send varint without deleting CodedOutputStream, ZeroCopyOutputStream - c++

Question

My application sends varints many times. Every time I have to allocate memory for 2 objetcs: CodedOutputStream and FileOutputStream and later relese it. IMO it is unnecessary time loss. How can I send the varint without all this process? (I don't want to do it manually but with protobuf)
I have found it:
delete coded_output;
/* delete raw_output;*/
((FileOutputStream*)raw_output)->Flush();
but still there is one object to allocate every time
void Connection::send(const Message& msg) throw(EmptyMessage) {
//CodedOutputStream* coded_output = new CodedOutputStream(raw_output);
CodedOutputStream coded_output(raw_output);
int n = msg.ByteSize();
if(n<=0) throw EmptyMessage();
//coded_output->WriteVarint32(n);
coded_output.WriteVarint32(n);
//delete coded_output;
coded_output.~CodedOutputStream();
raw_output->Flush();
msg.SerializeToArray(buffer, n);
SocketMaintenance::write(buffer, n);
}
Annoucement Connection::receive() throw(EmptySocket) {
//CodedInputStream* coded_input = new CodedInputStream(raw_input);
CodedInputStream coded_input(raw_input);
google::protobuf::uint32 n;
//coded_input->ReadVarint32(&n);
coded_input.ReadVarint32(&n);
char *b;
int m;
//coded_input->GetDirectBufferPointer((const void**)&b, &m);
coded_input.GetDirectBufferPointer((const void**)&b, &m);
Annoucement ann;
ann.ParseFromArray(b, n);
return ann;
}
When I use the code above, I get this error (runtime error) from my client application (this apps uses only the send function):
libprotobuf FATAL
google/protobuf/io/zero_copy_stream_impl_lite.cc:346]
CHECK failed: (buffer_used_) ==
(buffer_size_): BackUp() can only be
called after Next(). terminate called
after throwing an instance of
'google::protobuf::FatalException'
what(): CHECK failed: (buffer_used_)
== (buffer_size_): BackUp() can only be called after Next(). Stopped
When I use the commented out part of code instead the corresponding one all works fine.

Answer 1

You don't have to allocate the CodedOutputStream on the heap, you can just declare it as a local variable (or class member) where you need it. It doesn't look like the constructor is particularly expensive.
Are you always writing to the same file? If so you can just use a single CodedOuputStream and FileOutputStream for all the writes.