In the next commit this will allow to reduce intermediate calls, when
recursing into subtrees - at that stage we know only subtree sha1, and
it is natural for tree walker to start from that phase. For now we do
diff_tree
show_path
diff_tree_sha1
diff_tree
...
and the change will allow to reduce it to
diff_tree
show_path
diff_tree
Also, it will allow to omit allocating strbuf for each subtree, and just
reuse the common strbuf via playing with its len.
The above-mentioned improvements go in the next 2 patches.
The downside is that try_to_follow_renames(), if active, we cause
re-reading of 2 initial trees, which was negligible based on my timings,
and which is outweighed cogently by the upsides.
NOTE To keep with the current interface and semantics, I needed to
rename the function from diff_tree() to diff_tree_sha1(). As
diff_tree_sha1() was already used, and the function we are talking here
is its more low-level helper, let's use convention for prefixing
such helpers with "ll_". So the final renaming is
diff_tree() -> ll_diff_tree_sha1()
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We reworked all its users to use the functionality through
diff_tree_sha1 variant in recent patches (see "tree-diff: allow
diff_tree_sha1 to accept NULL sha1" and what comes next).
diff_tree() is now not used outside tree-diff.c - make it static.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While walking trees, we iterate their entries from lowest to highest in
sort order, so empty tree means all entries were already went over.
If we artificially assign +infinity value to such tree "entry", it will
go after all usual entries, and through the usual driver loop we will be
taking the same actions, which were hand-coded for special cases, i.e.
t1 empty, t2 non-empty
pathcmp(+∞, t2) -> +1
show_path(/*t1=*/NULL, t2); /* = t1 > t2 case in main loop */
t1 non-empty, t2-empty
pathcmp(t1, +∞) -> -1
show_path(t1, /*t2=*/NULL); /* = t1 < t2 case in main loop */
In other words when we have t1 and t2, we return a sign that tells the
caller to indicate the "earlier" one to be emitted, and by returning the
sign that causes the non-empty side to be emitted, we will automatically
cause the entries from the remaining side to be emitted, without
attempting to touch the empty side at all. We can teach
tree_entry_pathcmp() to pretend that an empty tree has an element that
sorts after anything else to achieve this.
Right now we never go to when compared tree descriptors are both
infinity, as this condition is checked in the loop beginning as
finishing criteria, but will do so in the future, when there will be
several parents iterated simultaneously, and some pair of them would run
to the end.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since an earlier "Finally switch over tree descriptors to contain a
pre-parsed entry", we can safely access all tree_desc->entry fields
directly instead of first "extracting" them through
tree_entry_extract.
Use it. The code generated stays the same - only it now visually looks
cleaner.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We moved all action-taking code below show_path() in recent HEAD~~
(tree-diff: move all action-taking code out of compare_tree_entry).
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since previous commit, this function does not compare entry hashes, and
mode are compared fully outside of it. So what it does is compare entry
names and DIR bit in modes. Reflect this in its name.
Add documentation stating the semantics, and move the note about
files/dirs comparison to it.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
- let it do only comparison.
This way the code is cleaner and more structured - cmp function only
compares, and the driver takes action based on comparison result.
There should be no change in performance, as effectively, we just move
if series from on place into another, and merge it to was-already-there
same switch/if, so the result is maybe a little bit faster.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It does, but we'll be reworking it in the next patch after it won't, and
besides it is better to stick to standard
strcmp/memcmp/base_name_compare/etc... convention, where comparison
function returns <0, =0, >0
Regarding performance, comparing for <0, =0, >0 should be a little bit
faster, than switch, because it is just 1 test-without-immediate
instruction and then up to 3 conditional branches, and in switch you
have up to 3 tests with immediate and up to 3 conditional branches.
No worry, that update_tree_entry(t2) is duplicated for =0 and >0 - it
will be good after we'll be adding support for multiparent walker and
will stay that way.
=0 case goes first, because it happens more often in real diffs - i.e.
paths are the same.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently both compare_tree_entry() and show_entry() invoke opt diff
callbacks (opt->add_remove() and opt->change()), and also they both have
code which decides whether to recurse into sub-tree, and whether to emit
a tree as separate entry if DIFF_OPT_TREE_IN_RECURSIVE is set.
I.e. we have code duplication and logic scattered on two places.
Let's consolidate it - all diff emiting code and recurion logic moves
to show_entry, which is now named as show_path, because it shows diff
for a path, based on up to two tree entries, with actual diff emitting
code being kept in new helper emit_diff() for clarity.
What we have as the result, is that compare_tree_entry is now free from
code with logic for diff generation, and also performance is not
affected as timings for
`git log --raw --no-abbrev --no-renames`
for navy.git and `linux.git v3.10..v3.11`, just like in previous patch,
stay the same.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We don't need special code for showing added/removed subtree, because we
can do the same via diff_tree_sha1, just passing NULL for absent tree.
And compared to show_tree(), which was calling show_entry() for every
tree entry, that would lead to the same show_entry() callings:
show_tree(t):
for e in t.entries:
show_entry(e)
diff_tree_sha1(NULL, new): /* the same applies to (old, NULL) */
diff_tree(t1=NULL, t2)
...
if (!t1->size)
show_entry(t2)
...
and possible overhead is negligible, since after the patch, timing for
`git log --raw --no-abbrev --no-renames`
for navy.git and `linux.git v3.10..v3.11` is practically the same.
So let's say goodbye to show_tree() - it removes some code, but also,
and what is important, consolidates more code for showing/recursing into
trees into one place.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is neither used there as input, nor the output written through it, is
used outside.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Because if there is, such two tree entries would never be compared as
equal - the code in base_name_compare() explicitly compares modes, if
there is a change for dir bit, even for equal paths, entries would
compare as different.
The code I'm removing here is from 2005 April 262e82b4 (Fix diff-tree
recursion), which pre-dates base_name_compare() introduction in 958ba6c9
(Introduce "base_name_compare()" helper function) by a month.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move code for finding paths for which diff(commit,parent_i) is not-empty
for all parents to separate function - at present we have generic (and
slow) code for this job, which translates 1 n-parent problem to n
1-parent problems and then intersect results, and will be adding another
limited, but faster, paths scanning implementation in the next patch.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Judging from sample outputs and tests nothing changes in diff -c output,
and this change will help later patches, when we'll be refactoring paths
scanning into its own function with several variants - the
show_log_first logic / code will stay common to all of them.
NOTE: only now we have to take care to explicitly not show anything if
parents array is empty, as in fact there are some clients in Git code,
which calls diff_tree_combined() in such a way.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
where "correct paths" stands for paths that are different to all
parents.
Up until now, we were testing combined diff only on one file, or on
several files which were all different (t4038-diff-combined.sh).
As recent thinko in "simplify intersect_paths() further" showed, and
also, since we are going to rework code for finding paths different to
all parents, lets write at least basic tests.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linus once said:
I actually wish more people understood the really core low-level
kind of coding. Not big, complex stuff like the lockless name
lookup, but simply good use of pointers-to-pointers etc. For
example, I've seen too many people who delete a singly-linked
list entry by keeping track of the "prev" entry, and then to
delete the entry, doing something like
if (prev)
prev->next = entry->next;
else
list_head = entry->next;
and whenever I see code like that, I just go "This person
doesn't understand pointers". And it's sadly quite common.
People who understand pointers just use a "pointer to the entry
pointer", and initialize that with the address of the
list_head. And then as they traverse the list, they can remove
the entry without using any conditionals, by just doing a "*pp =
entry->next".
Applying that simplification lets us lose 7 lines from this function
even while adding 2 lines of comment.
I was tempted to squash this into the original commit, but because
the benchmarking described in the commit log is without this
simplification, I decided to keep it a separate follow-up patch.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The field was used in order to speed-up name comparison and also to
mark removed paths by setting it to 0.
Because the updated code does significantly less strcmp and also
just removes paths from the list and free right after we know a path
will not be needed, it is not needed anymore.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When generating combined diff, for each commit, we intersect diff
paths from diff(parent_0,commit) to diff(parent_i,commit) comparing
all paths pairs, i.e. doing it the quadratic way. That is correct,
but could be optimized.
Paths come from trees in sorted (= tree) order, and so does diff_tree()
emits resulting paths in that order too. Now if we look at diffcore
transformations, all of them, except diffcore_order, preserve resulting
path ordering:
- skip_stat_unmatch, grep, pickaxe, filter
-- just skip elements -> order stays preserved
- break -- just breaks diff for a path, adding path
dup after the path -> order stays preserved
- detect rename/copy -- resulting paths are emitted sorted
(verified empirically)
So only diffcore_order changes diff paths ordering.
But diffcore_order meaning affects only presentation - i.e. only how to
show the diff, so we could do all the internal computations without
paths reordering, and order only resultant paths set. This is faster,
since, if we know two paths sets are all ordered, their intersection
could be done in linear time.
This patch does just that.
Timings for `git log --raw --no-abbrev --no-renames` without `-c` ("git log")
and with `-c` ("git log -c") before and after the patch are as follows:
linux.git v3.10..v3.11
log log -c
before 1.9s 20.4s
after 1.9s 16.6s
navy.git (private repo)
log log -c
before 0.83s 15.6s
after 0.83s 2.1s
P.S.
I think linux.git case is sped up not so much as the second one, since
in navy.git, there are more exotic (subtree, etc) merges.
P.P.S.
My tracing showed that the rest of the time (16.6s vs 1.9s) is usually
spent in computing huge diffs from commit to second parent. Will try to
deal with it, if I'll have time.
P.P.P.S.
For combine_diff_path, ->len is not needed anymore - will remove it in
the next noisy cleanup path, to maintain good signal/noise ratio here.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the next patch combine-diff will have special code-path for taking
orderfile into account. Prepare for making changes by introducing
coverage tests for that case.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diffcore_order() interface only accepts a queue of `struct
diff_filepair`.
In the next patches, we'll want to order `struct combine_diff_path`
by path, so let's first rework diffcore-order to also provide
generic low-level interface for ordering arbitrary objects, provided
they have path accessors.
The new interface is:
- `struct obj_order` for describing objects to ordering routine, and
- order_objects() for actually doing the ordering work.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This continues 4651ece8 (Switch over tree descriptors to contain a
pre-parsed entry) and moves the only rest computational part
mode = canon_mode(mode)
from tree_entry_extract() to tree entry decode phase - to
decode_tree_entry().
The reason to do it, is that canon_mode() is at least 2 conditional
jumps for regular files, and that could be noticeable should canon_mode()
be invoked several times.
That does not matter for current Git codebase, where typical tree
traversal is
while (t->size) {
sha1 = tree_entry_extract(t, &path, &mode);
...
update_tree_entry(t);
}
i.e. we do t -> sha1,path.mode "extraction" only once per entry. In such
cases, it does not matter performance-wise, where that mode
canonicalization is done - either once in tree_entry_extract(), or once
in decode_tree_entry() called by update_tree_entry() - it is
approximately the same.
But for future code, which could need to work with several tree_desc's
in parallel, it could be handy to operate on tree_desc descriptors, and
do "extracts" only when needed, or at all, access only relevant part of
it through structure fields directly.
And for such situations, having canon_mode() be done once in decode
phase is better - we won't need to pay the performance price of 2 extra
conditional jumps on every t->mode access.
So let's move mode canonicalization to decode_tree_entry(). That was the
final bit. Now after tree entry is decoded, it is fully ready and could
be accessed either directly via field, or through tree_entry_extract()
which this time got really "totally trivial".
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since diff_tree_sha1() can now accept empty trees via NULL sha1, we
could just call it without manually reading trees into tree_desc and
duplicating code.
Besides, that
if (!tree)
return 0;
looked suspect - we were saying an invalid tree != empty tree, but maybe it is
better to just say the tree is invalid here, which is what diff_tree_sha1()
does for such case.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since diff_tree_sha1() can now accept empty trees via NULL sha1, we
could just call it without manually reading trees into tree_desc and
duplicating code.
Cc: Thomas Rast <tr@thomasrast.ch>
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now since diff_tree_sha1 understands NULL for both old and new, we could
indicate an empty tree for root commit by providing just NULL for old
sha1.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
which would mean that corresponding tree - old or new - is empty.
As followup patches will show, that functionality was already needed in
several places of Git codebase, but there, we were preparing empty
tree_desc objects by hand, with some code duplication.
For handling sha1 = NULL case, let's reuse fill_tree_descriptor() which
returns just empty tree_desc in that case.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Otherwise there is a race: if 'git log' finishes writing before the
pager terminates and closes the pipe, all is well, and if the pager
finishes quickly enough then 'git log' terminates with SIGPIPE.
died of signal 13 at /build/buildd/git-1.9~rc1/t/test-terminal.perl line 33.
not ok 6 - LESS and LV envvars are set for pagination
Noticed on Ubuntu PPA builders, where the race was lost about half the
time. Compare v1.7.0.2~6^2 (tests: Fix race condition in t7006-pager,
2010-02-22).
Reported-by: Anders Kaseorg <andersk@MIT.EDU>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ta/doc-http-protocol-in-html:
http-protocol.txt: don't use uppercase for variable names in "The Negotiation Algorithm"
Documentation: make it easier to maintain enumerated documents
create HTML for http-protocol.txt
"git repack --max-pack-size=8g" stopped being parsed correctly when
the command was reimplemented in C.
* sb/repack-in-c:
repack: propagate pack-objects options as strings
repack: make parsed string options const-correct
repack: fix typo in max-pack-size option
"git clone $origin foo\bar\baz" on Windows failed to create the
leading directories (i.e. a moral-equivalent of "mkdir -p").
* ss/safe-create-leading-dir-with-slash:
safe_create_leading_directories(): on Windows, \ can separate path components
Code clean-up and protection against concurrent write access to the
ref namespace.
* mh/safe-create-leading-directories:
rename_tmp_log(): on SCLD_VANISHED, retry
rename_tmp_log(): limit the number of remote_empty_directories() attempts
rename_tmp_log(): handle a possible mkdir/rmdir race
rename_ref(): extract function rename_tmp_log()
remove_dir_recurse(): handle disappearing files and directories
remove_dir_recurse(): tighten condition for removing unreadable dir
lock_ref_sha1_basic(): if locking fails with ENOENT, retry
lock_ref_sha1_basic(): on SCLD_VANISHED, retry
safe_create_leading_directories(): add new error value SCLD_VANISHED
cmd_init_db(): when creating directories, handle errors conservatively
safe_create_leading_directories(): introduce enum for return values
safe_create_leading_directories(): always restore slash at end of loop
safe_create_leading_directories(): split on first of multiple slashes
safe_create_leading_directories(): rename local variable
safe_create_leading_directories(): add explicit "slash" pointer
safe_create_leading_directories(): reduce scope of local variable
safe_create_leading_directories(): fix format of "if" chaining
Fix performance regression in v1.8.4.x and later.
* jk/mark-edges-uninteresting:
list-objects: only look at cmdline trees with edge_hint
t/perf: time rev-list with UNINTERESTING commits
* jk/diff-filespec-cleanup:
diff_filespec: use only 2 bits for is_binary flag
diff_filespec: reorder is_binary field
diff_filespec: drop xfrm_flags field
diff_filespec: drop funcname_pattern_ident field
diff_filespec: reorder dirty_submodule macro definitions
The "if /etc/ssl/certs/ directory exists, explicitly telling the
library to use it as SSL_ca_path" blind-defaulting in "git
send-email" broke platforms where /etc/ssl/certs/ directory exists,
but it cannot used as SSL_ca_path (e.g. Fedora rawhide). Fix it by
not specifying any SSL_ca_path/SSL_ca_file but still asking for peer
verification in such a case.
* rk/send-email-ssl-cert:
send-email: /etc/ssl/certs/ directory may not be usable as ca_path
Explicitly list $HOME/.config/git/ignore as one of the places you
can use to keep ignore patterns that depend on your personal choice
of tools, e.g. *~ for Emacs users.
* jn/ignore-doc:
gitignore doc: add global gitignore to synopsis
Fix a handful of bugs around interpreting $branch@{upstream}
notation and its lookalike, when $branch part has interesting
characters, e.g. "@", and ":".
* jk/interpret-branch-name-fix:
interpret_branch_name: find all possible @-marks
interpret_branch_name: avoid @{upstream} past colon
interpret_branch_name: always respect "namelen" parameter
interpret_branch_name: rename "cp" variable to "at"
interpret_branch_name: factor out upstream handling
