git/builtin/reset.c
Junio C Hamano 788cef81d4 Merge branch 'nd/split-index'
An experiment to use two files (the base file and incremental
changes relative to it) to represent the index to reduce I/O cost
of rewriting a large index when only small part of the working tree
changes.

* nd/split-index: (32 commits)
  t1700: new tests for split-index mode
  t2104: make sure split index mode is off for the version test
  read-cache: force split index mode with GIT_TEST_SPLIT_INDEX
  read-tree: note about dropping split-index mode or index version
  read-tree: force split-index mode off on --index-output
  rev-parse: add --shared-index-path to get shared index path
  update-index --split-index: do not split if $GIT_DIR is read only
  update-index: new options to enable/disable split index mode
  split-index: strip pathname of on-disk replaced entries
  split-index: do not invalidate cache-tree at read time
  split-index: the reading part
  split-index: the writing part
  read-cache: mark updated entries for split index
  read-cache: save deleted entries in split index
  read-cache: mark new entries for split index
  read-cache: split-index mode
  read-cache: save index SHA-1 after reading
  entry.c: update cache_changed if refresh_cache is set in checkout_entry()
  cache-tree: mark istate->cache_changed on prime_cache_tree()
  cache-tree: mark istate->cache_changed on cache tree update
  ...
2014-07-16 11:25:40 -07:00

389 lines
11 KiB
C

/*
* "git reset" builtin command
*
* Copyright (c) 2007 Carlos Rica
*
* Based on git-reset.sh, which is
*
* Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
*/
#include "builtin.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "run-command.h"
#include "refs.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"
#include "branch.h"
#include "parse-options.h"
#include "unpack-trees.h"
#include "cache-tree.h"
static const char * const git_reset_usage[] = {
N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
N_("git reset [-q] <tree-ish> [--] <paths>..."),
N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
NULL
};
enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
static const char *reset_type_names[] = {
N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
};
static inline int is_merge(void)
{
return !access(git_path("MERGE_HEAD"), F_OK);
}
static int reset_index(const unsigned char *sha1, int reset_type, int quiet)
{
int nr = 1;
struct tree_desc desc[2];
struct tree *tree;
struct unpack_trees_options opts;
memset(&opts, 0, sizeof(opts));
opts.head_idx = 1;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.fn = oneway_merge;
opts.merge = 1;
if (!quiet)
opts.verbose_update = 1;
switch (reset_type) {
case KEEP:
case MERGE:
opts.update = 1;
break;
case HARD:
opts.update = 1;
/* fallthrough */
default:
opts.reset = 1;
}
read_cache_unmerged();
if (reset_type == KEEP) {
unsigned char head_sha1[20];
if (get_sha1("HEAD", head_sha1))
return error(_("You do not have a valid HEAD."));
if (!fill_tree_descriptor(desc, head_sha1))
return error(_("Failed to find tree of HEAD."));
nr++;
opts.fn = twoway_merge;
}
if (!fill_tree_descriptor(desc + nr - 1, sha1))
return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
if (unpack_trees(nr, desc, &opts))
return -1;
if (reset_type == MIXED || reset_type == HARD) {
tree = parse_tree_indirect(sha1);
prime_cache_tree(&the_index, tree);
}
return 0;
}
static void print_new_head_line(struct commit *commit)
{
const char *hex, *body;
const char *msg;
hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
printf(_("HEAD is now at %s"), hex);
msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
body = strstr(msg, "\n\n");
if (body) {
const char *eol;
size_t len;
body += 2;
eol = strchr(body, '\n');
len = eol ? eol - body : strlen(body);
printf(" %.*s\n", (int) len, body);
}
else
printf("\n");
unuse_commit_buffer(commit, msg);
}
static void update_index_from_diff(struct diff_queue_struct *q,
struct diff_options *opt, void *data)
{
int i;
int intent_to_add = *(int *)data;
for (i = 0; i < q->nr; i++) {
struct diff_filespec *one = q->queue[i]->one;
int is_missing = !(one->mode && !is_null_sha1(one->sha1));
struct cache_entry *ce;
if (is_missing && !intent_to_add) {
remove_file_from_cache(one->path);
continue;
}
ce = make_cache_entry(one->mode, one->sha1, one->path,
0, 0);
if (!ce)
die(_("make_cache_entry failed for path '%s'"),
one->path);
if (is_missing) {
ce->ce_flags |= CE_INTENT_TO_ADD;
set_object_name_for_intent_to_add_entry(ce);
}
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
}
}
static int read_from_tree(const struct pathspec *pathspec,
unsigned char *tree_sha1,
int intent_to_add)
{
struct diff_options opt;
memset(&opt, 0, sizeof(opt));
copy_pathspec(&opt.pathspec, pathspec);
opt.output_format = DIFF_FORMAT_CALLBACK;
opt.format_callback = update_index_from_diff;
opt.format_callback_data = &intent_to_add;
if (do_diff_cache(tree_sha1, &opt))
return 1;
diffcore_std(&opt);
diff_flush(&opt);
free_pathspec(&opt.pathspec);
return 0;
}
static void set_reflog_message(struct strbuf *sb, const char *action,
const char *rev)
{
const char *rla = getenv("GIT_REFLOG_ACTION");
strbuf_reset(sb);
if (rla)
strbuf_addf(sb, "%s: %s", rla, action);
else if (rev)
strbuf_addf(sb, "reset: moving to %s", rev);
else
strbuf_addf(sb, "reset: %s", action);
}
static void die_if_unmerged_cache(int reset_type)
{
if (is_merge() || unmerged_cache())
die(_("Cannot do a %s reset in the middle of a merge."),
_(reset_type_names[reset_type]));
}
static void parse_args(struct pathspec *pathspec,
const char **argv, const char *prefix,
int patch_mode,
const char **rev_ret)
{
const char *rev = "HEAD";
unsigned char unused[20];
/*
* Possible arguments are:
*
* git reset [-opts] [<rev>]
* git reset [-opts] <tree> [<paths>...]
* git reset [-opts] <tree> -- [<paths>...]
* git reset [-opts] -- [<paths>...]
* git reset [-opts] <paths>...
*
* At this point, argv points immediately after [-opts].
*/
if (argv[0]) {
if (!strcmp(argv[0], "--")) {
argv++; /* reset to HEAD, possibly with paths */
} else if (argv[1] && !strcmp(argv[1], "--")) {
rev = argv[0];
argv += 2;
}
/*
* Otherwise, argv[0] could be either <rev> or <paths> and
* has to be unambiguous. If there is a single argument, it
* can not be a tree
*/
else if ((!argv[1] && !get_sha1_committish(argv[0], unused)) ||
(argv[1] && !get_sha1_treeish(argv[0], unused))) {
/*
* Ok, argv[0] looks like a commit/tree; it should not
* be a filename.
*/
verify_non_filename(prefix, argv[0]);
rev = *argv++;
} else {
/* Otherwise we treat this as a filename */
verify_filename(prefix, argv[0], 1);
}
}
*rev_ret = rev;
if (read_cache() < 0)
die(_("index file corrupt"));
parse_pathspec(pathspec, 0,
PATHSPEC_PREFER_FULL |
PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP |
(patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
prefix, argv);
}
static int reset_refs(const char *rev, const unsigned char *sha1)
{
int update_ref_status;
struct strbuf msg = STRBUF_INIT;
unsigned char *orig = NULL, sha1_orig[20],
*old_orig = NULL, sha1_old_orig[20];
if (!get_sha1("ORIG_HEAD", sha1_old_orig))
old_orig = sha1_old_orig;
if (!get_sha1("HEAD", sha1_orig)) {
orig = sha1_orig;
set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
UPDATE_REFS_MSG_ON_ERR);
} else if (old_orig)
delete_ref("ORIG_HEAD", old_orig, 0);
set_reflog_message(&msg, "updating HEAD", rev);
update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0,
UPDATE_REFS_MSG_ON_ERR);
strbuf_release(&msg);
return update_ref_status;
}
int cmd_reset(int argc, const char **argv, const char *prefix)
{
int reset_type = NONE, update_ref_status = 0, quiet = 0;
int patch_mode = 0, unborn;
const char *rev;
unsigned char sha1[20];
struct pathspec pathspec;
int intent_to_add = 0;
const struct option options[] = {
OPT__QUIET(&quiet, N_("be quiet, only report errors")),
OPT_SET_INT(0, "mixed", &reset_type,
N_("reset HEAD and index"), MIXED),
OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
OPT_SET_INT(0, "hard", &reset_type,
N_("reset HEAD, index and working tree"), HARD),
OPT_SET_INT(0, "merge", &reset_type,
N_("reset HEAD, index and working tree"), MERGE),
OPT_SET_INT(0, "keep", &reset_type,
N_("reset HEAD but keep local changes"), KEEP),
OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
OPT_BOOL('N', "intent-to-add", &intent_to_add,
N_("record only the fact that removed paths will be added later")),
OPT_END()
};
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix, options, git_reset_usage,
PARSE_OPT_KEEP_DASHDASH);
parse_args(&pathspec, argv, prefix, patch_mode, &rev);
unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", sha1);
if (unborn) {
/* reset on unborn branch: treat as reset to empty tree */
hashcpy(sha1, EMPTY_TREE_SHA1_BIN);
} else if (!pathspec.nr) {
struct commit *commit;
if (get_sha1_committish(rev, sha1))
die(_("Failed to resolve '%s' as a valid revision."), rev);
commit = lookup_commit_reference(sha1);
if (!commit)
die(_("Could not parse object '%s'."), rev);
hashcpy(sha1, commit->object.sha1);
} else {
struct tree *tree;
if (get_sha1_treeish(rev, sha1))
die(_("Failed to resolve '%s' as a valid tree."), rev);
tree = parse_tree_indirect(sha1);
if (!tree)
die(_("Could not parse object '%s'."), rev);
hashcpy(sha1, tree->object.sha1);
}
if (patch_mode) {
if (reset_type != NONE)
die(_("--patch is incompatible with --{hard,mixed,soft}"));
return run_add_interactive(rev, "--patch=reset", &pathspec);
}
/* git reset tree [--] paths... can be used to
* load chosen paths from the tree into the index without
* affecting the working tree nor HEAD. */
if (pathspec.nr) {
if (reset_type == MIXED)
warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
else if (reset_type != NONE)
die(_("Cannot do %s reset with paths."),
_(reset_type_names[reset_type]));
}
if (reset_type == NONE)
reset_type = MIXED; /* by default */
if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
setup_work_tree();
if (reset_type == MIXED && is_bare_repository())
die(_("%s reset is not allowed in a bare repository"),
_(reset_type_names[reset_type]));
if (intent_to_add && reset_type != MIXED)
die(_("-N can only be used with --mixed"));
/* Soft reset does not touch the index file nor the working tree
* at all, but requires them in a good order. Other resets reset
* the index file to the tree object we are switching to. */
if (reset_type == SOFT || reset_type == KEEP)
die_if_unmerged_cache(reset_type);
if (reset_type != SOFT) {
struct lock_file *lock = xcalloc(1, sizeof(*lock));
hold_locked_index(lock, 1);
if (reset_type == MIXED) {
int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
if (read_from_tree(&pathspec, sha1, intent_to_add))
return 1;
if (get_git_work_tree())
refresh_index(&the_index, flags, NULL, NULL,
_("Unstaged changes after reset:"));
} else {
int err = reset_index(sha1, reset_type, quiet);
if (reset_type == KEEP && !err)
err = reset_index(sha1, MIXED, quiet);
if (err)
die(_("Could not reset index file to revision '%s'."), rev);
}
if (write_locked_index(&the_index, lock, COMMIT_LOCK))
die(_("Could not write new index file."));
}
if (!pathspec.nr && !unborn) {
/* Any resets without paths update HEAD to the head being
* switched to, saving the previous head in ORIG_HEAD before. */
update_ref_status = reset_refs(rev, sha1);
if (reset_type == HARD && !update_ref_status && !quiet)
print_new_head_line(lookup_commit_reference(sha1));
}
if (!pathspec.nr)
remove_branch_state();
return update_ref_status;
}