Hist: A Simple Eventstore in Go.

A data store for event sourced applications.

Usage

//Saving and retrieving events.
package main

import (
	"fmt"

	"github.com/robertreppel/hist/storage/leveldb"
)

const eventDataDirectory = "db"

func main() {
	eventStore, err := leveldb.Store(eventDataDirectory)
	failIf(err)

	aggregateType := "Customer"
	aggregateID := "12345"
	streamID := aggregateType + "-" + aggregateID
	eventType := "CustomerCreated"
	eventData := []byte("Bill Smith")
	err = eventStore.Save(streamID, eventType, eventData)
	failIf(err)

	eventHistory, err := eventStore.Get(aggregateType + "-" + aggregateID)
	failIf(err)

	fmt.Printf("Event: '%s' Event data: '%s'\n", eventHistory[0].Type, string(eventHistory[0].Data))
	// Output: Event: 'CustomerCreated' Event data: 'Bill Smith'
}

func failIf(err error) {
	if err != nil {
		panic(err)
	}
}

Full (minimalist) event sourcing example:

cd examples/planets
go get
go build
./planets

Tests

go test ./storage/leveldb/ . ./examples/trackmyships/ship/

Or use http://goconvey.co/. Run it to see BDD-style details about hist's business rules and behaviour:

goconvey

Production Use

Hist is considered alpha. Not safe for production use.

TODO: Optimistic Locking

Does not do (yet) support optimistic locking.