README.md

Buffered writes in Go

buffered is a package for buffered writing to a database. It's agnostic to the type of database used. It supports different flushing strategies based on:

1. The maximum amount of time an item should spend in the buffer
2. The maximum size of the buffer
3. The maximum amount of memory in the buffer

This library is used internally by Hatchet, but is meant to be general-purpose. Issues and PRs are welcome.

Usage

Install the package:

go get github.com/hatchet-dev/buffered

Basic usage is as follows:

package main

import (
	"context"
	"fmt"
	"time"

	"github.com/hatchet-dev/buffered"
)

type mockItem struct {
	ID    int
	Size  int
	Value string
}

type mockResult struct {
	ID int
}

func mockFlushFunc(ctx context.Context, items []mockItem) ([]mockResult, error) {
	var results []mockResult
	for _, item := range items {
		results = append(results, mockResult{ID: item.ID})
	}
	return results, nil
}

func mockSizeFunc(item mockItem) int {
	return item.Size
}

func main() {
	opts := buffered.BufferOpts[mockItem, mockResult]{
		Name:        "test",
		MaxCapacity: 2,
		// We set the flush period to be 5 seconds
		FlushPeriod:        5 * time.Second,
		MaxDataSizeInQueue: 100,
		FlushFunc:          mockFlushFunc,
		SizeFunc:           mockSizeFunc,
	}

	b := buffered.NewBuffer(opts)

	cleanup, err := b.Start()
	defer cleanup()

	if err != nil {
		panic(err)
	}

	doneChan, err := b.BuffItem(mockItem{
		ID:    1,
		Size:  10,
		Value: "one",
	})

	if err != nil {
		panic(err)
	}

	// This will return after 5 seconds
	resp := <-doneChan

	fmt.Println(resp.Result)
}