avro

AVRO-921. C: Default wrapped buffer implementation is zero-copy

The avro_wrapped_buffer_new_copy function creates a default
implementation of the wrapped buffer interface.  It creates a copy of
the data pointer that's passed in, which the wrapped buffer has full
control over.  Before, the wrapped buffer implementation would create
futher copies of the underlying buffer whenever the copy() method was
called.  Now, the wrapped buffer's copy is reference counted, and the
copy() and free() methods avoid making extra copies.


git-svn-id: https://svn.apache.org/repos/asf/avro/trunk@1183637 13f79535-47bb-0310-9956-ffa450edef68