with a GzipStore. This would automatically compress the cached data when put into the cache, and decompress it on the way out. You can even wrap strategy caches with other strategy caches. If your key was comprised of sensitive information, like a SSN, you might want to encrypt the key before storage. Wrapping your GzipStore in a SHA1Store would take care of that for you.

The AbstractStore class defines 9 methods as the API:

writable?(key, parameters = {}, conditions = {}) exists?(key, parameters = {}) read(key, parameters = {}) write(key, data = nil, parameters = {}, conditions = {}) write_all(key, data = nil, parameters = {}, conditions = {}) fetch(key, parameters = {}, conditions = {}, &blk) delete(key, parameters = {}) delete_all delete_all!

AbstractStrategyStore implements all of these with the exception of delete_all. If a strategy store can guarantee that calling delete_all on it’s wrapped store(s) will only delete entries populated by the strategy store, it may define the safe version of delete_all. However, this is usually not the case, hence delete_all is not part of the public API for AbstractStrategyStore.

### Methods

clone contextualize delete delete_all! exists? fetch new read writable? write write_all

### External Aliases

contextualize | -> | []

### Attributes

stores | [RW] |
stores | [RW] | END: interface for creating strategy stores.

### Public Class methods

contextualize(*stores)

START: interface for creating strategy stores. This should/might change.

new(config = {})

### Public Instance methods

clone()
delete(key, parameters = {})

deletes the entry for the key & parameter from the store.

delete_all!()

deletes all entries for the key & parameters for the store. considered dangerous because strategy stores which call delete_all! on their context stores could delete other store‘s entrees.

exists?(key, parameters = {})

returns true/false/nil based on if data identified by the key & parameters is persisted in the store.

fetch(key, parameters = {}, conditions = {}, &blk)

tries to read the data from the store. If that fails, it calls the block parameter and persists the result.

read(key, parameters = {})

gets the data from the store identified by the key & parameters. return nil if the entry does not exist.

writable?(key, parameters = {}, conditions = {})

determines if the store is able to persist data identified by the key & parameters with the given conditions.

write(key, data = nil, parameters = {}, conditions = {})

persists the data so that it can be retrieved by the key & parameters. returns nil if it is unable to persist the data. returns true if successful.

write_all(key, data = nil, parameters = {}, conditions = {})

persists the data to all context stores. returns nil if none of the stores were able to persist the data. returns true if at least one write was successful.

[Validate]