[Libguestfs] [PATCH nbdkit v4 6/7] python: Implement can_fua and can_cache.

--- plugins/python/nbdkit-python-plugin.pod | 18 +++++++- plugins/python/python.c | 58 +++++++++++++++++++++++++ 2 files changed, 74 insertions(+), 2 deletions(-) diff --git a/plugins/python/nbdkit-python-plugin.pod b/plugins/python/nbdkit-python-plugin.pod index a0b4d90..0b31ebc 100644 --- a/plugins/python/nbdkit-python-plugin.pod +++ b/plugins/python/nbdkit-python-plugin.pod @@ -229,6 +229,22 @@ contents will be garbage collected. def can_fast_zero(h): # return a boolean +=item C<can_fua> + +(Optional) + + def can_fua(h): + # return nbdkit.FUA_NONE or nbdkit.FUA_EMULATE + # or nbdkit.FUA_NATIVE + +=item C<can_cache> + +(Optional) + + def can_cache(h): + # return nbdkit.CACHE_NONE or nbdkit.CACHE_EMULATE + # or nbdkit.CACHE_NATIVE + =item C<pread> (Required) @@ -349,8 +365,6 @@ C<longname>, C<description>, C<config_help>, C<magic_config_key>, -C<can_fua>, -C<can_cache>, C<can_extents>, C<extents>. diff --git a/plugins/python/python.c b/plugins/python/python.c index 12f45f7..252ca37 100644 --- a/plugins/python/python.c +++ b/plugins/python/python.c @@ -808,6 +808,62 @@ py_can_fast_zero (void *handle) return boolean_callback (handle, "can_fast_zero", NULL); } +static int +py_can_fua (void *handle) +{ + PyObject *obj = handle; + PyObject *fn; + PyObject *r; + int ret; + + if (callback_defined ("can_fua", &fn)) { + PyErr_Clear (); + + r = PyObject_CallFunctionObjArgs (fn, obj, NULL); + Py_DECREF (fn); + if (check_python_failure ("can_fua") == -1) + return -1; + ret = PyLong_AsLong (r); + Py_DECREF (r); + return ret; + } + /* No Python ‘can_fua’, but check if there's a Python ‘flush’ + * callback defined. (In C modules, nbdkit would do this). + */ + else if (callback_defined ("flush", NULL)) + return NBDKIT_FUA_EMULATE; + else + return NBDKIT_FUA_NONE; +} + +static int +py_can_cache (void *handle) +{ + PyObject *obj = handle; + PyObject *fn; + PyObject *r; + int ret; + + if (callback_defined ("can_cache", &fn)) { + PyErr_Clear (); + + r = PyObject_CallFunctionObjArgs (fn, obj, NULL); + Py_DECREF (fn); + if (check_python_failure ("can_cache") == -1) + return -1; + ret = PyLong_AsLong (r); + Py_DECREF (r); + return ret; + } + /* No Python ‘can_cache’, but check if there's a Python ‘cache’ + * callback defined. (In C modules, nbdkit would do this). + */ + else if (callback_defined ("cache", NULL)) + return NBDKIT_CACHE_NATIVE; + else + return NBDKIT_CACHE_NONE; +} + #define py_config_help \ "script=<FILENAME> (required) The Python plugin to run.\n" \ "[other arguments may be used by the plugin that you load]" @@ -837,6 +893,8 @@ static struct nbdkit_plugin plugin = { .can_trim = py_can_trim, .can_zero = py_can_zero, .can_fast_zero = py_can_fast_zero, + .can_fua = py_can_fua, + .can_cache = py_can_cache, .pread = py_pread, .pwrite = py_pwrite, -- 2.23.0