Merge branch 'alloc-unsafe' of https://github.com/chkimes/amqplib int…

…o chkimes-alloc-unsafe

lib/connection.js

@@ -560,7 +560,10 @@ C.sendMessage = function(channel,
   var allLen = methodHeaderLen + bodyLen;
 
   if (allLen < SINGLE_CHUNK_THRESHOLD) {
-    var all = Buffer.alloc(allLen);
+    // Use `allocUnsafe` to avoid excessive allocations and CPU usage
+    // from zeroing. The returned Buffer is not zeroed and so must be
+    // completely filled to be used safely.
+    var all = Buffer.allocUnsafe(allLen);
     var offset = mframe.copy(all, 0);
     offset += pframe.copy(all, offset);
 
@@ -570,7 +573,10 @@ C.sendMessage = function(channel,
   }
   else {
     if (methodHeaderLen < SINGLE_CHUNK_THRESHOLD) {
-      var both = Buffer.alloc(methodHeaderLen);
+      // Use `allocUnsafe` to avoid excessive allocations and CPU usage
+      // from zeroing. The returned Buffer is not zeroed and so must be
+      // completely filled to be used safely.
+      var both = Buffer.allocUnsafe(methodHeaderLen);
       var offset = mframe.copy(both, 0);
       pframe.copy(both, offset);
       buffer.write(both);