README

Node Cache Manager store for Hasura GraphQL engine

The Hasura store for the node-cache-manager module.

Installation

npm install cache-manager-hasura --save

Requirements

Required components:

Hasura GraphQL Engine v1.3.x
PostgresSQL Database v11+

Required configuration:

Table "cache" should exist in PostgreSQL Database

Look at hasura/migrations/1613268748000_inital_schema/up.sql

  CREATE TABLE "public"."cache" (
      "key"          TEXT NOT NULL PRIMARY KEY,
      value          TEXT NULL,
      compressed     BOOLEAN NOT NULL DEFAULT FALSE,
      expires_at     TIMESTAMPTZ
  );

Table cache should be tracked by hasura (with necessary fields mapping)

Look at hasura/metadata/tables.yaml

  - table:
  schema: public
  name: cache
    configuration:
      custom_root_fields: {}
      custom_column_names:
        expires_at: expiresAt

Usage examples

Here are examples that demonstrate how to implement the Mongodb cache store.

Single store

var cacheManager = require('cache-manager');
var hasuraStore = require('cache-manager-hasura');


var cache = cacheManager.caching({
    store : hasuraStore,
    uri : "http://localhost:3001/v1/graphql",
    options : {
      secret : "secret", // from env HASURA_GRAPHQL_ADMIN_SECRET
      compression : false,
      ttl : 600, // default "time to live" for cache records
    }
  });

var ttl = 60;

cache.set('foo', 'bar', ttl)
    .then(()=>{
     return cache.get('foo')
    }).then((result) => {
        console.log(result);
        // >> 'bar'
        return cache.del('foo');
    });
});

function getUser(id) {
    return new Promise((resolve,reject)=>{
    setTimeout(function () {
        console.log("Returning user from slow database.");
        return resolve({id: id, name: 'Bob'});
    }, 100);
}

var userId = 123;
var key = 'user_' + userId;

// Note: ttl is optional in wrap()
cache.wrap(key, function () {
    return getUserPromise(userId);
}, ttl)
    .then((user) => {
     console.log(user);

    // Second time fetches user from mongoCache
    cache.wrap(key, function () {
       return getUserPromise(userId);
    }.then(( user) => {
        console.log(user);
    });
});

Multi-store

var cacheManager = require('cache-manager');
var hasuraStore = require('cache-manager-hasura');
var hasuraCache = cacheManager.caching({
    store : hasuraStore,
    uri : "http://localhost:3001/v1/graphql",
    options : {
        secret : "secret", // from env HASURA_GRAPHQL_ADMIN_SECRET
        compression : false,
        ttl : 600,
    }
});
var memoryCache = cacheManager.caching({store: 'memory', max: 100, ttl: 60});

var multiCache = cacheManager.multiCaching([memoryCache, hasuraCache]);


userId2 = 456;
key2 = 'user_' + userId;
ttl = 5;

// Sets in all caches.
multiCache.set('foo2', 'bar2', ttl)
    .then(()=>{
        // Fetches from highest priority cache that has the key.
        return multiCache.get('foo2')
    }).then((result) => {
        console.log(result);
        // >> 'bar2'
        // Delete from all caches
        return multiCache.del('foo2');
    });
});

// Note: ttl is optional in wrap()
multiCache.wrap(key2, function () {
    return getUserPromise(userId2);
}, ttl)
.then((user) => {
        console.log(user);
         // Second time fetches user from memoryCache, since it's highest priority.
        // If the data expires in the memory cache, the next fetch would pull it from
        // the 'someOtherCache', and set the data in memory again.
        return multiCache.wrap(key2, function () {
           return getUserPromise(userId2);
        });
}).then((user)=>{
    console.log(user);
});

function getUserPromise(id) {
    return new Promise((resolve,reject)=>{
        setTimeout(function () {
         console.log("Returning user from slow database.");
         return resolve({id: id, name: 'Bob'});
        }, 100);
    })
});

Credits

Thanks to owner of https://github.com/v4l3r10/node-cache-manager-mongodb repository for the foundation of code to implement this module.

Contribution

If you would like to contribute to the project, please fork it and send us a pull request.

License

node-cache-manager-hasura is licensed under the MIT license.

Usage no npm install needed!