1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-06-10 21:36:15 +02:00
git/builtin/sparse-checkout.c

679 lines
16 KiB
C
Raw Normal View History

#include "builtin.h"
#include "config.h"
#include "dir.h"
#include "parse-options.h"
#include "pathspec.h"
#include "repository.h"
#include "run-command.h"
#include "strbuf.h"
#include "string-list.h"
#include "cache.h"
#include "cache-tree.h"
#include "lockfile.h"
#include "resolve-undo.h"
#include "unpack-trees.h"
#include "wt-status.h"
#include "quote.h"
#include "sparse-index.h"
static const char *empty_base = "";
static char const * const builtin_sparse_checkout_usage[] = {
N_("git sparse-checkout (init|list|set|add|reapply|disable) <options>"),
NULL
};
static void write_patterns_to_file(FILE *fp, struct pattern_list *pl)
{
int i;
for (i = 0; i < pl->nr; i++) {
struct path_pattern *p = pl->patterns[i];
if (p->flags & PATTERN_FLAG_NEGATIVE)
fprintf(fp, "!");
fprintf(fp, "%s", p->pattern);
if (p->flags & PATTERN_FLAG_MUSTBEDIR)
fprintf(fp, "/");
fprintf(fp, "\n");
}
}
static char const * const builtin_sparse_checkout_list_usage[] = {
N_("git sparse-checkout list"),
NULL
};
static int sparse_checkout_list(int argc, const char **argv)
{
static struct option builtin_sparse_checkout_list_options[] = {
OPT_END(),
};
struct pattern_list pl;
char *sparse_filename;
int res;
argc = parse_options(argc, argv, NULL,
builtin_sparse_checkout_list_options,
builtin_sparse_checkout_list_usage, 0);
memset(&pl, 0, sizeof(pl));
pl.use_cone_patterns = core_sparse_checkout_cone;
sparse_filename = get_sparse_checkout_filename();
res = add_patterns_from_file_to_list(sparse_filename, "", 0, &pl, NULL, 0);
free(sparse_filename);
if (res < 0) {
warning(_("this worktree is not sparse (sparse-checkout file may not exist)"));
return 0;
}
if (pl.use_cone_patterns) {
int i;
struct pattern_entry *pe;
struct hashmap_iter iter;
struct string_list sl = STRING_LIST_INIT_DUP;
hashmap_for_each_entry(&pl.recursive_hashmap, &iter, pe, ent) {
/* pe->pattern starts with "/", skip it */
string_list_insert(&sl, pe->pattern + 1);
}
string_list_sort(&sl);
for (i = 0; i < sl.nr; i++) {
quote_c_style(sl.items[i].string, NULL, stdout, 0);
printf("\n");
}
return 0;
}
write_patterns_to_file(stdout, &pl);
clear_pattern_list(&pl);
return 0;
}
static int update_working_directory(struct pattern_list *pl)
{
enum update_sparsity_result result;
struct unpack_trees_options o;
struct lock_file lock_file = LOCK_INIT;
struct repository *r = the_repository;
sparse-checkout: avoid staging deletions of all files sparse-checkout's purpose is to update the working tree to have it reflect a subset of the tracked files. As such, it shouldn't be switching branches, making commits, downloading or uploading data, or staging or unstaging changes. Other than updating the worktree, the only thing sparse-checkout should touch is the SKIP_WORKTREE bit of the index. In particular, this sets up a nice invariant: running sparse-checkout will never change the status of any file in `git status` (reflecting the fact that we only set the SKIP_WORKTREE bit if the file is safe to delete, i.e. if the file is unmodified). Traditionally, we did a _really_ bad job with this goal. The predecessor to sparse-checkout involved manual editing of .git/info/sparse-checkout and running `git read-tree -mu HEAD`. That command would stage and unstage changes and overwrite dirty changes in the working tree. The initial implementation of the sparse-checkout command was no better; it simply invoked `git read-tree -mu HEAD` as a subprocess and had the same caveats, though this issue came up repeatedly in review comments and workarounds for the problems were put in place before the feature was merged[1, 2, 3, 4, 5, 6; especially see 4 & 6]. [1] https://lore.kernel.org/git/CABPp-BFT9A5n=_bx5LsjCvbogqwSjiwgr5amcjgbU1iAk4KLJg@mail.gmail.com/ [2] https://lore.kernel.org/git/CABPp-BEmwSwg4tgJg6nVG8a3Hpn_g-=ZjApZF4EiJO+qVgu4uw@mail.gmail.com/ [3] https://lore.kernel.org/git/CABPp-BFV7TA0qwZCQpHCqx9N+JifyRyuBQ-pZ_oGfe-NOgyh7A@mail.gmail.com/ [4] https://lore.kernel.org/git/CABPp-BHYCCD+Vx5fq35jH82eHc1-P53Lz_aGNpHJNcx9kg2K-A@mail.gmail.com/ [5] https://lore.kernel.org/git/CABPp-BF+JWYZfDqp2Tn4AEKVp4b0YMA=Mbz4Nz62D-gGgiduYQ@mail.gmail.com/ [6] https://lore.kernel.org/git/20191121163706.GV23183@szeder.dev/ However, these workarounds, in addition to disabling the feature in a number of important cases, also missed one special case. I'll get back to it later. In the 2.27.0 cycle, the disabling of the feature was lifted by finally replacing the internal equivalent of `git read-tree -mu HEAD` with something that did what we wanted: the new update_sparsity() function in unpack-trees.c that only ever updates SKIP_WORKTREE bits in the index and updates the working tree to match. This new function handles all the cases that were problematic for the old implementation, except that it breaks the same special case that avoided the workarounds of the old implementation, but broke it in a different way. So...that brings us to the special case: a git clone performed with --no-checkout. As per the meaning of the flag, --no-checkout does not check out any branch, with the implication that you aren't on one and need to switch to one after the clone. Implementationally, HEAD is still set (so in some sense you are partially on a branch), but * the index is "unborn" (non-existent) * there are no files in the working tree (other than .git/) * the next time git switch (or git checkout) is run it will run unpack_trees with `initial_checkout` flag set to true. It is not until you run, e.g. `git switch <somebranch>` that the index will be written and files in the working tree populated. With this special --no-checkout case, the traditional `read-tree -mu HEAD` behavior would have done the equivalent of acting like checkout -- switch to the default branch (HEAD), write out an index that matches HEAD, and update the working tree to match. This special case slipped through the avoid-making-changes checks in the original sparse-checkout command and thus continued there. After update_sparsity() was introduced and used (see commit f56f31af03 ("sparse-checkout: use new update_sparsity() function", 2020-03-27)), the behavior for the --no-checkout case changed: Due to git's auto-vivification of an empty in-memory index (see do_read_index() and note that `must_exist` is false), and due to sparse-checkout's update_working_directory() code to always write out the index after it was done, we got a new bug. That made it so that sparse-checkout would switch the repository from a clone with an "unborn" index (i.e. still needing an initial_checkout), to one that had a recorded index with no entries. Thus, instead of all the files appearing deleted in `git status` being known to git as a special artifact of not yet being on a branch, our recording of an empty index made it suddenly look to git as though it was definitely on a branch with ALL files staged for deletion! A subsequent checkout or switch then had to contend with the fact that it wasn't on an initial_checkout but had a bunch of staged deletions. Make sure that sparse-checkout changes nothing in the index other than the SKIP_WORKTREE bit; in particular, when the index is unborn we do not have any branch checked out so there is no sparsification or de-sparsification work to do. Simply return from update_working_directory() early. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-05 04:41:39 +02:00
/* If no branch has been checked out, there are no updates to make. */
if (is_index_unborn(r->index))
return UPDATE_SPARSITY_SUCCESS;
r->index->sparse_checkout_patterns = pl;
memset(&o, 0, sizeof(o));
o.verbose_update = isatty(2);
o.update = 1;
o.head_idx = -1;
o.src_index = r->index;
o.dst_index = r->index;
o.skip_sparse_checkout = 0;
o.pl = pl;
setup_work_tree();
repo_hold_locked_index(r, &lock_file, LOCK_DIE_ON_ERROR);
setup_unpack_trees_porcelain(&o, "sparse-checkout");
result = update_sparsity(&o);
clear_unpack_trees_porcelain(&o);
if (result == UPDATE_SPARSITY_WARNINGS)
/*
* We don't do any special handling of warnings from untracked
* files in the way or dirty entries that can't be removed.
*/
result = UPDATE_SPARSITY_SUCCESS;
if (result == UPDATE_SPARSITY_SUCCESS)
write_locked_index(r->index, &lock_file, COMMIT_LOCK);
else
rollback_lock_file(&lock_file);
r->index->sparse_checkout_patterns = NULL;
return result;
}
static char *escaped_pattern(char *pattern)
{
char *p = pattern;
struct strbuf final = STRBUF_INIT;
while (*p) {
if (is_glob_special(*p))
strbuf_addch(&final, '\\');
strbuf_addch(&final, *p);
p++;
}
return strbuf_detach(&final, NULL);
}
static void write_cone_to_file(FILE *fp, struct pattern_list *pl)
{
int i;
struct pattern_entry *pe;
struct hashmap_iter iter;
struct string_list sl = STRING_LIST_INIT_DUP;
struct strbuf parent_pattern = STRBUF_INIT;
hashmap_for_each_entry(&pl->parent_hashmap, &iter, pe, ent) {
if (hashmap_get_entry(&pl->recursive_hashmap, pe, ent, NULL))
continue;
if (!hashmap_contains_parent(&pl->recursive_hashmap,
pe->pattern,
&parent_pattern))
string_list_insert(&sl, pe->pattern);
}
string_list_sort(&sl);
string_list_remove_duplicates(&sl, 0);
fprintf(fp, "/*\n!/*/\n");
for (i = 0; i < sl.nr; i++) {
char *pattern = escaped_pattern(sl.items[i].string);
if (strlen(pattern))
fprintf(fp, "%s/\n!%s/*/\n", pattern, pattern);
free(pattern);
}
string_list_clear(&sl, 0);
hashmap_for_each_entry(&pl->recursive_hashmap, &iter, pe, ent) {
if (!hashmap_contains_parent(&pl->recursive_hashmap,
pe->pattern,
&parent_pattern))
string_list_insert(&sl, pe->pattern);
}
strbuf_release(&parent_pattern);
string_list_sort(&sl);
string_list_remove_duplicates(&sl, 0);
for (i = 0; i < sl.nr; i++) {
char *pattern = escaped_pattern(sl.items[i].string);
fprintf(fp, "%s/\n", pattern);
free(pattern);
}
}
static int write_patterns_and_update(struct pattern_list *pl)
{
char *sparse_filename;
FILE *fp;
int fd;
struct lock_file lk = LOCK_INIT;
int result;
sparse_filename = get_sparse_checkout_filename();
if (safe_create_leading_directories(sparse_filename))
die(_("failed to create directory for sparse-checkout file"));
fd = hold_lock_file_for_update(&lk, sparse_filename,
LOCK_DIE_ON_ERROR);
result = update_working_directory(pl);
if (result) {
rollback_lock_file(&lk);
free(sparse_filename);
clear_pattern_list(pl);
update_working_directory(NULL);
return result;
}
fp = xfdopen(fd, "w");
if (core_sparse_checkout_cone)
write_cone_to_file(fp, pl);
else
write_patterns_to_file(fp, pl);
fflush(fp);
commit_lock_file(&lk);
free(sparse_filename);
clear_pattern_list(pl);
return 0;
}
enum sparse_checkout_mode {
MODE_NO_PATTERNS = 0,
MODE_ALL_PATTERNS = 1,
MODE_CONE_PATTERNS = 2,
};
static int set_config(enum sparse_checkout_mode mode)
{
const char *config_path;
if (upgrade_repository_format(1) < 0)
die(_("unable to upgrade repository format to enable worktreeConfig"));
if (git_config_set_gently("extensions.worktreeConfig", "true")) {
error(_("failed to set extensions.worktreeConfig setting"));
return 1;
}
config_path = git_path("config.worktree");
git_config_set_in_file_gently(config_path,
"core.sparseCheckout",
mode ? "true" : NULL);
git_config_set_in_file_gently(config_path,
"core.sparseCheckoutCone",
mode == MODE_CONE_PATTERNS ? "true" : NULL);
if (mode == MODE_NO_PATTERNS)
set_sparse_index_config(the_repository, 0);
return 0;
}
static char const * const builtin_sparse_checkout_init_usage[] = {
N_("git sparse-checkout init [--cone] [--[no-]sparse-index]"),
NULL
};
static struct sparse_checkout_init_opts {
int cone_mode;
int sparse_index;
} init_opts;
static int sparse_checkout_init(int argc, const char **argv)
{
struct pattern_list pl;
char *sparse_filename;
int res;
struct object_id oid;
int mode;
struct strbuf pattern = STRBUF_INIT;
static struct option builtin_sparse_checkout_init_options[] = {
OPT_BOOL(0, "cone", &init_opts.cone_mode,
N_("initialize the sparse-checkout in cone mode")),
OPT_BOOL(0, "sparse-index", &init_opts.sparse_index,
N_("toggle the use of a sparse index")),
OPT_END(),
};
repo_read_index(the_repository);
init_opts.sparse_index = -1;
argc = parse_options(argc, argv, NULL,
builtin_sparse_checkout_init_options,
builtin_sparse_checkout_init_usage, 0);
if (init_opts.cone_mode) {
mode = MODE_CONE_PATTERNS;
core_sparse_checkout_cone = 1;
} else
mode = MODE_ALL_PATTERNS;
if (set_config(mode))
return 1;
memset(&pl, 0, sizeof(pl));
sparse_filename = get_sparse_checkout_filename();
res = add_patterns_from_file_to_list(sparse_filename, "", 0, &pl, NULL, 0);
if (init_opts.sparse_index >= 0) {
if (set_sparse_index_config(the_repository, init_opts.sparse_index) < 0)
die(_("failed to modify sparse-index config"));
/* force an index rewrite */
repo_read_index(the_repository);
the_repository->index->updated_workdir = 1;
}
core_apply_sparse_checkout = 1;
/* If we already have a sparse-checkout file, use it. */
if (res >= 0) {
free(sparse_filename);
return update_working_directory(NULL);
}
if (get_oid("HEAD", &oid)) {
FILE *fp;
/* assume we are in a fresh repo, but update the sparse-checkout file */
fp = xfopen(sparse_filename, "w");
if (!fp)
die(_("failed to open '%s'"), sparse_filename);
free(sparse_filename);
fprintf(fp, "/*\n!/*/\n");
fclose(fp);
return 0;
}
strbuf_addstr(&pattern, "/*");
add_pattern(strbuf_detach(&pattern, NULL), empty_base, 0, &pl, 0);
strbuf_addstr(&pattern, "!/*/");
add_pattern(strbuf_detach(&pattern, NULL), empty_base, 0, &pl, 0);
pl.use_cone_patterns = init_opts.cone_mode;
return write_patterns_and_update(&pl);
}
static void insert_recursive_pattern(struct pattern_list *pl, struct strbuf *path)
{
struct pattern_entry *e = xmalloc(sizeof(*e));
e->patternlen = path->len;
e->pattern = strbuf_detach(path, NULL);
hashmap_entry_init(&e->ent, fspathhash(e->pattern));
hashmap_add(&pl->recursive_hashmap, &e->ent);
while (e->patternlen) {
char *slash = strrchr(e->pattern, '/');
char *oldpattern = e->pattern;
size_t newlen;
if (slash == e->pattern)
break;
newlen = slash - e->pattern;
e = xmalloc(sizeof(struct pattern_entry));
e->patternlen = newlen;
e->pattern = xstrndup(oldpattern, newlen);
hashmap_entry_init(&e->ent, fspathhash(e->pattern));
if (!hashmap_get_entry(&pl->parent_hashmap, e, ent, NULL))
hashmap_add(&pl->parent_hashmap, &e->ent);
}
}
static void strbuf_to_cone_pattern(struct strbuf *line, struct pattern_list *pl)
{
strbuf_trim(line);
strbuf_trim_trailing_dir_sep(line);
if (strbuf_normalize_path(line))
die(_("could not normalize path %s"), line->buf);
if (!line->len)
return;
if (line->buf[0] != '/')
strbuf_insertstr(line, 0, "/");
insert_recursive_pattern(pl, line);
}
static char const * const builtin_sparse_checkout_set_usage[] = {
N_("git sparse-checkout (set|add) (--stdin | <patterns>)"),
NULL
};
static struct sparse_checkout_set_opts {
int use_stdin;
} set_opts;
static void add_patterns_from_input(struct pattern_list *pl,
int argc, const char **argv)
{
int i;
if (core_sparse_checkout_cone) {
struct strbuf line = STRBUF_INIT;
hashmap_init(&pl->recursive_hashmap, pl_hashmap_cmp, NULL, 0);
hashmap_init(&pl->parent_hashmap, pl_hashmap_cmp, NULL, 0);
pl->use_cone_patterns = 1;
if (set_opts.use_stdin) {
struct strbuf unquoted = STRBUF_INIT;
while (!strbuf_getline(&line, stdin)) {
if (line.buf[0] == '"') {
strbuf_reset(&unquoted);
if (unquote_c_style(&unquoted, line.buf, NULL))
die(_("unable to unquote C-style string '%s'"),
line.buf);
strbuf_swap(&unquoted, &line);
}
strbuf_to_cone_pattern(&line, pl);
}
strbuf_release(&unquoted);
} else {
for (i = 0; i < argc; i++) {
strbuf_setlen(&line, 0);
strbuf_addstr(&line, argv[i]);
strbuf_to_cone_pattern(&line, pl);
}
}
} else {
if (set_opts.use_stdin) {
struct strbuf line = STRBUF_INIT;
while (!strbuf_getline(&line, stdin)) {
size_t len;
char *buf = strbuf_detach(&line, &len);
add_pattern(buf, empty_base, 0, pl, 0);
}
} else {
for (i = 0; i < argc; i++)
add_pattern(argv[i], empty_base, 0, pl, 0);
}
}
}
enum modify_type {
REPLACE,
ADD,
};
static void add_patterns_cone_mode(int argc, const char **argv,
struct pattern_list *pl)
{
struct strbuf buffer = STRBUF_INIT;
struct pattern_entry *pe;
struct hashmap_iter iter;
struct pattern_list existing;
char *sparse_filename = get_sparse_checkout_filename();
add_patterns_from_input(pl, argc, argv);
memset(&existing, 0, sizeof(existing));
existing.use_cone_patterns = core_sparse_checkout_cone;
if (add_patterns_from_file_to_list(sparse_filename, "", 0,
&existing, NULL, 0))
die(_("unable to load existing sparse-checkout patterns"));
free(sparse_filename);
hashmap_for_each_entry(&existing.recursive_hashmap, &iter, pe, ent) {
if (!hashmap_contains_parent(&pl->recursive_hashmap,
pe->pattern, &buffer) ||
!hashmap_contains_parent(&pl->parent_hashmap,
pe->pattern, &buffer)) {
strbuf_reset(&buffer);
strbuf_addstr(&buffer, pe->pattern);
insert_recursive_pattern(pl, &buffer);
}
}
clear_pattern_list(&existing);
strbuf_release(&buffer);
}
static void add_patterns_literal(int argc, const char **argv,
struct pattern_list *pl)
{
char *sparse_filename = get_sparse_checkout_filename();
if (add_patterns_from_file_to_list(sparse_filename, "", 0,
pl, NULL, 0))
die(_("unable to load existing sparse-checkout patterns"));
free(sparse_filename);
add_patterns_from_input(pl, argc, argv);
}
static int modify_pattern_list(int argc, const char **argv, enum modify_type m)
{
int result;
int changed_config = 0;
struct pattern_list *pl = xcalloc(1, sizeof(*pl));
switch (m) {
case ADD:
if (core_sparse_checkout_cone)
add_patterns_cone_mode(argc, argv, pl);
else
add_patterns_literal(argc, argv, pl);
break;
case REPLACE:
add_patterns_from_input(pl, argc, argv);
break;
}
if (!core_apply_sparse_checkout) {
set_config(MODE_ALL_PATTERNS);
core_apply_sparse_checkout = 1;
changed_config = 1;
}
result = write_patterns_and_update(pl);
if (result && changed_config)
set_config(MODE_NO_PATTERNS);
clear_pattern_list(pl);
free(pl);
return result;
}
static int sparse_checkout_set(int argc, const char **argv, const char *prefix,
enum modify_type m)
{
static struct option builtin_sparse_checkout_set_options[] = {
OPT_BOOL(0, "stdin", &set_opts.use_stdin,
N_("read patterns from standard in")),
OPT_END(),
};
repo_read_index(the_repository);
argc = parse_options(argc, argv, prefix,
builtin_sparse_checkout_set_options,
builtin_sparse_checkout_set_usage,
PARSE_OPT_KEEP_UNKNOWN);
return modify_pattern_list(argc, argv, m);
}
static char const * const builtin_sparse_checkout_reapply_usage[] = {
N_("git sparse-checkout reapply"),
NULL
};
static int sparse_checkout_reapply(int argc, const char **argv)
{
static struct option builtin_sparse_checkout_reapply_options[] = {
OPT_END(),
};
argc = parse_options(argc, argv, NULL,
builtin_sparse_checkout_reapply_options,
builtin_sparse_checkout_reapply_usage, 0);
repo_read_index(the_repository);
return update_working_directory(NULL);
}
static char const * const builtin_sparse_checkout_disable_usage[] = {
N_("git sparse-checkout disable"),
NULL
};
static int sparse_checkout_disable(int argc, const char **argv)
{
static struct option builtin_sparse_checkout_disable_options[] = {
OPT_END(),
};
struct pattern_list pl;
struct strbuf match_all = STRBUF_INIT;
argc = parse_options(argc, argv, NULL,
builtin_sparse_checkout_disable_options,
builtin_sparse_checkout_disable_usage, 0);
repo_read_index(the_repository);
memset(&pl, 0, sizeof(pl));
hashmap_init(&pl.recursive_hashmap, pl_hashmap_cmp, NULL, 0);
hashmap_init(&pl.parent_hashmap, pl_hashmap_cmp, NULL, 0);
pl.use_cone_patterns = 0;
core_apply_sparse_checkout = 1;
strbuf_addstr(&match_all, "/*");
add_pattern(strbuf_detach(&match_all, NULL), empty_base, 0, &pl, 0);
prepare_repo_settings(the_repository);
the_repository->settings.sparse_index = 0;
if (update_working_directory(&pl))
die(_("error while refreshing working directory"));
clear_pattern_list(&pl);
return set_config(MODE_NO_PATTERNS);
}
int cmd_sparse_checkout(int argc, const char **argv, const char *prefix)
{
static struct option builtin_sparse_checkout_options[] = {
OPT_END(),
};
if (argc == 2 && !strcmp(argv[1], "-h"))
usage_with_options(builtin_sparse_checkout_usage,
builtin_sparse_checkout_options);
argc = parse_options(argc, argv, prefix,
builtin_sparse_checkout_options,
builtin_sparse_checkout_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
git_config(git_default_config, NULL);
if (argc > 0) {
if (!strcmp(argv[0], "list"))
return sparse_checkout_list(argc, argv);
if (!strcmp(argv[0], "init"))
return sparse_checkout_init(argc, argv);
if (!strcmp(argv[0], "set"))
return sparse_checkout_set(argc, argv, prefix, REPLACE);
if (!strcmp(argv[0], "add"))
return sparse_checkout_set(argc, argv, prefix, ADD);
if (!strcmp(argv[0], "reapply"))
return sparse_checkout_reapply(argc, argv);
if (!strcmp(argv[0], "disable"))
return sparse_checkout_disable(argc, argv);
}
usage_with_options(builtin_sparse_checkout_usage,
builtin_sparse_checkout_options);
}