example_test.go

/*
Copyright © 2025 Acronis International GmbH.

Released under MIT license.
*/

package distrlock_test

import (
	"context"
	"database/sql"
	"log"
	"os"
	"time"

	"github.com/acronis/go-dbkit"
	"github.com/acronis/go-dbkit/distrlock"
)

func ExampleDoExclusively() {
	// Setup database connection
	db, err := sql.Open("mysql", os.Getenv("MYSQL_DSN"))
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	ctx := context.Background()

	// Create "distributed_locks" table for locks.
	createTableSQL, err := distrlock.CreateTableSQL(dbkit.DialectMySQL)
	if err != nil {
		log.Fatal(err)
	}
	_, err = db.ExecContext(ctx, createTableSQL)
	if err != nil {
		log.Fatal(err)
	}

	// Do some work exclusively.
	const lockKey = "test-lock-key-1" // Unique key that will be used to ensure exclusive execution among multiple instances
	err = distrlock.DoExclusively(ctx, db, dbkit.DialectMySQL, lockKey, func(ctx context.Context) error {
		time.Sleep(10 * time.Second) // Simulate work.
		return nil
	})
	if err != nil {
		log.Fatal(err)
	}
}

func ExampleNewDBManager() {
	// Setup database connection
	db, err := sql.Open("mysql", os.Getenv("MYSQL_DSN"))
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	// Create DBManager
	lockManager, err := distrlock.NewDBManager(dbkit.DialectMySQL,
		distrlock.WithTableName("my_distributed_locks"))
	if err != nil {
		log.Fatal(err)
	}

	ctx := context.Background()

	// Create table for locks.
	_, err = db.ExecContext(ctx, lockManager.CreateTableSQL())
	if err != nil {
		log.Fatal(err)
	}

	const lockKey = "test-lock-key-2" // Unique key that will be used to ensure exclusive execution among multiple instances

	// Create lock.
	lock, err := lockManager.NewLock(ctx, db, lockKey)
	if err != nil {
		log.Fatal(err)
	}

	// Acquire lock, do some work and release lock.
	const lockTTL = 10 * time.Second
	if err = lock.Acquire(ctx, db, lockTTL); err != nil {
		log.Fatal(err)
	}
	defer func() {
		if err = lock.Release(ctx, db); err != nil {
			log.Fatal(err)
		}
	}()

	time.Sleep(10 * time.Second) // Simulate work
}