git/unpack-trees.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

929 lines
21 KiB
C

#include "cache.h"
#include "dir.h"
#include "tree.h"
#include "tree-walk.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#include "progress.h"
#include "refs.h"
#define DBRT_DEBUG 1
struct tree_entry_list {
struct tree_entry_list *next;
unsigned int mode;
const char *name;
const unsigned char *sha1;
};
static struct tree_entry_list *create_tree_entry_list(struct tree_desc *desc)
{
struct name_entry one;
struct tree_entry_list *ret = NULL;
struct tree_entry_list **list_p = &ret;
while (tree_entry(desc, &one)) {
struct tree_entry_list *entry;
entry = xmalloc(sizeof(struct tree_entry_list));
entry->name = one.path;
entry->sha1 = one.sha1;
entry->mode = one.mode;
entry->next = NULL;
*list_p = entry;
list_p = &entry->next;
}
return ret;
}
static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
{
int len1 = strlen(name1);
int len2 = strlen(name2);
int len = len1 < len2 ? len1 : len2;
int ret = memcmp(name1, name2, len);
unsigned char c1, c2;
if (ret)
return ret;
c1 = name1[len];
c2 = name2[len];
if (!c1 && dir1)
c1 = '/';
if (!c2 && dir2)
c2 = '/';
ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
if (c1 && c2 && !ret)
ret = len1 - len2;
return ret;
}
static inline void remove_entry(int remove)
{
if (remove >= 0)
remove_cache_entry_at(remove);
}
static int unpack_trees_rec(struct tree_entry_list **posns, int len,
const char *base, struct unpack_trees_options *o,
struct tree_entry_list *df_conflict_list)
{
int remove;
int baselen = strlen(base);
int src_size = len + 1;
int retval = 0;
do {
int i;
const char *first;
int firstdir = 0;
int pathlen;
unsigned ce_size;
struct tree_entry_list **subposns;
struct cache_entry **src;
int any_files = 0;
int any_dirs = 0;
char *cache_name;
int ce_stage;
/* Find the first name in the input. */
first = NULL;
cache_name = NULL;
/* Check the cache */
if (o->merge && o->pos < active_nr) {
/* This is a bit tricky: */
/* If the index has a subdirectory (with
* contents) as the first name, it'll get a
* filename like "foo/bar". But that's after
* "foo", so the entry in trees will get
* handled first, at which point we'll go into
* "foo", and deal with "bar" from the index,
* because the base will be "foo/". The only
* way we can actually have "foo/bar" first of
* all the things is if the trees don't
* contain "foo" at all, in which case we'll
* handle "foo/bar" without going into the
* directory, but that's fine (and will return
* an error anyway, with the added unknown
* file case.
*/
cache_name = active_cache[o->pos]->name;
if (strlen(cache_name) > baselen &&
!memcmp(cache_name, base, baselen)) {
cache_name += baselen;
first = cache_name;
} else {
cache_name = NULL;
}
}
#if DBRT_DEBUG > 1
if (first)
printf("index %s\n", first);
#endif
for (i = 0; i < len; i++) {
if (!posns[i] || posns[i] == df_conflict_list)
continue;
#if DBRT_DEBUG > 1
printf("%d %s\n", i + 1, posns[i]->name);
#endif
if (!first || entcmp(first, firstdir,
posns[i]->name,
S_ISDIR(posns[i]->mode)) > 0) {
first = posns[i]->name;
firstdir = S_ISDIR(posns[i]->mode);
}
}
/* No name means we're done */
if (!first)
goto leave_directory;
pathlen = strlen(first);
ce_size = cache_entry_size(baselen + pathlen);
src = xcalloc(src_size, sizeof(struct cache_entry *));
subposns = xcalloc(len, sizeof(struct tree_list_entry *));
remove = -1;
if (cache_name && !strcmp(cache_name, first)) {
any_files = 1;
src[0] = active_cache[o->pos];
remove = o->pos;
}
for (i = 0; i < len; i++) {
struct cache_entry *ce;
if (!posns[i] ||
(posns[i] != df_conflict_list &&
strcmp(first, posns[i]->name))) {
continue;
}
if (posns[i] == df_conflict_list) {
src[i + o->merge] = o->df_conflict_entry;
continue;
}
if (S_ISDIR(posns[i]->mode)) {
struct tree *tree = lookup_tree(posns[i]->sha1);
struct tree_desc t;
any_dirs = 1;
parse_tree(tree);
init_tree_desc(&t, tree->buffer, tree->size);
subposns[i] = create_tree_entry_list(&t);
posns[i] = posns[i]->next;
src[i + o->merge] = o->df_conflict_entry;
continue;
}
if (!o->merge)
ce_stage = 0;
else if (i + 1 < o->head_idx)
ce_stage = 1;
else if (i + 1 > o->head_idx)
ce_stage = 3;
else
ce_stage = 2;
ce = xcalloc(1, ce_size);
ce->ce_mode = create_ce_mode(posns[i]->mode);
ce->ce_flags = create_ce_flags(baselen + pathlen,
ce_stage);
memcpy(ce->name, base, baselen);
memcpy(ce->name + baselen, first, pathlen + 1);
any_files = 1;
hashcpy(ce->sha1, posns[i]->sha1);
src[i + o->merge] = ce;
subposns[i] = df_conflict_list;
posns[i] = posns[i]->next;
}
if (any_files) {
if (o->merge) {
int ret;
#if DBRT_DEBUG > 1
printf("%s:\n", first);
for (i = 0; i < src_size; i++) {
printf(" %d ", i);
if (src[i])
printf("%s\n", sha1_to_hex(src[i]->sha1));
else
printf("\n");
}
#endif
ret = o->fn(src, o, remove);
#if DBRT_DEBUG > 1
printf("Added %d entries\n", ret);
#endif
o->pos += ret;
} else {
remove_entry(remove);
for (i = 0; i < src_size; i++) {
if (src[i]) {
add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
}
}
}
}
if (any_dirs) {
char *newbase = xmalloc(baselen + 2 + pathlen);
memcpy(newbase, base, baselen);
memcpy(newbase + baselen, first, pathlen);
newbase[baselen + pathlen] = '/';
newbase[baselen + pathlen + 1] = '\0';
if (unpack_trees_rec(subposns, len, newbase, o,
df_conflict_list)) {
retval = -1;
goto leave_directory;
}
free(newbase);
}
free(subposns);
free(src);
} while (1);
leave_directory:
return retval;
}
/* Unlink the last component and attempt to remove leading
* directories, in case this unlink is the removal of the
* last entry in the directory -- empty directories are removed.
*/
static void unlink_entry(char *name, char *last_symlink)
{
char *cp, *prev;
if (has_symlink_leading_path(name, last_symlink))
return;
if (unlink(name))
return;
prev = NULL;
while (1) {
int status;
cp = strrchr(name, '/');
if (prev)
*prev = '/';
if (!cp)
break;
*cp = 0;
status = rmdir(name);
if (status) {
*cp = '/';
break;
}
prev = cp;
}
}
static struct checkout state;
static void check_updates(struct cache_entry **src, int nr,
struct unpack_trees_options *o)
{
unsigned short mask = htons(CE_UPDATE);
unsigned cnt = 0, total = 0;
struct progress *progress = NULL;
char last_symlink[PATH_MAX];
if (o->update && o->verbose_update) {
for (total = cnt = 0; cnt < nr; cnt++) {
struct cache_entry *ce = src[cnt];
if (!ce->ce_mode || ce->ce_flags & mask)
total++;
}
progress = start_progress_delay("Checking out files",
total, 50, 2);
cnt = 0;
}
*last_symlink = '\0';
while (nr--) {
struct cache_entry *ce = *src++;
if (!ce->ce_mode || ce->ce_flags & mask)
display_progress(progress, ++cnt);
if (!ce->ce_mode) {
if (o->update)
unlink_entry(ce->name, last_symlink);
continue;
}
if (ce->ce_flags & mask) {
ce->ce_flags &= ~mask;
if (o->update) {
checkout_entry(ce, &state, NULL);
*last_symlink = '\0';
}
}
}
stop_progress(&progress);
}
int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
{
struct tree_entry_list **posns;
int i;
struct tree_entry_list df_conflict_list;
static struct cache_entry *dfc;
memset(&df_conflict_list, 0, sizeof(df_conflict_list));
df_conflict_list.next = &df_conflict_list;
memset(&state, 0, sizeof(state));
state.base_dir = "";
state.force = 1;
state.quiet = 1;
state.refresh_cache = 1;
o->merge_size = len;
if (!dfc)
dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
o->df_conflict_entry = dfc;
if (len) {
posns = xmalloc(len * sizeof(struct tree_entry_list *));
for (i = 0; i < len; i++)
posns[i] = create_tree_entry_list(t+i);
if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
o, &df_conflict_list))
return -1;
}
if (o->trivial_merges_only && o->nontrivial_merge)
die("Merge requires file-level merging");
check_updates(active_cache, active_nr, o);
return 0;
}
/* Here come the merge functions */
static void reject_merge(struct cache_entry *ce)
{
die("Entry '%s' would be overwritten by merge. Cannot merge.",
ce->name);
}
static int same(struct cache_entry *a, struct cache_entry *b)
{
if (!!a != !!b)
return 0;
if (!a && !b)
return 1;
return a->ce_mode == b->ce_mode &&
!hashcmp(a->sha1, b->sha1);
}
/*
* When a CE gets turned into an unmerged entry, we
* want it to be up-to-date
*/
static void verify_uptodate(struct cache_entry *ce,
struct unpack_trees_options *o)
{
struct stat st;
if (o->index_only || o->reset)
return;
if (!lstat(ce->name, &st)) {
unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
if (!changed)
return;
/*
* NEEDSWORK: the current default policy is to allow
* submodule to be out of sync wrt the supermodule
* index. This needs to be tightened later for
* submodules that are marked to be automatically
* checked out.
*/
if (S_ISGITLINK(ntohl(ce->ce_mode)))
return;
errno = 0;
}
if (errno == ENOENT)
return;
die("Entry '%s' not uptodate. Cannot merge.", ce->name);
}
static void invalidate_ce_path(struct cache_entry *ce)
{
if (ce)
cache_tree_invalidate_path(active_cache_tree, ce->name);
}
/*
* Check that checking out ce->sha1 in subdir ce->name is not
* going to overwrite any working files.
*
* Currently, git does not checkout subprojects during a superproject
* checkout, so it is not going to overwrite anything.
*/
static int verify_clean_submodule(struct cache_entry *ce, const char *action,
struct unpack_trees_options *o)
{
return 0;
}
static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
struct unpack_trees_options *o)
{
/*
* we are about to extract "ce->name"; we would not want to lose
* anything in the existing directory there.
*/
int namelen;
int pos, i;
struct dir_struct d;
char *pathbuf;
int cnt = 0;
unsigned char sha1[20];
if (S_ISGITLINK(ntohl(ce->ce_mode)) &&
resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
/* If we are not going to update the submodule, then
* we don't care.
*/
if (!hashcmp(sha1, ce->sha1))
return 0;
return verify_clean_submodule(ce, action, o);
}
/*
* First let's make sure we do not have a local modification
* in that directory.
*/
namelen = strlen(ce->name);
pos = cache_name_pos(ce->name, namelen);
if (0 <= pos)
return cnt; /* we have it as nondirectory */
pos = -pos - 1;
for (i = pos; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
int len = ce_namelen(ce);
if (len < namelen ||
strncmp(ce->name, ce->name, namelen) ||
ce->name[namelen] != '/')
break;
/*
* ce->name is an entry in the subdirectory.
*/
if (!ce_stage(ce)) {
verify_uptodate(ce, o);
ce->ce_mode = 0;
}
cnt++;
}
/*
* Then we need to make sure that we do not lose a locally
* present file that is not ignored.
*/
pathbuf = xmalloc(namelen + 2);
memcpy(pathbuf, ce->name, namelen);
strcpy(pathbuf+namelen, "/");
memset(&d, 0, sizeof(d));
if (o->dir)
d.exclude_per_dir = o->dir->exclude_per_dir;
i = read_directory(&d, ce->name, pathbuf, namelen+1, NULL);
if (i)
die("Updating '%s' would lose untracked files in it",
ce->name);
free(pathbuf);
return cnt;
}
/*
* We do not want to remove or overwrite a working tree file that
* is not tracked, unless it is ignored.
*/
static void verify_absent(struct cache_entry *ce, const char *action,
struct unpack_trees_options *o)
{
struct stat st;
if (o->index_only || o->reset || !o->update)
return;
if (has_symlink_leading_path(ce->name, NULL))
return;
if (!lstat(ce->name, &st)) {
int cnt;
if (o->dir && excluded(o->dir, ce->name))
/*
* ce->name is explicitly excluded, so it is Ok to
* overwrite it.
*/
return;
if (S_ISDIR(st.st_mode)) {
/*
* We are checking out path "foo" and
* found "foo/." in the working tree.
* This is tricky -- if we have modified
* files that are in "foo/" we would lose
* it.
*/
cnt = verify_clean_subdirectory(ce, action, o);
/*
* If this removed entries from the index,
* what that means is:
*
* (1) the caller unpack_trees_rec() saw path/foo
* in the index, and it has not removed it because
* it thinks it is handling 'path' as blob with
* D/F conflict;
* (2) we will return "ok, we placed a merged entry
* in the index" which would cause o->pos to be
* incremented by one;
* (3) however, original o->pos now has 'path/foo'
* marked with "to be removed".
*
* We need to increment it by the number of
* deleted entries here.
*/
o->pos += cnt;
return;
}
/*
* The previous round may already have decided to
* delete this path, which is in a subdirectory that
* is being replaced with a blob.
*/
cnt = cache_name_pos(ce->name, strlen(ce->name));
if (0 <= cnt) {
struct cache_entry *ce = active_cache[cnt];
if (!ce_stage(ce) && !ce->ce_mode)
return;
}
die("Untracked working tree file '%s' "
"would be %s by merge.", ce->name, action);
}
}
static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
struct unpack_trees_options *o)
{
merge->ce_flags |= htons(CE_UPDATE);
if (old) {
/*
* See if we can re-use the old CE directly?
* That way we get the uptodate stat info.
*
* This also removes the UPDATE flag on
* a match.
*/
if (same(old, merge)) {
*merge = *old;
} else {
verify_uptodate(old, o);
invalidate_ce_path(old);
}
}
else {
verify_absent(merge, "overwritten", o);
invalidate_ce_path(merge);
}
merge->ce_flags &= ~htons(CE_STAGEMASK);
add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
return 1;
}
static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
struct unpack_trees_options *o)
{
if (old)
verify_uptodate(old, o);
else
verify_absent(ce, "removed", o);
ce->ce_mode = 0;
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
invalidate_ce_path(ce);
return 1;
}
static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
{
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
return 1;
}
#if DBRT_DEBUG
static void show_stage_entry(FILE *o,
const char *label, const struct cache_entry *ce)
{
if (!ce)
fprintf(o, "%s (missing)\n", label);
else
fprintf(o, "%s%06o %s %d\t%s\n",
label,
ntohl(ce->ce_mode),
sha1_to_hex(ce->sha1),
ce_stage(ce),
ce->name);
}
#endif
int threeway_merge(struct cache_entry **stages,
struct unpack_trees_options *o,
int remove)
{
struct cache_entry *index;
struct cache_entry *head;
struct cache_entry *remote = stages[o->head_idx + 1];
int count;
int head_match = 0;
int remote_match = 0;
int df_conflict_head = 0;
int df_conflict_remote = 0;
int any_anc_missing = 0;
int no_anc_exists = 1;
int i;
for (i = 1; i < o->head_idx; i++) {
if (!stages[i] || stages[i] == o->df_conflict_entry)
any_anc_missing = 1;
else
no_anc_exists = 0;
}
index = stages[0];
head = stages[o->head_idx];
if (head == o->df_conflict_entry) {
df_conflict_head = 1;
head = NULL;
}
if (remote == o->df_conflict_entry) {
df_conflict_remote = 1;
remote = NULL;
}
/* First, if there's a #16 situation, note that to prevent #13
* and #14.
*/
if (!same(remote, head)) {
for (i = 1; i < o->head_idx; i++) {
if (same(stages[i], head)) {
head_match = i;
}
if (same(stages[i], remote)) {
remote_match = i;
}
}
}
/* We start with cases where the index is allowed to match
* something other than the head: #14(ALT) and #2ALT, where it
* is permitted to match the result instead.
*/
/* #14, #14ALT, #2ALT */
if (remote && !df_conflict_head && head_match && !remote_match) {
if (index && !same(index, remote) && !same(index, head))
reject_merge(index);
return merged_entry(remote, index, o);
}
/*
* If we have an entry in the index cache, then we want to
* make sure that it matches head.
*/
if (index && !same(index, head)) {
reject_merge(index);
}
if (head) {
/* #5ALT, #15 */
if (same(head, remote))
return merged_entry(head, index, o);
/* #13, #3ALT */
if (!df_conflict_remote && remote_match && !head_match)
return merged_entry(head, index, o);
}
/* #1 */
if (!head && !remote && any_anc_missing) {
remove_entry(remove);
return 0;
}
/* Under the new "aggressive" rule, we resolve mostly trivial
* cases that we historically had git-merge-one-file resolve.
*/
if (o->aggressive) {
int head_deleted = !head && !df_conflict_head;
int remote_deleted = !remote && !df_conflict_remote;
struct cache_entry *ce = NULL;
if (index)
ce = index;
else if (head)
ce = head;
else if (remote)
ce = remote;
else {
for (i = 1; i < o->head_idx; i++) {
if (stages[i] && stages[i] != o->df_conflict_entry) {
ce = stages[i];
break;
}
}
}
/*
* Deleted in both.
* Deleted in one and unchanged in the other.
*/
if ((head_deleted && remote_deleted) ||
(head_deleted && remote && remote_match) ||
(remote_deleted && head && head_match)) {
remove_entry(remove);
if (index)
return deleted_entry(index, index, o);
else if (ce && !head_deleted)
verify_absent(ce, "removed", o);
return 0;
}
/*
* Added in both, identically.
*/
if (no_anc_exists && head && remote && same(head, remote))
return merged_entry(head, index, o);
}
/* Below are "no merge" cases, which require that the index be
* up-to-date to avoid the files getting overwritten with
* conflict resolution files.
*/
if (index) {
verify_uptodate(index, o);
}
remove_entry(remove);
o->nontrivial_merge = 1;
/* #2, #3, #4, #6, #7, #9, #10, #11. */
count = 0;
if (!head_match || !remote_match) {
for (i = 1; i < o->head_idx; i++) {
if (stages[i] && stages[i] != o->df_conflict_entry) {
keep_entry(stages[i], o);
count++;
break;
}
}
}
#if DBRT_DEBUG
else {
fprintf(stderr, "read-tree: warning #16 detected\n");
show_stage_entry(stderr, "head ", stages[head_match]);
show_stage_entry(stderr, "remote ", stages[remote_match]);
}
#endif
if (head) { count += keep_entry(head, o); }
if (remote) { count += keep_entry(remote, o); }
return count;
}
/*
* Two-way merge.
*
* The rule is to "carry forward" what is in the index without losing
* information across a "fast forward", favoring a successful merge
* over a merge failure when it makes sense. For details of the
* "carry forward" rule, please see <Documentation/git-read-tree.txt>.
*
*/
int twoway_merge(struct cache_entry **src,
struct unpack_trees_options *o,
int remove)
{
struct cache_entry *current = src[0];
struct cache_entry *oldtree = src[1];
struct cache_entry *newtree = src[2];
if (o->merge_size != 2)
return error("Cannot do a twoway merge of %d trees",
o->merge_size);
if (oldtree == o->df_conflict_entry)
oldtree = NULL;
if (newtree == o->df_conflict_entry)
newtree = NULL;
if (current) {
if ((!oldtree && !newtree) || /* 4 and 5 */
(!oldtree && newtree &&
same(current, newtree)) || /* 6 and 7 */
(oldtree && newtree &&
same(oldtree, newtree)) || /* 14 and 15 */
(oldtree && newtree &&
!same(oldtree, newtree) && /* 18 and 19 */
same(current, newtree))) {
return keep_entry(current, o);
}
else if (oldtree && !newtree && same(current, oldtree)) {
/* 10 or 11 */
remove_entry(remove);
return deleted_entry(oldtree, current, o);
}
else if (oldtree && newtree &&
same(current, oldtree) && !same(current, newtree)) {
/* 20 or 21 */
return merged_entry(newtree, current, o);
}
else {
/* all other failures */
remove_entry(remove);
if (oldtree)
reject_merge(oldtree);
if (current)
reject_merge(current);
if (newtree)
reject_merge(newtree);
return -1;
}
}
else if (newtree)
return merged_entry(newtree, current, o);
remove_entry(remove);
return deleted_entry(oldtree, current, o);
}
/*
* Bind merge.
*
* Keep the index entries at stage0, collapse stage1 but make sure
* stage0 does not have anything there.
*/
int bind_merge(struct cache_entry **src,
struct unpack_trees_options *o,
int remove)
{
struct cache_entry *old = src[0];
struct cache_entry *a = src[1];
if (o->merge_size != 1)
return error("Cannot do a bind merge of %d trees\n",
o->merge_size);
if (a && old)
die("Entry '%s' overlaps. Cannot bind.", a->name);
if (!a)
return keep_entry(old, o);
else
return merged_entry(a, NULL, o);
}
/*
* One-way merge.
*
* The rule is:
* - take the stat information from stage0, take the data from stage1
*/
int oneway_merge(struct cache_entry **src,
struct unpack_trees_options *o,
int remove)
{
struct cache_entry *old = src[0];
struct cache_entry *a = src[1];
if (o->merge_size != 1)
return error("Cannot do a oneway merge of %d trees",
o->merge_size);
if (!a) {
remove_entry(remove);
return deleted_entry(old, old, o);
}
if (old && same(old, a)) {
if (o->reset) {
struct stat st;
if (lstat(old->name, &st) ||
ce_match_stat(old, &st, CE_MATCH_IGNORE_VALID))
old->ce_flags |= htons(CE_UPDATE);
}
return keep_entry(old, o);
}
return merged_entry(a, old, o);
}