FOUNDRY

Provides commonly-used data structures suitable for distributed applications thanks to foundationdb.

Usage

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Before installing the package, you need to install the foundationdb client on your machine. Please follow this guide to install it.

Install foundry with your package manager:

Using npm

``sh
npm install --save @feedloop/foundry
`

Using yarn

`sh
yarn add @feedloop/foundry
`

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Foundry uses nodejs foundationdb client that looks for configs in several ways.

> Set FDB_API_VERSION to your environment variable to select the foundationdb api version, defaults to version 620.

`ts
import Foundry from "@feedloop/foundry";

// somewhere in your async scope
const foundry = await Foundry.init("your-database-name");
`

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`ts
import { Set } from "@feedloop/foundry";

// somewhere in your async scope
const hasBar = await foundry.exec(async (factory) => {
const set = factory.open(Set, "my-set");
await set.add("foo", "bar", "baz");
return set.has("bar");
});

// hasBar will be true
`

All foundry's operations must be run within the foundry.exec scope because they will run in the same transaction. Each transaction will be re-run when a conflict is detected, so keep it simple to reduce client overhead.

Available Data Structures

Foundry provides commonly used data structures suitable for distributed applications by utilizing foundationdb's transaction excellence.

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`ts
import { List } from "@feedloop/foundry";

// somewhere in your async scope
await foundry.exec(async (factory) => {
const list = factory.open>(List, "list1");
await list.push("a", "b", "c"); // ["a", "b", "c"]
const secondItem = await list.at(1); // returns "b"
const last = await list.pop(); // returns "c"
const len = await list.length(); // returns 2
});
`

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`ts
import { Set } from "@feedloop/foundry";

// somewhere in your async scope
await foundry.exec(async (factory) => {
const set = factory.open(Set, "my-set");
await set.add("foo", "bar", "baz"); // ["foo", "bar", "baz"]
await set.remove("bar"); // ["foo", "baz"]
await set.size(); // 2
});
`

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`ts
import { Map } from "@feedloop/foundry";

// somewhere in your async scope
await foundry.exec(async (factory) => {
const map = factory.open(Map, "my-map");
await map.set("foo", 1); // {foo: 1}
await map.set("bar", 2); // {foo: 1, bar: 2}
await map.delete("bar"); // {bar: 2}
await map.size(); // 2
});
`

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`ts
import { PersistentQueue } from "@feedloop/foundry";

// somewhere in your async scope
await foundry.exec(async (factory) => {
const queue = factory.open(PersistentQueue, "my-queue");
await queue.write("foo"); // ["foo"]
await queue.write("bar"); // ["foo", "bar"]

// reader1 consuming messages
await queue.read("reader1", 1, true); // returns ["foo"]
await queue.readOffset("reader1"); // returns 1
await queue.read("reader1", 1, true); // returns ["bar"]
await queue.read("reader1", 1, true); // returns []
await queue.readOffset("reader1"); // returns 2

// reader2 consuming messages
await queue.read("reader2", 2, true); // returns ["foo", "bar"]
await queue.read("reader2", 2, true); // returns []
await queue.size(); // return 2
});
`

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`ts
import { CronJob } from "@feedloop/foundry";

// somewhere in your async scope
// set a cron schedule
await foundry.exec(async (factory) => {
const cronjob = factory.open(CronJob, "my-cronjob");
// At every 5th minute (https://crontab.guru/#/5____*)
await cronjob.schedule("5 ");
});

// setup a polling to check for jobs
setInterval(async () => {
const hasJob = await foundry.exec(async (factory) => {
const cronjob = factory.open(CronJob, "my-cronjob");
return cronjob.take();
});
if (hasJob) {
console.log("I have a job!"); // will run at every 5th minute
}
}, 1000 * 60); // run every 1 minute
``