git/dir.c
Linus Torvalds 9fc42d6091 Optimize directory listing with pathspec limiter.
The way things are set up, you can now pass a "pathspec" to the
"read_directory()" function. If you pass NULL, it acts exactly
like it used to do (read everything). If you pass a non-NULL
pointer, it will simplify it into a "these are the prefixes
without any special characters", and stop any readdir() early if
the path in question doesn't match any of the prefixes.

NOTE! This does *not* obviate the need for the caller to do the *exact*
pathspec match later. It's a first-level filter on "read_directory()", but
it does not do the full pathspec thing. Maybe it should. But in the
meantime, builtin-add.c really does need to do first

	read_directory(dir, .., pathspec);
	if (pathspec)
		prune_directory(dir, pathspec, baselen);

ie the "prune_directory()" part will do the *exact* pathspec pruning,
while the "read_directory()" will use the pathspec just to do some quick
high-level pruning of the directories it will recurse into.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-31 17:41:32 -07:00

514 lines
11 KiB
C

/*
* This handles recursive filename detection with exclude
* files, index knowledge etc..
*
* Copyright (C) Linus Torvalds, 2005-2006
* Junio Hamano, 2005-2006
*/
#include "cache.h"
#include "dir.h"
struct path_simplify {
int len;
const char *path;
};
int common_prefix(const char **pathspec)
{
const char *path, *slash, *next;
int prefix;
if (!pathspec)
return 0;
path = *pathspec;
slash = strrchr(path, '/');
if (!slash)
return 0;
prefix = slash - path + 1;
while ((next = *++pathspec) != NULL) {
int len = strlen(next);
if (len >= prefix && !memcmp(path, next, len))
continue;
for (;;) {
if (!len)
return 0;
if (next[--len] != '/')
continue;
if (memcmp(path, next, len+1))
continue;
prefix = len + 1;
break;
}
}
return prefix;
}
/*
* Does 'match' matches the given name?
* A match is found if
*
* (1) the 'match' string is leading directory of 'name', or
* (2) the 'match' string is a wildcard and matches 'name', or
* (3) the 'match' string is exactly the same as 'name'.
*
* and the return value tells which case it was.
*
* It returns 0 when there is no match.
*/
static int match_one(const char *match, const char *name, int namelen)
{
int matchlen;
/* If the match was just the prefix, we matched */
matchlen = strlen(match);
if (!matchlen)
return MATCHED_RECURSIVELY;
/*
* If we don't match the matchstring exactly,
* we need to match by fnmatch
*/
if (strncmp(match, name, matchlen))
return !fnmatch(match, name, 0) ? MATCHED_FNMATCH : 0;
if (!name[matchlen])
return MATCHED_EXACTLY;
if (match[matchlen-1] == '/' || name[matchlen] == '/')
return MATCHED_RECURSIVELY;
return 0;
}
/*
* Given a name and a list of pathspecs, see if the name matches
* any of the pathspecs. The caller is also interested in seeing
* all pathspec matches some names it calls this function with
* (otherwise the user could have mistyped the unmatched pathspec),
* and a mark is left in seen[] array for pathspec element that
* actually matched anything.
*/
int match_pathspec(const char **pathspec, const char *name, int namelen, int prefix, char *seen)
{
int retval;
const char *match;
name += prefix;
namelen -= prefix;
for (retval = 0; (match = *pathspec++) != NULL; seen++) {
int how;
if (retval && *seen == MATCHED_EXACTLY)
continue;
match += prefix;
how = match_one(match, name, namelen);
if (how) {
if (retval < how)
retval = how;
if (*seen < how)
*seen = how;
}
}
return retval;
}
void add_exclude(const char *string, const char *base,
int baselen, struct exclude_list *which)
{
struct exclude *x = xmalloc(sizeof (*x));
x->pattern = string;
x->base = base;
x->baselen = baselen;
if (which->nr == which->alloc) {
which->alloc = alloc_nr(which->alloc);
which->excludes = xrealloc(which->excludes,
which->alloc * sizeof(x));
}
which->excludes[which->nr++] = x;
}
static int add_excludes_from_file_1(const char *fname,
const char *base,
int baselen,
struct exclude_list *which)
{
struct stat st;
int fd, i;
size_t size;
char *buf, *entry;
fd = open(fname, O_RDONLY);
if (fd < 0 || fstat(fd, &st) < 0)
goto err;
size = xsize_t(st.st_size);
if (size == 0) {
close(fd);
return 0;
}
buf = xmalloc(size+1);
if (read_in_full(fd, buf, size) != size)
goto err;
close(fd);
buf[size++] = '\n';
entry = buf;
for (i = 0; i < size; i++) {
if (buf[i] == '\n') {
if (entry != buf + i && entry[0] != '#') {
buf[i - (i && buf[i-1] == '\r')] = 0;
add_exclude(entry, base, baselen, which);
}
entry = buf + i + 1;
}
}
return 0;
err:
if (0 <= fd)
close(fd);
return -1;
}
void add_excludes_from_file(struct dir_struct *dir, const char *fname)
{
if (add_excludes_from_file_1(fname, "", 0,
&dir->exclude_list[EXC_FILE]) < 0)
die("cannot use %s as an exclude file", fname);
}
int push_exclude_per_directory(struct dir_struct *dir, const char *base, int baselen)
{
char exclude_file[PATH_MAX];
struct exclude_list *el = &dir->exclude_list[EXC_DIRS];
int current_nr = el->nr;
if (dir->exclude_per_dir) {
memcpy(exclude_file, base, baselen);
strcpy(exclude_file + baselen, dir->exclude_per_dir);
add_excludes_from_file_1(exclude_file, base, baselen, el);
}
return current_nr;
}
void pop_exclude_per_directory(struct dir_struct *dir, int stk)
{
struct exclude_list *el = &dir->exclude_list[EXC_DIRS];
while (stk < el->nr)
free(el->excludes[--el->nr]);
}
/* Scan the list and let the last match determines the fate.
* Return 1 for exclude, 0 for include and -1 for undecided.
*/
static int excluded_1(const char *pathname,
int pathlen,
struct exclude_list *el)
{
int i;
if (el->nr) {
for (i = el->nr - 1; 0 <= i; i--) {
struct exclude *x = el->excludes[i];
const char *exclude = x->pattern;
int to_exclude = 1;
if (*exclude == '!') {
to_exclude = 0;
exclude++;
}
if (!strchr(exclude, '/')) {
/* match basename */
const char *basename = strrchr(pathname, '/');
basename = (basename) ? basename+1 : pathname;
if (fnmatch(exclude, basename, 0) == 0)
return to_exclude;
}
else {
/* match with FNM_PATHNAME:
* exclude has base (baselen long) implicitly
* in front of it.
*/
int baselen = x->baselen;
if (*exclude == '/')
exclude++;
if (pathlen < baselen ||
(baselen && pathname[baselen-1] != '/') ||
strncmp(pathname, x->base, baselen))
continue;
if (fnmatch(exclude, pathname+baselen,
FNM_PATHNAME) == 0)
return to_exclude;
}
}
}
return -1; /* undecided */
}
int excluded(struct dir_struct *dir, const char *pathname)
{
int pathlen = strlen(pathname);
int st;
for (st = EXC_CMDL; st <= EXC_FILE; st++) {
switch (excluded_1(pathname, pathlen, &dir->exclude_list[st])) {
case 0:
return 0;
case 1:
return 1;
}
}
return 0;
}
struct dir_entry *dir_add_name(struct dir_struct *dir, const char *pathname, int len)
{
struct dir_entry *ent;
if (cache_name_pos(pathname, len) >= 0)
return NULL;
if (dir->nr == dir->alloc) {
int alloc = alloc_nr(dir->alloc);
dir->alloc = alloc;
dir->entries = xrealloc(dir->entries, alloc*sizeof(ent));
}
ent = xmalloc(sizeof(*ent) + len + 1);
ent->ignored = ent->ignored_dir = 0;
ent->len = len;
memcpy(ent->name, pathname, len);
ent->name[len] = 0;
dir->entries[dir->nr++] = ent;
return ent;
}
static int dir_exists(const char *dirname, int len)
{
int pos = cache_name_pos(dirname, len);
if (pos >= 0)
return 1;
pos = -pos-1;
if (pos >= active_nr) /* can't */
return 0;
return !strncmp(active_cache[pos]->name, dirname, len);
}
/*
* This is an inexact early pruning of any recursive directory
* reading - if the path cannot possibly be in the pathspec,
* return true, and we'll skip it early.
*/
static int simplify_away(const char *path, int pathlen, const struct path_simplify *simplify)
{
if (simplify) {
for (;;) {
const char *match = simplify->path;
int len = simplify->len;
if (!match)
break;
if (len > pathlen)
len = pathlen;
if (!memcmp(path, match, len))
return 0;
simplify++;
}
return 1;
}
return 0;
}
/*
* Read a directory tree. We currently ignore anything but
* directories, regular files and symlinks. That's because git
* doesn't handle them at all yet. Maybe that will change some
* day.
*
* Also, we ignore the name ".git" (even if it is not a directory).
* That likely will not change.
*/
static int read_directory_recursive(struct dir_struct *dir, const char *path, const char *base, int baselen, int check_only, const struct path_simplify *simplify)
{
DIR *fdir = opendir(path);
int contents = 0;
if (fdir) {
int exclude_stk;
struct dirent *de;
char fullname[PATH_MAX + 1];
memcpy(fullname, base, baselen);
exclude_stk = push_exclude_per_directory(dir, base, baselen);
while ((de = readdir(fdir)) != NULL) {
int len;
if ((de->d_name[0] == '.') &&
(de->d_name[1] == 0 ||
!strcmp(de->d_name + 1, ".") ||
!strcmp(de->d_name + 1, "git")))
continue;
len = strlen(de->d_name);
memcpy(fullname + baselen, de->d_name, len+1);
if (simplify_away(fullname, baselen + len, simplify))
continue;
if (excluded(dir, fullname) != dir->show_ignored) {
if (!dir->show_ignored || DTYPE(de) != DT_DIR) {
continue;
}
}
switch (DTYPE(de)) {
struct stat st;
default:
continue;
case DT_UNKNOWN:
if (lstat(fullname, &st))
continue;
if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode))
break;
if (!S_ISDIR(st.st_mode))
continue;
/* fallthrough */
case DT_DIR:
memcpy(fullname + baselen + len, "/", 2);
len++;
if (dir->show_other_directories &&
!dir_exists(fullname, baselen + len)) {
if (dir->hide_empty_directories &&
!read_directory_recursive(dir,
fullname, fullname,
baselen + len, 1, simplify))
continue;
break;
}
contents += read_directory_recursive(dir,
fullname, fullname, baselen + len, 0, simplify);
continue;
case DT_REG:
case DT_LNK:
break;
}
contents++;
if (check_only)
goto exit_early;
else
dir_add_name(dir, fullname, baselen + len);
}
exit_early:
closedir(fdir);
pop_exclude_per_directory(dir, exclude_stk);
}
return contents;
}
static int cmp_name(const void *p1, const void *p2)
{
const struct dir_entry *e1 = *(const struct dir_entry **)p1;
const struct dir_entry *e2 = *(const struct dir_entry **)p2;
return cache_name_compare(e1->name, e1->len,
e2->name, e2->len);
}
/*
* Return the length of the "simple" part of a path match limiter.
*/
static int simple_length(const char *match)
{
const char special[256] = {
[0] = 1, ['?'] = 1,
['\\'] = 1, ['*'] = 1,
['['] = 1
};
int len = -1;
for (;;) {
unsigned char c = *match++;
len++;
if (special[c])
return len;
}
}
static struct path_simplify *create_simplify(const char **pathspec)
{
int nr, alloc = 0;
struct path_simplify *simplify = NULL;
if (!pathspec)
return NULL;
for (nr = 0 ; ; nr++) {
const char *match;
if (nr >= alloc) {
alloc = alloc_nr(alloc);
simplify = xrealloc(simplify, alloc * sizeof(*simplify));
}
match = *pathspec++;
if (!match)
break;
simplify[nr].path = match;
simplify[nr].len = simple_length(match);
}
simplify[nr].path = NULL;
simplify[nr].len = 0;
return simplify;
}
static void free_simplify(struct path_simplify *simplify)
{
if (simplify)
free(simplify);
}
int read_directory(struct dir_struct *dir, const char *path, const char *base, int baselen, const char **pathspec)
{
struct path_simplify *simplify = create_simplify(pathspec);
/*
* Make sure to do the per-directory exclude for all the
* directories leading up to our base.
*/
if (baselen) {
if (dir->exclude_per_dir) {
char *p, *pp = xmalloc(baselen+1);
memcpy(pp, base, baselen+1);
p = pp;
while (1) {
char save = *p;
*p = 0;
push_exclude_per_directory(dir, pp, p-pp);
*p++ = save;
if (!save)
break;
p = strchr(p, '/');
if (p)
p++;
else
p = pp + baselen;
}
free(pp);
}
}
read_directory_recursive(dir, path, base, baselen, 0, simplify);
free_simplify(simplify);
qsort(dir->entries, dir->nr, sizeof(struct dir_entry *), cmp_name);
return dir->nr;
}
int
file_exists(const char *f)
{
struct stat sb;
return stat(f, &sb) == 0;
}