This gets rid of some more big memsets. It may replace them
with a lot of tiny mallocs, though. If this turns out to be
a bad idea then at least we can easily revert the change.
We really do need some large buffers for BtrfsIoctlSearchKey in some
cases, but we don't need to zero them out first. Don't do that so we
save some CPU.
Reduce the default buffer size to 4K because most BISK users don't get
need much more than 1K. Set the buffer size explicitly to the product of
the number of items and the desired item size in the places that really
need a lot of items.
The current crc64 algorithm is a variant of the Redis implementation.
Change it to a variant of the Adler implementation as described
at https://matt.sh/redis-crcspeed
Test program at https://github.com/PeeJay/crc64-compare
Filesize: 1.1G
Asking crc64-redis to sum "/media/peejay/BTRFS/1/ubuntu-14.04.5-desktop-amd64.iso"...
Asking crc64-adler to sum "/media/peejay/BTRFS/1/ubuntu-14.04.5-desktop-amd64.iso"...
Redis CRC-64: f971f9ac6c8ba458
Adler CRC-64: f971f9ac6c8ba458
Adler throughput: 1659.913308 MB/s
Redis throughput: 437.284661 MB/s
Adler is 3.79x faster than Redis
Signed-off-by: Paul Jones <paul@pauljones.id.au>
It turns out we never use a value for m_buf_size that isn't the default,
and we also never ask for more than a few thousand items; however,
we do spend a ton of time memsetting the huge buffer to zero.
I don't know what the ideal size is, but 16K is a far better guess
than 1MB. Let's reduce it for some immediate CPU benefit, and determine
what the size should be later.
Reported at https://github.com/Zygo/bees/issues/11
I got a little too enthusiastic when redacting the code, and removed some
overloaded functions bees was using. C++ silently found replacements,
and the result was a bug that prevented any data from being persisted
from the hash table.
Fixes: https://github.com/Zygo/bees/issues/7
I accidentally did a pre-push verification on a 32-bit build host.
There were a surprisingly small number of problems, so fix them.
Bees now builds on a 32-bit host. Let's not update README just yet,
though: the 32-bit ioctl support fails immediately after startup on a
64-bit kernel.
I'm not surprised that GCC 6 doesn't let me send an ostream ref to itself,
even inside an uninstantiated template specialization. I am a little
surprised I was trying to, and 4.9 let me get away with it.
It's 2016. auto_ptr is deprecated now.
Some things were including vector that don't any more.
https://github.com/Zygo/bees/issues/1
