Re: [Libguestfs] [PATCH libnbd 2/9] generator: Generalize OFlags.
On 8/10/19 8:02 AM, Richard W.M. Jones wrote:
In a future commit we want to add (non-optional) Flags arg. As a
step
to doing this, generalize OFlags so it's not tied to just
NBD_CMD_FLAG_*.
This does not change the C API.
It does introduce a small change to the OCaml API -- putting related
flags into a submodule, basically renaming them. Note we don't
provide guarantees for non-C APIs.
And even if we decide to provide guarantees for non-C, we're not at 1.0
yet ;)
@@ -1387,7 +1403,7 @@ Returns the size in bytes of the NBD
export."
"pread", {
default_call with
args = [ BytesOut ("buf", "count"); UInt64 "offset"
];
- optargs = [ OFlags "flags" ];
+ optargs = [ OFlags ("flags", cmd_flags) ];
Do we want to use this as a chance to document which flags a given API
supports? For example, pread supports DF but not FUA, REQ_ONE, or
MAY_TRIM. Then again, there's still a dynamic element - the API
supports the DF flag for compilation, but the server must also support
it (nbd_can_df) before you can use it. So any further restrictions we
decide to encode in the generator rather (or in addition) to
restrictions in lib/rw.c can be a later patch.
+++ b/ocaml/tests/test_405_pread_structured.ml
@@ -54,11 +54,13 @@ let () =
NBD.pread_structured nbd buf 0_L (f 42);
assert (buf = expected);
- NBD.pread_structured nbd buf 0_L (f 42) ~flags:[NBD.cmd_flag_df];
+ let flags = let open NBD.CMD_FLAG in [DF] in
+
+ NBD.pread_structured nbd buf 0_L (f 42) ~flags;
blank line here...
+++ b/ocaml/tests/test_410_pwrite.ml
@@ -33,7 +33,8 @@ let () =
let nbd = NBD.create () in
NBD.connect_command nbd ["nbdkit"; "-s";
"--exit-with-parent"; "-v";
"file"; datafile];
- NBD.pwrite nbd buf1 0_L ~flags:[NBD.cmd_flag_fua];
+ let flags = let open NBD.CMD_FLAG in [FUA] in
+ NBD.pwrite nbd buf1 0_L ~flags;
...but not here. It doesn't affect the code, but the consistency may be
worth it.
This and patch 1 look fine to me.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
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