varint: make it available outside the context of pack

Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache.h: hide on-disk index details

The on-disk format of the index file is a detail whose implementation is
neatly encapsulated in read-cache.c; there is no need to expose it to the
general public that include the cache.h header file.

Also add a prominent mark to read-cache.c to delineate the parts that deal
with the index file I/O routines from the remainder of the file.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache.c: allow unaligned mapping of the index file

Both the on-disk format v2 and v3 pads the "name" field to the multiple of
eight to make sure that various quantities in network long/short type can
be accessed with ntohl/ntohs without having to worry about alignment, but
this forces us to waste disk I/O bandwidth.

Introduce ntoh_s()/ntoh_l() macros that the callers can use as if they were
the regular ntohs()/ntohl() on a field that may not be aligned correctly.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache.c: make create_from_disk() report number of bytes it consumed

The function is the one that is reading from the data stream. It only is
natural to make it responsible for reporting this number, not the caller.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache.c: report the header version we do not understand

Instead of just saying "bad index version", report the value we read
from the disk.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache.c: move code to copy ondisk to incore cache to a helper function

This makes the change in a later patch look less scary.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache.c: move code to copy incore to ondisk cache to a helper function

This makes the change in a later patch look less scary.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache.c: read prefix-compressed names in index on-disk version v4

Because the entries are sorted by path, adjacent entries in the index tend
to share the leading components of them, and it makes sense to only store
the differences in later entries.  In the v4 on-disk format of the index,
each on-disk cache entry stores the number of bytes to be stripped from
the end of the previous name, and the bytes to append to the result, to
come up with its name.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
read-cache.c: write prefix-compressed names in the index

Teach the code to write the index in the v4 on-disk format.

Record the format version of the on-disk index we read from in the
index_state, and use the format when writing the new index out.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
update-index: upgrade/downgrade on-disk index version

With the "--index-version <n>" parameter, write the index out in the
specified version.  With this, an index file that is written in newer
format (say v4) can be downgraded to be read by older versions of Git.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
xdiff: load full words in the inner loop of xdl_hash_record

Redo the hashing loop in xdl_hash_record in a way that loads an entire
'long' at a time, using masking tricks to see when and where we found
the terminating '\n'.

I stole inspiration and code from the posts by Linus Torvalds around

  https://lkml.org/lkml/2012/3/2/452
  https://lkml.org/lkml/2012/3/5/6

His method reads the buffers in sizeof(long) increments, and may thus
overrun it by at most sizeof(long)-1 bytes before it sees the final
newline (or hits the buffer length check).  I considered padding out
all buffers by a suitable amount to "catch" the overrun, but

* this does not work for mmap()'d buffers: if you map 4096+8 bytes
  from a 4096 byte file, accessing the last 8 bytes results in a
  SIGBUS on my machine; and

* it would also be extremely ugly because it intrudes deep into the
  unpacking machinery.

So I adapted it to not read beyond the buffer at all.  Instead, it
reads the final partial word byte-by-byte and strings it together.
Then it can use the same logic as before to finish the hashing.

So far we enable this only on x86_64, where it provides nice speedup
for diff-related work:

  Test                                  origin/next      tr/xdiff-fast-hash
  -----------------------------------------------------------------------------
  4000.1: log -3000 (baseline)          0.07(0.05+0.02)  0.08(0.06+0.02) +14.3%
  4000.2: log --raw -3000 (tree-only)   0.37(0.33+0.04)  0.37(0.32+0.04) +0.0%
  4000.3: log -p -3000 (Myers)          1.75(1.65+0.09)  1.60(1.49+0.10) -8.6%
  4000.4: log -p -3000 --histogram      1.73(1.62+0.09)  1.58(1.49+0.08) -8.7%
  4000.5: log -p -3000 --patience       2.11(2.00+0.10)  1.94(1.80+0.11) -8.1%

Perhaps other platforms could also benefit.  However it does NOT work
on big-endian systems!

[jc: minimum style and compilation fixes]

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
l10n: Updated pt_PT language
l10n: New da.po file with 0 translations
l10n: Add Danish team (da) to list of teams
t4052: test --stat output with --graph

Add tests which show that the width of the --prefix added by --graph
is not taken into consideration when the diff stat output width is
calculated.

Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Lucian Poston <lucian.poston@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add output_prefix_length to diff_options

Add output_prefix_length to diff_options. Initialize the value to 0 and only
set it when graph.c:diff_output_prefix_callback() is called.

Signed-off-by: Lucian Poston <lucian.poston@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adjust stat width calculations to take --graph output into account

The recent change to compute the width of diff --stat did not take into
consideration the output from --graph. The consequence is that when both
options are used, e.g. in 'log --stat --graph', the lines are too long.

Adjust stat width calculations to take --graph output into account.

Signed-off-by: Lucian Poston <lucian.poston@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4052: Adjust --graph --stat output for prefixes

Adjust tests to verify that the commit history graph tree is taken into
consideration when the diff stat output width is calculated.

Signed-off-by: Lucian Poston <lucian.poston@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4052: Test diff-stat output with minimum columns

When COLUMNS or --stat-width restricts the diff-stat width to near the
minimum, 26 columns, the graph_width value becomes negative. Consequently, the
graph part of diff-stat is not resized properly.

Signed-off-by: Lucian Poston <lucian.poston@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prevent graph_width of stat width from falling below min

Update tests in t4052 fixed by this change.

Signed-off-by: Lucian Poston <lucian.poston@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>