THRIFT-922. cpp: Add shortcutted version of readAll() in TBufferBase

Just perform a memcpy() if all of the requested data is available in the
buffer.  This improves performance a little in the common case.  It has
a bigger impact with the upcoming template changes.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@1005133 13f79535-47bb-0310-9956-ffa450edef68
2 files changed