Re: [Libguestfs] [PATCH nbdkit v2 02/10] python: Add various constants to the API.

On Fri, Nov 22, 2019 at 9:54 PM Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: > > These are accessible from the plugin by: > > import nbdkit > > if flags & nbdkit.FLAG_MAY_TRIM: > &c. Nice way to expose the flags! > Many (all?) of these are not yet useful for plugins, some will never > be useful, but they only consume a tiny bit of memory and it's nice to > have the complete set available for future use. > --- > plugins/python/python.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/plugins/python/python.c b/plugins/python/python.c > index d65ac45..69cf4e9 100644 > --- a/plugins/python/python.c > +++ b/plugins/python/python.c > @@ -231,6 +231,33 @@ create_nbdkit_module (void) > nbdkit_error ("could not create the nbdkit API module"); > exit (EXIT_FAILURE); > } > + > + /* Constants corresponding to various flags. */ > + PyModule_AddIntConstant (m, "THREAD_MODEL_SERIALIZE_CONNECTIONS", > + NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS); This can fail and needs cleanup. Very unlikely and a lot of code in the standard library have this issue. In sanlock we do: if (PyModule_AddIntConstant(m, "LSFLAG_ADD", SANLK_LSF_ADD)) return -1; And the caller decref the module object and return NULL. See https://github.com/nirs/sanlock/blob/53f7f0284c084ac2e4542fd1f71d0406075a... https://github.com/nirs/sanlock/blob/53f7f0284c084ac2e4542fd1f71d0406075a...

> + PyModule_AddIntConstant (m, "THREAD_MODEL_SERIALIZE_ALL_REQUESTS", > + NBDKIT_THREAD_MODEL_SERIALIZE_ALL_REQUESTS); > + PyModule_AddIntConstant (m, "THREAD_MODEL_SERIALIZE_REQUESTS", > + NBDKIT_THREAD_MODEL_SERIALIZE_REQUESTS); > + PyModule_AddIntConstant (m, "THREAD_MODEL_PARALLEL", > + NBDKIT_THREAD_MODEL_PARALLEL); > + > + PyModule_AddIntConstant (m, "FLAG_MAY_TRIM", NBDKIT_FLAG_MAY_TRIM); > + PyModule_AddIntConstant (m, "FLAG_FUA", NBDKIT_FLAG_FUA); > + PyModule_AddIntConstant (m, "FLAG_REQ_ONE", NBDKIT_FLAG_REQ_ONE); > + PyModule_AddIntConstant (m, "FLAG_FAST_ZERO", NBDKIT_FLAG_FAST_ZERO); > + > + PyModule_AddIntConstant (m, "FUA_NONE", NBDKIT_FUA_NONE); > + PyModule_AddIntConstant (m, "FUA_EMULATE", NBDKIT_FUA_EMULATE); > + PyModule_AddIntConstant (m, "FUA_NATIVE", NBDKIT_FUA_NATIVE); > + > + PyModule_AddIntConstant (m, "CACHE_NONE", NBDKIT_CACHE_NONE); > + PyModule_AddIntConstant (m, "CACHE_EMULATE", NBDKIT_CACHE_EMULATE); > + PyModule_AddIntConstant (m, "CACHE_NATIVE", NBDKIT_CACHE_NATIVE); > + > + PyModule_AddIntConstant (m, "EXTENT_HOLE", NBDKIT_EXTENT_HOLE); > + PyModule_AddIntConstant (m, "EXTENT_ZERO", NBDKIT_EXTENT_ZERO); > + > return m; > } > > -- > 2.23.0 >