Class ExpiringMap<K, V>

A map that can have a capacity limit. The elapsed time for each get/set operation is maintained allowing for items to be automatically removed. has() does not affect the last access time.

By default, it uses the none eviction policy, meaning that when full an error will be thrown if attempting to add new keys.

Eviction policies: oldestGet removes the item that hasn't been accessed the longest, oldestSet removes the item that hasn't been updated the longest.

const map = new ExpiringMap();
map.set(`fruit`, `apple`);

// Remove all entries that were set more than 100ms ago
map.deleteWithElapsed(100, `set`);
// Remove all entries that were last accessed more than 100ms ago
map.deleteWithElapsed(100, `get`);
// Returns the elapsed time since `fruit` was last accessed
map.elapsedGet(`fruit`);
// Returns the elapsed time since `fruit` was last set
map.elapsedSet(`fruit`);
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Last set/get time for a key can be manually reset using touch.

Events:

• 'expired': when an item is automatically removed.
• 'removed': when an item is manually or automatically removed.
• 'newKey': when a new key is added

map.addEventListener(`expired`, evt => {
 const { key, value } = evt;
});
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The map can automatically remove items based on elapsed intervals.

Example

Automatically delete items that haven't been accessed for one second

const map = new ExpiringMap({
 autoDeleteElapsed: 1000,
 autoDeletePolicy: `get`
});
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Example

Automatically delete the oldest item if we reach a capacity limit

const map = new ExpiringMap({
 capacity: 5,
 evictPolicy: `oldestSet`
});
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