git/builtin/read-tree.c
Derrick Stolee e091228e17 sparse-checkout: update working directory in-process
The sparse-checkout builtin used 'git read-tree -mu HEAD' to update the
skip-worktree bits in the index and to update the working directory.
This extra process is overly complex, and prone to failure. It also
requires that we write our changes to the sparse-checkout file before
trying to update the index.

Remove this extra process call by creating a direct call to
unpack_trees() in the same way 'git read-tree -mu HEAD' does. In
addition, provide an in-memory list of patterns so we can avoid
reading from the sparse-checkout file. This allows us to test a
proposed change to the file before writing to it.

An earlier version of this patch included a bug when the 'set' command
failed due to the "Sparse checkout leaves no entry on working directory"
error. It would not rollback the index.lock file, so the replay of the
old sparse-checkout specification would fail. A test in t1091 now
covers that scenario.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00

271 lines
7.6 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#define USE_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
#include "config.h"
#include "lockfile.h"
#include "object.h"
#include "tree.h"
#include "tree-walk.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#include "dir.h"
#include "builtin.h"
#include "parse-options.h"
#include "resolve-undo.h"
#include "submodule.h"
#include "submodule-config.h"
static int nr_trees;
static int read_empty;
static struct tree *trees[MAX_UNPACK_TREES];
static int list_tree(struct object_id *oid)
{
struct tree *tree;
if (nr_trees >= MAX_UNPACK_TREES)
die("I cannot read more than %d trees", MAX_UNPACK_TREES);
tree = parse_tree_indirect(oid);
if (!tree)
return -1;
trees[nr_trees++] = tree;
return 0;
}
static const char * const read_tree_usage[] = {
N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>) [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
NULL
};
static int index_output_cb(const struct option *opt, const char *arg,
int unset)
{
BUG_ON_OPT_NEG(unset);
set_alternate_index_output(arg);
return 0;
}
static int exclude_per_directory_cb(const struct option *opt, const char *arg,
int unset)
{
struct dir_struct *dir;
struct unpack_trees_options *opts;
BUG_ON_OPT_NEG(unset);
opts = (struct unpack_trees_options *)opt->value;
if (opts->dir)
die("more than one --exclude-per-directory given.");
dir = xcalloc(1, sizeof(*opts->dir));
dir->flags |= DIR_SHOW_IGNORED;
dir->exclude_per_dir = arg;
opts->dir = dir;
/* We do not need to nor want to do read-directory
* here; we are merely interested in reusing the
* per directory ignore stack mechanism.
*/
return 0;
}
static void debug_stage(const char *label, const struct cache_entry *ce,
struct unpack_trees_options *o)
{
printf("%s ", label);
if (!ce)
printf("(missing)\n");
else if (ce == o->df_conflict_entry)
printf("(conflict)\n");
else
printf("%06o #%d %s %.8s\n",
ce->ce_mode, ce_stage(ce), ce->name,
oid_to_hex(&ce->oid));
}
static int debug_merge(const struct cache_entry * const *stages,
struct unpack_trees_options *o)
{
int i;
printf("* %d-way merge\n", o->merge_size);
debug_stage("index", stages[0], o);
for (i = 1; i <= o->merge_size; i++) {
char buf[24];
xsnprintf(buf, sizeof(buf), "ent#%d", i);
debug_stage(buf, stages[i], o);
}
return 0;
}
static int git_read_tree_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, "submodule.recurse"))
return git_default_submodule_config(var, value, cb);
return git_default_config(var, value, cb);
}
int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
{
int i, stage = 0;
struct object_id oid;
struct tree_desc t[MAX_UNPACK_TREES];
struct unpack_trees_options opts;
int prefix_set = 0;
struct lock_file lock_file = LOCK_INIT;
const struct option read_tree_options[] = {
{ OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
N_("write resulting index to <file>"),
PARSE_OPT_NONEG, index_output_cb },
OPT_BOOL(0, "empty", &read_empty,
N_("only empty the index")),
OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
OPT_GROUP(N_("Merging")),
OPT_BOOL('m', NULL, &opts.merge,
N_("perform a merge in addition to a read")),
OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
N_("3-way merge if no file level merging required")),
OPT_BOOL(0, "aggressive", &opts.aggressive,
N_("3-way merge in presence of adds and removes")),
OPT_BOOL(0, "reset", &opts.reset,
N_("same as -m, but discard unmerged entries")),
{ OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
N_("read the tree into the index under <subdirectory>/"),
PARSE_OPT_NONEG },
OPT_BOOL('u', NULL, &opts.update,
N_("update working tree with merge result")),
{ OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
N_("gitignore"),
N_("allow explicitly ignored files to be overwritten"),
PARSE_OPT_NONEG, exclude_per_directory_cb },
OPT_BOOL('i', NULL, &opts.index_only,
N_("don't check the working tree after merging")),
OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
N_("skip applying sparse checkout filter")),
OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
N_("debug unpack-trees")),
{ OPTION_CALLBACK, 0, "recurse-submodules", NULL,
"checkout", "control recursive updating of submodules",
PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
OPT_END()
};
memset(&opts, 0, sizeof(opts));
opts.head_idx = -1;
opts.src_index = &the_index;
opts.dst_index = &the_index;
git_config(git_read_tree_config, NULL);
argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
read_tree_usage, 0);
hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
prefix_set = opts.prefix ? 1 : 0;
if (1 < opts.merge + opts.reset + prefix_set)
die("Which one? -m, --reset, or --prefix?");
/*
* NEEDSWORK
*
* The old index should be read anyway even if we're going to
* destroy all index entries because we still need to preserve
* certain information such as index version or split-index
* mode.
*/
if (opts.reset || opts.merge || opts.prefix) {
if (read_cache_unmerged() && (opts.prefix || opts.merge))
die(_("You need to resolve your current index first"));
stage = opts.merge = 1;
}
resolve_undo_clear();
for (i = 0; i < argc; i++) {
const char *arg = argv[i];
if (get_oid(arg, &oid))
die("Not a valid object name %s", arg);
if (list_tree(&oid) < 0)
die("failed to unpack tree object %s", arg);
stage++;
}
if (!nr_trees && !read_empty && !opts.merge)
warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
else if (nr_trees > 0 && read_empty)
die("passing trees as arguments contradicts --empty");
if (1 < opts.index_only + opts.update)
die("-u and -i at the same time makes no sense");
if ((opts.update || opts.index_only) && !opts.merge)
die("%s is meaningless without -m, --reset, or --prefix",
opts.update ? "-u" : "-i");
if ((opts.dir && !opts.update))
die("--exclude-per-directory is meaningless unless -u");
if (opts.merge && !opts.index_only)
setup_work_tree();
if (opts.merge) {
switch (stage - 1) {
case 0:
die("you must specify at least one tree to merge");
break;
case 1:
opts.fn = opts.prefix ? bind_merge : oneway_merge;
break;
case 2:
opts.fn = twoway_merge;
opts.initial_checkout = is_cache_unborn();
break;
case 3:
default:
opts.fn = threeway_merge;
break;
}
if (stage - 1 >= 3)
opts.head_idx = stage - 2;
else
opts.head_idx = 1;
}
if (opts.debug_unpack)
opts.fn = debug_merge;
cache_tree_free(&active_cache_tree);
for (i = 0; i < nr_trees; i++) {
struct tree *tree = trees[i];
parse_tree(tree);
init_tree_desc(t+i, tree->buffer, tree->size);
}
if (unpack_trees(nr_trees, t, &opts))
return 128;
if (opts.debug_unpack || opts.dry_run)
return 0; /* do not write the index out */
/*
* When reading only one tree (either the most basic form,
* "-m ent" or "--reset ent" form), we can obtain a fully
* valid cache-tree because the index must match exactly
* what came from the tree.
*/
if (nr_trees == 1 && !opts.prefix)
prime_cache_tree(the_repository,
the_repository->index,
trees[0]);
if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
die("unable to write new index file");
return 0;
}