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2ede073fd2
git-commit-vandalism/read-cache.c
Marc Strapetz 2ede073fd2 update-index: refresh should rewrite index in case of racy timestamps 
'git update-index --refresh' and '--really-refresh' should force writing
of the index file if racy timestamps have been encountered, as
'git status' already does [1].

Note that calling 'git update-index --refresh' still does not guarantee
that there will be no more racy timestamps afterwards (the same holds
true for 'git status'):

- calling 'git update-index --refresh' immediately after touching and
  adding a file may still leave racy timestamps if all three operations
  occur within the racy-tolerance (usually 1 second unless USE_NSEC has
  been defined)

- calling 'git update-index --refresh' for timestamps which are set into
  the future will leave them racy

To guarantee that such racy timestamps will be resolved would require to
wait until the system clock has passed beyond these timestamps and only
then write the index file. Especially for future timestamps, this does
not seem feasible because of possibly long delays/hangs.

[1] https://lore.kernel.org/git/d3dd805c-7c1d-30a9-6574-a7bfcb7fc013@syntevo.com/

Signed-off-by: Marc Strapetz <marc.strapetz@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-07 12:37:31 -08:00

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/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "config.h"
#include "diff.h"
#include "diffcore.h"
#include "tempfile.h"
#include "lockfile.h"
#include "cache-tree.h"
#include "refs.h"
#include "dir.h"
#include "object-store.h"
#include "tree.h"
#include "commit.h"
#include "blob.h"
#include "resolve-undo.h"
#include "run-command.h"
#include "strbuf.h"
#include "varint.h"
#include "split-index.h"
#include "utf8.h"
#include "fsmonitor.h"
#include "thread-utils.h"
#include "progress.h"
#include "sparse-index.h"
#include "csum-file.h"
#include "promisor-remote.h"
/* 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" */
#define CACHE_EXT_LINK 0x6c696e6b /* "link" */
#define CACHE_EXT_UNTRACKED 0x554E5452 /* "UNTR" */
#define CACHE_EXT_FSMONITOR 0x46534D4E /* "FSMN" */
#define CACHE_EXT_ENDOFINDEXENTRIES 0x454F4945 /* "EOIE" */
#define CACHE_EXT_INDEXENTRYOFFSETTABLE 0x49454F54 /* "IEOT" */
#define CACHE_EXT_SPARSE_DIRECTORIES 0x73646972 /* "sdir" */
/* changes that can be kept in $GIT_DIR/index (basically all extensions) */
#define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \
CE_ENTRY_ADDED | CE_ENTRY_REMOVED | CE_ENTRY_CHANGED | \
SPLIT_INDEX_ORDERED | UNTRACKED_CHANGED | FSMONITOR_CHANGED)
/*
* This is an estimate of the pathname length in the index. We use
* this for V4 index files to guess the un-deltafied size of the index
* in memory because of pathname deltafication. This is not required
* for V2/V3 index formats because their pathnames are not compressed.
* If the initial amount of memory set aside is not sufficient, the
* mem pool will allocate extra memory.
*/
#define CACHE_ENTRY_PATH_LENGTH 80
enum index_search_mode {
NO_EXPAND_SPARSE = 0,
EXPAND_SPARSE = 1
};
static inline struct cache_entry *mem_pool__ce_alloc(struct mem_pool *mem_pool, size_t len)
{
struct cache_entry *ce;
ce = mem_pool_alloc(mem_pool, cache_entry_size(len));
ce->mem_pool_allocated = 1;
return ce;
}
static inline struct cache_entry *mem_pool__ce_calloc(struct mem_pool *mem_pool, size_t len)
{
struct cache_entry * ce;
ce = mem_pool_calloc(mem_pool, 1, cache_entry_size(len));
ce->mem_pool_allocated = 1;
return ce;
}
static struct mem_pool *find_mem_pool(struct index_state *istate)
{
struct mem_pool **pool_ptr;
if (istate->split_index && istate->split_index->base)
pool_ptr = &istate->split_index->base->ce_mem_pool;
else
pool_ptr = &istate->ce_mem_pool;
if (!*pool_ptr) {
*pool_ptr = xmalloc(sizeof(**pool_ptr));
mem_pool_init(*pool_ptr, 0);
}
return *pool_ptr;
}
static const char *alternate_index_output;
static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
{
if (S_ISSPARSEDIR(ce->ce_mode))
istate->sparse_index = 1;
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];
replace_index_entry_in_base(istate, old, ce);
remove_name_hash(istate, old);
discard_cache_entry(old);
ce->ce_flags &= ~CE_HASHED;
set_index_entry(istate, nr, ce);
ce->ce_flags |= CE_UPDATE_IN_BASE;
mark_fsmonitor_invalid(istate, ce);
istate->cache_changed |= CE_ENTRY_CHANGED;
}
void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
{
struct cache_entry *old_entry = istate->cache[nr], *new_entry;
int namelen = strlen(new_name);
new_entry = make_empty_cache_entry(istate, namelen);
copy_cache_entry(new_entry, old_entry);
new_entry->ce_flags &= ~CE_HASHED;
new_entry->ce_namelen = namelen;
new_entry->index = 0;
memcpy(new_entry->name, new_name, namelen + 1);
cache_tree_invalidate_path(istate, old_entry->name);
untracked_cache_remove_from_index(istate, old_entry->name);
remove_index_entry_at(istate, nr);
add_index_entry(istate, new_entry, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
}
void fill_stat_data(struct stat_data *sd, struct stat *st)
{
sd->sd_ctime.sec = (unsigned int)st->st_ctime;
sd->sd_mtime.sec = (unsigned int)st->st_mtime;
sd->sd_ctime.nsec = ST_CTIME_NSEC(*st);
sd->sd_mtime.nsec = ST_MTIME_NSEC(*st);
sd->sd_dev = st->st_dev;
sd->sd_ino = st->st_ino;
sd->sd_uid = st->st_uid;
sd->sd_gid = st->st_gid;
sd->sd_size = st->st_size;
}
int match_stat_data(const struct stat_data *sd, struct stat *st)
{
int changed = 0;
if (sd->sd_mtime.sec != (unsigned int)st->st_mtime)
changed |= MTIME_CHANGED;
if (trust_ctime && check_stat &&
sd->sd_ctime.sec != (unsigned int)st->st_ctime)
changed |= CTIME_CHANGED;
#ifdef USE_NSEC
if (check_stat && sd->sd_mtime.nsec != ST_MTIME_NSEC(*st))
changed |= MTIME_CHANGED;
if (trust_ctime && check_stat &&
sd->sd_ctime.nsec != ST_CTIME_NSEC(*st))
changed |= CTIME_CHANGED;
#endif
if (check_stat) {
if (sd->sd_uid != (unsigned int) st->st_uid ||
sd->sd_gid != (unsigned int) st->st_gid)
changed |= OWNER_CHANGED;
if (sd->sd_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 && sd->sd_dev != (unsigned int) st->st_dev)
changed |= INODE_CHANGED;
#endif
if (sd->sd_size != (unsigned int) st->st_size)
changed |= DATA_CHANGED;
return changed;
}
/*
* 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 index_state *istate, struct cache_entry *ce, struct stat *st)
{
fill_stat_data(&ce->ce_stat_data, st);
if (assume_unchanged)
ce->ce_flags |= CE_VALID;
if (S_ISREG(st->st_mode)) {
ce_mark_uptodate(ce);
mark_fsmonitor_valid(istate, ce);
}
}
static int ce_compare_data(struct index_state *istate,
const struct cache_entry *ce,
struct stat *st)
{
int match = -1;
int fd = git_open_cloexec(ce->name, O_RDONLY);
if (fd >= 0) {
struct object_id oid;
if (!index_fd(istate, &oid, fd, st, OBJ_BLOB, ce->name, 0))
match = !oideq(&oid, &ce->oid);
/* index_fd() closed the file descriptor already */
}
return match;
}
static int ce_compare_link(const 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_object_file(&ce->oid, &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(const struct cache_entry *ce)
{
struct object_id oid;
/*
* 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", &oid) < 0)
return 0;
return !oideq(&oid, &ce->oid);
}
static int ce_modified_check_fs(struct index_state *istate,
const struct cache_entry *ce,
struct stat *st)
{
switch (st->st_mode & S_IFMT) {
case S_IFREG:
if (ce_compare_data(istate, 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;
/* else fallthrough */
default:
return TYPE_CHANGED;
}
return 0;
}
static int ce_match_stat_basic(const 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:
BUG("unsupported ce_mode: %o", ce->ce_mode);
}
changed |= match_stat_data(&ce->ce_stat_data, st);
/* Racily smudged entry? */
if (!ce->ce_stat_data.sd_size) {
if (!is_empty_blob_sha1(ce->oid.hash))
changed |= DATA_CHANGED;
}
return changed;
}
static int is_racy_stat(const struct index_state *istate,
const struct stat_data *sd)
{
return (istate->timestamp.sec &&
#ifdef USE_NSEC
/* nanosecond timestamped files can also be racy! */
(istate->timestamp.sec < sd->sd_mtime.sec ||
(istate->timestamp.sec == sd->sd_mtime.sec &&
istate->timestamp.nsec <= sd->sd_mtime.nsec))
#else
istate->timestamp.sec <= sd->sd_mtime.sec
#endif
);
}
int is_racy_timestamp(const struct index_state *istate,
const struct cache_entry *ce)
{
return (!S_ISGITLINK(ce->ce_mode) &&
is_racy_stat(istate, &ce->ce_stat_data));
}
int match_stat_data_racy(const struct index_state *istate,
const struct stat_data *sd, struct stat *st)
{
if (is_racy_stat(istate, sd))
return MTIME_CHANGED;
return match_stat_data(sd, st);
}
int ie_match_stat(struct index_state *istate,
const 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;
int ignore_fsmonitor = options & CE_MATCH_IGNORE_FSMONITOR;
if (!ignore_fsmonitor)
refresh_fsmonitor(istate);
/*
* 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;
if (!ignore_fsmonitor && (ce->ce_flags & CE_FSMONITOR_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_intent_to_add(ce))
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(istate, ce, st);
}
return changed;
}
int ie_modified(struct index_state *istate,
const 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_stat_data.sd_size != 0))
return changed;
changed_fs = ce_modified_check_fs(istate, 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 name_compare(const char *name1, size_t len1, const char *name2, size_t len2)
{
size_t min_len = (len1 < len2) ? len1 : len2;
int cmp = memcmp(name1, name2, min_len);
if (cmp)
return cmp;
if (len1 < len2)
return -1;
if (len1 > len2)
return 1;
return 0;
}
int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2)
{
int cmp;
cmp = name_compare(name1, len1, name2, len2);
if (cmp)
return cmp;
if (stage1 < stage2)
return -1;
if (stage1 > stage2)
return 1;
return 0;
}
static int index_name_stage_pos(struct index_state *istate,
const char *name, int namelen,
int stage,
enum index_search_mode search_mode)
{
int first, last;
first = 0;
last = istate->cache_nr;
while (last > first) {
int next = first + ((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;
}
if (search_mode == EXPAND_SPARSE && istate->sparse_index &&
first > 0) {
/* Note: first <= istate->cache_nr */
struct cache_entry *ce = istate->cache[first - 1];
/*
* If we are in a sparse-index _and_ the entry before the
* insertion position is a sparse-directory entry that is
* an ancestor of 'name', then we need to expand the index
* and search again. This will only trigger once, because
* thereafter the index is fully expanded.
*/
if (S_ISSPARSEDIR(ce->ce_mode) &&
ce_namelen(ce) < namelen &&
!strncmp(name, ce->name, ce_namelen(ce))) {
ensure_full_index(istate);
return index_name_stage_pos(istate, name, namelen, stage, search_mode);
}
}
return -first-1;
}
int index_name_pos(struct index_state *istate, const char *name, int namelen)
{
return index_name_stage_pos(istate, name, namelen, 0, EXPAND_SPARSE);
}
int index_entry_exists(struct index_state *istate, const char *name, int namelen)
{
return index_name_stage_pos(istate, name, namelen, 0, NO_EXPAND_SPARSE) >= 0;
}
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(istate, ce);
save_or_free_index_entry(istate, ce);
istate->cache_changed |= CE_ENTRY_REMOVED;
istate->cache_nr--;
if (pos >= istate->cache_nr)
return 0;
MOVE_ARRAY(istate->cache + pos, istate->cache + pos + 1,
istate->cache_nr - pos);
return 1;
}
/*
* Remove all cache entries 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, int invalidate)
{
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) {
if (invalidate) {
cache_tree_invalidate_path(istate,
ce_array[i]->name);
untracked_cache_remove_from_index(istate,
ce_array[i]->name);
}
remove_name_hash(istate, ce_array[i]);
save_or_free_index_entry(istate, ce_array[i]);
}
else
ce_array[j++] = ce_array[i];
}
if (j == istate->cache_nr)
return;
istate->cache_changed |= CE_ENTRY_REMOVED;
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, path);
untracked_cache_remove_from_index(istate, 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 index_state *istate,
struct cache_entry *ce,
struct cache_entry *alias)
{
int len;
struct cache_entry *new_entry;
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_entry = make_empty_cache_entry(istate, len);
memcpy(new_entry->name, alias->name, len);
copy_cache_entry(new_entry, ce);
save_or_free_index_entry(istate, ce);
return new_entry;
}
void set_object_name_for_intent_to_add_entry(struct cache_entry *ce)
{
struct object_id oid;
if (write_object_file("", 0, blob_type, &oid))
die(_("cannot create an empty blob in the object database"));
oidcpy(&ce->oid, &oid);
}
int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
{
int namelen, was_same;
mode_t st_mode = st->st_mode;
struct cache_entry *ce, *alias = NULL;
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));
unsigned hash_flags = pretend ? 0 : HASH_WRITE_OBJECT;
struct object_id oid;
if (flags & ADD_CACHE_RENORMALIZE)
hash_flags |= HASH_RENORMALIZE;
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)) {
if (resolve_gitlink_ref(path, "HEAD", &oid) < 0)
return error(_("'%s' does not have a commit checked out"), path);
while (namelen && path[namelen-1] == '/')
namelen--;
}
ce = make_empty_cache_entry(istate, namelen);
memcpy(ce->name, path, namelen);
ce->ce_namelen = namelen;
if (!intent_only)
fill_stat_cache_info(istate, 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) {
adjust_dirname_case(istate, ce->name);
}
if (!(flags & ADD_CACHE_RENORMALIZE)) {
alias = index_file_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 */
if (!S_ISGITLINK(alias->ce_mode))
ce_mark_uptodate(alias);
alias->ce_flags |= CE_ADDED;
discard_cache_entry(ce);
return 0;
}
}
if (!intent_only) {
if (index_path(istate, &ce->oid, path, st, hash_flags)) {
discard_cache_entry(ce);
return error(_("unable to index file '%s'"), path);
}
} else
set_object_name_for_intent_to_add_entry(ce);
if (ignore_case && alias && different_name(ce, alias))
ce = create_alias_ce(istate, 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) &&
oideq(&alias->oid, &ce->oid) &&
ce->ce_mode == alias->ce_mode);
if (pretend)
discard_cache_entry(ce);
else if (add_index_entry(istate, ce, add_option)) {
discard_cache_entry(ce);
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_empty_cache_entry(struct index_state *istate, size_t len)
{
return mem_pool__ce_calloc(find_mem_pool(istate), len);
}
struct cache_entry *make_empty_transient_cache_entry(size_t len,
struct mem_pool *ce_mem_pool)
{
if (ce_mem_pool)
return mem_pool__ce_calloc(ce_mem_pool, len);
return xcalloc(1, cache_entry_size(len));
}
enum verify_path_result {
PATH_OK,
PATH_INVALID,
PATH_DIR_WITH_SEP,
};
static enum verify_path_result verify_path_internal(const char *, unsigned);
int verify_path(const char *path, unsigned mode)
{
return verify_path_internal(path, mode) == PATH_OK;
}
struct cache_entry *make_cache_entry(struct index_state *istate,
unsigned int mode,
const struct object_id *oid,
const char *path,
int stage,
unsigned int refresh_options)
{
struct cache_entry *ce, *ret;
int len;
if (verify_path_internal(path, mode) == PATH_INVALID) {
error(_("invalid path '%s'"), path);
return NULL;
}
len = strlen(path);
ce = make_empty_cache_entry(istate, len);
oidcpy(&ce->oid, oid);
memcpy(ce->name, path, len);
ce->ce_flags = create_ce_flags(stage);
ce->ce_namelen = len;
ce->ce_mode = create_ce_mode(mode);
ret = refresh_cache_entry(istate, ce, refresh_options);
if (ret != ce)
discard_cache_entry(ce);
return ret;
}
struct cache_entry *make_transient_cache_entry(unsigned int mode,
const struct object_id *oid,
const char *path,
int stage,
struct mem_pool *ce_mem_pool)
{
struct cache_entry *ce;
int len;
if (!verify_path(path, mode)) {
error(_("invalid path '%s'"), path);
return NULL;
}
len = strlen(path);
ce = make_empty_transient_cache_entry(len, ce_mem_pool);
oidcpy(&ce->oid, oid);
memcpy(ce->name, path, len);
ce->ce_flags = create_ce_flags(stage);
ce->ce_namelen = len;
ce->ce_mode = create_ce_mode(mode);
return ce;
}
/*
* Chmod an index entry with either +x or -x.
*
* Returns -1 if the chmod for the particular cache entry failed (if it's
* not a regular file), -2 if an invalid flip argument is passed in, 0
* otherwise.
*/
int chmod_index_entry(struct index_state *istate, struct cache_entry *ce,
char flip)
{
if (!S_ISREG(ce->ce_mode))
return -1;
switch (flip) {
case '+':
ce->ce_mode |= 0111;
break;
case '-':
ce->ce_mode &= ~0111;
break;
default:
return -2;
}
cache_tree_invalidate_path(istate, ce->name);
ce->ce_flags |= CE_UPDATE_IN_BASE;
mark_fsmonitor_invalid(istate, ce);
istate->cache_changed |= CE_ENTRY_CHANGED;
return 0;
}
int ce_same_name(const struct cache_entry *a, const struct cache_entry *b)
{
int len = ce_namelen(a);
return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
}
/*
* 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, unsigned mode)
{
/*
* 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. Note that we match
* case-insensitively here, even if ignore_case is not set.
* This outlaws ".GIT" everywhere out of an abundance of caution,
* since there's really no good reason to allow it.
*
* Once we've seen ".git", we can also find ".gitmodules", etc (also
* case-insensitively).
*/
case 'g':
case 'G':
if (rest[1] != 'i' && rest[1] != 'I')
break;
if (rest[2] != 't' && rest[2] != 'T')
break;
if (rest[3] == '\0' || is_dir_sep(rest[3]))
return 0;
if (S_ISLNK(mode)) {
rest += 3;
if (skip_iprefix(rest, "modules", &rest) &&
(*rest == '\0' || is_dir_sep(*rest)))
return 0;
}
break;
case '.':
if (rest[1] == '\0' || is_dir_sep(rest[1]))
return 0;
}
return 1;
}
static enum verify_path_result verify_path_internal(const char *path,
unsigned mode)
{
char c = 0;
if (has_dos_drive_prefix(path))
return PATH_INVALID;
if (!is_valid_path(path))
return PATH_INVALID;
goto inside;
for (;;) {
if (!c)
return PATH_OK;
if (is_dir_sep(c)) {
inside:
if (protect_hfs) {
if (is_hfs_dotgit(path))
return PATH_INVALID;
if (S_ISLNK(mode)) {
if (is_hfs_dotgitmodules(path))
return PATH_INVALID;
}
}
if (protect_ntfs) {
#if defined GIT_WINDOWS_NATIVE || defined __CYGWIN__
if (c == '\\')
return PATH_INVALID;
#endif
if (is_ntfs_dotgit(path))
return PATH_INVALID;
if (S_ISLNK(mode)) {
if (is_ntfs_dotgitmodules(path))
return PATH_INVALID;
}
}
c = *path++;
if ((c == '.' && !verify_dotfile(path, mode)) ||
is_dir_sep(c))
return PATH_INVALID;
/*
* allow terminating directory separators for
* sparse directory entries.
*/
if (c == '\0')
return S_ISDIR(mode) ? PATH_DIR_WITH_SEP :
PATH_INVALID;
} else if (c == '\\' && protect_ntfs) {
if (is_ntfs_dotgit(path))
return PATH_INVALID;
if (S_ISLNK(mode)) {
if (is_ntfs_dotgitmodules(path))
return PATH_INVALID;
}
}
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;
}
/*
* Like strcmp(), but also return the offset of the first change.
* If strings are equal, return the length.
*/
int strcmp_offset(const char *s1, const char *s2, size_t *first_change)
{
size_t k;
if (!first_change)
return strcmp(s1, s2);
for (k = 0; s1[k] == s2[k]; k++)
if (s1[k] == '\0')
break;
*first_change = k;
return (unsigned char)s1[k] - (unsigned char)s2[k];
}
/*
* Do we have another file with a pathname that is a proper
* subset of the name we're trying to add?
*
* That is, is there another file in the index with a path
* that matches a sub-directory in the given entry?
*/
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);
size_t len_eq_last;
int cmp_last = 0;
/*
* We are frequently called during an iteration on a sorted
* list of pathnames and while building a new index. Therefore,
* there is a high probability that this entry will eventually
* be appended to the index, rather than inserted in the middle.
* If we can confirm that, we can avoid binary searches on the
* components of the pathname.
*
* Compare the entry's full path with the last path in the index.
*/
if (istate->cache_nr > 0) {
cmp_last = strcmp_offset(name,
istate->cache[istate->cache_nr - 1]->name,
&len_eq_last);
if (cmp_last > 0) {
if (len_eq_last == 0) {
/*
* The entry sorts AFTER the last one in the
* index and their paths have no common prefix,
* so there cannot be a F/D conflict.
*/
return retval;
} else {
/*
* The entry sorts AFTER the last one in the
* index, but has a common prefix. Fall through
* to the loop below to disect the entry's path
* and see where the difference is.
*/
}
} else if (cmp_last == 0) {
/*
* The entry exactly matches the last one in the
* index, but because of multiple stage and CE_REMOVE
* items, we fall through and let the regular search
* code handle it.
*/
}
}
for (;;) {
size_t len;
for (;;) {
if (*--slash == '/')
break;
if (slash <= ce->name)
return retval;
}
len = slash - name;
if (cmp_last > 0) {
/*
* (len + 1) is a directory boundary (including
* the trailing slash). And since the loop is
* decrementing "slash", the first iteration is
* the longest directory prefix; subsequent
* iterations consider parent directories.
*/
if (len + 1 <= len_eq_last) {
/*
* The directory prefix (including the trailing
* slash) also appears as a prefix in the last
* entry, so the remainder cannot collide (because
* strcmp said the whole path was greater).
*
* EQ: last: xxx/A
* this: xxx/B
*
* LT: last: xxx/file_A
* this: xxx/file_B
*/
return retval;
}
if (len > len_eq_last) {
/*
* This part of the directory prefix (excluding
* the trailing slash) is longer than the known
* equal portions, so this sub-directory cannot
* collide with a file.
*
* GT: last: xxxA
* this: xxxB/file
*/
return retval;
}
/*
* This is a possible collision. Fall through and
* let the regular search code handle it.
*
* last: xxx
* this: xxx/file
*/
}
pos = index_name_stage_pos(istate, name, len, stage, EXPAND_SPARSE);
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;
if (!(option & ADD_CACHE_KEEP_CACHE_TREE))
cache_tree_invalidate_path(istate, ce->name);
/*
* If this entry's path sorts after the last entry in the index,
* we can avoid searching for it.
*/
if (istate->cache_nr > 0 &&
strcmp(ce->name, istate->cache[istate->cache_nr - 1]->name) > 0)
pos = index_pos_to_insert_pos(istate->cache_nr);
else
pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce), EXPAND_SPARSE);
/* existing match? Just replace it. */
if (pos >= 0) {
if (!new_only)
replace_index_entry(istate, pos, ce);
return 0;
}
pos = -pos-1;
if (!(option & ADD_CACHE_KEEP_CACHE_TREE))
untracked_cache_add_to_index(istate, ce->name);
/*
* 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_internal(ce->name, ce->ce_mode) == PATH_INVALID)
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), EXPAND_SPARSE);
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 .. */
ALLOC_GROW(istate->cache, istate->cache_nr + 1, istate->cache_alloc);
/* Add it in.. */
istate->cache_nr++;
if (istate->cache_nr > pos + 1)
MOVE_ARRAY(istate->cache + pos + 1, istate->cache + pos,
istate->cache_nr - pos - 1);
set_index_entry(istate, pos, ce);
istate->cache_changed |= CE_ENTRY_ADDED;
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,
int *t2_did_lstat,
int *t2_did_scan)
{
struct stat st;
struct cache_entry *updated;
int changed;
int refresh = options & CE_MATCH_REFRESH;
int ignore_valid = options & CE_MATCH_IGNORE_VALID;
int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
int ignore_missing = options & CE_MATCH_IGNORE_MISSING;
int ignore_fsmonitor = options & CE_MATCH_IGNORE_FSMONITOR;
if (!refresh || ce_uptodate(ce))
return ce;
if (!ignore_fsmonitor)
refresh_fsmonitor(istate);
/*
* 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 (!ignore_fsmonitor && (ce->ce_flags & CE_FSMONITOR_VALID)) {
ce_mark_uptodate(ce);
return ce;
}
if (has_symlink_leading_path(ce->name, ce_namelen(ce))) {
if (ignore_missing)
return ce;
if (err)
*err = ENOENT;
return NULL;
}
if (t2_did_lstat)
*t2_did_lstat = 1;
if (lstat(ce->name, &st) < 0) {
if (ignore_missing && errno == ENOENT)
return ce;
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);
mark_fsmonitor_valid(istate, ce);
}
return ce;
}
}
if (t2_did_scan)
*t2_did_scan = 1;
if (ie_modified(istate, ce, &st, options)) {
if (err)
*err = EINVAL;
return NULL;
}
updated = make_empty_cache_entry(istate, ce_namelen(ce));
copy_cache_entry(updated, ce);
memcpy(updated->name, ce->name, ce->ce_namelen + 1);
fill_stat_cache_info(istate, 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;
/* istate->cache_changed is updated in the caller */
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 repo_refresh_and_write_index(struct repository *repo,
unsigned int refresh_flags,
unsigned int write_flags,
int gentle,
const struct pathspec *pathspec,
char *seen, const char *header_msg)
{
struct lock_file lock_file = LOCK_INIT;
int fd, ret = 0;
fd = repo_hold_locked_index(repo, &lock_file, 0);
if (!gentle && fd < 0)
return -1;
if (refresh_index(repo->index, refresh_flags, pathspec, seen, header_msg))
ret = 1;
if (0 <= fd && write_locked_index(repo->index, &lock_file, COMMIT_LOCK | write_flags))
ret = -1;
return ret;
}
int refresh_index(struct index_state *istate, unsigned int flags,
const struct pathspec *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 ignore_skip_worktree = (flags & REFRESH_IGNORE_SKIP_WORKTREE) != 0;
int first = 1;
int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
unsigned int options = (CE_MATCH_REFRESH |
(really ? CE_MATCH_IGNORE_VALID : 0) |
(not_new ? CE_MATCH_IGNORE_MISSING : 0));
const char *modified_fmt;
const char *deleted_fmt;
const char *typechange_fmt;
const char *added_fmt;
const char *unmerged_fmt;
struct progress *progress = NULL;
int t2_sum_lstat = 0;
int t2_sum_scan = 0;
if (flags & REFRESH_PROGRESS && isatty(2))
progress = start_delayed_progress(_("Refresh index"),
istate->cache_nr);
trace_performance_enter();
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";
/*
* Use the multi-threaded preload_index() to refresh most of the
* cache entries quickly then in the single threaded loop below,
* we only have to do the special cases that are left.
*/
preload_index(istate, pathspec, 0);
trace2_region_enter("index", "refresh", NULL);
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce, *new_entry;
int cache_errno = 0;
int changed = 0;
int filtered = 0;
int t2_did_lstat = 0;
int t2_did_scan = 0;
ce = istate->cache[i];
if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
continue;
if (ignore_skip_worktree && ce_skip_worktree(ce))
continue;
/*
* If this entry is a sparse directory, then there isn't
* any stat() information to update. Ignore the entry.
*/
if (S_ISSPARSEDIR(ce->ce_mode))
continue;
if (pathspec && !ce_path_match(istate, ce, pathspec, 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_entry = refresh_cache_ent(istate, ce, options,
&cache_errno, &changed,
&t2_did_lstat, &t2_did_scan);
t2_sum_lstat += t2_did_lstat;
t2_sum_scan += t2_did_scan;
if (new_entry == ce)
continue;
display_progress(progress, i);
if (!new_entry) {
const char *fmt;
if (really && cache_errno == EINVAL) {
/* If we are doing --really-refresh that
* means the index is not valid anymore.
*/
ce->ce_flags &= ~CE_VALID;
ce->ce_flags |= CE_UPDATE_IN_BASE;
mark_fsmonitor_invalid(istate, ce);
istate->cache_changed |= CE_ENTRY_CHANGED;
}
if (quiet)
continue;
if (cache_errno == ENOENT)
fmt = deleted_fmt;
else if (ce_intent_to_add(ce))
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_entry);
}
trace2_data_intmax("index", NULL, "refresh/sum_lstat", t2_sum_lstat);
trace2_data_intmax("index", NULL, "refresh/sum_scan", t2_sum_scan);
trace2_region_leave("index", "refresh", NULL);
display_progress(progress, istate->cache_nr);
stop_progress(&progress);
trace_performance_leave("refresh index");
return has_errors;
}
struct cache_entry *refresh_cache_entry(struct index_state *istate,
struct cache_entry *ce,
unsigned int options)
{
return refresh_cache_ent(istate, ce, options, NULL, NULL, NULL, NULL);
}
/*****************************************************************
* Index File I/O
*****************************************************************/
#define INDEX_FORMAT_DEFAULT 3
static unsigned int get_index_format_default(struct repository *r)
{
char *envversion = getenv("GIT_INDEX_VERSION");
char *endp;
unsigned int version = INDEX_FORMAT_DEFAULT;
if (!envversion) {
prepare_repo_settings(r);
if (r->settings.index_version >= 0)
version = r->settings.index_version;
if (version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) {
warning(_("index.version set, but the value is invalid.\n"
"Using version %i"), INDEX_FORMAT_DEFAULT);
return INDEX_FORMAT_DEFAULT;
}
return version;
}
version = strtoul(envversion, &endp, 10);
if (*endp ||
version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) {
warning(_("GIT_INDEX_VERSION set, but the value is invalid.\n"
"Using version %i"), INDEX_FORMAT_DEFAULT);
version = INDEX_FORMAT_DEFAULT;
}
return version;
}
/*
* 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;
uint32_t dev;
uint32_t ino;
uint32_t mode;
uint32_t uid;
uint32_t gid;
uint32_t size;
/*
* unsigned char hash[hashsz];
* uint16_t flags;
* if (flags & CE_EXTENDED)
* uint16_t flags2;
*/
unsigned char data[GIT_MAX_RAWSZ + 2 * sizeof(uint16_t)];
char name[FLEX_ARRAY];
};
/* These are only used for v3 or lower */
#define align_padding_size(size, len) ((size + (len) + 8) & ~7) - (size + len)
#define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,data) + (len) + 8) & ~7)
#define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
#define ondisk_data_size(flags, len) (the_hash_algo->rawsz + \
((flags & CE_EXTENDED) ? 2 : 1) * sizeof(uint16_t) + len)
#define ondisk_data_size_max(len) (ondisk_data_size(CE_EXTENDED, len))
#define ondisk_ce_size(ce) (ondisk_cache_entry_size(ondisk_data_size((ce)->ce_flags, ce_namelen(ce))))
/* Allow fsck to force verification of the index checksum. */
int verify_index_checksum;
/* Allow fsck to force verification of the cache entry order. */
int verify_ce_order;
static int verify_hdr(const struct cache_header *hdr, unsigned long size)
{
git_hash_ctx c;
unsigned char hash[GIT_MAX_RAWSZ];
int hdr_version;
if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
return error(_("bad signature 0x%08x"), hdr->hdr_signature);
hdr_version = ntohl(hdr->hdr_version);
if (hdr_version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < hdr_version)
return error(_("bad index version %d"), hdr_version);
if (!verify_index_checksum)
return 0;
the_hash_algo->init_fn(&c);
the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz);
the_hash_algo->final_fn(hash, &c);
if (!hasheq(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz))
return error(_("bad index file sha1 signature"));
return 0;
}
static int read_index_extension(struct index_state *istate,
const char *ext, const char *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;
case CACHE_EXT_LINK:
if (read_link_extension(istate, data, sz))
return -1;
break;
case CACHE_EXT_UNTRACKED:
istate->untracked = read_untracked_extension(data, sz);
break;
case CACHE_EXT_FSMONITOR:
read_fsmonitor_extension(istate, data, sz);
break;
case CACHE_EXT_ENDOFINDEXENTRIES:
case CACHE_EXT_INDEXENTRYOFFSETTABLE:
/* already handled in do_read_index() */
break;
case CACHE_EXT_SPARSE_DIRECTORIES:
/* no content, only an indicator */
istate->sparse_index = 1;
break;
default:
if (*ext < 'A' || 'Z' < *ext)
return error(_("index uses %.4s extension, which we do not understand"),
ext);
fprintf_ln(stderr, _("ignoring %.4s extension"), ext);
break;
}
return 0;
}
static struct cache_entry *create_from_disk(struct mem_pool *ce_mem_pool,
unsigned int version,
struct ondisk_cache_entry *ondisk,
unsigned long *ent_size,
const struct cache_entry *previous_ce)
{
struct cache_entry *ce;
size_t len;
const char *name;
const unsigned hashsz = the_hash_algo->rawsz;
const uint16_t *flagsp = (const uint16_t *)(ondisk->data + hashsz);
unsigned int flags;
size_t copy_len = 0;
/*
* 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.
*/
int expand_name_field = version == 4;
/* On-disk flags are just 16 bits */
flags = get_be16(flagsp);
len = flags & CE_NAMEMASK;
if (flags & CE_EXTENDED) {
int extended_flags;
extended_flags = get_be16(flagsp + 1) << 16;
/* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
if (extended_flags & ~CE_EXTENDED_FLAGS)
die(_("unknown index entry format 0x%08x"), extended_flags);
flags |= extended_flags;
name = (const char *)(flagsp + 2);
}
else
name = (const char *)(flagsp + 1);
if (expand_name_field) {
const unsigned char *cp = (const unsigned char *)name;
size_t strip_len, previous_len;
/* If we're at the beginning of a block, ignore the previous name */
strip_len = decode_varint(&cp);
if (previous_ce) {
previous_len = previous_ce->ce_namelen;
if (previous_len < strip_len)
die(_("malformed name field in the index, near path '%s'"),
previous_ce->name);
copy_len = previous_len - strip_len;
}
name = (const char *)cp;
}
if (len == CE_NAMEMASK) {
len = strlen(name);
if (expand_name_field)
len += copy_len;
}
ce = mem_pool__ce_alloc(ce_mem_pool, len);
ce->ce_stat_data.sd_ctime.sec = get_be32(&ondisk->ctime.sec);
ce->ce_stat_data.sd_mtime.sec = get_be32(&ondisk->mtime.sec);
ce->ce_stat_data.sd_ctime.nsec = get_be32(&ondisk->ctime.nsec);
ce->ce_stat_data.sd_mtime.nsec = get_be32(&ondisk->mtime.nsec);
ce->ce_stat_data.sd_dev = get_be32(&ondisk->dev);
ce->ce_stat_data.sd_ino = get_be32(&ondisk->ino);
ce->ce_mode = get_be32(&ondisk->mode);
ce->ce_stat_data.sd_uid = get_be32(&ondisk->uid);
ce->ce_stat_data.sd_gid = get_be32(&ondisk->gid);
ce->ce_stat_data.sd_size = get_be32(&ondisk->size);
ce->ce_flags = flags & ~CE_NAMEMASK;
ce->ce_namelen = len;
ce->index = 0;
oidread(&ce->oid, ondisk->data);
memcpy(ce->name, name, len);
ce->name[len] = '\0';
if (expand_name_field) {
if (copy_len)
memcpy(ce->name, previous_ce->name, copy_len);
memcpy(ce->name + copy_len, name, len + 1 - copy_len);
*ent_size = (name - ((char *)ondisk)) + len + 1 - copy_len;
} else {
memcpy(ce->name, name, len + 1);
*ent_size = ondisk_ce_size(ce);
}
return ce;
}
static void check_ce_order(struct index_state *istate)
{
unsigned int i;
if (!verify_ce_order)
return;
for (i = 1; i < istate->cache_nr; i++) {
struct cache_entry *ce = istate->cache[i - 1];
struct cache_entry *next_ce = istate->cache[i];
int name_compare = strcmp(ce->name, next_ce->name);
if (0 < name_compare)
die(_("unordered stage entries in index"));
if (!name_compare) {
if (!ce_stage(ce))
die(_("multiple stage entries for merged file '%s'"),
ce->name);
if (ce_stage(ce) > ce_stage(next_ce))
die(_("unordered stage entries for '%s'"),
ce->name);
}
}
}
static void tweak_untracked_cache(struct index_state *istate)
{
struct repository *r = the_repository;
prepare_repo_settings(r);
switch (r->settings.core_untracked_cache) {
case UNTRACKED_CACHE_REMOVE:
remove_untracked_cache(istate);
break;
case UNTRACKED_CACHE_WRITE:
add_untracked_cache(istate);
break;
case UNTRACKED_CACHE_KEEP:
/*
* Either an explicit "core.untrackedCache=keep", the
* default if "core.untrackedCache" isn't configured,
* or a fallback on an unknown "core.untrackedCache"
* value.
*/
break;
}
}
static void tweak_split_index(struct index_state *istate)
{
switch (git_config_get_split_index()) {
case -1: /* unset: do nothing */
break;
case 0: /* false */
remove_split_index(istate);
break;
case 1: /* true */
add_split_index(istate);
break;
default: /* unknown value: do nothing */
break;
}
}
static void post_read_index_from(struct index_state *istate)
{
check_ce_order(istate);
tweak_untracked_cache(istate);
tweak_split_index(istate);
tweak_fsmonitor(istate);
}
static size_t estimate_cache_size_from_compressed(unsigned int entries)
{
return entries * (sizeof(struct cache_entry) + CACHE_ENTRY_PATH_LENGTH);
}
static size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
{
long per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
/*
* Account for potential alignment differences.
*/
per_entry += align_padding_size(per_entry, 0);
return ondisk_size + entries * per_entry;
}
struct index_entry_offset
{
/* starting byte offset into index file, count of index entries in this block */
int offset, nr;
};
struct index_entry_offset_table
{
int nr;
struct index_entry_offset entries[FLEX_ARRAY];
};
static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset);
static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot);
static size_t read_eoie_extension(const char *mmap, size_t mmap_size);
static void write_eoie_extension(struct strbuf *sb, git_hash_ctx *eoie_context, size_t offset);
struct load_index_extensions
{
pthread_t pthread;
struct index_state *istate;
const char *mmap;
size_t mmap_size;
unsigned long src_offset;
};
static void *load_index_extensions(void *_data)
{
struct load_index_extensions *p = _data;
unsigned long src_offset = p->src_offset;
while (src_offset <= p->mmap_size - the_hash_algo->rawsz - 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 = get_be32(p->mmap + src_offset + 4);
if (read_index_extension(p->istate,
p->mmap + src_offset,
p->mmap + src_offset + 8,
extsize) < 0) {
munmap((void *)p->mmap, p->mmap_size);
die(_("index file corrupt"));
}
src_offset += 8;
src_offset += extsize;
}
return NULL;
}
/*
* A helper function that will load the specified range of cache entries
* from the memory mapped file and add them to the given index.
*/
static unsigned long load_cache_entry_block(struct index_state *istate,
struct mem_pool *ce_mem_pool, int offset, int nr, const char *mmap,
unsigned long start_offset, const struct cache_entry *previous_ce)
{
int i;
unsigned long src_offset = start_offset;
for (i = offset; i < offset + nr; i++) {
struct ondisk_cache_entry *disk_ce;
struct cache_entry *ce;
unsigned long consumed;
disk_ce = (struct ondisk_cache_entry *)(mmap + src_offset);
ce = create_from_disk(ce_mem_pool, istate->version, disk_ce, &consumed, previous_ce);
set_index_entry(istate, i, ce);
src_offset += consumed;
previous_ce = ce;
}
return src_offset - start_offset;
}
static unsigned long load_all_cache_entries(struct index_state *istate,
const char *mmap, size_t mmap_size, unsigned long src_offset)
{
unsigned long consumed;
istate->ce_mem_pool = xmalloc(sizeof(*istate->ce_mem_pool));
if (istate->version == 4) {
mem_pool_init(istate->ce_mem_pool,
estimate_cache_size_from_compressed(istate->cache_nr));
} else {
mem_pool_init(istate->ce_mem_pool,
estimate_cache_size(mmap_size, istate->cache_nr));
}
consumed = load_cache_entry_block(istate, istate->ce_mem_pool,
0, istate->cache_nr, mmap, src_offset, NULL);
return consumed;
}
/*
* Mostly randomly chosen maximum thread counts: we
* cap the parallelism to online_cpus() threads, and we want
* to have at least 10000 cache entries per thread for it to
* be worth starting a thread.
*/
#define THREAD_COST (10000)
struct load_cache_entries_thread_data
{
pthread_t pthread;
struct index_state *istate;
struct mem_pool *ce_mem_pool;
int offset;
const char *mmap;
struct index_entry_offset_table *ieot;
int ieot_start; /* starting index into the ieot array */
int ieot_blocks; /* count of ieot entries to process */
unsigned long consumed; /* return # of bytes in index file processed */
};
/*
* A thread proc to run the load_cache_entries() computation
* across multiple background threads.
*/
static void *load_cache_entries_thread(void *_data)
{
struct load_cache_entries_thread_data *p = _data;
int i;
/* iterate across all ieot blocks assigned to this thread */
for (i = p->ieot_start; i < p->ieot_start + p->ieot_blocks; i++) {
p->consumed += load_cache_entry_block(p->istate, p->ce_mem_pool,
p->offset, p->ieot->entries[i].nr, p->mmap, p->ieot->entries[i].offset, NULL);
p->offset += p->ieot->entries[i].nr;
}
return NULL;
}
static unsigned long load_cache_entries_threaded(struct index_state *istate, const char *mmap, size_t mmap_size,
int nr_threads, struct index_entry_offset_table *ieot)
{
int i, offset, ieot_blocks, ieot_start, err;
struct load_cache_entries_thread_data *data;
unsigned long consumed = 0;
/* a little sanity checking */
if (istate->name_hash_initialized)
BUG("the name hash isn't thread safe");
istate->ce_mem_pool = xmalloc(sizeof(*istate->ce_mem_pool));
mem_pool_init(istate->ce_mem_pool, 0);
/* ensure we have no more threads than we have blocks to process */
if (nr_threads > ieot->nr)
nr_threads = ieot->nr;
CALLOC_ARRAY(data, nr_threads);
offset = ieot_start = 0;
ieot_blocks = DIV_ROUND_UP(ieot->nr, nr_threads);
for (i = 0; i < nr_threads; i++) {
struct load_cache_entries_thread_data *p = &data[i];
int nr, j;
if (ieot_start + ieot_blocks > ieot->nr)
ieot_blocks = ieot->nr - ieot_start;
p->istate = istate;
p->offset = offset;
p->mmap = mmap;
p->ieot = ieot;
p->ieot_start = ieot_start;
p->ieot_blocks = ieot_blocks;
/* create a mem_pool for each thread */
nr = 0;
for (j = p->ieot_start; j < p->ieot_start + p->ieot_blocks; j++)
nr += p->ieot->entries[j].nr;
p->ce_mem_pool = xmalloc(sizeof(*istate->ce_mem_pool));
if (istate->version == 4) {
mem_pool_init(p->ce_mem_pool,
estimate_cache_size_from_compressed(nr));
} else {
mem_pool_init(p->ce_mem_pool,
estimate_cache_size(mmap_size, nr));
}
err = pthread_create(&p->pthread, NULL, load_cache_entries_thread, p);
if (err)
die(_("unable to create load_cache_entries thread: %s"), strerror(err));
/* increment by the number of cache entries in the ieot block being processed */
for (j = 0; j < ieot_blocks; j++)
offset += ieot->entries[ieot_start + j].nr;
ieot_start += ieot_blocks;
}
for (i = 0; i < nr_threads; i++) {
struct load_cache_entries_thread_data *p = &data[i];
err = pthread_join(p->pthread, NULL);
if (err)
die(_("unable to join load_cache_entries thread: %s"), strerror(err));
mem_pool_combine(istate->ce_mem_pool, p->ce_mem_pool);
consumed += p->consumed;
}
free(data);
return consumed;
}
/* remember to discard_cache() before reading a different cache! */
int do_read_index(struct index_state *istate, const char *path, int must_exist)
{
int fd;
struct stat st;
unsigned long src_offset;
const struct cache_header *hdr;
const char *mmap;
size_t mmap_size;
struct load_index_extensions p;
size_t extension_offset = 0;
int nr_threads, cpus;
struct index_entry_offset_table *ieot = NULL;
if (istate->initialized)
return istate->cache_nr;
istate->timestamp.sec = 0;
istate->timestamp.nsec = 0;
fd = open(path, O_RDONLY);
if (fd < 0) {
if (!must_exist && errno == ENOENT)
return 0;
die_errno(_("%s: index file open failed"), path);
}
if (fstat(fd, &st))
die_errno(_("%s: cannot stat the open index"), path);
mmap_size = xsize_t(st.st_size);
if (mmap_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
die(_("%s: index file smaller than expected"), path);
mmap = xmmap_gently(NULL, mmap_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (mmap == MAP_FAILED)
die_errno(_("%s: unable to map index file%s"), path,
mmap_os_err());
close(fd);
hdr = (const struct cache_header *)mmap;
if (verify_hdr(hdr, mmap_size) < 0)
goto unmap;
oidread(&istate->oid, (const unsigned char *)hdr + mmap_size - the_hash_algo->rawsz);
istate->version = ntohl(hdr->hdr_version);
istate->cache_nr = ntohl(hdr->hdr_entries);
istate->cache_alloc = alloc_nr(istate->cache_nr);
CALLOC_ARRAY(istate->cache, istate->cache_alloc);
istate->initialized = 1;
p.istate = istate;
p.mmap = mmap;
p.mmap_size = mmap_size;
src_offset = sizeof(*hdr);
if (git_config_get_index_threads(&nr_threads))
nr_threads = 1;
/* TODO: does creating more threads than cores help? */
if (!nr_threads) {
nr_threads = istate->cache_nr / THREAD_COST;
cpus = online_cpus();
if (nr_threads > cpus)
nr_threads = cpus;
}
if (!HAVE_THREADS)
nr_threads = 1;
if (nr_threads > 1) {
extension_offset = read_eoie_extension(mmap, mmap_size);
if (extension_offset) {
int err;
p.src_offset = extension_offset;
err = pthread_create(&p.pthread, NULL, load_index_extensions, &p);
if (err)
die(_("unable to create load_index_extensions thread: %s"), strerror(err));
nr_threads--;
}
}
/*
* Locate and read the index entry offset table so that we can use it
* to multi-thread the reading of the cache entries.
*/
if (extension_offset && nr_threads > 1)
ieot = read_ieot_extension(mmap, mmap_size, extension_offset);
if (ieot) {
src_offset += load_cache_entries_threaded(istate, mmap, mmap_size, nr_threads, ieot);
free(ieot);
} else {
src_offset += load_all_cache_entries(istate, mmap, mmap_size, src_offset);
}
istate->timestamp.sec = st.st_mtime;
istate->timestamp.nsec = ST_MTIME_NSEC(st);
/* if we created a thread, join it otherwise load the extensions on the primary thread */
if (extension_offset) {
int ret = pthread_join(p.pthread, NULL);
if (ret)
die(_("unable to join load_index_extensions thread: %s"), strerror(ret));
} else {
p.src_offset = src_offset;
load_index_extensions(&p);
}
munmap((void *)mmap, mmap_size);
/*
* TODO trace2: replace "the_repository" with the actual repo instance
* that is associated with the given "istate".
*/
trace2_data_intmax("index", the_repository, "read/version",
istate->version);
trace2_data_intmax("index", the_repository, "read/cache_nr",
istate->cache_nr);
if (!istate->repo)
istate->repo = the_repository;
/*
* If the command explicitly requires a full index, force it
* to be full. Otherwise, correct the sparsity based on repository
* settings and other properties of the index (if necessary).
*/
prepare_repo_settings(istate->repo);
if (istate->repo->settings.command_requires_full_index)
ensure_full_index(istate);
else
ensure_correct_sparsity(istate);
return istate->cache_nr;
unmap:
munmap((void *)mmap, mmap_size);
die(_("index file corrupt"));
}
/*
* Signal that the shared index is used by updating its mtime.
*
* This way, shared index can be removed if they have not been used
* for some time.
*/
static void freshen_shared_index(const char *shared_index, int warn)
{
if (!check_and_freshen_file(shared_index, 1) && warn)
warning(_("could not freshen shared index '%s'"), shared_index);
}
int read_index_from(struct index_state *istate, const char *path,
const char *gitdir)
{
struct split_index *split_index;
int ret;
char *base_oid_hex;
char *base_path;
/* istate->initialized covers both .git/index and .git/sharedindex.xxx */
if (istate->initialized)
return istate->cache_nr;
/*
* TODO trace2: replace "the_repository" with the actual repo instance
* that is associated with the given "istate".
*/
trace2_region_enter_printf("index", "do_read_index", the_repository,
"%s", path);
trace_performance_enter();
ret = do_read_index(istate, path, 0);
trace_performance_leave("read cache %s", path);
trace2_region_leave_printf("index", "do_read_index", the_repository,
"%s", path);
split_index = istate->split_index;
if (!split_index || is_null_oid(&split_index->base_oid)) {
post_read_index_from(istate);
return ret;
}
trace_performance_enter();
if (split_index->base)
discard_index(split_index->base);
else
CALLOC_ARRAY(split_index->base, 1);
base_oid_hex = oid_to_hex(&split_index->base_oid);
base_path = xstrfmt("%s/sharedindex.%s", gitdir, base_oid_hex);
trace2_region_enter_printf("index", "shared/do_read_index",
the_repository, "%s", base_path);
ret = do_read_index(split_index->base, base_path, 0);
trace2_region_leave_printf("index", "shared/do_read_index",
the_repository, "%s", base_path);
if (!ret) {
char *path_copy = xstrdup(path);
const char *base_path2 = xstrfmt("%s/sharedindex.%s",
dirname(path_copy),
base_oid_hex);
free(path_copy);
trace2_region_enter_printf("index", "shared/do_read_index",
the_repository, "%s", base_path2);
ret = do_read_index(split_index->base, base_path2, 1);
trace2_region_leave_printf("index", "shared/do_read_index",
the_repository, "%s", base_path2);
}
if (!oideq(&split_index->base_oid, &split_index->base->oid))
die(_("broken index, expect %s in %s, got %s"),
base_oid_hex, base_path,
oid_to_hex(&split_index->base->oid));
freshen_shared_index(base_path, 0);
merge_base_index(istate);
post_read_index_from(istate);
trace_performance_leave("read cache %s", base_path);
free(base_path);
return ret;
}
int is_index_unborn(struct index_state *istate)
{
return (!istate->cache_nr && !istate->timestamp.sec);
}
int discard_index(struct index_state *istate)
{
/*
* Cache entries in istate->cache[] should have been allocated
* from the memory pool associated with this index, or from an
* associated split_index. There is no need to free individual
* cache entries. validate_cache_entries can detect when this
* assertion does not hold.
*/
validate_cache_entries(istate);
resolve_undo_clear_index(istate);
istate->cache_nr = 0;
istate->cache_changed = 0;
istate->timestamp.sec = 0;
istate->timestamp.nsec = 0;
free_name_hash(istate);
cache_tree_free(&(istate->cache_tree));
istate->initialized = 0;
istate->fsmonitor_has_run_once = 0;
FREE_AND_NULL(istate->fsmonitor_last_update);
FREE_AND_NULL(istate->cache);
istate->cache_alloc = 0;
discard_split_index(istate);
free_untracked_cache(istate->untracked);
istate->untracked = NULL;
if (istate->ce_mem_pool) {
mem_pool_discard(istate->ce_mem_pool, should_validate_cache_entries());
FREE_AND_NULL(istate->ce_mem_pool);
}
return 0;
}
/*
* Validate the cache entries of this index.
* All cache entries associated with this index
* should have been allocated by the memory pool
* associated with this index, or by a referenced
* split index.
*/
void validate_cache_entries(const struct index_state *istate)
{
int i;
if (!should_validate_cache_entries() ||!istate || !istate->initialized)
return;
for (i = 0; i < istate->cache_nr; i++) {
if (!istate) {
BUG("cache entry is not allocated from expected memory pool");
} else if (!istate->ce_mem_pool ||
!mem_pool_contains(istate->ce_mem_pool, istate->cache[i])) {
if (!istate->split_index ||
!istate->split_index->base ||
!istate->split_index->base->ce_mem_pool ||
!mem_pool_contains(istate->split_index->base->ce_mem_pool, istate->cache[i])) {
BUG("cache entry is not allocated from expected memory pool");
}
}
}
if (istate->split_index)
validate_cache_entries(istate->split_index->base);
}
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;
}
int repo_index_has_changes(struct repository *repo,
struct tree *tree,
struct strbuf *sb)
{
struct index_state *istate = repo->index;
struct object_id cmp;
int i;
if (tree)
cmp = tree->object.oid;
if (tree || !get_oid_tree("HEAD", &cmp)) {
struct diff_options opt;
repo_diff_setup(repo, &opt);
opt.flags.exit_with_status = 1;
if (!sb)
opt.flags.quick = 1;
diff_setup_done(&opt);
do_diff_cache(&cmp, &opt);
diffcore_std(&opt);
for (i = 0; sb && i < diff_queued_diff.nr; i++) {
if (i)
strbuf_addch(sb, ' ');
strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
}
diff_flush(&opt);
return opt.flags.has_changes != 0;
} else {
/* TODO: audit for interaction with sparse-index. */
ensure_full_index(istate);
for (i = 0; sb && i < istate->cache_nr; i++) {
if (i)
strbuf_addch(sb, ' ');
strbuf_addstr(sb, istate->cache[i]->name);
}
return !!istate->cache_nr;
}
}
static int write_index_ext_header(struct hashfile *f,
git_hash_ctx *eoie_f,
unsigned int ext,
unsigned int sz)
{
hashwrite_be32(f, ext);
hashwrite_be32(f, sz);
if (eoie_f) {
ext = htonl(ext);
sz = htonl(sz);
the_hash_algo->update_fn(eoie_f, &ext, sizeof(ext));
the_hash_algo->update_fn(eoie_f, &sz, sizeof(sz));
}
return 0;
}
static void ce_smudge_racily_clean_entry(struct index_state *istate,
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_stat_data.sd_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(istate, 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_stat_data.sd_size = 0;
}
}
/* Copy miscellaneous fields but not the name */
static void copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
struct cache_entry *ce)
{
short flags;
const unsigned hashsz = the_hash_algo->rawsz;
uint16_t *flagsp = (uint16_t *)(ondisk->data + hashsz);
ondisk->ctime.sec = htonl(ce->ce_stat_data.sd_ctime.sec);
ondisk->mtime.sec = htonl(ce->ce_stat_data.sd_mtime.sec);
ondisk->ctime.nsec = htonl(ce->ce_stat_data.sd_ctime.nsec);
ondisk->mtime.nsec = htonl(ce->ce_stat_data.sd_mtime.nsec);
ondisk->dev = htonl(ce->ce_stat_data.sd_dev);
ondisk->ino = htonl(ce->ce_stat_data.sd_ino);
ondisk->mode = htonl(ce->ce_mode);
ondisk->uid = htonl(ce->ce_stat_data.sd_uid);
ondisk->gid = htonl(ce->ce_stat_data.sd_gid);
ondisk->size = htonl(ce->ce_stat_data.sd_size);
hashcpy(ondisk->data, ce->oid.hash);
flags = ce->ce_flags & ~CE_NAMEMASK;
flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
flagsp[0] = htons(flags);
if (ce->ce_flags & CE_EXTENDED) {
flagsp[1] = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
}
}
static int ce_write_entry(struct hashfile *f, struct cache_entry *ce,
struct strbuf *previous_name, struct ondisk_cache_entry *ondisk)
{
int size;
unsigned int saved_namelen;
int stripped_name = 0;
static unsigned char padding[8] = { 0x00 };
if (ce->ce_flags & CE_STRIP_NAME) {
saved_namelen = ce_namelen(ce);
ce->ce_namelen = 0;
stripped_name = 1;
}
size = offsetof(struct ondisk_cache_entry,data) + ondisk_data_size(ce->ce_flags, 0);
if (!previous_name) {
int len = ce_namelen(ce);
copy_cache_entry_to_ondisk(ondisk, ce);
hashwrite(f, ondisk, size);
hashwrite(f, ce->name, len);
hashwrite(f, padding, align_padding_size(size, len));
} 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);
copy_cache_entry_to_ondisk(ondisk, ce);
hashwrite(f, ondisk, size);
hashwrite(f, to_remove_vi, prefix_size);
hashwrite(f, ce->name + common, ce_namelen(ce) - common);
hashwrite(f, padding, 1);
strbuf_splice(previous_name, common, to_remove,
ce->name + common, ce_namelen(ce) - common);
}
if (stripped_name) {
ce->ce_namelen = saved_namelen;
ce->ce_flags &= ~CE_STRIP_NAME;
}
return 0;
}
/*
* This function verifies if index_state has the correct sha1 of the
* index file. Don't die if we have any other failure, just return 0.
*/
static int verify_index_from(const struct index_state *istate, const char *path)
{
int fd;
ssize_t n;
struct stat st;
unsigned char hash[GIT_MAX_RAWSZ];
if (!istate->initialized)
return 0;
fd = open(path, O_RDONLY);
if (fd < 0)
return 0;
if (fstat(fd, &st))
goto out;
if (st.st_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
goto out;
n = pread_in_full(fd, hash, the_hash_algo->rawsz, st.st_size - the_hash_algo->rawsz);
if (n != the_hash_algo->rawsz)
goto out;
if (!hasheq(istate->oid.hash, hash))
goto out;
close(fd);
return 1;
out:
close(fd);
return 0;
}
static int repo_verify_index(struct repository *repo)
{
return verify_index_from(repo->index, repo->index_file);
}
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;
}
void repo_update_index_if_able(struct repository *repo,
struct lock_file *lockfile)
{
if ((repo->index->cache_changed ||
has_racy_timestamp(repo->index)) &&
repo_verify_index(repo))
write_locked_index(repo->index, lockfile, COMMIT_LOCK);
else
rollback_lock_file(lockfile);
}
static int record_eoie(void)
{
int val;
if (!git_config_get_bool("index.recordendofindexentries", &val))
return val;
/*
* As a convenience, the end of index entries extension
* used for threading is written by default if the user
* explicitly requested threaded index reads.
*/
return !git_config_get_index_threads(&val) && val != 1;
}
static int record_ieot(void)
{
int val;
if (!git_config_get_bool("index.recordoffsettable", &val))
return val;
/*
* As a convenience, the offset table used for threading is
* written by default if the user explicitly requested
* threaded index reads.
*/
return !git_config_get_index_threads(&val) && val != 1;
}
/*
* On success, `tempfile` is closed. If it is the temporary file
* of a `struct lock_file`, we will therefore effectively perform
* a 'close_lock_file_gently()`. Since that is an implementation
* detail of lockfiles, callers of `do_write_index()` should not
* rely on it.
*/
static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
int strip_extensions)
{
uint64_t start = getnanotime();
struct hashfile *f;
git_hash_ctx *eoie_c = NULL;
struct cache_header hdr;
int i, err = 0, removed, extended, hdr_version;
struct cache_entry **cache = istate->cache;
int entries = istate->cache_nr;
struct stat st;
struct ondisk_cache_entry ondisk;
struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
int drop_cache_tree = istate->drop_cache_tree;
off_t offset;
int ieot_entries = 1;
struct index_entry_offset_table *ieot = NULL;
int nr, nr_threads;
f = hashfd(tempfile->fd, tempfile->filename.buf);
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 = get_index_format_default(the_repository);
/* 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);
hashwrite(f, &hdr, sizeof(hdr));
if (!HAVE_THREADS || git_config_get_index_threads(&nr_threads))
nr_threads = 1;
if (nr_threads != 1 && record_ieot()) {
int ieot_blocks, cpus;
/*
* ensure default number of ieot blocks maps evenly to the
* default number of threads that will process them leaving
* room for the thread to load the index extensions.
*/
if (!nr_threads) {
ieot_blocks = istate->cache_nr / THREAD_COST;
cpus = online_cpus();
if (ieot_blocks > cpus - 1)
ieot_blocks = cpus - 1;
} else {
ieot_blocks = nr_threads;
if (ieot_blocks > istate->cache_nr)
ieot_blocks = istate->cache_nr;
}
/*
* no reason to write out the IEOT extension if we don't
* have enough blocks to utilize multi-threading
*/
if (ieot_blocks > 1) {
ieot = xcalloc(1, sizeof(struct index_entry_offset_table)
+ (ieot_blocks * sizeof(struct index_entry_offset)));
ieot_entries = DIV_ROUND_UP(entries, ieot_blocks);
}
}
offset = hashfile_total(f);
nr = 0;
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(istate, ce);
if (is_null_oid(&ce->oid)) {
static const char msg[] = "cache entry has null sha1: %s";
static int allow = -1;
if (allow < 0)
allow = git_env_bool("GIT_ALLOW_NULL_SHA1", 0);
if (allow)
warning(msg, ce->name);
else
err = error(msg, ce->name);
drop_cache_tree = 1;
}
if (ieot && i && (i % ieot_entries == 0)) {
ieot->entries[ieot->nr].nr = nr;
ieot->entries[ieot->nr].offset = offset;
ieot->nr++;
/*
* If we have a V4 index, set the first byte to an invalid
* character to ensure there is nothing common with the previous
* entry
*/
if (previous_name)
previous_name->buf[0] = 0;
nr = 0;
offset = hashfile_total(f);
}
if (ce_write_entry(f, ce, previous_name, (struct ondisk_cache_entry *)&ondisk) < 0)
err = -1;
if (err)
break;
nr++;
}
if (ieot && nr) {
ieot->entries[ieot->nr].nr = nr;
ieot->entries[ieot->nr].offset = offset;
ieot->nr++;
}
strbuf_release(&previous_name_buf);
if (err) {
free(ieot);
return err;
}
offset = hashfile_total(f);
/*
* The extension headers must be hashed on their own for the
* EOIE extension. Create a hashfile here to compute that hash.
*/
if (offset && record_eoie()) {
CALLOC_ARRAY(eoie_c, 1);
the_hash_algo->init_fn(eoie_c);
}
/*
* Lets write out CACHE_EXT_INDEXENTRYOFFSETTABLE first so that we
* can minimize the number of extensions we have to scan through to
* find it during load. Write it out regardless of the
* strip_extensions parameter as we need it when loading the shared
* index.
*/
if (ieot) {
struct strbuf sb = STRBUF_INIT;
write_ieot_extension(&sb, ieot);
err = write_index_ext_header(f, eoie_c, CACHE_EXT_INDEXENTRYOFFSETTABLE, sb.len) < 0;
hashwrite(f, sb.buf, sb.len);
strbuf_release(&sb);
free(ieot);
if (err)
return -1;
}
if (!strip_extensions && istate->split_index &&
!is_null_oid(&istate->split_index->base_oid)) {
struct strbuf sb = STRBUF_INIT;
err = write_link_extension(&sb, istate) < 0 ||
write_index_ext_header(f, eoie_c, CACHE_EXT_LINK,
sb.len) < 0;
hashwrite(f, sb.buf, sb.len);
strbuf_release(&sb);
if (err)
return -1;
}
if (!strip_extensions && !drop_cache_tree && istate->cache_tree) {
struct strbuf sb = STRBUF_INIT;
cache_tree_write(&sb, istate->cache_tree);
err = write_index_ext_header(f, eoie_c, CACHE_EXT_TREE, sb.len) < 0;
hashwrite(f, sb.buf, sb.len);
strbuf_release(&sb);
if (err)
return -1;
}
if (!strip_extensions && istate->resolve_undo) {
struct strbuf sb = STRBUF_INIT;
resolve_undo_write(&sb, istate->resolve_undo);
err = write_index_ext_header(f, eoie_c, CACHE_EXT_RESOLVE_UNDO,
sb.len) < 0;
hashwrite(f, sb.buf, sb.len);
strbuf_release(&sb);
if (err)
return -1;
}
if (!strip_extensions && istate->untracked) {
struct strbuf sb = STRBUF_INIT;
write_untracked_extension(&sb, istate->untracked);
err = write_index_ext_header(f, eoie_c, CACHE_EXT_UNTRACKED,
sb.len) < 0;
hashwrite(f, sb.buf, sb.len);
strbuf_release(&sb);
if (err)
return -1;
}
if (!strip_extensions && istate->fsmonitor_last_update) {
struct strbuf sb = STRBUF_INIT;
write_fsmonitor_extension(&sb, istate);
err = write_index_ext_header(f, eoie_c, CACHE_EXT_FSMONITOR, sb.len) < 0;
hashwrite(f, sb.buf, sb.len);
strbuf_release(&sb);
if (err)
return -1;
}
if (istate->sparse_index) {
if (write_index_ext_header(f, eoie_c, CACHE_EXT_SPARSE_DIRECTORIES, 0) < 0)
return -1;
}
/*
* CACHE_EXT_ENDOFINDEXENTRIES must be written as the last entry before the SHA1
* so that it can be found and processed before all the index entries are
* read. Write it out regardless of the strip_extensions parameter as we need it
* when loading the shared index.
*/
if (eoie_c) {
struct strbuf sb = STRBUF_INIT;
write_eoie_extension(&sb, eoie_c, offset);
err = write_index_ext_header(f, NULL, CACHE_EXT_ENDOFINDEXENTRIES, sb.len) < 0;
hashwrite(f, sb.buf, sb.len);
strbuf_release(&sb);
if (err)
return -1;
}
finalize_hashfile(f, istate->oid.hash, CSUM_HASH_IN_STREAM);
if (close_tempfile_gently(tempfile)) {
error(_("could not close '%s'"), get_tempfile_path(tempfile));
return -1;
}
if (stat(get_tempfile_path(tempfile), &st))
return -1;
istate->timestamp.sec = (unsigned int)st.st_mtime;
istate->timestamp.nsec = ST_MTIME_NSEC(st);
trace_performance_since(start, "write index, changed mask = %x", istate->cache_changed);
/*
* TODO trace2: replace "the_repository" with the actual repo instance
* that is associated with the given "istate".
*/
trace2_data_intmax("index", the_repository, "write/version",
istate->version);
trace2_data_intmax("index", the_repository, "write/cache_nr",
istate->cache_nr);
return 0;
}
void set_alternate_index_output(const char *name)
{
alternate_index_output = name;
}
static int commit_locked_index(struct lock_file *lk)
{
if (alternate_index_output)
return commit_lock_file_to(lk, alternate_index_output);
else
return commit_lock_file(lk);
}
static int do_write_locked_index(struct index_state *istate, struct lock_file *lock,
unsigned flags)
{
int ret;
int was_full = !istate->sparse_index;
ret = convert_to_sparse(istate, 0);
if (ret) {
warning(_("failed to convert to a sparse-index"));
return ret;
}
/*
* TODO trace2: replace "the_repository" with the actual repo instance
* that is associated with the given "istate".
*/
trace2_region_enter_printf("index", "do_write_index", the_repository,
"%s", get_lock_file_path(lock));
ret = do_write_index(istate, lock->tempfile, 0);
trace2_region_leave_printf("index", "do_write_index", the_repository,
"%s", get_lock_file_path(lock));
if (was_full)
ensure_full_index(istate);
if (ret)
return ret;
if (flags & COMMIT_LOCK)
ret = commit_locked_index(lock);
else
ret = close_lock_file_gently(lock);
run_hook_le(NULL, "post-index-change",
istate->updated_workdir ? "1" : "0",
istate->updated_skipworktree ? "1" : "0", NULL);
istate->updated_workdir = 0;
istate->updated_skipworktree = 0;
return ret;
}
static int write_split_index(struct index_state *istate,
struct lock_file *lock,
unsigned flags)
{
int ret;
prepare_to_write_split_index(istate);
ret = do_write_locked_index(istate, lock, flags);
finish_writing_split_index(istate);
return ret;
}
static const char *shared_index_expire = "2.weeks.ago";
static unsigned long get_shared_index_expire_date(void)
{
static unsigned long shared_index_expire_date;
static int shared_index_expire_date_prepared;
if (!shared_index_expire_date_prepared) {
git_config_get_expiry("splitindex.sharedindexexpire",
&shared_index_expire);
shared_index_expire_date = approxidate(shared_index_expire);
shared_index_expire_date_prepared = 1;
}
return shared_index_expire_date;
}
static int should_delete_shared_index(const char *shared_index_path)
{
struct stat st;
unsigned long expiration;
/* Check timestamp */
expiration = get_shared_index_expire_date();
if (!expiration)
return 0;
if (stat(shared_index_path, &st))
return error_errno(_("could not stat '%s'"), shared_index_path);
if (st.st_mtime > expiration)
return 0;
return 1;
}
static int clean_shared_index_files(const char *current_hex)
{
struct dirent *de;
DIR *dir = opendir(get_git_dir());
if (!dir)
return error_errno(_("unable to open git dir: %s"), get_git_dir());
while ((de = readdir(dir)) != NULL) {
const char *sha1_hex;
const char *shared_index_path;
if (!skip_prefix(de->d_name, "sharedindex.", &sha1_hex))
continue;
if (!strcmp(sha1_hex, current_hex))
continue;
shared_index_path = git_path("%s", de->d_name);
if (should_delete_shared_index(shared_index_path) > 0 &&
unlink(shared_index_path))
warning_errno(_("unable to unlink: %s"), shared_index_path);
}
closedir(dir);
return 0;
}
static int write_shared_index(struct index_state *istate,
struct tempfile **temp)
{
struct split_index *si = istate->split_index;
int ret, was_full = !istate->sparse_index;
move_cache_to_base_index(istate);
convert_to_sparse(istate, 0);
trace2_region_enter_printf("index", "shared/do_write_index",
the_repository, "%s", get_tempfile_path(*temp));
ret = do_write_index(si->base, *temp, 1);
trace2_region_leave_printf("index", "shared/do_write_index",
the_repository, "%s", get_tempfile_path(*temp));
if (was_full)
ensure_full_index(istate);
if (ret)
return ret;
ret = adjust_shared_perm(get_tempfile_path(*temp));
if (ret) {
error(_("cannot fix permission bits on '%s'"), get_tempfile_path(*temp));
return ret;
}
ret = rename_tempfile(temp,
git_path("sharedindex.%s", oid_to_hex(&si->base->oid)));
if (!ret) {
oidcpy(&si->base_oid, &si->base->oid);
clean_shared_index_files(oid_to_hex(&si->base->oid));
}
return ret;
}
static const int default_max_percent_split_change = 20;
static int too_many_not_shared_entries(struct index_state *istate)
{
int i, not_shared = 0;
int max_split = git_config_get_max_percent_split_change();
switch (max_split) {
case -1:
/* not or badly configured: use the default value */
max_split = default_max_percent_split_change;
break;
case 0:
return 1; /* 0% means always write a new shared index */
case 100:
return 0; /* 100% means never write a new shared index */
default:
break; /* just use the configured value */
}
/* Count not shared entries */
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce = istate->cache[i];
if (!ce->index)
not_shared++;
}
return (int64_t)istate->cache_nr * max_split < (int64_t)not_shared * 100;
}
int write_locked_index(struct index_state *istate, struct lock_file *lock,
unsigned flags)
{
int new_shared_index, ret, test_split_index_env;
struct split_index *si = istate->split_index;
if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0))
cache_tree_verify(the_repository, istate);
if ((flags & SKIP_IF_UNCHANGED) && !istate->cache_changed) {
if (flags & COMMIT_LOCK)
rollback_lock_file(lock);
return 0;
}
if (istate->fsmonitor_last_update)
fill_fsmonitor_bitmap(istate);
test_split_index_env = git_env_bool("GIT_TEST_SPLIT_INDEX", 0);
if ((!si && !test_split_index_env) ||
alternate_index_output ||
(istate->cache_changed & ~EXTMASK)) {
if (si)
oidclr(&si->base_oid);
ret = do_write_locked_index(istate, lock, flags);
goto out;
}
if (test_split_index_env) {
if (!si) {
si = init_split_index(istate);
istate->cache_changed |= SPLIT_INDEX_ORDERED;
} else {
int v = si->base_oid.hash[0];
if ((v & 15) < 6)
istate->cache_changed |= SPLIT_INDEX_ORDERED;
}
}
if (too_many_not_shared_entries(istate))
istate->cache_changed |= SPLIT_INDEX_ORDERED;
new_shared_index = istate->cache_changed & SPLIT_INDEX_ORDERED;
if (new_shared_index) {
struct tempfile *temp;
int saved_errno;
/* Same initial permissions as the main .git/index file */
temp = mks_tempfile_sm(git_path("sharedindex_XXXXXX"), 0, 0666);
if (!temp) {
oidclr(&si->base_oid);
ret = do_write_locked_index(istate, lock, flags);
goto out;
}
ret = write_shared_index(istate, &temp);
saved_errno = errno;
if (is_tempfile_active(temp))
delete_tempfile(&temp);
errno = saved_errno;
if (ret)
goto out;
}
ret = write_split_index(istate, lock, flags);
/* Freshen the shared index only if the split-index was written */
if (!ret && !new_shared_index && !is_null_oid(&si->base_oid)) {
const char *shared_index = git_path("sharedindex.%s",
oid_to_hex(&si->base_oid));
freshen_shared_index(shared_index, 1);
}
out:
if (flags & COMMIT_LOCK)
rollback_lock_file(lock);
return ret;
}
/*
* Read the index file that is potentially unmerged into given
* index_state, dropping any unmerged entries to stage #0 (potentially
* resulting in a path appearing as both a file and a directory in the
* index; the caller is responsible to clear out the extra entries
* before writing the index to a tree). 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 repo_read_index_unmerged(struct repository *repo)
{
struct index_state *istate;
int i;
int unmerged = 0;
repo_read_index(repo);
istate = repo->index;
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce = istate->cache[i];
struct cache_entry *new_ce;
int len;
if (!ce_stage(ce))
continue;
unmerged = 1;
len = ce_namelen(ce);
new_ce = make_empty_cache_entry(istate, len);
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, ADD_CACHE_SKIP_DFCHECK))
return error(_("%s: cannot drop to stage #0"),
new_ce->name);
}
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(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;
}
void *read_blob_data_from_index(struct index_state *istate,
const char *path, unsigned long *size)
{
int pos, len;
unsigned long sz;
enum object_type type;
void *data;
len = strlen(path);
pos = index_name_pos(istate, path, len);
if (pos < 0) {
/*
* We might be in the middle of a merge, in which
* case we would read stage #2 (ours).
*/
int i;
for (i = -pos - 1;
(pos < 0 && i < istate->cache_nr &&
!strcmp(istate->cache[i]->name, path));
i++)
if (ce_stage(istate->cache[i]) == 2)
pos = i;
}
if (pos < 0)
return NULL;
data = read_object_file(&istate->cache[pos]->oid, &type, &sz);
if (!data || type != OBJ_BLOB) {
free(data);
return NULL;
}
if (size)
*size = sz;
return data;
}
void stat_validity_clear(struct stat_validity *sv)
{
FREE_AND_NULL(sv->sd);
}
int stat_validity_check(struct stat_validity *sv, const char *path)
{
struct stat st;
if (stat(path, &st) < 0)
return sv->sd == NULL;
if (!sv->sd)
return 0;
return S_ISREG(st.st_mode) && !match_stat_data(sv->sd, &st);
}
void stat_validity_update(struct stat_validity *sv, int fd)
{
struct stat st;
if (fstat(fd, &st) < 0 || !S_ISREG(st.st_mode))
stat_validity_clear(sv);
else {
if (!sv->sd)
CALLOC_ARRAY(sv->sd, 1);
fill_stat_data(sv->sd, &st);
}
}
void move_index_extensions(struct index_state *dst, struct index_state *src)
{
dst->untracked = src->untracked;
src->untracked = NULL;
dst->cache_tree = src->cache_tree;
src->cache_tree = NULL;
}
struct cache_entry *dup_cache_entry(const struct cache_entry *ce,
struct index_state *istate)
{
unsigned int size = ce_size(ce);
int mem_pool_allocated;
struct cache_entry *new_entry = make_empty_cache_entry(istate, ce_namelen(ce));
mem_pool_allocated = new_entry->mem_pool_allocated;
memcpy(new_entry, ce, size);
new_entry->mem_pool_allocated = mem_pool_allocated;
return new_entry;
}
void discard_cache_entry(struct cache_entry *ce)
{
if (ce && should_validate_cache_entries())
memset(ce, 0xCD, cache_entry_size(ce->ce_namelen));
if (ce && ce->mem_pool_allocated)
return;
free(ce);
}
int should_validate_cache_entries(void)
{
static int validate_index_cache_entries = -1;
if (validate_index_cache_entries < 0) {
if (getenv("GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES"))
validate_index_cache_entries = 1;
else
validate_index_cache_entries = 0;
}
return validate_index_cache_entries;
}
#define EOIE_SIZE (4 + GIT_SHA1_RAWSZ) /* <4-byte offset> + <20-byte hash> */
#define EOIE_SIZE_WITH_HEADER (4 + 4 + EOIE_SIZE) /* <4-byte signature> + <4-byte length> + EOIE_SIZE */
static size_t read_eoie_extension(const char *mmap, size_t mmap_size)
{
/*
* The end of index entries (EOIE) extension is guaranteed to be last
* so that it can be found by scanning backwards from the EOF.
*
* "EOIE"
* <4-byte length>
* <4-byte offset>
* <20-byte hash>
*/
const char *index, *eoie;
uint32_t extsize;
size_t offset, src_offset;
unsigned char hash[GIT_MAX_RAWSZ];
git_hash_ctx c;
/* ensure we have an index big enough to contain an EOIE extension */
if (mmap_size < sizeof(struct cache_header) + EOIE_SIZE_WITH_HEADER + the_hash_algo->rawsz)
return 0;
/* validate the extension signature */
index = eoie = mmap + mmap_size - EOIE_SIZE_WITH_HEADER - the_hash_algo->rawsz;
if (CACHE_EXT(index) != CACHE_EXT_ENDOFINDEXENTRIES)
return 0;
index += sizeof(uint32_t);
/* validate the extension size */
extsize = get_be32(index);
if (extsize != EOIE_SIZE)
return 0;
index += sizeof(uint32_t);
/*
* Validate the offset we're going to look for the first extension
* signature is after the index header and before the eoie extension.
*/
offset = get_be32(index);
if (mmap + offset < mmap + sizeof(struct cache_header))
return 0;
if (mmap + offset >= eoie)
return 0;
index += sizeof(uint32_t);
/*
* The hash is computed over extension types and their sizes (but not
* their contents). E.g. if we have "TREE" extension that is N-bytes
* long, "REUC" extension that is M-bytes long, followed by "EOIE",
* then the hash would be:
*
* SHA-1("TREE" + <binary representation of N> +
* "REUC" + <binary representation of M>)
*/
src_offset = offset;
the_hash_algo->init_fn(&c);
while (src_offset < mmap_size - the_hash_algo->rawsz - EOIE_SIZE_WITH_HEADER) {
/* 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, mmap + src_offset + 4, 4);
extsize = ntohl(extsize);
/* verify the extension size isn't so large it will wrap around */
if (src_offset + 8 + extsize < src_offset)
return 0;
the_hash_algo->update_fn(&c, mmap + src_offset, 8);
src_offset += 8;
src_offset += extsize;
}
the_hash_algo->final_fn(hash, &c);
if (!hasheq(hash, (const unsigned char *)index))
return 0;
/* Validate that the extension offsets returned us back to the eoie extension. */
if (src_offset != mmap_size - the_hash_algo->rawsz - EOIE_SIZE_WITH_HEADER)
return 0;
return offset;
}
static void write_eoie_extension(struct strbuf *sb, git_hash_ctx *eoie_context, size_t offset)
{
uint32_t buffer;
unsigned char hash[GIT_MAX_RAWSZ];
/* offset */
put_be32(&buffer, offset);
strbuf_add(sb, &buffer, sizeof(uint32_t));
/* hash */
the_hash_algo->final_fn(hash, eoie_context);
strbuf_add(sb, hash, the_hash_algo->rawsz);
}
#define IEOT_VERSION (1)
static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset)
{
const char *index = NULL;
uint32_t extsize, ext_version;
struct index_entry_offset_table *ieot;
int i, nr;
/* find the IEOT extension */
if (!offset)
return NULL;
while (offset <= mmap_size - the_hash_algo->rawsz - 8) {
extsize = get_be32(mmap + offset + 4);
if (CACHE_EXT((mmap + offset)) == CACHE_EXT_INDEXENTRYOFFSETTABLE) {
index = mmap + offset + 4 + 4;
break;
}
offset += 8;
offset += extsize;
}
if (!index)
return NULL;
/* validate the version is IEOT_VERSION */
ext_version = get_be32(index);
if (ext_version != IEOT_VERSION) {
error("invalid IEOT version %d", ext_version);
return NULL;
}
index += sizeof(uint32_t);
/* extension size - version bytes / bytes per entry */
nr = (extsize - sizeof(uint32_t)) / (sizeof(uint32_t) + sizeof(uint32_t));
if (!nr) {
error("invalid number of IEOT entries %d", nr);
return NULL;
}
ieot = xmalloc(sizeof(struct index_entry_offset_table)
+ (nr * sizeof(struct index_entry_offset)));
ieot->nr = nr;
for (i = 0; i < nr; i++) {
ieot->entries[i].offset = get_be32(index);
index += sizeof(uint32_t);
ieot->entries[i].nr = get_be32(index);
index += sizeof(uint32_t);
}
return ieot;
}
static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot)
{
uint32_t buffer;
int i;
/* version */
put_be32(&buffer, IEOT_VERSION);
strbuf_add(sb, &buffer, sizeof(uint32_t));
/* ieot */
for (i = 0; i < ieot->nr; i++) {
/* offset */
put_be32(&buffer, ieot->entries[i].offset);
strbuf_add(sb, &buffer, sizeof(uint32_t));
/* count */
put_be32(&buffer, ieot->entries[i].nr);
strbuf_add(sb, &buffer, sizeof(uint32_t));
}
}
void prefetch_cache_entries(const struct index_state *istate,
must_prefetch_predicate must_prefetch)
{
int i;
struct oid_array to_fetch = OID_ARRAY_INIT;
for (i = 0; i < istate->cache_nr; i++) {
struct cache_entry *ce = istate->cache[i];
if (S_ISGITLINK(ce->ce_mode) || !must_prefetch(ce))
continue;
if (!oid_object_info_extended(the_repository, &ce->oid,
NULL,
OBJECT_INFO_FOR_PREFETCH))
continue;
oid_array_append(&to_fetch, &ce->oid);
}
promisor_remote_get_direct(the_repository,
to_fetch.oid, to_fetch.nr);
oid_array_clear(&to_fetch);
}
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