builtin-reset.c - jrn/git - Git at Google

 /*
  * "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 "cache.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"

 static const char builtin_reset_usage[] =
 "git-reset [--mixed | --soft | --hard] [-q] [<commit-ish>] [ [--] <paths>...]";

 static char *args_to_str(const char **argv)
 {
 	char *buf = NULL;
 	unsigned long len, space = 0, nr = 0;

 	for (; *argv; argv++) {
 		len = strlen(*argv);
 		ALLOC_GROW(buf, nr + 1 + len, space);
 		if (nr)
 			buf[nr++] = ' ';
 		memcpy(buf + nr, *argv, len);
 		nr += len;
 	}
 	ALLOC_GROW(buf, nr + 1, space);
 	buf[nr] = '\0';

 	return buf;
 }

 static inline int is_merge(void)
 {
 	return !access(git_path("MERGE_HEAD"), F_OK);
 }

 static int unmerged_files(void)
 {
 	int i;
 	read_cache();
 	for (i = 0; i < active_nr; i++) {
 		struct cache_entry *ce = active_cache[i];
 		if (ce_stage(ce))
 			return 1;
 	}
 	return 0;
 }

 static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
 {
 	int i = 0;
 	const char *args[6];

 	args[i++] = "read-tree";
 	args[i++] = "-v";
 	args[i++] = "--reset";
 	if (is_hard_reset)
 		args[i++] = "-u";
 	args[i++] = sha1_to_hex(sha1);
 	args[i] = NULL;

 	return run_command_v_opt(args, RUN_GIT_CMD);
 }

 static void print_new_head_line(struct commit *commit)
 {
 	const char *hex, *dots = "...", *body;

 	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 	if (!hex) {
 		hex = sha1_to_hex(commit->object.sha1);
 		dots = "";
 	}
 	printf("HEAD is now at %s%s", hex, dots);
 	body = strstr(commit->buffer, "\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");
 }

 static int update_index_refresh(int fd, struct lock_file *index_lock)
 {
 	int result;

 	if (!index_lock) {
 		index_lock = xcalloc(1, sizeof(struct lock_file));
 		fd = hold_locked_index(index_lock, 1);
 	}

 	if (read_cache() < 0)
 		return error("Could not read index");
 	result = refresh_cache(0) ? 1 : 0;
 	if (write_cache(fd, active_cache, active_nr) ||
 			commit_locked_index(index_lock))
 		return error ("Could not refresh index");
 	return result;
 }

 static void update_index_from_diff(struct diff_queue_struct *q,
 		struct diff_options *opt, void *data)
 {
 	int i;
 	int *discard_flag = data;

 	/* do_diff_cache() mangled the index */
 	discard_cache();
 	*discard_flag = 1;
 	read_cache();

 	for (i = 0; i < q->nr; i++) {
 		struct diff_filespec *one = q->queue[i]->one;
 		if (one->mode) {
 			struct cache_entry *ce;
 			ce = make_cache_entry(one->mode, one->sha1, one->path,
 				0, 0);
 			add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 				ADD_CACHE_OK_TO_REPLACE);
 		} else
 			remove_file_from_cache(one->path);
 	}
 }

 static int read_from_tree(const char *prefix, const char **argv,
 		unsigned char *tree_sha1)
 {
 	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 	int index_fd, index_was_discarded = 0;
 	struct diff_options opt;

 	memset(&opt, 0, sizeof(opt));
 	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 	opt.output_format = DIFF_FORMAT_CALLBACK;
 	opt.format_callback = update_index_from_diff;
 	opt.format_callback_data = &index_was_discarded;

 	index_fd = hold_locked_index(lock, 1);
 	index_was_discarded = 0;
 	read_cache();
 	if (do_diff_cache(tree_sha1, &opt))
 		return 1;
 	diffcore_std(&opt);
 	diff_flush(&opt);
 	diff_tree_release_paths(&opt);

 	if (!index_was_discarded)
 		/* The index is still clobbered from do_diff_cache() */
 		discard_cache();
 	return update_index_refresh(index_fd, lock);
 }

 static void prepend_reflog_action(const char *action, char *buf, size_t size)
 {
 	const char *sep = ": ";
 	const char *rla = getenv("GIT_REFLOG_ACTION");
 	if (!rla)
 		rla = sep = "";
 	if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
 		warning("Reflog action message too long: %.*s...", 50, buf);
 }

 enum reset_type { MIXED, SOFT, HARD, NONE };
 static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };

 int cmd_reset(int argc, const char **argv, const char *prefix)
 {
 	int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
 	const char *rev = "HEAD";
 	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 				*old_orig = NULL, sha1_old_orig[20];
 	struct commit *commit;
 	char *reflog_action, msg[1024];

 	git_config(git_default_config);

 	reflog_action = args_to_str(argv);
 	setenv("GIT_REFLOG_ACTION", reflog_action, 0);

 	while (i < argc) {
 		if (!strcmp(argv[i], "--mixed")) {
 			reset_type = MIXED;
 			i++;
 		}
 		else if (!strcmp(argv[i], "--soft")) {
 			reset_type = SOFT;
 			i++;
 		}
 		else if (!strcmp(argv[i], "--hard")) {
 			reset_type = HARD;
 			i++;
 		}
 		else if (!strcmp(argv[i], "-q")) {
 			quiet = 1;
 			i++;
 		}
 		else
 			break;
 	}

 	if (i < argc && argv[i][0] != '-')
 		rev = argv[i++];

 	if (get_sha1(rev, sha1))
 		die("Failed to resolve '%s' as a valid ref.", rev);

 	commit = lookup_commit_reference(sha1);
 	if (!commit)
 		die("Could not parse object '%s'.", rev);
 	hashcpy(sha1, commit->object.sha1);

 	if (i < argc && !strcmp(argv[i], "--"))
 		i++;
 	else if (i < argc && argv[i][0] == '-')
 		usage(builtin_reset_usage);

 	/* 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 (i < argc) {
 		if (reset_type == MIXED)
 			warning("--mixed option is deprecated with paths.");
 		else if (reset_type != NONE)
 			die("Cannot do %s reset with paths.",
 					reset_type_names[reset_type]);
 		return read_from_tree(prefix, argv + i, sha1);
 	}
 	if (reset_type == NONE)
 		reset_type = MIXED; /* by default */

 	if (reset_type == HARD && is_bare_repository())
 		die("hard reset makes no sense in a bare repository");

 	/* 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) {
 		if (is_merge() || unmerged_files())
 			die("Cannot do a soft reset in the middle of a merge.");
 	}
 	else if (reset_index_file(sha1, (reset_type == HARD)))
 		die("Could not reset index file to revision '%s'.", rev);

 	/* Any resets update HEAD to the head being switched to,
 	 * saving the previous head in ORIG_HEAD before. */
 	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 		old_orig = sha1_old_orig;
 	if (!get_sha1("HEAD", sha1_orig)) {
 		orig = sha1_orig;
 		prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
 		update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 	}
 	else if (old_orig)
 		delete_ref("ORIG_HEAD", old_orig);
 	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
 	update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);

 	switch (reset_type) {
 	case HARD:
 		if (!update_ref_status && !quiet)
 			print_new_head_line(commit);
 		break;
 	case SOFT: /* Nothing else to do. */
 		break;
 	case MIXED: /* Report what has not been updated. */
 		update_index_refresh(0, NULL);
 		break;
 	}

 	unlink(git_path("MERGE_HEAD"));
 	unlink(git_path("rr-cache/MERGE_RR"));
 	unlink(git_path("MERGE_MSG"));
 	unlink(git_path("SQUASH_MSG"));

 	free(reflog_action);

 	return update_ref_status;
 }
	/*
	* "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 "cache.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"

	static const char builtin_reset_usage[] =
	"git-reset [--mixed \| --soft \| --hard] [-q] [<commit-ish>] [ [--] <paths>...]";

	static char args_to_str(const char *argv)
	{
	char *buf = NULL;
	unsigned long len, space = 0, nr = 0;

	for (; *argv; argv++) {
	len = strlen(*argv);
	ALLOC_GROW(buf, nr + 1 + len, space);
	if (nr)
	buf[nr++] = ' ';
	memcpy(buf + nr, *argv, len);
	nr += len;
	}
	ALLOC_GROW(buf, nr + 1, space);
	buf[nr] = '\0';

	return buf;
	}

	static inline int is_merge(void)
	{
	return !access(git_path("MERGE_HEAD"), F_OK);
	}

	static int unmerged_files(void)
	{
	int i;
	read_cache();
	for (i = 0; i < active_nr; i++) {
	struct cache_entry *ce = active_cache[i];
	if (ce_stage(ce))
	return 1;
	}
	return 0;
	}

	static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
	{
	int i = 0;
	const char *args[6];

	args[i++] = "read-tree";
	args[i++] = "-v";
	args[i++] = "--reset";
	if (is_hard_reset)
	args[i++] = "-u";
	args[i++] = sha1_to_hex(sha1);
	args[i] = NULL;

	return run_command_v_opt(args, RUN_GIT_CMD);
	}

	static void print_new_head_line(struct commit *commit)
	{
	const char hex, dots = "...", *body;

	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	if (!hex) {
	hex = sha1_to_hex(commit->object.sha1);
	dots = "";
	}
	printf("HEAD is now at %s%s", hex, dots);
	body = strstr(commit->buffer, "\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");
	}

	static int update_index_refresh(int fd, struct lock_file *index_lock)
	{
	int result;

	if (!index_lock) {
	index_lock = xcalloc(1, sizeof(struct lock_file));
	fd = hold_locked_index(index_lock, 1);
	}

	if (read_cache() < 0)
	return error("Could not read index");
	result = refresh_cache(0) ? 1 : 0;
	if (write_cache(fd, active_cache, active_nr) \|\|
	commit_locked_index(index_lock))
	return error ("Could not refresh index");
	return result;
	}

	static void update_index_from_diff(struct diff_queue_struct *q,
	struct diff_options opt, void data)
	{
	int i;
	int *discard_flag = data;

	/* do_diff_cache() mangled the index */
	discard_cache();
	*discard_flag = 1;
	read_cache();

	for (i = 0; i < q->nr; i++) {
	struct diff_filespec *one = q->queue[i]->one;
	if (one->mode) {
	struct cache_entry *ce;
	ce = make_cache_entry(one->mode, one->sha1, one->path,
	0, 0);
	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD \|
	ADD_CACHE_OK_TO_REPLACE);
	} else
	remove_file_from_cache(one->path);
	}
	}

	static int read_from_tree(const char prefix, const char *argv,
	unsigned char *tree_sha1)
	{
	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
	int index_fd, index_was_discarded = 0;
	struct diff_options opt;

	memset(&opt, 0, sizeof(opt));
	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
	opt.output_format = DIFF_FORMAT_CALLBACK;
	opt.format_callback = update_index_from_diff;
	opt.format_callback_data = &index_was_discarded;

	index_fd = hold_locked_index(lock, 1);
	index_was_discarded = 0;
	read_cache();
	if (do_diff_cache(tree_sha1, &opt))
	return 1;
	diffcore_std(&opt);
	diff_flush(&opt);
	diff_tree_release_paths(&opt);

	if (!index_was_discarded)
	/* The index is still clobbered from do_diff_cache() */
	discard_cache();
	return update_index_refresh(index_fd, lock);
	}

	static void prepend_reflog_action(const char action, char buf, size_t size)
	{
	const char *sep = ": ";
	const char *rla = getenv("GIT_REFLOG_ACTION");
	if (!rla)
	rla = sep = "";
	if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
	warning("Reflog action message too long: %.*s...", 50, buf);
	}

	enum reset_type { MIXED, SOFT, HARD, NONE };
	static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };

	int cmd_reset(int argc, const char *argv, const char prefix)
	{
	int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
	const char *rev = "HEAD";
	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
	*old_orig = NULL, sha1_old_orig[20];
	struct commit *commit;
	char *reflog_action, msg[1024];

	git_config(git_default_config);

	reflog_action = args_to_str(argv);
	setenv("GIT_REFLOG_ACTION", reflog_action, 0);

	while (i < argc) {
	if (!strcmp(argv[i], "--mixed")) {
	reset_type = MIXED;
	i++;
	}
	else if (!strcmp(argv[i], "--soft")) {
	reset_type = SOFT;
	i++;
	}
	else if (!strcmp(argv[i], "--hard")) {
	reset_type = HARD;
	i++;
	}
	else if (!strcmp(argv[i], "-q")) {
	quiet = 1;
	i++;
	}
	else
	break;
	}

	if (i < argc && argv[i][0] != '-')
	rev = argv[i++];

	if (get_sha1(rev, sha1))
	die("Failed to resolve '%s' as a valid ref.", rev);

	commit = lookup_commit_reference(sha1);
	if (!commit)
	die("Could not parse object '%s'.", rev);
	hashcpy(sha1, commit->object.sha1);

	if (i < argc && !strcmp(argv[i], "--"))
	i++;
	else if (i < argc && argv[i][0] == '-')
	usage(builtin_reset_usage);

	/* 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 (i < argc) {
	if (reset_type == MIXED)
	warning("--mixed option is deprecated with paths.");
	else if (reset_type != NONE)
	die("Cannot do %s reset with paths.",
	reset_type_names[reset_type]);
	return read_from_tree(prefix, argv + i, sha1);
	}
	if (reset_type == NONE)
	reset_type = MIXED; /* by default */

	if (reset_type == HARD && is_bare_repository())
	die("hard reset makes no sense in a bare repository");

	/* 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) {
	if (is_merge() \|\| unmerged_files())
	die("Cannot do a soft reset in the middle of a merge.");
	}
	else if (reset_index_file(sha1, (reset_type == HARD)))
	die("Could not reset index file to revision '%s'.", rev);

	/* Any resets update HEAD to the head being switched to,
	* saving the previous head in ORIG_HEAD before. */
	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
	old_orig = sha1_old_orig;
	if (!get_sha1("HEAD", sha1_orig)) {
	orig = sha1_orig;
	prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
	update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	}
	else if (old_orig)
	delete_ref("ORIG_HEAD", old_orig);
	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
	update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);

	switch (reset_type) {
	case HARD:
	if (!update_ref_status && !quiet)
	print_new_head_line(commit);
	break;
	case SOFT: /* Nothing else to do. */
	break;
	case MIXED: /* Report what has not been updated. */
	update_index_refresh(0, NULL);
	break;
	}

	unlink(git_path("MERGE_HEAD"));
	unlink(git_path("rr-cache/MERGE_RR"));
	unlink(git_path("MERGE_MSG"));
	unlink(git_path("SQUASH_MSG"));

	free(reflog_action);

	return update_ref_status;
	}