Cache service lib

Presenting a reusable cache library to Node.Js. This library uses well defined cache solutions such as redis and node-cache to deliver scalable and reusable cache services.

An abstraction layer is provided through Adapter and Strategy design patterns, allowing also to simplify multilevel cache solutions.

Simple usage

``typescript
import { createCacheService } from 'cache-service-lib';
import { RedisCacheStrategy } from 'cache-service-lib/lib/strategies/RedisCacheStrategy';

const cacheService = createCacheService();
cacheService.registerStrategy(
'redis',
new RedisCacheStrategy({
host: 'localhost',
port: 6379,
})
);

cacheService.set('key', 'value', 30); // Will expire cache entry in 30s
`

Multilevel cache Usage with sync scenarios

`typescript
import { createCacheService } from 'cache-service-lib';
import { RedisCacheStrategy } from 'cache-service-lib/lib/strategies/RedisCacheStrategy';
import { MemCacheStrategy } from 'cache-service-lib/lib/strategies/MemCacheStrategy';

const cacheService = createCacheService();
cacheService.registerStrategy('mem', new MemCacheStrategy());
cacheService.registerStrategy(
'redis',
new RedisCacheStrategy({
host: 'localhost',
port: 6379,
})
);
cacheService.chooseStrategy('redis').set('key', 'value', 30); // Will expire cache entry in 30s
`

Multilevel cache Usage with async scenarios

In async scenarios, in order to ensure the correct strategy at each call is recommended to pass the parameter \_strategyStorage_:'async'\ to createCacheService.

This parameter enables the usage of the async_hooks Node.Js api to store and retrieve the current strategy. Please make sure the client node version supports this feature.

`typescript
import { createCacheService } from 'cache-service-lib';
import { RedisCacheStrategy } from 'cache-service-lib/lib/strategies/RedisCacheStrategy';
import { MemCacheStrategy } from 'cache-service-lib/lib/strategies/MemCacheStrategy';

const cacheService = createCacheService({ strategyStorage: 'async' });
cacheService.registerStrategy('mem', new MemCacheStrategy());
cacheService.registerStrategy(
'redis',
new RedisCacheStrategy({
host: 'localhost',
port: 6379,
})
);
cacheService.chooseStrategy('redis').set('key', 'value', 30); // Will expire cache entry in 30s
`

$3

> The first strategy registered will be automatically marked as the currentStrategy.

$3

- registerStrategy(name: string, strategy: CacheStrategy): void
- chooseStrategy(name: string) : void
- listStrategies() : Array\
- call\(fn: () => Promise\, key: string, expiresIn?: number) : Promise\
- get\(key: string): Promise;
- set(key: string, value: unknown, expiresIn?: number): Promise\;
- del(key: string): Promise\;
- delByPrefix(prefix: string): Promise\;
- flush(): Promise\;

Plugins

There are some modifiers available to enable functionalities on top of the default CacheService. This plugins can be used as decorators of CacheServiceProtocols.

$3

Enable auto refresh functionality at call function.

- call\(fn: () => Promise\, key: string, refreshsIn?: number) : Promise\

`typescript
import { createCacheService, MemcacheStrategy, plugins } from 'cache-service-lib';
const cacheService = plugins.autoRefresh(createCacheService());
cacheService.registerStrategy('mem', new MemCacheStrategy());

const fn = async () => ['value'];
cacheService.call(fn, 'key', 30); // Will autorefresh cache entry every 30s
`

Conflicting set operations will cancel auto refresh schedules.

$3

Commands to create test dynamodb table:

`bash
aws dynamodb --region us-east-1 --endpoint-url http://localhost:8000 create-table --table-name table-1 \
--attribute-definitions AttributeName=kind,AttributeType=S AttributeName=key,AttributeType=S --key-schema AttributeName=kind,KeyType=HASH AttributeName=key,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

aws dynamodb --region us-east-1 --endpoint-url http://localhost:8000 update-time-to-live --table-name table-1 --time-to-live-specification "Enabled=true, AttributeName=ttl"
``