initial commit

pkg/locker/locker.go

@@ -0,0 +1,98 @@
+package locker
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/rs/zerolog"
+
+	"github.com/redis/go-redis/v9"
+)
+
+type locker struct {
+	client *redis.Client
+	logger zerolog.Logger
+}
+
+func NewLocker(client *redis.Client, logger zerolog.Logger) Locker {
+	return &locker{
+		client: client,
+		logger: logger,
+	}
+}
+
+func (l locker) Lock(ctx context.Context, id string, ttl time.Duration) (bool, error) {
+	status := l.client.SetNX(ctx, id, "locked", ttl)
+	if err := status.Err(); err != nil {
+		return false, err
+	}
+
+	// Return whether the lock was acquired
+	return status.Val(), nil
+}
+
+func (l locker) Unlock(ctx context.Context, id string) error {
+	// Delete the lock by its ID
+	_, err := l.client.Del(ctx, id).Result()
+	return err
+}
+
+// WithLock acquires a lock for a specific vendor, executes the provided function,
+// and ensures that the lock is released afterward. If any error occurs, it returns the
+// error, preserving the context of the lock operation.
+func (l locker) WithLock(
+	ctx context.Context,
+	lockKey string,
+	lockTime time.Duration,
+	fn func(context.Context) error,
+) error {
+	lg := l.logger.With().
+		Str("method", "WithLock").
+		Str("key", lockKey).
+		Logger()
+
+	maxRetries := 5
+	retryDelay := 10 * time.Millisecond //TODO: Replace with proper logging
+
+	var locked bool
+	var acquireErr error
+
+	for attempt := 0; attempt <= maxRetries; attempt++ {
+		locked, acquireErr = l.Lock(ctx, lockKey, lockTime)
+
+		if locked {
+			lg.Info().Msg("LockAcquired")
+			break
+		}
+
+		if attempt == maxRetries {
+			break
+		}
+
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-time.After(retryDelay):
+			retryDelay *= 2 // Exponential backoff
+		}
+	}
+
+	if !locked || acquireErr != nil {
+		lg.Error().Err(acquireErr).Msg("LockErr")
+		return NewLockError(lockKey, uint32(maxRetries), acquireErr)
+	}
+
+	fnErr := fn(ctx)
+	if fnErr != nil {
+		return fmt.Errorf("failed to execute function for %s due to error %v", lockKey, fnErr)
+	}
+
+	if unlockErr := l.Unlock(ctx, lockKey); unlockErr != nil {
+		return fmt.Errorf("failed to unlock lock for %s: %v", lockKey, unlockErr)
+	}
+
+	lg.Info().Msg("Unlocked")
+
+	return nil
+}