https://github.com/graph-gophers/dataloader

Implementation of Facebook's DataLoader in Golang
https://github.com/graph-gophers/dataloader

cache dataloader facebook-dataloader golang graphql

Last synced: about 1 month ago
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Implementation of Facebook's DataLoader in Golang

• Host: GitHub
• URL: https://github.com/graph-gophers/dataloader
• Owner: graph-gophers
• License: mit
• Created: 2016-11-23T17:40:48.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2024-05-27T15:39:56.000Z (3 months ago)
• Last Synced: 2024-07-04T23:55:11.500Z (2 months ago)
• Topics: cache, dataloader, facebook-dataloader, golang, graphql
• Language: Go
• Size: 170 KB
• Stars: 1,173
• Watchers: 15
• Forks: 76
• Open Issues: 20
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• awesome-ccamel - graph-gophers/dataloader - Implementation of Facebook's DataLoader in Golang (Go)

README

        
# DataLoader

[![GoDoc](https://godoc.org/gopkg.in/graph-gophers/dataloader.v7?status.svg)](https://pkg.go.dev/github.com/graph-gophers/dataloader/v7)

[![Build Status](https://travis-ci.org/graph-gophers/dataloader.svg?branch=master)](https://travis-ci.org/graph-gophers/dataloader)

This is an implementation of [Facebook's DataLoader](https://github.com/facebook/dataloader) in Golang.

## Install

`go get -u github.com/graph-gophers/dataloader`

## Usage

```go

// setup batch function - the first Context passed to the Loader's Load

// function will be provided when the batch function is called.

batchFn := func(ctx context.Context, keys dataloader.Keys) []*dataloader.Result {

  var results []*dataloader.Result

  // do some async work to get data for specified keys

  // append to this list resolved values

  return results

}

// create Loader with an in-memory cache

loader := dataloader.NewBatchedLoader(batchFn)

/**

 * Use loader

 *

 * A thunk is a function returned from a function that is a

 * closure over a value (in this case an interface value and error).

 * When called, it will block until the value is resolved.

 *

 * loader.Load() may be called multiple times for a given batch window.

 * The first context passed to Load is the object that will be passed

 * to the batch function.

 */

thunk := loader.Load(context.TODO(), dataloader.StringKey("key1")) // StringKey is a convenience method that make wraps string to implement `Key` interface

result, err := thunk()

if err != nil {

  // handle data error

}

log.Printf("value: %#v", result)

```

### Don't need/want to use context?

You're welcome to install the v1 version of this library.

## Cache

This implementation contains a very basic cache that is intended only to be used for short lived DataLoaders (i.e. DataLoaders that only exist for the life of an http request). You may use your own implementation if you want.

> it also has a `NoCache` type that implements the cache interface but all methods are noop. If you do not wish to cache anything.

## Examples

There are a few basic examples in the example folder.