Reference memory into an evbuffer without copying.
The memory needs to remain valid until all the added data has been
read. This function keeps just a reference to the memory without
actually incurring the overhead of a copy.
@param outbuf the output buffer
@param data the memory to reference
@param datlen how memory to reference
@param cleanupfn callback to be invoked when the memory is no longer
referenced by this evbuffer.
@param cleanupfn_arg optional argument to the cleanup callback
@return 0 if successful, or -1 if an error occurred
Reference memory into an evbuffer without copying.
The memory needs to remain valid until all the added data has been read. This function keeps just a reference to the memory without actually incurring the overhead of a copy.
@param outbuf the output buffer @param data the memory to reference @param datlen how memory to reference @param cleanupfn callback to be invoked when the memory is no longer referenced by this evbuffer. @param cleanupfn_arg optional argument to the cleanup callback @return 0 if successful, or -1 if an error occurred