git/read-cache.c
Robin Rosenberg c08e4d5b5c Enable minimal stat checking
Specifically the fields uid, gid, ctime, ino and dev are set to zero
by JGit. Other implementations, eg. Git in cygwin are allegedly also
somewhat incompatible with Git For Windows and on *nix platforms
the resolution of the timestamps may differ.

Any stat checking by git will then need to check content, which may
be very slow, particularly on Windows. Since mtime and size
is typically enough we should allow the user to tell git to avoid
checking these fields if they are set to zero in the index.

This change introduces a core.checkstat config option where the
the user can select to check all fields (default), or just size
and the whole second part of mtime (minimal).

Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-22 09:33:16 -08:00

1903 lines
51 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#define NO_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
#include "cache-tree.h"
#include "refs.h"
#include "dir.h"
#include "tree.h"
#include "commit.h"
#include "blob.h"
#include "resolve-undo.h"
#include "strbuf.h"
#include "varint.h"
static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
/* Mask for the name length in ce_flags in the on-disk index */
#define CE_NAMEMASK (0x0fff)
/* Index extensions.
*
* The first letter should be 'A'..'Z' for extensions that are not
* necessary for a correct operation (i.e. optimization data).
* When new extensions are added that _needs_ to be understood in
* order to correctly interpret the index file, pick character that
* is outside the range, to cause the reader to abort.
*/
#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
struct index_state the_index;
static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
{
istate->cache[nr] = ce;
add_name_hash(istate, ce);
}
static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
{
struct cache_entry *old = istate->cache[nr];
remove_name_hash(old);
set_index_entry(istate, nr, ce);
istate->cache_changed = 1;
}
void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
{
struct cache_entry *old = istate->cache[nr], *new;
int namelen = strlen(new_name);
new = xmalloc(cache_entry_size(namelen));
copy_cache_entry(new, old);
new->ce_flags &= ~CE_STATE_MASK;
new->ce_namelen = namelen;
memcpy(new->name, new_name, namelen + 1);
cache_tree_invalidate_path(istate->cache_tree, old->name);
remove_index_entry_at(istate, nr);
add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
}
/*
* This only updates the "non-critical" parts of the directory
* cache, ie the parts that aren't tracked by GIT, and only used
* to validate the cache.
*/
void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
{
ce->ce_ctime.sec = (unsigned int)st->st_ctime;
ce->ce_mtime.sec = (unsigned int)st->st_mtime;
ce->ce_ctime.nsec = ST_CTIME_NSEC(*st);
ce->ce_mtime.nsec = ST_MTIME_NSEC(*st);
ce->ce_dev = st->st_dev;
ce->ce_ino = st->st_ino;
ce->ce_uid = st->st_uid;
ce->ce_gid = st->st_gid;
ce->ce_size = st->st_size;
if (assume_unchanged)
ce->ce_flags |= CE_VALID;
if (S_ISREG(st->st_mode))
ce_mark_uptodate(ce);
}
static int ce_compare_data(struct cache_entry *ce, struct stat *st)
{
int match = -1;
int fd = open(ce->name, O_RDONLY);
if (fd >= 0) {
unsigned char sha1[20];
if (!index_fd(sha1, fd, st, OBJ_BLOB, ce->name, 0))
match = hashcmp(sha1, ce->sha1);
/* index_fd() closed the file descriptor already */
}
return match;
}
static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
{
int match = -1;
void *buffer;
unsigned long size;
enum object_type type;
struct strbuf sb = STRBUF_INIT;
if (strbuf_readlink(&sb, ce->name, expected_size))
return -1;
buffer = read_sha1_file(ce->sha1, &type, &size);
if (buffer) {
if (size == sb.len)
match = memcmp(buffer, sb.buf, size);
free(buffer);
}
strbuf_release(&sb);
return match;
}
static int ce_compare_gitlink(struct cache_entry *ce)
{
unsigned char sha1[20];
/*
* We don't actually require that the .git directory
* under GITLINK directory be a valid git directory. It
* might even be missing (in case nobody populated that
* sub-project).
*
* If so, we consider it always to match.
*/
if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
return 0;
return hashcmp(sha1, ce->sha1);
}
static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
{
switch (st->st_mode & S_IFMT) {
case S_IFREG:
if (ce_compare_data(ce, st))
return DATA_CHANGED;
break;
case S_IFLNK:
if (ce_compare_link(ce, xsize_t(st->st_size)))
return DATA_CHANGED;
break;
case S_IFDIR:
if (S_ISGITLINK(ce->ce_mode))
return ce_compare_gitlink(ce) ? DATA_CHANGED : 0;
default:
return TYPE_CHANGED;
}
return 0;
}
static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
{
unsigned int changed = 0;
if (ce->ce_flags & CE_REMOVE)
return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
switch (ce->ce_mode & S_IFMT) {
case S_IFREG:
changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
/* We consider only the owner x bit to be relevant for
* "mode changes"
*/
if (trust_executable_bit &&
(0100 & (ce->ce_mode ^ st->st_mode)))
changed |= MODE_CHANGED;
break;
case S_IFLNK:
if (!S_ISLNK(st->st_mode) &&
(has_symlinks || !S_ISREG(st->st_mode)))
changed |= TYPE_CHANGED;
break;
case S_IFGITLINK:
/* We ignore most of the st_xxx fields for gitlinks */
if (!S_ISDIR(st->st_mode))
changed |= TYPE_CHANGED;
else if (ce_compare_gitlink(ce))
changed |= DATA_CHANGED;
return changed;
default:
die("internal error: ce_mode is %o", ce->ce_mode);
}
if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
changed |= MTIME_CHANGED;
if (trust_ctime && check_stat &&
ce->ce_ctime.sec != (unsigned int)st->st_ctime)
changed |= CTIME_CHANGED;
#ifdef USE_NSEC
if (check_stat && ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
changed |= MTIME_CHANGED;
if (trust_ctime && check_stat &&
ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
changed |= CTIME_CHANGED;
#endif
if (check_stat) {
if (ce->ce_uid != (unsigned int) st->st_uid ||
ce->ce_gid != (unsigned int) st->st_gid)
changed |= OWNER_CHANGED;
if (ce->ce_ino != (unsigned int) st->st_ino)
changed |= INODE_CHANGED;
}
#ifdef USE_STDEV
/*
* st_dev breaks on network filesystems where different
* clients will have different views of what "device"
* the filesystem is on
*/
if (check_stat && ce->ce_dev != (unsigned int) st->st_dev)
changed |= INODE_CHANGED;
#endif
if (ce->ce_size != (unsigned int) st->st_size)
changed |= DATA_CHANGED;
/* Racily smudged entry? */
if (!ce->ce_size) {
if (!is_empty_blob_sha1(ce->sha1))
changed |= DATA_CHANGED;
}
return changed;
}
static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
{
return (!S_ISGITLINK(ce->ce_mode) &&
istate->timestamp.sec &&
#ifdef USE_NSEC
/* nanosecond timestamped files can also be racy! */
(istate->timestamp.sec < ce->ce_mtime.sec ||
(istate->timestamp.sec == ce->ce_mtime.sec &&
istate->timestamp.nsec <= ce->ce_mtime.nsec))
#else
istate->timestamp.sec <= ce->ce_mtime.sec
#endif
);
}
int ie_match_stat(const struct index_state *istate,
struct cache_entry *ce, struct stat *st,
unsigned int options)
{
unsigned int changed;
int ignore_valid = options & CE_MATCH_IGNORE_VALID;
int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
/*
* If it's marked as always valid in the index, it's
* valid whatever the checked-out copy says.
*
* skip-worktree has the same effect with higher precedence
*/
if (!ignore_skip_worktree && ce_skip_worktree(ce))
return 0;
if (!ignore_valid && (ce->ce_flags & CE_VALID))
return 0;
/*
* Intent-to-add entries have not been added, so the index entry
* by definition never matches what is in the work tree until it
* actually gets added.
*/
if (ce->ce_flags & CE_INTENT_TO_ADD)
return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED;
changed = ce_match_stat_basic(ce, st);
/*
* Within 1 second of this sequence:
* echo xyzzy >file && git-update-index --add file
* running this command:
* echo frotz >file
* would give a falsely clean cache entry. The mtime and
* length match the cache, and other stat fields do not change.
*
* We could detect this at update-index time (the cache entry
* being registered/updated records the same time as "now")
* and delay the return from git-update-index, but that would
* effectively mean we can make at most one commit per second,
* which is not acceptable. Instead, we check cache entries
* whose mtime are the same as the index file timestamp more
* carefully than others.
*/
if (!changed && is_racy_timestamp(istate, ce)) {
if (assume_racy_is_modified)
changed |= DATA_CHANGED;
else
changed |= ce_modified_check_fs(ce, st);
}
return changed;
}
int ie_modified(const struct index_state *istate,
struct cache_entry *ce, struct stat *st, unsigned int options)
{
int changed, changed_fs;
changed = ie_match_stat(istate, ce, st, options);
if (!changed)
return 0;
/*
* If the mode or type has changed, there's no point in trying
* to refresh the entry - it's not going to match
*/
if (changed & (MODE_CHANGED | TYPE_CHANGED))
return changed;
/*
* Immediately after read-tree or update-index --cacheinfo,
* the length field is zero, as we have never even read the
* lstat(2) information once, and we cannot trust DATA_CHANGED
* returned by ie_match_stat() which in turn was returned by
* ce_match_stat_basic() to signal that the filesize of the
* blob changed. We have to actually go to the filesystem to
* see if the contents match, and if so, should answer "unchanged".
*
* The logic does not apply to gitlinks, as ce_match_stat_basic()
* already has checked the actual HEAD from the filesystem in the
* subproject. If ie_match_stat() already said it is different,
* then we know it is.
*/
if ((changed & DATA_CHANGED) &&
(S_ISGITLINK(ce->ce_mode) || ce->ce_size != 0))
return changed;
changed_fs = ce_modified_check_fs(ce, st);
if (changed_fs)
return changed | changed_fs;
return 0;
}
int base_name_compare(const char *name1, int len1, int mode1,
const char *name2, int len2, int mode2)
{
unsigned char c1, c2;
int len = len1 < len2 ? len1 : len2;
int cmp;
cmp = memcmp(name1, name2, len);
if (cmp)
return cmp;
c1 = name1[len];
c2 = name2[len];
if (!c1 && S_ISDIR(mode1))
c1 = '/';
if (!c2 && S_ISDIR(mode2))
c2 = '/';
return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
}
/*
* df_name_compare() is identical to base_name_compare(), except it
* compares conflicting directory/file entries as equal. Note that
* while a directory name compares as equal to a regular file, they
* then individually compare _differently_ to a filename that has
* a dot after the basename (because '\0' < '.' < '/').
*
* This is used by routines that want to traverse the git namespace
* but then handle conflicting entries together when possible.
*/
int df_name_compare(const char *name1, int len1, int mode1,
const char *name2, int len2, int mode2)
{
int len = len1 < len2 ? len1 : len2, cmp;
unsigned char c1, c2;
cmp = memcmp(name1, name2, len);
if (cmp)
return cmp;
/* Directories and files compare equal (same length, same name) */
if (len1 == len2)
return 0;
c1 = name1[len];
if (!c1 && S_ISDIR(mode1))
c1 = '/';
c2 = name2[len];
if (!c2 && S_ISDIR(mode2))
c2 = '/';
if (c1 == '/' && !c2)
return 0;
if (c2 == '/' && !c1)
return 0;
return c1 - c2;
}
int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2)
{
int len = len1 < len2 ? len1 : len2;
int cmp;
cmp = memcmp(name1, name2, len);
if (cmp)
return cmp;
if (len1 < len2)
return -1;
if (len1 > len2)
return 1;
if (stage1 < stage2)
return -1;
if (stage1 > stage2)
return 1;
return 0;
}
int cache_name_compare(const char *name1, int len1, const char *name2, int len2)
{
return cache_name_stage_compare(name1, len1, 0, name2, len2, 0);
}
static int index_name_stage_pos(const struct index_state *istate, const char *name, int namelen, int stage)
{
int first, last;
first = 0;
last = istate->cache_nr;
while (last > first) {
int next = (last + first) >> 1;
struct cache_entry *ce = istate->cache[next];
int cmp = cache_name_stage_compare(name, namelen, stage, ce->name, ce_namelen(ce), ce_stage(ce));
if (!cmp)
return next;
if (cmp < 0) {
last = next;
continue;
}
first = next+1;
}
return -first-1;
}
int index_name_pos(const struct index_state *istate, const char *name, int namelen)
{
return index_name_stage_pos(istate, name, namelen, 0);
}
/* Remove entry, return true if there are more entries to go.. */
int remove_index_entry_at(struct index_state *istate, int pos)
{
struct cache_entry *ce = istate->cache[pos];
record_resolve_undo(istate, ce);
remove_name_hash(ce);
istate->cache_changed = 1;
istate->cache_nr--;
if (pos >= istate->cache_nr)
return 0;
memmove(istate->cache + pos,
istate->cache + pos + 1,
(istate->cache_nr - pos) * sizeof(struct cache_entry *));
return 1;
}
/*
* Remove all cache ententries marked for removal, that is where
* CE_REMOVE is set in ce_flags. This is much more effective than
* calling remove_index_entry_at() for each entry to be removed.
*/
void remove_marked_cache_entries(struct index_state *istate)
{
struct cache_entry **ce_array = istate->cache;
unsigned int i, j;
for (i = j = 0; i < istate->cache_nr; i++) {
if (ce_array[i]->ce_flags & CE_REMOVE)
remove_name_hash(ce_array[i]);
else
ce_array[j++] = ce_array[i];
}
istate->cache_changed = 1;
istate->cache_nr = j;
}
int remove_file_from_index(struct index_state *istate, const char *path)
{
int pos = index_name_pos(istate, path, strlen(path));
if (pos < 0)
pos = -pos-1;
cache_tree_invalidate_path(istate->cache_tree, path);
while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
remove_index_entry_at(istate, pos);
return 0;
}
static int compare_name(struct cache_entry *ce, const char *path, int namelen)
{
return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
}
static int index_name_pos_also_unmerged(struct index_state *istate,
const char *path, int namelen)
{
int pos = index_name_pos(istate, path, namelen);
struct cache_entry *ce;
if (pos >= 0)
return pos;
/* maybe unmerged? */
pos = -1 - pos;
if (pos >= istate->cache_nr ||
compare_name((ce = istate->cache[pos]), path, namelen))
return -1;
/* order of preference: stage 2, 1, 3 */
if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
ce_stage((ce = istate->cache[pos + 1])) == 2 &&
!compare_name(ce, path, namelen))
pos++;
return pos;
}
static int different_name(struct cache_entry *ce, struct cache_entry *alias)
{
int len = ce_namelen(ce);
return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
}
/*
* If we add a filename that aliases in the cache, we will use the
* name that we already have - but we don't want to update the same
* alias twice, because that implies that there were actually two
* different files with aliasing names!
*
* So we use the CE_ADDED flag to verify that the alias was an old
* one before we accept it as
*/
static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
{
int len;
struct cache_entry *new;
if (alias->ce_flags & CE_ADDED)
die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
/* Ok, create the new entry using the name of the existing alias */
len = ce_namelen(alias);
new = xcalloc(1, cache_entry_size(len));
memcpy(new->name, alias->name, len);
copy_cache_entry(new, ce);
free(ce);
return new;
}
static void record_intent_to_add(struct cache_entry *ce)
{
unsigned char sha1[20];
if (write_sha1_file("", 0, blob_type, sha1))
die("cannot create an empty blob in the object database");
hashcpy(ce->sha1, sha1);
}
int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
{
int size, namelen, was_same;
mode_t st_mode = st->st_mode;
struct cache_entry *ce, *alias;
unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY;
int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND);
int pretend = flags & ADD_CACHE_PRETEND;
int intent_only = flags & ADD_CACHE_INTENT;
int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|
(intent_only ? ADD_CACHE_NEW_ONLY : 0));
if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
return error("%s: can only add regular files, symbolic links or git-directories", path);
namelen = strlen(path);
if (S_ISDIR(st_mode)) {
while (namelen && path[namelen-1] == '/')
namelen--;
}
size = cache_entry_size(namelen);
ce = xcalloc(1, size);
memcpy(ce->name, path, namelen);
ce->ce_namelen = namelen;
if (!intent_only)
fill_stat_cache_info(ce, st);
else
ce->ce_flags |= CE_INTENT_TO_ADD;
if (trust_executable_bit && has_symlinks)
ce->ce_mode = create_ce_mode(st_mode);
else {
/* If there is an existing entry, pick the mode bits and type
* from it, otherwise assume unexecutable regular file.
*/
struct cache_entry *ent;
int pos = index_name_pos_also_unmerged(istate, path, namelen);
ent = (0 <= pos) ? istate->cache[pos] : NULL;
ce->ce_mode = ce_mode_from_stat(ent, st_mode);
}
/* When core.ignorecase=true, determine if a directory of the same name but differing
* case already exists within the Git repository. If it does, ensure the directory
* case of the file being added to the repository matches (is folded into) the existing
* entry's directory case.
*/
if (ignore_case) {
const char *startPtr = ce->name;
const char *ptr = startPtr;
while (*ptr) {
while (*ptr && *ptr != '/')
++ptr;
if (*ptr == '/') {
struct cache_entry *foundce;
++ptr;
foundce = index_name_exists(&the_index, ce->name, ptr - ce->name, ignore_case);
if (foundce) {
memcpy((void *)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr);
startPtr = ptr;
}
}
}
}
alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) {
/* Nothing changed, really */
free(ce);
if (!S_ISGITLINK(alias->ce_mode))
ce_mark_uptodate(alias);
alias->ce_flags |= CE_ADDED;
return 0;
}
if (!intent_only) {
if (index_path(ce->sha1, path, st, HASH_WRITE_OBJECT))
return error("unable to index file %s", path);
} else
record_intent_to_add(ce);
if (ignore_case && alias && different_name(ce, alias))
ce = create_alias_ce(ce, alias);
ce->ce_flags |= CE_ADDED;
/* It was suspected to be racily clean, but it turns out to be Ok */
was_same = (alias &&
!ce_stage(alias) &&
!hashcmp(alias->sha1, ce->sha1) &&
ce->ce_mode == alias->ce_mode);
if (pretend)
;
else if (add_index_entry(istate, ce, add_option))
return error("unable to add %s to index",path);
if (verbose && !was_same)
printf("add '%s'\n", path);
return 0;
}
int add_file_to_index(struct index_state *istate, const char *path, int flags)
{
struct stat st;
if (lstat(path, &st))
die_errno("unable to stat '%s'", path);
return add_to_index(istate, path, &st, flags);
}
struct cache_entry *make_cache_entry(unsigned int mode,
const unsigned char *sha1, const char *path, int stage,
int refresh)
{
int size, len;
struct cache_entry *ce;
if (!verify_path(path)) {
error("Invalid path '%s'", path);
return NULL;
}
len = strlen(path);
size = cache_entry_size(len);
ce = xcalloc(1, size);
hashcpy(ce->sha1, sha1);
memcpy(ce->name, path, len);
ce->ce_flags = create_ce_flags(stage);
ce->ce_namelen = len;
ce->ce_mode = create_ce_mode(mode);
if (refresh)
return refresh_cache_entry(ce, 0);
return ce;
}
int ce_same_name(struct cache_entry *a, struct cache_entry *b)
{
int len = ce_namelen(a);
return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
}
int ce_path_match(const struct cache_entry *ce, const struct pathspec *pathspec)
{
return match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL);
}
/*
* We fundamentally don't like some paths: we don't want
* dot or dot-dot anywhere, and for obvious reasons don't
* want to recurse into ".git" either.
*
* Also, we don't want double slashes or slashes at the
* end that can make pathnames ambiguous.
*/
static int verify_dotfile(const char *rest)
{
/*
* The first character was '.', but that
* has already been discarded, we now test
* the rest.
*/
/* "." is not allowed */
if (*rest == '\0' || is_dir_sep(*rest))
return 0;
switch (*rest) {
/*
* ".git" followed by NUL or slash is bad. This
* shares the path end test with the ".." case.
*/
case 'g':
if (rest[1] != 'i')
break;
if (rest[2] != 't')
break;
rest += 2;
/* fallthrough */
case '.':
if (rest[1] == '\0' || is_dir_sep(rest[1]))
return 0;
}
return 1;
}
int verify_path(const char *path)
{
char c;
if (has_dos_drive_prefix(path))
return 0;
goto inside;
for (;;) {
if (!c)
return 1;
if (is_dir_sep(c)) {
inside:
c = *path++;
if ((c == '.' && !verify_dotfile(path)) ||
is_dir_sep(c) || c == '\0')
return 0;
}
c = *path++;
}
}
/*
* Do we have another file that has the beginning components being a
* proper superset of the name we're trying to add?
*/
static int has_file_name(struct index_state *istate,
const struct cache_entry *ce, int pos, int ok_to_replace)
{
int retval = 0;
int len = ce_namelen(ce);
int stage = ce_stage(ce);
const char *name = ce->name;
while (pos < istate->cache_nr) {
struct cache_entry *p = istate->cache[pos++];
if (len >= ce_namelen(p))
break;
if (memcmp(name, p->name, len))
break;
if (ce_stage(p) != stage)
continue;
if (p->name[len] != '/')
continue;
if (p->ce_flags & CE_REMOVE)
continue;
retval = -1;
if (!ok_to_replace)
break;
remove_index_entry_at(istate, --pos);
}
return retval;
}
/*
* Do we have another file with a pathname that is a proper
* subset of the name we're trying to add?
*/
static int has_dir_name(struct index_state *istate,
const struct cache_entry *ce, int pos, int ok_to_replace)
{
int retval = 0;
int stage = ce_stage(ce);
const char *name = ce->name;
const char *slash = name + ce_namelen(ce);
for (;;) {
int len;
for (;;) {
if (*--slash == '/')
break;
if (slash <= ce->name)
return retval;
}
len = slash - name;
pos = index_name_stage_pos(istate, name, len, stage);
if (pos >= 0) {
/*
* Found one, but not so fast. This could
* be a marker that says "I was here, but
* I am being removed". Such an entry is
* not a part of the resulting tree, and
* it is Ok to have a directory at the same
* path.
*/
if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
retval = -1;
if (!ok_to_replace)
break;
remove_index_entry_at(istate, pos);
continue;
}
}
else
pos = -pos-1;
/*
* Trivial optimization: if we find an entry that
* already matches the sub-directory, then we know
* we're ok, and we can exit.
*/
while (pos < istate->cache_nr) {
struct cache_entry *p = istate->cache[pos];
if ((ce_namelen(p) <= len) ||
(p->name[len] != '/') ||
memcmp(p->name, name, len))
break; /* not our subdirectory */
if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
/*
* p is at the same stage as our entry, and
* is a subdirectory of what we are looking
* at, so we cannot have conflicts at our
* level or anything shorter.
*/
return retval;
pos++;
}
}
return retval;
}
/* We may be in a situation where we already have path/file and path
* is being added, or we already have path and path/file is being
* added. Either one would result in a nonsense tree that has path
* twice when git-write-tree tries to write it out. Prevent it.
*
* If ok-to-replace is specified, we remove the conflicting entries
* from the cache so the caller should recompute the insert position.
* When this happens, we return non-zero.
*/
static int check_file_directory_conflict(struct index_state *istate,
const struct cache_entry *ce,
int pos, int ok_to_replace)
{
int retval;
/*
* When ce is an "I am going away" entry, we allow it to be added
*/
if (ce->ce_flags & CE_REMOVE)
return 0;
/*
* We check if the path is a sub-path of a subsequent pathname
* first, since removing those will not change the position
* in the array.
*/
retval = has_file_name(istate, ce, pos, ok_to_replace);
/*
* Then check if the path might have a clashing sub-directory
* before it.
*/
return retval + has_dir_name(istate, ce, pos, ok_to_replace);
}
static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
{
int pos;
int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
int new_only = option & ADD_CACHE_NEW_ONLY;
cache_tree_invalidate_path(istate->cache_tree, ce->name);
pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
/* existing match? Just replace it. */
if (pos >= 0) {
if (!new_only)
replace_index_entry(istate, pos, ce);
return 0;
}
pos = -pos-1;
/*
* Inserting a merged entry ("stage 0") into the index
* will always replace all non-merged entries..
*/
if (pos < istate->cache_nr && ce_stage(ce) == 0) {
while (ce_same_name(istate->cache[pos], ce)) {
ok_to_add = 1;
if (!remove_index_entry_at(istate, pos))
break;
}
}
if (!ok_to_add)
return -1;
if (!verify_path(ce->name))
return error("Invalid path '%s'", ce->name);
if (!skip_df_check &&
check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
if (!ok_to_replace)
return error("'%s' appears as both a file and as a directory",
ce->name);
pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
pos = -pos-1;
}
return pos + 1;
}
int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
{
int pos;
if (option & ADD_CACHE_JUST_APPEND)
pos = istate->cache_nr;
else {
int ret;
ret = add_index_entry_with_check(istate, ce, option);
if (ret <= 0)
return ret;
pos = ret - 1;
}
/* Make sure the array is big enough .. */
if (istate->cache_nr == istate->cache_alloc) {
istate->cache_alloc = alloc_nr(istate->cache_alloc);
istate->cache = xrealloc(istate->cache,
istate->cache_alloc * sizeof(struct cache_entry *));
}
/* Add it in.. */
istate->cache_nr++;
if (istate->cache_nr > pos + 1)
memmove(istate->cache + pos + 1,
istate->cache + pos,
(istate->cache_nr - pos - 1) * sizeof(ce));
set_index_entry(istate, pos, ce);
istate->cache_changed = 1;
return 0;
}
/*
* "refresh" does not calculate a new sha1 file or bring the
* cache up-to-date for mode/content changes. But what it
* _does_ do is to "re-match" the stat information of a file
* with the cache, so that you can refresh the cache for a
* file that hasn't been changed but where the stat entry is
* out of date.
*
* For example, you'd want to do this after doing a "git-read-tree",
* to link up the stat cache details with the proper files.
*/
static struct cache_entry *refresh_cache_ent(struct index_state *istate,
struct cache_entry *ce,
unsigned int options, int *err,
int *changed_ret)
{
struct stat st;
struct cache_entry *updated;
int changed, size;
int ignore_valid = options & CE_MATCH_IGNORE_VALID;
int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
if (ce_uptodate(ce))
return ce;
/*
* CE_VALID or CE_SKIP_WORKTREE means the user promised us
* that the change to the work tree does not matter and told
* us not to worry.
*/
if (!ignore_skip_worktree && ce_skip_worktree(ce)) {
ce_mark_uptodate(ce);
return ce;
}
if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
ce_mark_uptodate(ce);
return ce;
}
if (lstat(ce->name, &st) < 0) {
if (err)
*err = errno;
return NULL;
}
changed = ie_match_stat(istate, ce, &st, options);
if (changed_ret)
*changed_ret = changed;
if (!changed) {
/*
* The path is unchanged. If we were told to ignore
* valid bit, then we did the actual stat check and
* found that the entry is unmodified. If the entry
* is not marked VALID, this is the place to mark it
* valid again, under "assume unchanged" mode.
*/
if (ignore_valid && assume_unchanged &&
!(ce->ce_flags & CE_VALID))
; /* mark this one VALID again */
else {
/*
* We do not mark the index itself "modified"
* because CE_UPTODATE flag is in-core only;
* we are not going to write this change out.
*/
if (!S_ISGITLINK(ce->ce_mode))
ce_mark_uptodate(ce);
return ce;
}
}
if (ie_modified(istate, ce, &st, options)) {
if (err)
*err = EINVAL;
return NULL;
}
size = ce_size(ce);
updated = xmalloc(size);
memcpy(updated, ce, size);
fill_stat_cache_info(updated, &st);
/*
* If ignore_valid is not set, we should leave CE_VALID bit
* alone. Otherwise, paths marked with --no-assume-unchanged
* (i.e. things to be edited) will reacquire CE_VALID bit
* automatically, which is not really what we want.
*/
if (!ignore_valid && assume_unchanged &&
!(ce->ce_flags & CE_VALID))
updated->ce_flags &= ~CE_VALID;
return updated;
}
static void show_file(const char * fmt, const char * name, int in_porcelain,
int * first, const char *header_msg)
{
if (in_porcelain && *first && header_msg) {
printf("%s\n", header_msg);
*first = 0;
}
printf(fmt, name);
}
int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec,
char *seen, const char *header_msg)
{
int i;
int has_errors = 0;
int really = (flags & REFRESH_REALLY) != 0;
int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
int quiet = (flags & REFRESH_QUIET) != 0;
int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
int first = 1;
int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
const char *modified_fmt;
const char *deleted_fmt;
const char *typechange_fmt;
const char *added_fmt;
const char *unmerged_fmt;
modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n");
unmerged_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce, *new;
int cache_errno = 0;
int changed = 0;
int filtered = 0;
ce = istate->cache[i];
if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
continue;
if (pathspec &&
!match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, seen))
filtered = 1;
if (ce_stage(ce)) {
while ((i < istate->cache_nr) &&
! strcmp(istate->cache[i]->name, ce->name))
i++;
i--;
if (allow_unmerged)
continue;
if (!filtered)
show_file(unmerged_fmt, ce->name, in_porcelain,
&first, header_msg);
has_errors = 1;
continue;
}
if (filtered)
continue;
new = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
if (new == ce)
continue;
if (!new) {
const char *fmt;
if (not_new && cache_errno == ENOENT)
continue;
if (really && cache_errno == EINVAL) {
/* If we are doing --really-refresh that
* means the index is not valid anymore.
*/
ce->ce_flags &= ~CE_VALID;
istate->cache_changed = 1;
}
if (quiet)
continue;
if (cache_errno == ENOENT)
fmt = deleted_fmt;
else if (ce->ce_flags & CE_INTENT_TO_ADD)
fmt = added_fmt; /* must be before other checks */
else if (changed & TYPE_CHANGED)
fmt = typechange_fmt;
else
fmt = modified_fmt;
show_file(fmt,
ce->name, in_porcelain, &first, header_msg);
has_errors = 1;
continue;
}
replace_index_entry(istate, i, new);
}
return has_errors;
}
static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
{
return refresh_cache_ent(&the_index, ce, really, NULL, NULL);
}
/*****************************************************************
* Index File I/O
*****************************************************************/
#define INDEX_FORMAT_DEFAULT 3
/*
* dev/ino/uid/gid/size are also just tracked to the low 32 bits
* Again - this is just a (very strong in practice) heuristic that
* the inode hasn't changed.
*
* We save the fields in big-endian order to allow using the
* index file over NFS transparently.
*/
struct ondisk_cache_entry {
struct cache_time ctime;
struct cache_time mtime;
unsigned int dev;
unsigned int ino;
unsigned int mode;
unsigned int uid;
unsigned int gid;
unsigned int size;
unsigned char sha1[20];
unsigned short flags;
char name[FLEX_ARRAY]; /* more */
};
/*
* This struct is used when CE_EXTENDED bit is 1
* The struct must match ondisk_cache_entry exactly from
* ctime till flags
*/
struct ondisk_cache_entry_extended {
struct cache_time ctime;
struct cache_time mtime;
unsigned int dev;
unsigned int ino;
unsigned int mode;
unsigned int uid;
unsigned int gid;
unsigned int size;
unsigned char sha1[20];
unsigned short flags;
unsigned short flags2;
char name[FLEX_ARRAY]; /* more */
};
/* These are only used for v3 or lower */
#define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
#define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
#define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
#define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
ondisk_cache_entry_size(ce_namelen(ce)))
static int verify_hdr(struct cache_header *hdr, unsigned long size)
{
git_SHA_CTX c;
unsigned char sha1[20];
int hdr_version;
if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
return error("bad signature");
hdr_version = ntohl(hdr->hdr_version);
if (hdr_version < 2 || 4 < hdr_version)
return error("bad index version %d", hdr_version);
git_SHA1_Init(&c);
git_SHA1_Update(&c, hdr, size - 20);
git_SHA1_Final(sha1, &c);
if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
return error("bad index file sha1 signature");
return 0;
}
static int read_index_extension(struct index_state *istate,
const char *ext, void *data, unsigned long sz)
{
switch (CACHE_EXT(ext)) {
case CACHE_EXT_TREE:
istate->cache_tree = cache_tree_read(data, sz);
break;
case CACHE_EXT_RESOLVE_UNDO:
istate->resolve_undo = resolve_undo_read(data, sz);
break;
default:
if (*ext < 'A' || 'Z' < *ext)
return error("index uses %.4s extension, which we do not understand",
ext);
fprintf(stderr, "ignoring %.4s extension\n", ext);
break;
}
return 0;
}
int read_index(struct index_state *istate)
{
return read_index_from(istate, get_index_file());
}
#ifndef NEEDS_ALIGNED_ACCESS
#define ntoh_s(var) ntohs(var)
#define ntoh_l(var) ntohl(var)
#else
static inline uint16_t ntoh_s_force_align(void *p)
{
uint16_t x;
memcpy(&x, p, sizeof(x));
return ntohs(x);
}
static inline uint32_t ntoh_l_force_align(void *p)
{
uint32_t x;
memcpy(&x, p, sizeof(x));
return ntohl(x);
}
#define ntoh_s(var) ntoh_s_force_align(&(var))
#define ntoh_l(var) ntoh_l_force_align(&(var))
#endif
static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
unsigned int flags,
const char *name,
size_t len)
{
struct cache_entry *ce = xmalloc(cache_entry_size(len));
ce->ce_ctime.sec = ntoh_l(ondisk->ctime.sec);
ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec);
ce->ce_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
ce->ce_dev = ntoh_l(ondisk->dev);
ce->ce_ino = ntoh_l(ondisk->ino);
ce->ce_mode = ntoh_l(ondisk->mode);
ce->ce_uid = ntoh_l(ondisk->uid);
ce->ce_gid = ntoh_l(ondisk->gid);
ce->ce_size = ntoh_l(ondisk->size);
ce->ce_flags = flags & ~CE_NAMEMASK;
ce->ce_namelen = len;
hashcpy(ce->sha1, ondisk->sha1);
memcpy(ce->name, name, len);
ce->name[len] = '\0';
return ce;
}
/*
* Adjacent cache entries tend to share the leading paths, so it makes
* sense to only store the differences in later entries. In the v4
* on-disk format of the index, each on-disk cache entry stores the
* number of bytes to be stripped from the end of the previous name,
* and the bytes to append to the result, to come up with its name.
*/
static unsigned long expand_name_field(struct strbuf *name, const char *cp_)
{
const unsigned char *ep, *cp = (const unsigned char *)cp_;
size_t len = decode_varint(&cp);
if (name->len < len)
die("malformed name field in the index");
strbuf_remove(name, name->len - len, len);
for (ep = cp; *ep; ep++)
; /* find the end */
strbuf_add(name, cp, ep - cp);
return (const char *)ep + 1 - cp_;
}
static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk,
unsigned long *ent_size,
struct strbuf *previous_name)
{
struct cache_entry *ce;
size_t len;
const char *name;
unsigned int flags;
/* On-disk flags are just 16 bits */
flags = ntoh_s(ondisk->flags);
len = flags & CE_NAMEMASK;
if (flags & CE_EXTENDED) {
struct ondisk_cache_entry_extended *ondisk2;
int extended_flags;
ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
extended_flags = ntoh_s(ondisk2->flags2) << 16;
/* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
if (extended_flags & ~CE_EXTENDED_FLAGS)
die("Unknown index entry format %08x", extended_flags);
flags |= extended_flags;
name = ondisk2->name;
}
else
name = ondisk->name;
if (!previous_name) {
/* v3 and earlier */
if (len == CE_NAMEMASK)
len = strlen(name);
ce = cache_entry_from_ondisk(ondisk, flags, name, len);
*ent_size = ondisk_ce_size(ce);
} else {
unsigned long consumed;
consumed = expand_name_field(previous_name, name);
ce = cache_entry_from_ondisk(ondisk, flags,
previous_name->buf,
previous_name->len);
*ent_size = (name - ((char *)ondisk)) + consumed;
}
return ce;
}
/* remember to discard_cache() before reading a different cache! */
int read_index_from(struct index_state *istate, const char *path)
{
int fd, i;
struct stat st;
unsigned long src_offset;
struct cache_header *hdr;
void *mmap;
size_t mmap_size;
struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
if (istate->initialized)
return istate->cache_nr;
istate->timestamp.sec = 0;
istate->timestamp.nsec = 0;
fd = open(path, O_RDONLY);
if (fd < 0) {
if (errno == ENOENT)
return 0;
die_errno("index file open failed");
}
if (fstat(fd, &st))
die_errno("cannot stat the open index");
mmap_size = xsize_t(st.st_size);
if (mmap_size < sizeof(struct cache_header) + 20)
die("index file smaller than expected");
mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if (mmap == MAP_FAILED)
die_errno("unable to map index file");
close(fd);
hdr = mmap;
if (verify_hdr(hdr, mmap_size) < 0)
goto unmap;
istate->version = ntohl(hdr->hdr_version);
istate->cache_nr = ntohl(hdr->hdr_entries);
istate->cache_alloc = alloc_nr(istate->cache_nr);
istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
istate->initialized = 1;
if (istate->version == 4)
previous_name = &previous_name_buf;
else
previous_name = NULL;
src_offset = sizeof(*hdr);
for (i = 0; i < istate->cache_nr; i++) {
struct ondisk_cache_entry *disk_ce;
struct cache_entry *ce;
unsigned long consumed;
disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
ce = create_from_disk(disk_ce, &consumed, previous_name);
set_index_entry(istate, i, ce);
src_offset += consumed;
}
strbuf_release(&previous_name_buf);
istate->timestamp.sec = st.st_mtime;
istate->timestamp.nsec = ST_MTIME_NSEC(st);
while (src_offset <= mmap_size - 20 - 8) {
/* After an array of active_nr index entries,
* there can be arbitrary number of extended
* sections, each of which is prefixed with
* extension name (4-byte) and section length
* in 4-byte network byte order.
*/
uint32_t extsize;
memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
extsize = ntohl(extsize);
if (read_index_extension(istate,
(const char *) mmap + src_offset,
(char *) mmap + src_offset + 8,
extsize) < 0)
goto unmap;
src_offset += 8;
src_offset += extsize;
}
munmap(mmap, mmap_size);
return istate->cache_nr;
unmap:
munmap(mmap, mmap_size);
die("index file corrupt");
}
int is_index_unborn(struct index_state *istate)
{
return (!istate->cache_nr && !istate->timestamp.sec);
}
int discard_index(struct index_state *istate)
{
int i;
for (i = 0; i < istate->cache_nr; i++)
free(istate->cache[i]);
resolve_undo_clear_index(istate);
istate->cache_nr = 0;
istate->cache_changed = 0;
istate->timestamp.sec = 0;
istate->timestamp.nsec = 0;
istate->name_hash_initialized = 0;
free_hash(&istate->name_hash);
cache_tree_free(&(istate->cache_tree));
istate->initialized = 0;
/* no need to throw away allocated active_cache */
return 0;
}
int unmerged_index(const struct index_state *istate)
{
int i;
for (i = 0; i < istate->cache_nr; i++) {
if (ce_stage(istate->cache[i]))
return 1;
}
return 0;
}
#define WRITE_BUFFER_SIZE 8192
static unsigned char write_buffer[WRITE_BUFFER_SIZE];
static unsigned long write_buffer_len;
static int ce_write_flush(git_SHA_CTX *context, int fd)
{
unsigned int buffered = write_buffer_len;
if (buffered) {
git_SHA1_Update(context, write_buffer, buffered);
if (write_in_full(fd, write_buffer, buffered) != buffered)
return -1;
write_buffer_len = 0;
}
return 0;
}
static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
{
while (len) {
unsigned int buffered = write_buffer_len;
unsigned int partial = WRITE_BUFFER_SIZE - buffered;
if (partial > len)
partial = len;
memcpy(write_buffer + buffered, data, partial);
buffered += partial;
if (buffered == WRITE_BUFFER_SIZE) {
write_buffer_len = buffered;
if (ce_write_flush(context, fd))
return -1;
buffered = 0;
}
write_buffer_len = buffered;
len -= partial;
data = (char *) data + partial;
}
return 0;
}
static int write_index_ext_header(git_SHA_CTX *context, int fd,
unsigned int ext, unsigned int sz)
{
ext = htonl(ext);
sz = htonl(sz);
return ((ce_write(context, fd, &ext, 4) < 0) ||
(ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
}
static int ce_flush(git_SHA_CTX *context, int fd)
{
unsigned int left = write_buffer_len;
if (left) {
write_buffer_len = 0;
git_SHA1_Update(context, write_buffer, left);
}
/* Flush first if not enough space for SHA1 signature */
if (left + 20 > WRITE_BUFFER_SIZE) {
if (write_in_full(fd, write_buffer, left) != left)
return -1;
left = 0;
}
/* Append the SHA1 signature at the end */
git_SHA1_Final(write_buffer + left, context);
left += 20;
return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
}
static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
{
/*
* The only thing we care about in this function is to smudge the
* falsely clean entry due to touch-update-touch race, so we leave
* everything else as they are. We are called for entries whose
* ce_mtime match the index file mtime.
*
* Note that this actually does not do much for gitlinks, for
* which ce_match_stat_basic() always goes to the actual
* contents. The caller checks with is_racy_timestamp() which
* always says "no" for gitlinks, so we are not called for them ;-)
*/
struct stat st;
if (lstat(ce->name, &st) < 0)
return;
if (ce_match_stat_basic(ce, &st))
return;
if (ce_modified_check_fs(ce, &st)) {
/* This is "racily clean"; smudge it. Note that this
* is a tricky code. At first glance, it may appear
* that it can break with this sequence:
*
* $ echo xyzzy >frotz
* $ git-update-index --add frotz
* $ : >frotz
* $ sleep 3
* $ echo filfre >nitfol
* $ git-update-index --add nitfol
*
* but it does not. When the second update-index runs,
* it notices that the entry "frotz" has the same timestamp
* as index, and if we were to smudge it by resetting its
* size to zero here, then the object name recorded
* in index is the 6-byte file but the cached stat information
* becomes zero --- which would then match what we would
* obtain from the filesystem next time we stat("frotz").
*
* However, the second update-index, before calling
* this function, notices that the cached size is 6
* bytes and what is on the filesystem is an empty
* file, and never calls us, so the cached size information
* for "frotz" stays 6 which does not match the filesystem.
*/
ce->ce_size = 0;
}
}
/* Copy miscellaneous fields but not the name */
static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
struct cache_entry *ce)
{
short flags;
ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
ondisk->dev = htonl(ce->ce_dev);
ondisk->ino = htonl(ce->ce_ino);
ondisk->mode = htonl(ce->ce_mode);
ondisk->uid = htonl(ce->ce_uid);
ondisk->gid = htonl(ce->ce_gid);
ondisk->size = htonl(ce->ce_size);
hashcpy(ondisk->sha1, ce->sha1);
flags = ce->ce_flags;
flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
ondisk->flags = htons(flags);
if (ce->ce_flags & CE_EXTENDED) {
struct ondisk_cache_entry_extended *ondisk2;
ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
return ondisk2->name;
}
else {
return ondisk->name;
}
}
static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
struct strbuf *previous_name)
{
int size;
struct ondisk_cache_entry *ondisk;
char *name;
int result;
if (!previous_name) {
size = ondisk_ce_size(ce);
ondisk = xcalloc(1, size);
name = copy_cache_entry_to_ondisk(ondisk, ce);
memcpy(name, ce->name, ce_namelen(ce));
} else {
int common, to_remove, prefix_size;
unsigned char to_remove_vi[16];
for (common = 0;
(ce->name[common] &&
common < previous_name->len &&
ce->name[common] == previous_name->buf[common]);
common++)
; /* still matching */
to_remove = previous_name->len - common;
prefix_size = encode_varint(to_remove, to_remove_vi);
if (ce->ce_flags & CE_EXTENDED)
size = offsetof(struct ondisk_cache_entry_extended, name);
else
size = offsetof(struct ondisk_cache_entry, name);
size += prefix_size + (ce_namelen(ce) - common + 1);
ondisk = xcalloc(1, size);
name = copy_cache_entry_to_ondisk(ondisk, ce);
memcpy(name, to_remove_vi, prefix_size);
memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common);
strbuf_splice(previous_name, common, to_remove,
ce->name + common, ce_namelen(ce) - common);
}
result = ce_write(c, fd, ondisk, size);
free(ondisk);
return result;
}
static int has_racy_timestamp(struct index_state *istate)
{
int entries = istate->cache_nr;
int i;
for (i = 0; i < entries; i++) {
struct cache_entry *ce = istate->cache[i];
if (is_racy_timestamp(istate, ce))
return 1;
}
return 0;
}
/*
* Opportunisticly update the index but do not complain if we can't
*/
void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
{
if ((istate->cache_changed || has_racy_timestamp(istate)) &&
!write_index(istate, lockfile->fd))
commit_locked_index(lockfile);
else
rollback_lock_file(lockfile);
}
int write_index(struct index_state *istate, int newfd)
{
git_SHA_CTX c;
struct cache_header hdr;
int i, err, removed, extended, hdr_version;
struct cache_entry **cache = istate->cache;
int entries = istate->cache_nr;
struct stat st;
struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
for (i = removed = extended = 0; i < entries; i++) {
if (cache[i]->ce_flags & CE_REMOVE)
removed++;
/* reduce extended entries if possible */
cache[i]->ce_flags &= ~CE_EXTENDED;
if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
extended++;
cache[i]->ce_flags |= CE_EXTENDED;
}
}
if (!istate->version)
istate->version = INDEX_FORMAT_DEFAULT;
/* demote version 3 to version 2 when the latter suffices */
if (istate->version == 3 || istate->version == 2)
istate->version = extended ? 3 : 2;
hdr_version = istate->version;
hdr.hdr_signature = htonl(CACHE_SIGNATURE);
hdr.hdr_version = htonl(hdr_version);
hdr.hdr_entries = htonl(entries - removed);
git_SHA1_Init(&c);
if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
return -1;
previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
for (i = 0; i < entries; i++) {
struct cache_entry *ce = cache[i];
if (ce->ce_flags & CE_REMOVE)
continue;
if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
ce_smudge_racily_clean_entry(ce);
if (is_null_sha1(ce->sha1))
return error("cache entry has null sha1: %s", ce->name);
if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
return -1;
}
strbuf_release(&previous_name_buf);
/* Write extension data here */
if (istate->cache_tree) {
struct strbuf sb = STRBUF_INIT;
cache_tree_write(&sb, istate->cache_tree);
err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
|| ce_write(&c, newfd, sb.buf, sb.len) < 0;
strbuf_release(&sb);
if (err)
return -1;
}
if (istate->resolve_undo) {
struct strbuf sb = STRBUF_INIT;
resolve_undo_write(&sb, istate->resolve_undo);
err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
sb.len) < 0
|| ce_write(&c, newfd, sb.buf, sb.len) < 0;
strbuf_release(&sb);
if (err)
return -1;
}
if (ce_flush(&c, newfd) || fstat(newfd, &st))
return -1;
istate->timestamp.sec = (unsigned int)st.st_mtime;
istate->timestamp.nsec = ST_MTIME_NSEC(st);
return 0;
}
/*
* Read the index file that is potentially unmerged into given
* index_state, dropping any unmerged entries. Returns true if
* the index is unmerged. Callers who want to refuse to work
* from an unmerged state can call this and check its return value,
* instead of calling read_cache().
*/
int read_index_unmerged(struct index_state *istate)
{
int i;
int unmerged = 0;
read_index(istate);
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce = istate->cache[i];
struct cache_entry *new_ce;
int size, len;
if (!ce_stage(ce))
continue;
unmerged = 1;
len = ce_namelen(ce);
size = cache_entry_size(len);
new_ce = xcalloc(1, size);
memcpy(new_ce->name, ce->name, len);
new_ce->ce_flags = create_ce_flags(0) | CE_CONFLICTED;
new_ce->ce_namelen = len;
new_ce->ce_mode = ce->ce_mode;
if (add_index_entry(istate, new_ce, 0))
return error("%s: cannot drop to stage #0",
ce->name);
i = index_name_pos(istate, new_ce->name, len);
}
return unmerged;
}
/*
* Returns 1 if the path is an "other" path with respect to
* the index; that is, the path is not mentioned in the index at all,
* either as a file, a directory with some files in the index,
* or as an unmerged entry.
*
* We helpfully remove a trailing "/" from directories so that
* the output of read_directory can be used as-is.
*/
int index_name_is_other(const struct index_state *istate, const char *name,
int namelen)
{
int pos;
if (namelen && name[namelen - 1] == '/')
namelen--;
pos = index_name_pos(istate, name, namelen);
if (0 <= pos)
return 0; /* exact match */
pos = -pos - 1;
if (pos < istate->cache_nr) {
struct cache_entry *ce = istate->cache[pos];
if (ce_namelen(ce) == namelen &&
!memcmp(ce->name, name, namelen))
return 0; /* Yup, this one exists unmerged */
}
return 1;
}