kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Linus Torvalds	eb4d0e3f45	optimize diffcore-delta by sorting hash entries. Here's a test-patch. I don't guarantee anything, except that when I did the timings I also did a "wc" on the result, and they matched.. Before: [torvalds@woody linux]$ time git diff -l0 --stat -C v2.6.22.. \| wc 7104 28574 438020 real 0m10.526s user 0m10.401s sys 0m0.136s After: [torvalds@woody linux]$ time ~/git/git diff -l0 --stat -C v2.6.22.. \| wc 7104 28574 438020 real 0m8.876s user 0m8.761s sys 0m0.128s but the diff is fairly simple, so if somebody will go over it and say whether it's likely to be correct too, that 15% may well be worth it. [ Side note, without rename detection, that diff takes just under three seconds for me, so in that sense the improvement to the rename detection itself is larger than the overall 15% - it brings the cost of just rename detection from 7.5s to 5.9s, which would be on the order of just over a 20% performance improvement. ] Hmm. The patch depends on half-way subtle issues like the fact that the hashtables are guaranteed to not be full => we're guaranteed to have zero counts at the end => we don't need to do any steenking iterator count in the loop. A few comments might in order. Linus	17 years ago
Junio C Hamano	29a3eefde1	Introduce diff_filespec_is_binary() This replaces an explicit initialization of filespec->is_binary field used for rename/break followed by direct access to that field with a wrapper function that lazily iniaitlizes and accesses the field. We would add more attribute accesses for the use of diff routines, and it would be better to make this abstraction earlier. Signed-off-by: Junio C Hamano <gitster@pobox.com>	18 years ago
Junio C Hamano	b9905fed7a	diffcore-delta.c: Ignore CR in CRLF for text files This ignores CR byte in CRLF sequence in text file when computing similarity of two blobs. Usually this should not matter as nobody sane would be checking in a file with CRLF line endings to the repository (they would use autocrlf so that the repository copy would have LF line endings). Signed-off-by: Junio C Hamano <gitster@pobox.com>	18 years ago
Junio C Hamano	af3abef94a	diffcore-delta.c: update the comment on the algorithm. The comment at the top of the file described an old algorithm that was neutral to text/binary differences (it hashed sliding window of N-byte sequences and counted overlaps), but long time ago we switched to a new heuristics that are more suitable for line oriented (read: text) files that are much faster. Signed-off-by: Junio C Hamano <gitster@pobox.com>	18 years ago
Junio C Hamano	d8c3d03a0b	diffcore_count_changes: pass diffcore_filespec We may want to use richer information on the data we are dealing with in this function, so instead of passing a buffer address and length, just pass the diffcore_filespec structure. Existing callers always call this function with parameters taken from a filespec anyway, so there is no functionality changes. Signed-off-by: Junio C Hamano <gitster@pobox.com>	18 years ago
Linus Torvalds	e31c9f241a	diffcore-delta: 64-byte-or-EOL ultrafast replacement (hash fix). The rotating 64-bit number was not really rotating, and worse yet ulong was longer than 64-bit on 64-bit architectures X-<. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Linus Torvalds	3c7ceba4f1	diffcore-delta: 64-byte-or-EOL ultrafast replacement. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	fc66d213f8	diffcore-delta: tweak hashbase value. This tweaks the maximum hashvalue we use to hash the string into without making the maximum size of the hashtable can grow from the current limit. With this, the renames detected becomes a bit more precise without incurring additional paging cost. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	2821104db7	diffcore-delta: make the hash a bit denser. To reduce wasted memory, wait until the hash fills up more densely before we rehash. This reduces the working set size a bit further. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	c06c79667c	diffcore-rename: somewhat optimized. This changes diffcore-rename to reuse statistics information gathered during similarity estimation, and updates the hashtable implementation used to keep track of the statistics to be denser. This seems to give better performance. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	ba23bbc8ef	diffcore-delta: make change counter to byte oriented again. The textual line oriented change counter was fun but was not very effective. It tended to overcount the changes. This one changes it to a simple N-letter substring based implementation. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	e29e1147e4	diffcore-delta: stop using deltifier for packing. This switches the change estimation logic used by break, rename and copy detection from delta packing code to a more line oriented one. This way, thee performance-density tradeoff by delta packing code can be made without worrying about breaking the rename detection. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	65416758cd	diffcore-rename: split out the delta counting code. This is to rework diffcore break/rename/copy detection code so that it does not affected when deltifier code gets improved. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago

12 Commits (e5f591720caea0c6645fa9852903a1c43d7c3672)