Revision d699676dda5fdf0996601006c3bac2a9c077a862 authored by Linus Torvalds on 10 August 2007, 19:31:20 UTC, committed by Junio C Hamano on 10 August 2007, 21:00:25 UTC
This trivially optimizes the two-way merge case of git-read-tree too, which affects switching branches. When you have tons and tons of files in your repository, but there are only small differences in the branches (maybe just a couple of files changed), the biggest cost of the branch switching was actually just the index calculations. This fixes it (timings for switching between the "testing" and "master" branches in the 100,000 file testing-repo-from-hell, where the branches only differ in one small file). Before: [torvalds@woody bummer]$ time git checkout master real 0m9.919s user 0m8.461s sys 0m0.264s After: [torvalds@woody bummer]$ time git checkout testing real 0m0.576s user 0m0.348s sys 0m0.228s so it's easily an order of magnitude different. This concludes the series. I think we could/should do the three-way merge too (to speed up merges), but I'm lazy. Somebody else can do it. The rule is very simple: you need to remove the old entry if: - you want to remove the file entirely - you replace it with a "merge conflict" entry (ie a non-stage-0 entry) and you can avoid removing it if you either - keep the old one - or resolve it to a new one. and these rules should all be valid for the three-way case too. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 288f072
builtin-mv.c
/*
* "git mv" builtin command
*
* Copyright (C) 2006 Johannes Schindelin
*/
#include "cache.h"
#include "builtin.h"
#include "dir.h"
#include "cache-tree.h"
#include "path-list.h"
static const char builtin_mv_usage[] =
"git-mv [-n] [-f] (<source> <destination> | [-k] <source>... <destination>)";
static const char **copy_pathspec(const char *prefix, const char **pathspec,
int count, int base_name)
{
int i;
const char **result = xmalloc((count + 1) * sizeof(const char *));
memcpy(result, pathspec, count * sizeof(const char *));
result[count] = NULL;
for (i = 0; i < count; i++) {
int length = strlen(result[i]);
if (length > 0 && result[i][length - 1] == '/') {
char *without_slash = xmalloc(length);
memcpy(without_slash, result[i], length - 1);
without_slash[length - 1] = '\0';
result[i] = without_slash;
}
if (base_name) {
const char *last_slash = strrchr(result[i], '/');
if (last_slash)
result[i] = last_slash + 1;
}
}
return get_pathspec(prefix, result);
}
static void show_list(const char *label, struct path_list *list)
{
if (list->nr > 0) {
int i;
printf("%s", label);
for (i = 0; i < list->nr; i++)
printf("%s%s", i > 0 ? ", " : "", list->items[i].path);
putchar('\n');
}
}
static const char *add_slash(const char *path)
{
int len = strlen(path);
if (path[len - 1] != '/') {
char *with_slash = xmalloc(len + 2);
memcpy(with_slash, path, len);
with_slash[len++] = '/';
with_slash[len] = 0;
return with_slash;
}
return path;
}
static struct lock_file lock_file;
int cmd_mv(int argc, const char **argv, const char *prefix)
{
int i, newfd, count;
int verbose = 0, show_only = 0, force = 0, ignore_errors = 0;
const char **source, **destination, **dest_path;
enum update_mode { BOTH = 0, WORKING_DIRECTORY, INDEX } *modes;
struct stat st;
struct path_list overwritten = {NULL, 0, 0, 0};
struct path_list src_for_dst = {NULL, 0, 0, 0};
struct path_list added = {NULL, 0, 0, 0};
struct path_list deleted = {NULL, 0, 0, 0};
struct path_list changed = {NULL, 0, 0, 0};
git_config(git_default_config);
newfd = hold_locked_index(&lock_file, 1);
if (read_cache() < 0)
die("index file corrupt");
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (arg[0] != '-')
break;
if (!strcmp(arg, "--")) {
i++;
break;
}
if (!strcmp(arg, "-n")) {
show_only = 1;
continue;
}
if (!strcmp(arg, "-f")) {
force = 1;
continue;
}
if (!strcmp(arg, "-k")) {
ignore_errors = 1;
continue;
}
usage(builtin_mv_usage);
}
count = argc - i - 1;
if (count < 1)
usage(builtin_mv_usage);
source = copy_pathspec(prefix, argv + i, count, 0);
modes = xcalloc(count, sizeof(enum update_mode));
dest_path = copy_pathspec(prefix, argv + argc - 1, 1, 0);
if (dest_path[0][0] == '\0')
/* special case: "." was normalized to "" */
destination = copy_pathspec(dest_path[0], argv + i, count, 1);
else if (!lstat(dest_path[0], &st) &&
S_ISDIR(st.st_mode)) {
dest_path[0] = add_slash(dest_path[0]);
destination = copy_pathspec(dest_path[0], argv + i, count, 1);
} else {
if (count != 1)
usage(builtin_mv_usage);
destination = dest_path;
}
/* Checking */
for (i = 0; i < count; i++) {
const char *src = source[i], *dst = destination[i];
int length, src_is_dir;
const char *bad = NULL;
if (show_only)
printf("Checking rename of '%s' to '%s'\n", src, dst);
length = strlen(src);
if (lstat(src, &st) < 0)
bad = "bad source";
else if (!strncmp(src, dst, length) &&
(dst[length] == 0 || dst[length] == '/')) {
bad = "can not move directory into itself";
} else if ((src_is_dir = S_ISDIR(st.st_mode))
&& lstat(dst, &st) == 0)
bad = "cannot move directory over file";
else if (src_is_dir) {
const char *src_w_slash = add_slash(src);
int len_w_slash = length + 1;
int first, last;
modes[i] = WORKING_DIRECTORY;
first = cache_name_pos(src_w_slash, len_w_slash);
if (first >= 0)
die ("Huh? %.*s is in index?",
len_w_slash, src_w_slash);
first = -1 - first;
for (last = first; last < active_nr; last++) {
const char *path = active_cache[last]->name;
if (strncmp(path, src_w_slash, len_w_slash))
break;
}
free((char *)src_w_slash);
if (last - first < 1)
bad = "source directory is empty";
else {
int j, dst_len;
if (last - first > 0) {
source = xrealloc(source,
(count + last - first)
* sizeof(char *));
destination = xrealloc(destination,
(count + last - first)
* sizeof(char *));
modes = xrealloc(modes,
(count + last - first)
* sizeof(enum update_mode));
}
dst = add_slash(dst);
dst_len = strlen(dst) - 1;
for (j = 0; j < last - first; j++) {
const char *path =
active_cache[first + j]->name;
source[count + j] = path;
destination[count + j] =
prefix_path(dst, dst_len,
path + length);
modes[count + j] = INDEX;
}
count += last - first;
}
} else if (lstat(dst, &st) == 0) {
bad = "destination exists";
if (force) {
/*
* only files can overwrite each other:
* check both source and destination
*/
if (S_ISREG(st.st_mode)) {
fprintf(stderr, "Warning: %s;"
" will overwrite!\n",
bad);
bad = NULL;
path_list_insert(dst, &overwritten);
} else
bad = "Cannot overwrite";
}
} else if (cache_name_pos(src, length) < 0)
bad = "not under version control";
else if (path_list_has_path(&src_for_dst, dst))
bad = "multiple sources for the same target";
else
path_list_insert(dst, &src_for_dst);
if (bad) {
if (ignore_errors) {
if (--count > 0) {
memmove(source + i, source + i + 1,
(count - i) * sizeof(char *));
memmove(destination + i,
destination + i + 1,
(count - i) * sizeof(char *));
}
} else
die ("%s, source=%s, destination=%s",
bad, src, dst);
}
}
for (i = 0; i < count; i++) {
const char *src = source[i], *dst = destination[i];
enum update_mode mode = modes[i];
if (show_only || verbose)
printf("Renaming %s to %s\n", src, dst);
if (!show_only && mode != INDEX &&
rename(src, dst) < 0 && !ignore_errors)
die ("renaming %s failed: %s", src, strerror(errno));
if (mode == WORKING_DIRECTORY)
continue;
if (cache_name_pos(src, strlen(src)) >= 0) {
path_list_insert(src, &deleted);
/* destination can be a directory with 1 file inside */
if (path_list_has_path(&overwritten, dst))
path_list_insert(dst, &changed);
else
path_list_insert(dst, &added);
} else
path_list_insert(dst, &added);
}
if (show_only) {
show_list("Changed : ", &changed);
show_list("Adding : ", &added);
show_list("Deleting : ", &deleted);
} else {
for (i = 0; i < changed.nr; i++) {
const char *path = changed.items[i].path;
int j = cache_name_pos(path, strlen(path));
struct cache_entry *ce = active_cache[j];
if (j < 0)
die ("Huh? Cache entry for %s unknown?", path);
refresh_cache_entry(ce, 0);
}
for (i = 0; i < added.nr; i++) {
const char *path = added.items[i].path;
add_file_to_cache(path, verbose);
}
for (i = 0; i < deleted.nr; i++) {
const char *path = deleted.items[i].path;
remove_file_from_cache(path);
cache_tree_invalidate_path(active_cache_tree, path);
}
if (active_cache_changed) {
if (write_cache(newfd, active_cache, active_nr) ||
close(newfd) ||
commit_locked_index(&lock_file))
die("Unable to write new index file");
}
}
return 0;
}
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