ut-port-redis

ut-port-redis is a redis object caching port. It is a convinient wrapper for ionredis and provides on top of that the standard ut mechanisms for logging, monitoring, error handling, etc. inherited from ut-port.

Usage

This port can be used the same way as any other ut compliant port. For more information about how to bootstrap a ut port click here

Configuration

Besides logLevel, concurrency, and other configuration options which are common for all ports, ut-port-redis defines 2 additional properties:

• client - This object provides a low-level cache abstraction.
  • options - The strategy configuration object

More information about how to configure the policy options can be found here

Configuration example

function cache() {
    return class cache extends require('ut-port-redis')(...arguments) {
        get defaults() {
            options: {} // ionredis-redis options
        }
    };
}

API

By setting up the port using the example above it will expose the following set of methods available through ut-bus:

• bus.importMethod('cache/module.entity.action')(msg, $meta)

  • module.entity.action is arbitrary string, usually corresponding to a namespaced method call
  • msg is the value for the cache operation and has the following structure {operation, key, value }
    • operation is a valid redis command
    • key is a string identifier used to locate/create a key value pair
    • value is optional depending on the redis operation
  • $meta contains the metadata associated with the request
  • return value is determined by the redis operation

Example

This is a trivial example illustrating a set and get operation

const msg = {
    key : 'foo',
    operation: 'set',
    value: 'bar'
}
Promise.resolve()
    .then(result => {
        return bus.importMethod('cache/module.foo.set')(msg, $meta)
                // returns promise which resolves to string, "OK"
                .then(() => { 
                    return bus.importMethod('cache/module.foo.get')({
                      key : 'foo',
                      operation: 'get'
                    }, $meta) // Promise resolves to "bar"
                });
    })
    .catch(e => { // an exception in case any of the above calls fail
        throw e;
    });