Inspired by some changes made in game of trees, I've
implemented a number of speedups in git9.
First, hashing the chunks during deltification with
murmurhash instead of sha1 speeds up the delta search
significantly.
The stretch function was micro-optimized a bit as well,
since that was taking a large portion of the time when
chunking.
Finally, the full path is not stored. We only care about
grouping files with the same name and path. We don't care
about the ordering. Therefore, only the hash of the path
xored with the hash of the diretory is kept, which saves
a bunch of mallocs and string munging.
This reduces the time spent repacking some test repos
significantly.
9front:
% time git/repack
deltifying 97473 objects: 100%
writing 97473 objects: 100%
indexing 97473 objects: 100%
58.85u 1.39s 61.82r git/repack
% time /sys/src/cmd/git/6.repack
deltifying 97473 objects: 100%
writing 97473 objects: 100%
indexing 97473 objects: 100%
43.86u 1.29s 47.51r /sys/src/cmd/git/6.repack
openbsd:
% time git/repack
deltifying 2092325 objects: 100%
writing 2092325 objects: 100%
indexing 2092325 objects: 100%
1589.48u 45.03s 1729.18r git/repack
% time /sys/src/cmd/git/6.repack
deltifying 2092325 objects: 100%
writing 2092325 objects: 100%
indexing 2092325 objects: 100%
1238.68u 41.49s 1373.15r /sys/src/cmd/git/6.repack
go:
% time git/repack
deltifying 529507 objects: 100%
writing 529507 objects: 100%
indexing 529507 objects: 100%
345.32u 7.71s 369.25r git/repack
% time /sys/src/cmd/git/6.repack
deltifying 529507 objects: 100%
writing 529507 objects: 100%
indexing 529507 objects: 100%
248.07u 4.47s 257.59r /sys/src/cmd/git/6.repack
Checking the range of c|0x60 incorrectly classifies many characters
as alphabetic (digits, control characters 0x01-0x20, and punctuation
characters '!'-':'). This prevents tmparse from parsing dates with
a timezone bounded by those characters (for example, "12:11:56 (PDT)").
Instead, just reuse the isalpha macro provided by ctype.h.
When diffing non-regular files, like /dev/null,
pipes, and similar, diff will generate a temp
file to diff against. This is the right thing
to do, but the temp file leaks into the diff.
This patch retains the original file name all
the way through to diff output.
This code is checking the return of devwalk for
a walk resulting in a clone of an open pipe file. However,
devclone ensures that the chan we are cloning is not
currently open.
The getserv function has remained mostly unchanged since
1ed. These checks are for handling string local ports
or lack thereof. This was used by datakit at the time,
where 'ports' were service strings. This made the default
datakit service 'login' when a connector did not give
a specific service. The checks for directory traversal also
seemed specifically to guard against a connector from providing
a malicious service string. With datakit gone all current protocols
use numerics as ports so these checks and defaults become uneeded.
1ed reference:
https://github.com/plan9foundation/plan9/tree/1e-1992-09-21
This is mostly a copy of port/usbxhci.c with PCIWADDR() replaced
by PADDR() and the pci specific code stripped out.
This could be refactored at a later time.
There is a gpio line for the main hub reset that needs to be
asserted and some power management functions that are currently
done by u-boot (using "usb start" command).
We will do these ourselfs once we have the infrastructure for
it in place.
This is a work in progress port to the mntreform2 laptop.
Working so far:
- mmu (same as raspberry pi 3b+)
- arm generic timer
- gicv3
- uart1
- enet
With access to the uart, one can netboot this kernel in u-boot
using the following commands:
> dhcp
> bootm
devproc allows changing the noteid of another process
which opens a race condition in sysrfork(), when deciding
to inherit the noteid of "up" to the child and calling
pidalloc() later to take the reference, the noteid could
have been changed and the childs noteid could have been
freed already in the process.
this bug can only happen when one writes the /proc/n/noteid
file of a another process than your own that is in the
process of forking.
the noteid changing functionality of devproc seems questinable
and seems to be only used by ape's setpgrid() implementation.
Scrollbar was drawn using a wide dark gutter over a white background
whereas other applications (window, sam, ...) use a thinner scrollbar with an
inverse colorscheme.
This makes the scrollbar more consistent with other 9front applications.
When writing to a large variable in /env, we
spam 'Write error', in spite of the env var
working. This is new behavior, as of commit
b90036a062.
It produces a lot of scary, noisy warnings,
which are probably bogus.
When pushing, git/send would sometimes decide we had all the
objects that we'd need to update the remote, and would try
to pack and send the entire history of the repository. This
is because we only set the 'theirs' ref when we had the object.
If we didn't have the object, we would set a zero hash,
then when deciding if we needed to force, we would think
that we were updating a new branch and send everything,
which would fail to update the remote.
A while ago, qwx noticed that we clobbered the exec
bit when merging files. This is not what we want, so
we changed the operator precedence to avoid merging
dirty files implicitly.
But we do want to merge, because it's convenient for
maintaining permissions. So, instead, we should do a
3 way merge of the exec bit.
This patch does that, as well as reverting the rollback
of that change.
While we're here, we adjust the timestamps correctly
in git/branch.
This requires changes to git/fs, because without an open
handler, lib9p allows opening any file with any mode,
which confuses 'test -x'.
there was a diff that went in a while ago to improve
this, but it got backed out because it encounters a
bug in upstream git -- the spec says that a single
ACK should be sent when not using multi-ack modes,
but they send back multiple ones.
This commit brings back the functionality, and works
around the upstream git bug in two different ways.
First, it skips the packets up until it finds the
start of a pack header.
Second, it deduplicates the want messages, which
is what seems to trigger the duplicate ACKs that
cause us trouble.
This patch makes sam's = cmd output what seems to me a more
useful (plumbable) format: /full/path/to/file:addr , where
addr is line(s) under = and rune(s) under =#.
