search for: pymemoryview_frommemori

Passing a memoryview we avoid unneeded copy of the original buffer. On the python side memoryview object can be used for slicing, writing to file, or sending to socket. This may break plugins assuming that the they get a bytearray, but good python code should not care about the type of the buffer, only about the behaviour. Testing with a plugin writing to /dev/null shows 2.7x speedup. Real

It's more efficient if we pass the C buffer directly to Python code. In some cases the Python code will be able to write directly into the C buffer using functions like file.readinto and socket.recv_into. This avoids an extra copy. Thanks: Nir Soffer --- plugins/python/example.py | 8 ++++--- plugins/python/nbdkit-python-plugin.pod | 16 +++++-------- plugins/python/python.c

When I added .can_FOO caching in 1.16, I missed the case that the sh plugin itself was calling .can_flush twice in some situations (in order to default .can_fua). Then right after, I regressed it to call .can_zero twice (in order to default .can_fast_zero). I also missed that .thread_model could use better caching, because at the time, I did not add testsuite coverage. Fix that now. Eric Blake

As suggested by Nir, here: https://www.redhat.com/archives/libguestfs/2019-November/thread.html#00220

v3 was here: https://www.redhat.com/archives/libguestfs/2019-November/msg00209.html In v4: - Rebase on top of current master. Includes various fixes and updates required because of Nir's patches that went into master. - Fix api_version() -> API_VERSION in patch 2 noted previously on the mailing list. Rich.

As mentioned in my reviews, I wonder if we should make our python callbacks look a bit more Pythonic by having kwargs added for each new flag that we want to expose. The idea was first floated here: https://www.redhat.com/archives/libguestfs/2018-April/msg00108.html Note that with my proposal, there is no need for a python script to expose a global API_VERSION variable; new flags are added