feat(sender): add PoolFromOptions pool constructor (#52)

Author: sklarsa

sender_pool.go

@@ -37,13 +37,19 @@ import (
 //
 // WARNING: This is an experimental API that is designed to work with HTTP senders ONLY.
 type LineSenderPool struct {
+	// options
 	maxSenders int
-	conf       string
 
-	closed bool
+	// presence of a non-empty conf takes precedence over opts
+	conf string
+	opts []LineSenderOption
 
+	// senders are stored here
 	senders []LineSender
-	mu      *sync.Mutex
+
+	// plumbing fields
+	closed bool
+	mu     *sync.Mutex
 }
 
 // LineSenderPoolOption defines line sender pool config option.
@@ -74,6 +80,37 @@ func PoolFromConf(conf string, opts ...LineSenderPoolOption) (*LineSenderPool, e
 	return pool, nil
 }
 
+// PoolFromOptions instantiates a new LineSenderPool using programmatic options.
+// Any sender acquired from this pool will be initialized with the same options
+// that were passed into the opts argument.
+//
+// Unlike [PoolFromConf], PoolFromOptions does not have the ability to customize
+// the returned LineSenderPool. In this case, to add options (such as [WithMaxSenders]),
+// you need manually apply these options after calling this method.
+//
+//	// Create a PoolFromOptions with LineSender options
+//	p, err := PoolFromOptions(
+//		WithHttp(),
+//		WithAutoFlushRows(1000000),
+//	)
+//
+//	if err != nil {
+//		panic(err)
+//	}
+//
+//	// Add Pool-level options manually
+//	WithMaxSenders(32)(p)
+func PoolFromOptions(opts ...LineSenderOption) (*LineSenderPool, error) {
+	pool := &LineSenderPool{
+		maxSenders: 64,
+		opts:       opts,
+		senders:    []LineSender{},
+		mu:         &sync.Mutex{},
+	}
+
+	return pool, nil
+}
+
 // WithMaxSenders sets the maximum number of senders in the pool.
 // The default maximum number of senders is 64.
 func WithMaxSenders(count int) LineSenderPoolOption {
@@ -99,7 +136,19 @@ func (p *LineSenderPool) Acquire(ctx context.Context) (LineSender, error) {
 		return s, nil
 	}
 
-	return LineSenderFromConf(ctx, p.conf)
+	if p.conf != "" {
+		return LineSenderFromConf(ctx, p.conf)
+	} else {
+		conf := newLineSenderConfig(httpSenderType)
+		for _, opt := range p.opts {
+			opt(conf)
+			if conf.senderType == tcpSenderType {
+				return nil, errors.New("tcp/s not supported for pooled senders, use http/s only")
+			}
+		}
+		return newHttpLineSender(conf)
+	}
+
 }
 
 // Release flushes the LineSender and returns it back to the pool. If the pool