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2006-05-30tree_entry(): new tree-walking helper functionLibravatar Linus Torvalds1-2/+31
This adds a "tree_entry()" function that combines the common operation of doing a "tree_entry_extract()" + "update_tree_entry()". It also has a simplified calling convention, designed for simple loops that traverse over a whole tree: the arguments are pointers to the tree descriptor and a name_entry structure to fill in, and it returns a boolean "true" if there was an entry left to be gotten in the tree. This allows tree traversal with struct tree_desc desc; struct name_entry entry; desc.buf = tree->buffer; desc.size = tree->size; while (tree_entry(&desc, &entry) { ... use "entry.{path, sha1, mode, pathlen}" ... } which is not only shorter than writing it out in full, it's hopefully less error prone too. [ It's actually a tad faster too - we don't need to recalculate the entry pathlength in both extract and update, but need to do it only once. Also, some callers can avoid doing a "strlen()" on the result, since it's returned as part of the name_entry structure. However, by now we're talking just 1% speedup on "git-rev-list --objects --all", and we're definitely at the point where tree walking is no longer the issue any more. ] NOTE! Not everybody wants to use this new helper function, since some of the tree walkers very much on purpose do the descriptor update separately from the entry extraction. So the "extract + update" sequence still remains as the core sequence, this is just a simplified interface. We should probably add a silly two-line inline helper function for initializing the descriptor from the "struct tree" too, just to cut down on the noise from that common "desc" initializer. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-28Don't use "sscanf()" for tree mode scanningLibravatar Linus Torvalds1-3/+18
Doing an oprofile run on the result of my git rev-list memory leak fixes and tree parsing cleanups, I was surprised by the third-highest entry being samples % image name app name symbol name 179751 2.7163 libc-2.4.so libc-2.4.so _IO_vfscanf@@GLIBC_2.4 where that 2.7% is actually more than 5% of one CPU, because this was run on a dual CPU setup with the other CPU just being idle. That seems to all be from the use of 'sscanf(tree, "%o", &mode)' for the tree buffer parsing. So do the trivial octal parsing by hand, which also gives us where the first space in the string is (and thus where the pathname starts) so we can get rid of the "strchr(tree, ' ')" call too. This brings the "git rev-list --all --objects" time down from 63 seconds to 55 seconds on the historical kernel archive for me, so it's quite noticeable - tree parsing is a lot of what we end up doing when following all the objects. [ I also see a 5% speedup on a full "git fsck-objects" on the current kernel archive, so that sscanf() really does seem to have hurt our performance by a surprising amount ] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-19get_tree_entry(): make it available from tree-walkLibravatar Junio C Hamano1-0/+50
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-04Use blob_, commit_, tag_, and tree_type throughout.Libravatar Peter Eriksen1-1/+2
This replaces occurences of "blob", "commit", "tag", and "tree", where they're really used as type specifiers, which we already have defined global constants for. Signed-off-by: Peter Eriksen <s022018@student.dtu.dk> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-29tree/diff header cleanup.Libravatar Junio C Hamano1-0/+116
Introduce tree-walk.[ch] and move "struct tree_desc" and associated functions from various places. Rename DIFF_FILE_CANON_MODE(mode) macro to canon_mode(mode) and move it to cache.h. This macro returns the canonicalized st_mode value in the host byte order for files, symlinks and directories -- to be compared with a tree_desc entry. create_ce_mode(mode) in cache.h is similar but is intended to be used for index entries (so it does not work for directories) and returns the value in the network byte order. Signed-off-by: Junio C Hamano <junkio@cox.net>