This is a library to
- manage singleton client & cluster instances
- cache entity identifiers in groups for a given time with scheduler to trigger callback(s) on expiration.
- track entity identifiers in groups by creation date.
Table of Contents
npm install redis-extension --saveTo create a configuration for the driver Client or Cluster, a configuration must be specified,
like described in the following:
Client
import {
setConfig
} from "redis-extension";
setConfig({
connectionString: 'redis://127.0.0.1',
options: {
reconnectOnError(error: Error): boolean {
return true;
}
}
}, 'alias');A configuration is always identified by a string, in this example: alias (default: default),
so multiple configurations can be registered.
In the upper example, the options property is used to pass information to the underneath driver (IORedis) and the connectionString (optional) property is a way to specify the Redis server to which the driver should connect to.
Cluster
import {
setConfig
} from "redis-extension";
setConfig({
clusterNodes: [
'redis://127.0.0.1'
],
clusterOptions: {
// ...
}
}, 'alias');A singleton instance associated for a given configuration key, can be acquired like described in the following:
Client
import {
useClient
} from "redis-extension";
const client = useClient('alias');
(async () => {
await client.set('key', 'value');
const payload = await client.get('key');
console.log(payload);
// value
})();Cluster
import {
useCluster
} from "redis-extension";
const cluster = useCluster('alias');
(async () => {
await cluster.set('key', 'value');
const payload = await cluster.get('key');
console.log(payload);
// value
})();The cache submodule requires a Redis instance, which can either be created with this library or with the underneath ioredis driver itself.
import {
Cache,
useClient
} from "redis-extension";
(async () => {
type User = {
id: number,
name: string,
realm_id: string
};
const cache = new Cache<number, User>(
{
redis: useClient()
},
{
prefix: 'user',
context: {
realm_id: 'master'
}
}
);
// Register events
cache.on('expired', (data) => {
console.log(data);
// { id: 'foo', prefix: 'user', context: {realm_id: 'master'}
// Important: The value will not be part of the expired event payload!
});
// Start scheduler to watch cached entries and trigger specific events.
await cache.start();
await cache.set('foo', 'bar');
const payload = cache.get('foo');
console.log(payload);
// bar
});import {
Tracker,
useClient
} from "redis-extension";
(async () => {
const tracker = new Tracker<number>(
{
redis: useClient()
},
{
prefix: 'users-online'
}
);
// add user with id: 1 to the stack (time: 1642423766)
tracker.add(1);
// add user with id: 2 to the stack (time: 1642423866)
tracker.add(2);
const items = tracker.getMeta({
sort: 'DESC'
});
console.log(items);
// {
// data: [
// {id: 1, score: 1642423766},
// {id: 2, score: 1642423866}
// ],
// meta: {}
// }
})();The score property represents the unix timestamp, when the entry was added.
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Published under MIT License.