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>
		
	
		
			
				
	
	
		
			77 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef TREE_WALK_H
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#define TREE_WALK_H
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struct name_entry {
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	const unsigned char *sha1;
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	const char *path;
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	unsigned int mode;
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};
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struct tree_desc {
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	const void *buffer;
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	struct name_entry entry;
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	unsigned int size;
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};
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static inline const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
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{
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	*pathp = desc->entry.path;
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	*modep = desc->entry.mode;
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	return desc->entry.sha1;
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}
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static inline int tree_entry_len(const struct name_entry *ne)
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{
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	return (const char *)ne->sha1 - ne->path - 1;
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}
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void update_tree_entry(struct tree_desc *);
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void init_tree_desc(struct tree_desc *desc, const void *buf, unsigned long size);
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/*
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 * Helper function that does both tree_entry_extract() and update_tree_entry()
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 * and returns true for success
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 */
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int tree_entry(struct tree_desc *, struct name_entry *);
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void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1);
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struct traverse_info;
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typedef int (*traverse_callback_t)(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *);
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int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info);
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struct traverse_info {
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	struct traverse_info *prev;
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	struct name_entry name;
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	int pathlen;
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	struct pathspec *pathspec;
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	unsigned long df_conflicts;
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	traverse_callback_t fn;
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	void *data;
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	int show_all_errors;
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};
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int get_tree_entry(const unsigned char *, const char *, unsigned char *, unsigned *);
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extern char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n);
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extern void setup_traverse_info(struct traverse_info *info, const char *base);
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static inline int traverse_path_len(const struct traverse_info *info, const struct name_entry *n)
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{
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	return info->pathlen + tree_entry_len(n);
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}
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/* in general, positive means "kind of interesting" */
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enum interesting {
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	all_entries_not_interesting = -1, /* no, and no subsequent entries will be either */
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	entry_not_interesting = 0,
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	entry_interesting = 1,
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	all_entries_interesting = 2 /* yes, and all subsequent entries will be */
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};
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extern enum interesting tree_entry_interesting(const struct name_entry *,
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					       struct strbuf *, int,
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					       const struct pathspec *ps);
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#endif
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