Moving the errutil pkg to "internal/errutil" makes errutil private-like
and accessible to only other go-ceph packages. The functions it provided
were always meant to be used only by go-ceph, this just makes it more
official. This is a breaking change but it was only available to
outside users for 1 release and it is somewhat doubtful users outside
of go-ceph would have reached for these functions.
Signed-off-by: John Mulligan <jmulligan@redhat.com>
As per the Go Wiki page on cgo [1] passing callback with data between C
and Go is non-trivial due to the pointer passing rules [2]. This change
creates a new helper type, based on the examples on the wiki, that uses
opaque indexes to exchange between C and Go.
For now, this type is simple as we're only going to have a few callbacks
initially but this could easily be improved and made more general in the
future as needed. Because we anticipate having to use this type in all
of our core packages (rados and cephfs as well as rbd) we are creating
the type in an "internal" package so that we don't treat the new type
as public despite the capitalized method names.
[1]: https://github.com/golang/go/wiki/cgo
[2]: https://golang.org/cmd/cgo/#hdr-Passing_pointers
Signed-off-by: John Mulligan <jmulligan@redhat.com>
