Altera número de goroutines padrão

Adiciona função para definir quantidade com base na variável de ambiente.
Utiliza número de CPUs como fallback para valores inválidos ou não definidos.

Author: jpfaria

wrapper/publisher/driver/contrib/cloud.google.com/pubsub/v1/config.go

@@ -1,6 +1,9 @@
 package pubsub
 
 import (
+	"os"
+	"runtime"
+	"strconv"
 	"time"
 
 	"github.com/xgodev/boost/wrapper/config"
@@ -30,14 +33,26 @@ func init() {
 	ConfigAdd(root)
 }
 
+func getMaxProcs() int {
+	val := os.Getenv("GOMAXPROCS")
+	if val == "" {
+		return runtime.NumCPU() // fallback padrão
+	}
+	n, err := strconv.Atoi(val)
+	if err != nil || n <= 0 {
+		return runtime.NumCPU() // fallback se inválido
+	}
+	return n
+}
+
 func ConfigAdd(path string) {
 	config.Add(path+level, "DEBUG", "defines log level")
 	config.Add(path+orderingKey, false, "defines ordering key")
 
 	config.Add(path+delayThreshold, 10*time.Millisecond, "the maximum duration to wait before sending a batch of messages")
 	config.Add(path+countThreshold, 100, "the maximum number of messages to include in a batch")
 	config.Add(path+byteThreshold, 1e6, "the maximum total size of messages to include in a batch")
-	config.Add(path+numGoroutines, 1, "the number of goroutines that process batches of messages")
+	config.Add(path+numGoroutines, getMaxProcs(), "the number of goroutines that process batches of messages")
 	config.Add(path+timeout, 60*time.Second, "the maximum duration to block Publish calls")
 	config.Add(path+bufferedByteLimit, 10*1e7, "the maximum number of bytes that can be pending in memory across all topics")
 	config.Add(path+maxOutstandingMessages, 1000, "the maximum number of messages that can be pending in memory for publishing")