Cache

A simple, fast, least-recently-used cache (specifically, last set) with active time-to-live eviction, optimized for large-string keys and frequent reads.

It has no dependencies, other than a jasmine dev-dependencies for unit tests.

The implementation has identical performance to Map for reading, and slightly longer than Map for writing and deleting.

The API is identical to Map(), except that:

• The constructor takes a required integer maxSize and an optional defaultTimeToLive.
  • The cache keeps track of the order in which keys are set, and will remove the maxSize oldest key as new ones are set. Note that this keeps the size below maxSize, but the actual size may be less than maxSize as more recent keys are removed by the client or by timers.
  • The defaultTimeToLive is the default for value for set(). Defaults to 0.
• set(key, value, timeToLive = this.defaultTimeToLive) takes an optional third parameter that actively deletes key from the cache after the specified number of milliseconds. A timeToLive of 0 means that there is no time limit for that particular key. (The key is still subject to maxSize.)
• clear(newMaxSize = this.maxSize) takes an optional parameter that is the new maxSize.