similar to: [PATCH libnbd] python: Add AIO buffer is_zero method.

Create a class for AIO buffers. This is a mostly neutral code refactoring, but we add a convenient function for getting the size of the buffer (same as previous commit for OCaml). --- generator/generator | 111 +++++++++++++++++------------ python/handle.c | 26 +++++-- python/t/500-aio-pread.py | 4 +- python/t/505-aio-pread-callback.py | 10 +--

Currently this adds two useful header files containing functions which will be consumed by filters in later commits. --- Makefile.am | 5 +++- common/include/Makefile.am | 39 ++++++++++++++++++++++++ common/include/ispowerof2.h | 50 +++++++++++++++++++++++++++++++ common/include/iszero.h | 60 +++++++++++++++++++++++++++++++++++++ configure.ac | 1 + 5

On 1/30/20 8:05 AM, Richard W.M. Jones wrote: > Fast testing whether the AIO buffer (or regions within it) contain all > zeroes, which allows Python code to quickly do sparsification when > copying. > > This includes the iszero.h header from nbdkit which is distributed > under a compatible license. > --- > common/include/Makefile.am | 5 +-- >

On Thu, Jan 30, 2020 at 02:29:21PM +0000, Richard W.M. Jones wrote: >On Thu, Jan 30, 2020 at 08:16:30AM -0600, Eric Blake wrote: >> On 1/30/20 8:05 AM, Richard W.M. Jones wrote: >> >Fast testing whether the AIO buffer (or regions within it) contain all >> >zeroes, which allows Python code to quickly do sparsification when >> >copying. >> > >>

On Wed, Aug 1, 2018 at 2:14 PM Richard W.M. Jones <rjones@redhat.com> wrote: > Currently this adds two useful header files containing functions which > will be consumed by filters in later commits. > --- > Makefile.am | 5 +++- > common/include/Makefile.am | 39 ++++++++++++++++++++++++ > common/include/ispowerof2.h | 50 +++++++++++++++++++++++++++++++

On Thu, Jan 30, 2020 at 08:16:30AM -0600, Eric Blake wrote: > On 1/30/20 8:05 AM, Richard W.M. Jones wrote: > >Fast testing whether the AIO buffer (or regions within it) contain all > >zeroes, which allows Python code to quickly do sparsification when > >copying. > > > >This includes the iszero.h header from nbdkit which is distributed > >under a compatible

On Wed, Aug 01, 2018 at 04:24:58PM +0300, Nir Soffer wrote: > On Wed, Aug 1, 2018 at 2:14 PM Richard W.M. Jones <rjones at redhat.com> wrote: > > > Currently this adds two useful header files containing functions which > > will be consumed by filters in later commits. > > --- > > Makefile.am | 5 +++- > > common/include/Makefile.am | 39

This is largely a simple refactoring, but it combines another definition of this function from virt-builder which had a slightly different prototype. --- builder/pxzcat-c.c | 20 +------------------- daemon/daemon.h | 18 ------------------ lib/guestfs-internal-all.h | 18 ++++++++++++++++++ 3 files changed, 19 insertions(+), 37 deletions(-) diff --git a/builder/pxzcat-c.c

On Thu, Jan 30, 2020 at 04:16:09PM +0100, Martin Kletzander wrote: > I know this probably got answered somewhere, but I've never gotten > any when asking myself. So let me use this opportunity. > > Because I really despise useless processes and duplicated > information I always hated the way all the "mandatory" file headers. > As far as I understand it's

On 04/19/2017 09:17 AM, Richard W.M. Jones wrote: > This is largely a simple refactoring, but it combines another > definition of this function from virt-builder which had a slightly > different prototype. > --- > +/* Return true iff the buffer is all zero bytes. > + * > + * Note that gcc is smart enough to optimize this properly: > + *

On Wednesday, 19 April 2017 18:46:37 CEST Richard W.M. Jones wrote: > v1 -> v2: > > The first patch is the same (the pure refactoring), but in the second > patch I implement Eric Blake's suggested version. LGTM -- can you please add Eric's text to the comment of is_zero, so it is easier to remember why the 16-bytes trick is done? Thanks, -- Pino Toscano

It's useful to be able to search for the next non-zero entry in a bitmap. This commit adds a ?bitmap_next? function to do that. Because the bitmap is just a uint8_t buffer, using fast string functions we should be able to do this quickly even if the bitmap is sparse. (However the actual implementation is not optimized since that is quite complicated - see to-do comments in

On Wed, Apr 19, 2017 at 09:35:16AM -0500, Eric Blake wrote: > On 04/19/2017 09:17 AM, Richard W.M. Jones wrote: > > This is largely a simple refactoring, but it combines another > > definition of this function from virt-builder which had a slightly > > different prototype. > > --- > > > +/* Return true iff the buffer is all zero bytes. > > + * > > +

Annotate some function parameters with attribute((nonnull)). Only do this for internal headers where we are sure that we will be using sufficiently recent GCC or Clang. For the public header files (ie. include/nbdkit-*.h) it may be that people building out of tree plugins are using old GCC which had problems, or even other compilers that don't support this extension at all. Libvirt has an

v1 -> v2: The first patch is the same (the pure refactoring), but in the second patch I implement Eric Blake's suggested version. Rich.

Hi there, I am currently trying to create an LLVM Backend for a RISC architecture and running into problems with setCC and brcond. First a few explanations: The architecture doesn't have a dedicated flag register, but seven 1-bit-wide so called "condition registers", c0-c6, which can be set by e.g. a compare instruction: > cmp ne, c0, r1, 123 It also supports conditional

If we compare the "common" subdirectory between nbdkit @ 6b4178d0fdfe ("ci: Temporarily disable perl in MacOS", 2023-02-27) and libnbd @ d05cd8f384a7 ("Version 1.15.11.", 2023-02-28), we find differences. We can categorize these differences along two (orthogonal) axes: - Intentional or unintentional. Intentional differences are for example when one of the libnbd

I have dropped the map filter from this series for now while I try to get it working. However I think the truncate filter is in a good shape. This incorporates all feedback from Eric's review. Also there are three small fixes to the filter code, all revealed when I was testing using multiple filters which we'd not done much of before. Rich.

When sparse_array_zero() is used for a range larger than a page, there's no need to waste time in memset() or is_zero() - we already know the page will be free()d. Signed-off-by: Eric Blake <eblake@redhat.com> --- Here's a fun one :) common/sparse/sparse.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/common/sparse/sparse.c b/common/sparse/sparse.c

On Tue, Jul 07, 2020 at 09:51:53AM -0500, Eric Blake wrote: > While we support compilation with CFLAGS=-DNDEBUG for the brave user > desiring to avoid assertion overhead, this causes the tests to be less > powerful. Fortunately, a quick test of './configure CFLAGS=-DNDEBUG' > didn't hit any test failures, but it seems better to just ensure that > assertions always work