Commit Graph

5 Commits

Author SHA1 Message Date
John Mulligan ebea82dda5 cutil: add Iovec type wrapping C struct iovec arrays
This type is useful for passing disparate buffers to be read or
written in a single call. Functions using this type exist in cephfs
and rbd. Currently this is needed for cephfs calls.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
2020-08-28 10:07:34 -04:00
Sven Anderson 4706453428 rbd: remove unnecessary C wrapper functions
Signed-off-by: Sven Anderson <sven@redhat.com>
2020-08-28 09:51:06 -04:00
John Mulligan e5d1a53060 cutil: add SplitBuffer and SplitSparseBuffer helper functions
Add SplitBuffer and SplitSparseBuffer functions for extracting a list
of strings from a single buffer, typically returned in C code, from
a single Go buffer. The SplitBuffer variant will return empty strings
if multiple nulls are found in sequence, assuming that the C code
packs data between on single null byte (expect the final byte).
The SplitSparseBuffer variant assumes that the C code may not
tightly pack the data with single null bytes and thus will not
return any empty strings (unless the input buffer is empty
or only contains nulls).
Most of the code in the go-ceph codebase is doing the latter but
probably should have been doing the former. Thus both approaches
are provided.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
2020-07-23 16:38:39 -04:00
John Mulligan e2a78eec02 cutil: allow passing free functions to command output type
The *_command functions in librados and libcephfs document the use
of specific free functions for data allocated. These functions are
currently just wrappers around C's free() function. However, to be
more strictly compliant this change adds a free-function callback
to the CommandOutput type and the specific free functions are now
used outside the unit tests.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
2020-05-12 17:18:08 -04:00
John Mulligan e40744fdf6 cutil: add a new internal package for c+go utility functions
Now we have sufficient boilerplate in our code for interacting with
various types and ceph calls with similar needs we establish a new
internal package, "cutil" (C utilities).

Note that many of the return types are wrapped. This is due to the
limits placed on us by cgo.  Despite the irritating limitations Go
places on "exporting" C types it still ought to help in the long run for
patterns that are very common or patterns that are subtle and we want to
write specific tests for.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
2020-05-12 17:18:08 -04:00