git/builtin-update-index.c
Linus Torvalds 22631473e0 Fix "git commit directory/" performance anomaly
This trivial patch avoids re-hashing files that are already clean in the
index. This mirrors what commit 0781b8a9b2
did for "git add .", only for "git commit ." instead.

This improves the cold-cache case immensely, since we don't need to bring
in all the file contents, just the index and any files dirty in the index.

Before:

	[torvalds@woody linux]$ time git commit .
	real    1m49.537s
	user    0m3.892s
	sys     0m2.432s

After:

	[torvalds@woody linux]$ time git commit .
	real    0m14.273s
	user    0m1.312s
	sys     0m0.516s

(both after doing a "echo 3 > /proc/sys/vm/drop_caches" to get cold-cache
behaviour - even with the index optimization git still has to "lstat()"
all the files, so with a truly cold cache, bringing all the inodes in
will take some time).

[jc: trivial "return 0;" fixed]

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-10 13:57:43 -07:00

758 lines
19 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "strbuf.h"
#include "quote.h"
#include "cache-tree.h"
#include "tree-walk.h"
#include "builtin.h"
#include "refs.h"
/*
* Default to not allowing changes to the list of files. The
* tool doesn't actually care, but this makes it harder to add
* files to the revision control by mistake by doing something
* like "git-update-index *" and suddenly having all the object
* files be revision controlled.
*/
static int allow_add;
static int allow_remove;
static int allow_replace;
static int info_only;
static int force_remove;
static int verbose;
static int mark_valid_only;
#define MARK_VALID 1
#define UNMARK_VALID 2
static void report(const char *fmt, ...)
{
va_list vp;
if (!verbose)
return;
va_start(vp, fmt);
vprintf(fmt, vp);
putchar('\n');
va_end(vp);
}
static int mark_valid(const char *path)
{
int namelen = strlen(path);
int pos = cache_name_pos(path, namelen);
if (0 <= pos) {
switch (mark_valid_only) {
case MARK_VALID:
active_cache[pos]->ce_flags |= htons(CE_VALID);
break;
case UNMARK_VALID:
active_cache[pos]->ce_flags &= ~htons(CE_VALID);
break;
}
cache_tree_invalidate_path(active_cache_tree, path);
active_cache_changed = 1;
return 0;
}
return -1;
}
static int remove_one_path(const char *path)
{
if (!allow_remove)
return error("%s: does not exist and --remove not passed", path);
if (remove_file_from_cache(path))
return error("%s: cannot remove from the index", path);
return 0;
}
/*
* Handle a path that couldn't be lstat'ed. It's either:
* - missing file (ENOENT or ENOTDIR). That's ok if we're
* supposed to be removing it and the removal actually
* succeeds.
* - permission error. That's never ok.
*/
static int process_lstat_error(const char *path, int err)
{
if (err == ENOENT || err == ENOTDIR)
return remove_one_path(path);
return error("lstat(\"%s\"): %s", path, strerror(errno));
}
static int add_one_path(struct cache_entry *old, const char *path, int len, struct stat *st)
{
int option, size;
struct cache_entry *ce;
/* Was the old index entry already up-to-date? */
if (old && !ce_stage(old) && !ce_match_stat(old, st, 0))
return 0;
size = cache_entry_size(len);
ce = xcalloc(1, size);
memcpy(ce->name, path, len);
ce->ce_flags = htons(len);
fill_stat_cache_info(ce, st);
ce->ce_mode = ce_mode_from_stat(old, st->st_mode);
if (index_path(ce->sha1, path, st, !info_only))
return -1;
option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
if (add_cache_entry(ce, option))
return error("%s: cannot add to the index - missing --add option?", path);
return 0;
}
/*
* Handle a path that was a directory. Four cases:
*
* - it's already a gitlink in the index, and we keep it that
* way, and update it if we can (if we cannot find the HEAD,
* we're going to keep it unchanged in the index!)
*
* - it's a *file* in the index, in which case it should be
* removed as a file if removal is allowed, since it doesn't
* exist as such any more. If removal isn't allowed, it's
* an error.
*
* (NOTE! This is old and arguably fairly strange behaviour.
* We might want to make this an error unconditionally, and
* use "--force-remove" if you actually want to force removal).
*
* - it used to exist as a subdirectory (ie multiple files with
* this particular prefix) in the index, in which case it's wrong
* to try to update it as a directory.
*
* - it doesn't exist at all in the index, but it is a valid
* git directory, and it should be *added* as a gitlink.
*/
static int process_directory(const char *path, int len, struct stat *st)
{
unsigned char sha1[20];
int pos = cache_name_pos(path, len);
/* Exact match: file or existing gitlink */
if (pos >= 0) {
struct cache_entry *ce = active_cache[pos];
if (S_ISGITLINK(ntohl(ce->ce_mode))) {
/* Do nothing to the index if there is no HEAD! */
if (resolve_gitlink_ref(path, "HEAD", sha1) < 0)
return 0;
return add_one_path(ce, path, len, st);
}
/* Should this be an unconditional error? */
return remove_one_path(path);
}
/* Inexact match: is there perhaps a subdirectory match? */
pos = -pos-1;
while (pos < active_nr) {
struct cache_entry *ce = active_cache[pos++];
if (strncmp(ce->name, path, len))
break;
if (ce->name[len] > '/')
break;
if (ce->name[len] < '/')
continue;
/* Subdirectory match - error out */
return error("%s: is a directory - add individual files instead", path);
}
/* No match - should we add it as a gitlink? */
if (!resolve_gitlink_ref(path, "HEAD", sha1))
return add_one_path(NULL, path, len, st);
/* Error out. */
return error("%s: is a directory - add files inside instead", path);
}
/*
* Process a regular file
*/
static int process_file(const char *path, int len, struct stat *st)
{
int pos = cache_name_pos(path, len);
struct cache_entry *ce = pos < 0 ? NULL : active_cache[pos];
if (ce && S_ISGITLINK(ntohl(ce->ce_mode)))
return error("%s is already a gitlink, not replacing", path);
return add_one_path(ce, path, len, st);
}
static int process_path(const char *path)
{
int len;
struct stat st;
/* We probably want to do this in remove_file_from_cache() and
* add_cache_entry() instead...
*/
cache_tree_invalidate_path(active_cache_tree, path);
/*
* First things first: get the stat information, to decide
* what to do about the pathname!
*/
if (lstat(path, &st) < 0)
return process_lstat_error(path, errno);
len = strlen(path);
if (S_ISDIR(st.st_mode))
return process_directory(path, len, &st);
return process_file(path, len, &st);
}
static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
const char *path, int stage)
{
int size, len, option;
struct cache_entry *ce;
if (!verify_path(path))
return -1;
len = strlen(path);
size = cache_entry_size(len);
ce = xcalloc(1, size);
hashcpy(ce->sha1, sha1);
memcpy(ce->name, path, len);
ce->ce_flags = create_ce_flags(len, stage);
ce->ce_mode = create_ce_mode(mode);
if (assume_unchanged)
ce->ce_flags |= htons(CE_VALID);
option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
if (add_cache_entry(ce, option))
return error("%s: cannot add to the index - missing --add option?",
path);
report("add '%s'", path);
cache_tree_invalidate_path(active_cache_tree, path);
return 0;
}
static void chmod_path(int flip, const char *path)
{
int pos;
struct cache_entry *ce;
unsigned int mode;
pos = cache_name_pos(path, strlen(path));
if (pos < 0)
goto fail;
ce = active_cache[pos];
mode = ntohl(ce->ce_mode);
if (!S_ISREG(mode))
goto fail;
switch (flip) {
case '+':
ce->ce_mode |= htonl(0111); break;
case '-':
ce->ce_mode &= htonl(~0111); break;
default:
goto fail;
}
cache_tree_invalidate_path(active_cache_tree, path);
active_cache_changed = 1;
report("chmod %cx '%s'", flip, path);
return;
fail:
die("git-update-index: cannot chmod %cx '%s'", flip, path);
}
static void update_one(const char *path, const char *prefix, int prefix_length)
{
const char *p = prefix_path(prefix, prefix_length, path);
if (!verify_path(p)) {
fprintf(stderr, "Ignoring path %s\n", path);
goto free_return;
}
if (mark_valid_only) {
if (mark_valid(p))
die("Unable to mark file %s", path);
goto free_return;
}
cache_tree_invalidate_path(active_cache_tree, path);
if (force_remove) {
if (remove_file_from_cache(p))
die("git-update-index: unable to remove %s", path);
report("remove '%s'", path);
goto free_return;
}
if (process_path(p))
die("Unable to process path %s", path);
report("add '%s'", path);
free_return:
if (p < path || p > path + strlen(path))
free((char*)p);
}
static void read_index_info(int line_termination)
{
struct strbuf buf;
strbuf_init(&buf);
while (1) {
char *ptr, *tab;
char *path_name;
unsigned char sha1[20];
unsigned int mode;
unsigned long ul;
int stage;
/* This reads lines formatted in one of three formats:
*
* (1) mode SP sha1 TAB path
* The first format is what "git-apply --index-info"
* reports, and used to reconstruct a partial tree
* that is used for phony merge base tree when falling
* back on 3-way merge.
*
* (2) mode SP type SP sha1 TAB path
* The second format is to stuff git-ls-tree output
* into the index file.
*
* (3) mode SP sha1 SP stage TAB path
* This format is to put higher order stages into the
* index file and matches git-ls-files --stage output.
*/
read_line(&buf, stdin, line_termination);
if (buf.eof)
break;
errno = 0;
ul = strtoul(buf.buf, &ptr, 8);
if (ptr == buf.buf || *ptr != ' '
|| errno || (unsigned int) ul != ul)
goto bad_line;
mode = ul;
tab = strchr(ptr, '\t');
if (!tab || tab - ptr < 41)
goto bad_line;
if (tab[-2] == ' ' && '0' <= tab[-1] && tab[-1] <= '3') {
stage = tab[-1] - '0';
ptr = tab + 1; /* point at the head of path */
tab = tab - 2; /* point at tail of sha1 */
}
else {
stage = 0;
ptr = tab + 1; /* point at the head of path */
}
if (get_sha1_hex(tab - 40, sha1) || tab[-41] != ' ')
goto bad_line;
if (line_termination && ptr[0] == '"')
path_name = unquote_c_style(ptr, NULL);
else
path_name = ptr;
if (!verify_path(path_name)) {
fprintf(stderr, "Ignoring path %s\n", path_name);
if (path_name != ptr)
free(path_name);
continue;
}
cache_tree_invalidate_path(active_cache_tree, path_name);
if (!mode) {
/* mode == 0 means there is no such path -- remove */
if (remove_file_from_cache(path_name))
die("git-update-index: unable to remove %s",
ptr);
}
else {
/* mode ' ' sha1 '\t' name
* ptr[-1] points at tab,
* ptr[-41] is at the beginning of sha1
*/
ptr[-42] = ptr[-1] = 0;
if (add_cacheinfo(mode, sha1, path_name, stage))
die("git-update-index: unable to update %s",
path_name);
}
if (path_name != ptr)
free(path_name);
continue;
bad_line:
die("malformed index info %s", buf.buf);
}
}
static const char update_index_usage[] =
"git-update-index [-q] [--add] [--replace] [--remove] [--unmerged] [--refresh] [--really-refresh] [--cacheinfo] [--chmod=(+|-)x] [--assume-unchanged] [--info-only] [--force-remove] [--stdin] [--index-info] [--unresolve] [--again | -g] [--ignore-missing] [-z] [--verbose] [--] <file>...";
static unsigned char head_sha1[20];
static unsigned char merge_head_sha1[20];
static struct cache_entry *read_one_ent(const char *which,
unsigned char *ent, const char *path,
int namelen, int stage)
{
unsigned mode;
unsigned char sha1[20];
int size;
struct cache_entry *ce;
if (get_tree_entry(ent, path, sha1, &mode)) {
if (which)
error("%s: not in %s branch.", path, which);
return NULL;
}
if (mode == S_IFDIR) {
if (which)
error("%s: not a blob in %s branch.", path, which);
return NULL;
}
size = cache_entry_size(namelen);
ce = xcalloc(1, size);
hashcpy(ce->sha1, sha1);
memcpy(ce->name, path, namelen);
ce->ce_flags = create_ce_flags(namelen, stage);
ce->ce_mode = create_ce_mode(mode);
return ce;
}
static int unresolve_one(const char *path)
{
int namelen = strlen(path);
int pos;
int ret = 0;
struct cache_entry *ce_2 = NULL, *ce_3 = NULL;
/* See if there is such entry in the index. */
pos = cache_name_pos(path, namelen);
if (pos < 0) {
/* If there isn't, either it is unmerged, or
* resolved as "removed" by mistake. We do not
* want to do anything in the former case.
*/
pos = -pos-1;
if (pos < active_nr) {
struct cache_entry *ce = active_cache[pos];
if (ce_namelen(ce) == namelen &&
!memcmp(ce->name, path, namelen)) {
fprintf(stderr,
"%s: skipping still unmerged path.\n",
path);
goto free_return;
}
}
}
/* Grab blobs from given path from HEAD and MERGE_HEAD,
* stuff HEAD version in stage #2,
* stuff MERGE_HEAD version in stage #3.
*/
ce_2 = read_one_ent("our", head_sha1, path, namelen, 2);
ce_3 = read_one_ent("their", merge_head_sha1, path, namelen, 3);
if (!ce_2 || !ce_3) {
ret = -1;
goto free_return;
}
if (!hashcmp(ce_2->sha1, ce_3->sha1) &&
ce_2->ce_mode == ce_3->ce_mode) {
fprintf(stderr, "%s: identical in both, skipping.\n",
path);
goto free_return;
}
cache_tree_invalidate_path(active_cache_tree, path);
remove_file_from_cache(path);
if (add_cache_entry(ce_2, ADD_CACHE_OK_TO_ADD)) {
error("%s: cannot add our version to the index.", path);
ret = -1;
goto free_return;
}
if (!add_cache_entry(ce_3, ADD_CACHE_OK_TO_ADD))
return 0;
error("%s: cannot add their version to the index.", path);
ret = -1;
free_return:
free(ce_2);
free(ce_3);
return ret;
}
static void read_head_pointers(void)
{
if (read_ref("HEAD", head_sha1))
die("No HEAD -- no initial commit yet?\n");
if (read_ref("MERGE_HEAD", merge_head_sha1)) {
fprintf(stderr, "Not in the middle of a merge.\n");
exit(0);
}
}
static int do_unresolve(int ac, const char **av,
const char *prefix, int prefix_length)
{
int i;
int err = 0;
/* Read HEAD and MERGE_HEAD; if MERGE_HEAD does not exist, we
* are not doing a merge, so exit with success status.
*/
read_head_pointers();
for (i = 1; i < ac; i++) {
const char *arg = av[i];
const char *p = prefix_path(prefix, prefix_length, arg);
err |= unresolve_one(p);
if (p < arg || p > arg + strlen(arg))
free((char*)p);
}
return err;
}
static int do_reupdate(int ac, const char **av,
const char *prefix, int prefix_length)
{
/* Read HEAD and run update-index on paths that are
* merged and already different between index and HEAD.
*/
int pos;
int has_head = 1;
const char **pathspec = get_pathspec(prefix, av + 1);
if (read_ref("HEAD", head_sha1))
/* If there is no HEAD, that means it is an initial
* commit. Update everything in the index.
*/
has_head = 0;
redo:
for (pos = 0; pos < active_nr; pos++) {
struct cache_entry *ce = active_cache[pos];
struct cache_entry *old = NULL;
int save_nr;
if (ce_stage(ce) || !ce_path_match(ce, pathspec))
continue;
if (has_head)
old = read_one_ent(NULL, head_sha1,
ce->name, ce_namelen(ce), 0);
if (old && ce->ce_mode == old->ce_mode &&
!hashcmp(ce->sha1, old->sha1)) {
free(old);
continue; /* unchanged */
}
/* Be careful. The working tree may not have the
* path anymore, in which case, under 'allow_remove',
* or worse yet 'allow_replace', active_nr may decrease.
*/
save_nr = active_nr;
update_one(ce->name + prefix_length, prefix, prefix_length);
if (save_nr != active_nr)
goto redo;
}
return 0;
}
int cmd_update_index(int argc, const char **argv, const char *prefix)
{
int i, newfd, entries, has_errors = 0, line_termination = '\n';
int allow_options = 1;
int read_from_stdin = 0;
int prefix_length = prefix ? strlen(prefix) : 0;
char set_executable_bit = 0;
unsigned int refresh_flags = 0;
int lock_error = 0;
struct lock_file *lock_file;
git_config(git_default_config);
/* We can't free this memory, it becomes part of a linked list parsed atexit() */
lock_file = xcalloc(1, sizeof(struct lock_file));
newfd = hold_locked_index(lock_file, 0);
if (newfd < 0)
lock_error = errno;
entries = read_cache();
if (entries < 0)
die("cache corrupted");
for (i = 1 ; i < argc; i++) {
const char *path = argv[i];
const char *p;
if (allow_options && *path == '-') {
if (!strcmp(path, "--")) {
allow_options = 0;
continue;
}
if (!strcmp(path, "-q")) {
refresh_flags |= REFRESH_QUIET;
continue;
}
if (!strcmp(path, "--add")) {
allow_add = 1;
continue;
}
if (!strcmp(path, "--replace")) {
allow_replace = 1;
continue;
}
if (!strcmp(path, "--remove")) {
allow_remove = 1;
continue;
}
if (!strcmp(path, "--unmerged")) {
refresh_flags |= REFRESH_UNMERGED;
continue;
}
if (!strcmp(path, "--refresh")) {
has_errors |= refresh_cache(refresh_flags);
continue;
}
if (!strcmp(path, "--really-refresh")) {
has_errors |= refresh_cache(REFRESH_REALLY | refresh_flags);
continue;
}
if (!strcmp(path, "--cacheinfo")) {
unsigned char sha1[20];
unsigned int mode;
if (i+3 >= argc)
die("git-update-index: --cacheinfo <mode> <sha1> <path>");
if (strtoul_ui(argv[i+1], 8, &mode) ||
get_sha1_hex(argv[i+2], sha1) ||
add_cacheinfo(mode, sha1, argv[i+3], 0))
die("git-update-index: --cacheinfo"
" cannot add %s", argv[i+3]);
i += 3;
continue;
}
if (!strcmp(path, "--chmod=-x") ||
!strcmp(path, "--chmod=+x")) {
if (argc <= i+1)
die("git-update-index: %s <path>", path);
set_executable_bit = path[8];
continue;
}
if (!strcmp(path, "--assume-unchanged")) {
mark_valid_only = MARK_VALID;
continue;
}
if (!strcmp(path, "--no-assume-unchanged")) {
mark_valid_only = UNMARK_VALID;
continue;
}
if (!strcmp(path, "--info-only")) {
info_only = 1;
continue;
}
if (!strcmp(path, "--force-remove")) {
force_remove = 1;
continue;
}
if (!strcmp(path, "-z")) {
line_termination = 0;
continue;
}
if (!strcmp(path, "--stdin")) {
if (i != argc - 1)
die("--stdin must be at the end");
read_from_stdin = 1;
break;
}
if (!strcmp(path, "--index-info")) {
if (i != argc - 1)
die("--index-info must be at the end");
allow_add = allow_replace = allow_remove = 1;
read_index_info(line_termination);
break;
}
if (!strcmp(path, "--unresolve")) {
has_errors = do_unresolve(argc - i, argv + i,
prefix, prefix_length);
if (has_errors)
active_cache_changed = 0;
goto finish;
}
if (!strcmp(path, "--again") || !strcmp(path, "-g")) {
has_errors = do_reupdate(argc - i, argv + i,
prefix, prefix_length);
if (has_errors)
active_cache_changed = 0;
goto finish;
}
if (!strcmp(path, "--ignore-missing")) {
refresh_flags |= REFRESH_IGNORE_MISSING;
continue;
}
if (!strcmp(path, "--verbose")) {
verbose = 1;
continue;
}
if (!strcmp(path, "-h") || !strcmp(path, "--help"))
usage(update_index_usage);
die("unknown option %s", path);
}
p = prefix_path(prefix, prefix_length, path);
update_one(p, NULL, 0);
if (set_executable_bit)
chmod_path(set_executable_bit, p);
if (p < path || p > path + strlen(path))
free((char*)p);
}
if (read_from_stdin) {
struct strbuf buf;
strbuf_init(&buf);
while (1) {
char *path_name;
const char *p;
read_line(&buf, stdin, line_termination);
if (buf.eof)
break;
if (line_termination && buf.buf[0] == '"')
path_name = unquote_c_style(buf.buf, NULL);
else
path_name = buf.buf;
p = prefix_path(prefix, prefix_length, path_name);
update_one(p, NULL, 0);
if (set_executable_bit)
chmod_path(set_executable_bit, p);
if (p < path_name || p > path_name + strlen(path_name))
free((char*) p);
if (path_name != buf.buf)
free(path_name);
}
}
finish:
if (active_cache_changed) {
if (newfd < 0) {
if (refresh_flags & REFRESH_QUIET)
exit(128);
die("unable to create '%s.lock': %s",
get_index_file(), strerror(lock_error));
}
if (write_cache(newfd, active_cache, active_nr) ||
close(newfd) || commit_locked_index(lock_file))
die("Unable to write new index file");
}
rollback_lock_file(lock_file);
return has_errors ? 1 : 0;
}