Ccache Intro

原repo

CCache is an LRU Cache, written in Go, focused on supporting high concurrency.

Lock contention on the list is reduced by:

• Introducing a window which limits the frequency that an item can get promoted
• Using a buffered channel to queue promotions for a single worker
• Garbage collecting within the same thread as the worker

如何实现

type Cache struct {
	*Configuration
	list        *list.List
	size        int64
	buckets     []*bucket
	bucketMask  uint32
	deletables  chan *Item
	promotables chan *Item
	control     chan interface{}
}

数据存放在bucket里

type bucket struct {
	sync.RWMutex
	lookup map[string]*Item
}

CCache’s LayeredCache stores and retrieves values by both a primary and secondary key. Deletion can happen against either the primary and secondary key, or the primary key only (removing all values that share the same primary key).

双层key？