cache-flex

Cache flex

An in-memory cache with extra options to fix value types and set constants in cache, for more consistency.

Methods

.set(key, value, options)

• Returns a promise that resolves with the set value.
• key should be a string.
• value can be anything except for undefined, null or NaN.
• options (object)
  • makeConstant (boolean): if set to true, does not allow the value to be updated.
  • fixType (boolean): if set to true, does not allow the type of the value to be changed.
  • ttl (number) (time in milliseconds): if specified, removes the value after the given interval.
  • expiryCallback(value) (function): if provided with valid ttl, this function gets called right after a value is expired with the value.
• .setSync(...) is the synchronous version with the same parameters, returns the value.

.setFixType(key, value)

• fixes the type for the value against the given key, and can be only updated with a value with same type as inital type of value.
• Returns a promise that resolves with the set value.
• .setFixTypeSync(...) is the synchronous version with the same parameters, returns the value.

.setConstant(key, value)

• sets the value as a constant i.e. the value cannot be changed later on.
• Returns a promise that resolves with the set value.
• .setConstantSync(...) is the synchronous version with the same parameters, returns the value.

.get(key)

• Returns a promise that resolves with the value stored against the key.
• .getSync(...) is the synchronous version with the same parameters, returns the value.

.update(key, value)

• Updates existing value against key with value.
• Returns a promise that resolves with the updated value.

.setOrUpdate(key, value)

• Updates or sets value against key with value.
• Returns a promise that resolves with the updated or set value.

Usage

const cache = require('cache-flex');

cache.setSync('someKey', 'someValue')
let value = cache.getSync('someKey');

cache.set('someKey', {a: 'some value'})
  .then(value => {
    // 'value' is {a: 'some value'}
    let result = cache.get('someKey')
      .then(result => {
        // 'value' is {a: 'some value'}
      })
      .catch(err => {
        // handle error with 'get'
      });
  })
  .catch(err => {
    // handle error with 'set'
  });