git-commit-vandalism/dir.c
Junio C Hamano 63d285c849 per-directory-exclude: lazily read .gitignore files
Operations that walk directories or trees, which potentially need to
consult the .gitignore files, used to always try to open the .gitignore
file every time they entered a new directory, even when they ended up
not needing to call excluded() function to see if a path in the
directory is ignored.  This was done by push/pop exclude_per_directory()
functions that managed the data in a stack.

This changes the directory walking API to remove the need to call these
two functions.  Instead, the directory walk data structure caches the
data used by excluded() function the last time, and lazily reuses it as
much as possible.  Among the data the last check used, the ones from
deeper directories that the path we are checking is outside are
discarded, data from the common leading directories are reused, and then
the directories between the common directory and the directory the path
being checked is in are checked for .gitignore file.  This is very
similar to the way gitattributes are handled.

This API change also fixes "ls-files -c -i", which called excluded()
without setting up the gitignore data via the old push/pop functions.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-29 02:19:14 -08:00

793 lines
19 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"
#include "refs.h"
struct path_simplify {
int len;
const char *path;
};
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);
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, prefix))
continue;
len = prefix - 1;
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;
}
static int no_wildcard(const char *string)
{
return string[strcspn(string, "*?[{")] == '\0';
}
void add_exclude(const char *string, const char *base,
int baselen, struct exclude_list *which)
{
struct exclude *x = xmalloc(sizeof (*x));
x->to_exclude = 1;
if (*string == '!') {
x->to_exclude = 0;
string++;
}
x->pattern = string;
x->patternlen = strlen(string);
x->base = base;
x->baselen = baselen;
x->flags = 0;
if (!strchr(string, '/'))
x->flags |= EXC_FLAG_NODIR;
if (no_wildcard(string))
x->flags |= EXC_FLAG_NOWILDCARD;
if (*string == '*' && no_wildcard(string+1))
x->flags |= EXC_FLAG_ENDSWITH;
ALLOC_GROW(which->excludes, which->nr + 1, which->alloc);
which->excludes[which->nr++] = x;
}
static int add_excludes_from_file_1(const char *fname,
const char *base,
int baselen,
char **buf_p,
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);
if (buf_p)
*buf_p = buf;
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, NULL,
&dir->exclude_list[EXC_FILE]) < 0)
die("cannot use %s as an exclude file", fname);
}
static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
{
struct exclude_list *el;
struct exclude_stack *stk = NULL;
int current;
if ((!dir->exclude_per_dir) ||
(baselen + strlen(dir->exclude_per_dir) >= PATH_MAX))
return; /* too long a path -- ignore */
/* Pop the ones that are not the prefix of the path being checked. */
el = &dir->exclude_list[EXC_DIRS];
while ((stk = dir->exclude_stack) != NULL) {
if (stk->baselen <= baselen &&
!strncmp(dir->basebuf, base, stk->baselen))
break;
dir->exclude_stack = stk->prev;
while (stk->exclude_ix < el->nr)
free(el->excludes[--el->nr]);
free(stk->filebuf);
free(stk);
}
/* Read from the parent directories and push them down. */
current = stk ? stk->baselen : -1;
while (current < baselen) {
struct exclude_stack *stk = xcalloc(1, sizeof(*stk));
const char *cp;
if (current < 0) {
cp = base;
current = 0;
}
else {
cp = strchr(base + current + 1, '/');
if (!cp)
die("oops in prep_exclude");
cp++;
}
stk->prev = dir->exclude_stack;
stk->baselen = cp - base;
stk->exclude_ix = el->nr;
memcpy(dir->basebuf + current, base + current,
stk->baselen - current);
strcpy(dir->basebuf + stk->baselen, dir->exclude_per_dir);
add_excludes_from_file_1(dir->basebuf,
dir->basebuf, stk->baselen,
&stk->filebuf, el);
dir->exclude_stack = stk;
current = stk->baselen;
}
dir->basebuf[baselen] = '\0';
}
/* 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, const char *basename,
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 = x->to_exclude;
if (x->flags & EXC_FLAG_NODIR) {
/* match basename */
if (x->flags & EXC_FLAG_NOWILDCARD) {
if (!strcmp(exclude, basename))
return to_exclude;
} else if (x->flags & EXC_FLAG_ENDSWITH) {
if (x->patternlen - 1 <= pathlen &&
!strcmp(exclude + 1, pathname + pathlen - x->patternlen + 1))
return to_exclude;
} else {
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 (x->flags & EXC_FLAG_NOWILDCARD) {
if (!strcmp(exclude, pathname + baselen))
return to_exclude;
} else {
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;
const char *basename = strrchr(pathname, '/');
basename = (basename) ? basename+1 : pathname;
prep_exclude(dir, pathname, basename-pathname);
for (st = EXC_CMDL; st <= EXC_FILE; st++) {
switch (excluded_1(pathname, pathlen, basename, &dir->exclude_list[st])) {
case 0:
return 0;
case 1:
return 1;
}
}
return 0;
}
static struct dir_entry *dir_entry_new(const char *pathname, int len)
{
struct dir_entry *ent;
ent = xmalloc(sizeof(*ent) + len + 1);
ent->len = len;
memcpy(ent->name, pathname, len);
ent->name[len] = 0;
return ent;
}
struct dir_entry *dir_add_name(struct dir_struct *dir, const char *pathname, int len)
{
if (cache_name_pos(pathname, len) >= 0)
return NULL;
ALLOC_GROW(dir->entries, dir->nr+1, dir->alloc);
return dir->entries[dir->nr++] = dir_entry_new(pathname, len);
}
struct dir_entry *dir_add_ignored(struct dir_struct *dir, const char *pathname, int len)
{
if (cache_name_pos(pathname, len) >= 0)
return NULL;
ALLOC_GROW(dir->ignored, dir->ignored_nr+1, dir->ignored_alloc);
return dir->ignored[dir->ignored_nr++] = dir_entry_new(pathname, len);
}
enum exist_status {
index_nonexistent = 0,
index_directory,
index_gitdir,
};
/*
* The index sorts alphabetically by entry name, which
* means that a gitlink sorts as '\0' at the end, while
* a directory (which is defined not as an entry, but as
* the files it contains) will sort with the '/' at the
* end.
*/
static enum exist_status directory_exists_in_index(const char *dirname, int len)
{
int pos = cache_name_pos(dirname, len);
if (pos < 0)
pos = -pos-1;
while (pos < active_nr) {
struct cache_entry *ce = active_cache[pos++];
unsigned char endchar;
if (strncmp(ce->name, dirname, len))
break;
endchar = ce->name[len];
if (endchar > '/')
break;
if (endchar == '/')
return index_directory;
if (!endchar && S_ISGITLINK(ntohl(ce->ce_mode)))
return index_gitdir;
}
return index_nonexistent;
}
/*
* When we find a directory when traversing the filesystem, we
* have three distinct cases:
*
* - ignore it
* - see it as a directory
* - recurse into it
*
* and which one we choose depends on a combination of existing
* git index contents and the flags passed into the directory
* traversal routine.
*
* Case 1: If we *already* have entries in the index under that
* directory name, we always recurse into the directory to see
* all the files.
*
* Case 2: If we *already* have that directory name as a gitlink,
* we always continue to see it as a gitlink, regardless of whether
* there is an actual git directory there or not (it might not
* be checked out as a subproject!)
*
* Case 3: if we didn't have it in the index previously, we
* have a few sub-cases:
*
* (a) if "show_other_directories" is true, we show it as
* just a directory, unless "hide_empty_directories" is
* also true and the directory is empty, in which case
* we just ignore it entirely.
* (b) if it looks like a git directory, and we don't have
* 'no_gitlinks' set we treat it as a gitlink, and show it
* as a directory.
* (c) otherwise, we recurse into it.
*/
enum directory_treatment {
show_directory,
ignore_directory,
recurse_into_directory,
};
static enum directory_treatment treat_directory(struct dir_struct *dir,
const char *dirname, int len,
const struct path_simplify *simplify)
{
/* The "len-1" is to strip the final '/' */
switch (directory_exists_in_index(dirname, len-1)) {
case index_directory:
return recurse_into_directory;
case index_gitdir:
if (dir->show_other_directories)
return ignore_directory;
return show_directory;
case index_nonexistent:
if (dir->show_other_directories)
break;
if (!dir->no_gitlinks) {
unsigned char sha1[20];
if (resolve_gitlink_ref(dirname, "HEAD", sha1) == 0)
return show_directory;
}
return recurse_into_directory;
}
/* This is the "show_other_directories" case */
if (!dir->hide_empty_directories)
return show_directory;
if (!read_directory_recursive(dir, dirname, dirname, len, 1, simplify))
return ignore_directory;
return show_directory;
}
/*
* 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;
}
static int in_pathspec(const char *path, int len, const struct path_simplify *simplify)
{
if (simplify) {
for (; simplify->path; simplify++) {
if (len == simplify->len
&& !memcmp(path, simplify->path, len))
return 1;
}
}
return 0;
}
static int get_dtype(struct dirent *de, const char *path)
{
int dtype = DTYPE(de);
struct stat st;
if (dtype != DT_UNKNOWN)
return dtype;
if (lstat(path, &st))
return dtype;
if (S_ISREG(st.st_mode))
return DT_REG;
if (S_ISDIR(st.st_mode))
return DT_DIR;
if (S_ISLNK(st.st_mode))
return DT_LNK;
return dtype;
}
/*
* 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) {
struct dirent *de;
char fullname[PATH_MAX + 1];
memcpy(fullname, base, baselen);
while ((de = readdir(fdir)) != NULL) {
int len, dtype;
int exclude;
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);
/* Ignore overly long pathnames! */
if (len + baselen + 8 > sizeof(fullname))
continue;
memcpy(fullname + baselen, de->d_name, len+1);
if (simplify_away(fullname, baselen + len, simplify))
continue;
exclude = excluded(dir, fullname);
if (exclude && dir->collect_ignored
&& in_pathspec(fullname, baselen + len, simplify))
dir_add_ignored(dir, fullname, baselen + len);
/*
* Excluded? If we don't explicitly want to show
* ignored files, ignore it
*/
if (exclude && !dir->show_ignored)
continue;
dtype = get_dtype(de, fullname);
/*
* Do we want to see just the ignored files?
* We still need to recurse into directories,
* even if we don't ignore them, since the
* directory may contain files that we do..
*/
if (!exclude && dir->show_ignored) {
if (dtype != DT_DIR)
continue;
}
switch (dtype) {
default:
continue;
case DT_DIR:
memcpy(fullname + baselen + len, "/", 2);
len++;
switch (treat_directory(dir, fullname, baselen + len, simplify)) {
case show_directory:
if (exclude != dir->show_ignored)
continue;
break;
case recurse_into_directory:
contents += read_directory_recursive(dir,
fullname, fullname, baselen + len, 0, simplify);
continue;
case ignore_directory:
continue;
}
break;
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);
}
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);
read_directory_recursive(dir, path, base, baselen, 0, simplify);
free_simplify(simplify);
qsort(dir->entries, dir->nr, sizeof(struct dir_entry *), cmp_name);
qsort(dir->ignored, dir->ignored_nr, sizeof(struct dir_entry *), cmp_name);
return dir->nr;
}
int file_exists(const char *f)
{
struct stat sb;
return stat(f, &sb) == 0;
}
/*
* get_relative_cwd() gets the prefix of the current working directory
* relative to 'dir'. If we are not inside 'dir', it returns NULL.
*
* As a convenience, it also returns NULL if 'dir' is already NULL. The
* reason for this behaviour is that it is natural for functions returning
* directory names to return NULL to say "this directory does not exist"
* or "this directory is invalid". These cases are usually handled the
* same as if the cwd is not inside 'dir' at all, so get_relative_cwd()
* returns NULL for both of them.
*
* Most notably, get_relative_cwd(buffer, size, get_git_work_tree())
* unifies the handling of "outside work tree" with "no work tree at all".
*/
char *get_relative_cwd(char *buffer, int size, const char *dir)
{
char *cwd = buffer;
if (!dir)
return NULL;
if (!getcwd(buffer, size))
die("can't find the current directory: %s", strerror(errno));
if (!is_absolute_path(dir))
dir = make_absolute_path(dir);
while (*dir && *dir == *cwd) {
dir++;
cwd++;
}
if (*dir)
return NULL;
if (*cwd == '/')
return cwd + 1;
return cwd;
}
int is_inside_dir(const char *dir)
{
char buffer[PATH_MAX];
return get_relative_cwd(buffer, sizeof(buffer), dir) != NULL;
}
int remove_dir_recursively(struct strbuf *path, int only_empty)
{
DIR *dir = opendir(path->buf);
struct dirent *e;
int ret = 0, original_len = path->len, len;
if (!dir)
return -1;
if (path->buf[original_len - 1] != '/')
strbuf_addch(path, '/');
len = path->len;
while ((e = readdir(dir)) != NULL) {
struct stat st;
if ((e->d_name[0] == '.') &&
((e->d_name[1] == 0) ||
((e->d_name[1] == '.') && e->d_name[2] == 0)))
continue; /* "." and ".." */
strbuf_setlen(path, len);
strbuf_addstr(path, e->d_name);
if (lstat(path->buf, &st))
; /* fall thru */
else if (S_ISDIR(st.st_mode)) {
if (!remove_dir_recursively(path, only_empty))
continue; /* happy */
} else if (!only_empty && !unlink(path->buf))
continue; /* happy, too */
/* path too long, stat fails, or non-directory still exists */
ret = -1;
break;
}
closedir(dir);
strbuf_setlen(path, original_len);
if (!ret)
ret = rmdir(path->buf);
return ret;
}
void setup_standard_excludes(struct dir_struct *dir)
{
const char *path;
dir->exclude_per_dir = ".gitignore";
path = git_path("info/exclude");
if (!access(path, R_OK))
add_excludes_from_file(dir, path);
if (excludes_file && !access(excludes_file, R_OK))
add_excludes_from_file(dir, excludes_file);
}