C++ refresh_cache函数代码示例

static inline unsigned char do_cache2(struct cache2 *self)
{
    uint32_t current_serial;
    int change_detected;
    unsigned char c;

    if (pthread_mutex_trylock(&self->lock)) {
        /* We are willing to accept some race in this context */
        return self->evaluate(self);
    }

    change_detected = check_cache(&self->cache_persist)
                   || check_cache(&self->cache_ro);
    current_serial = __system_property_area_serial();
    if (current_serial != self->serial) {
        change_detected = 1;
    }
    if (change_detected) {
        refresh_cache(&self->cache_persist, self->key_persist);
        refresh_cache(&self->cache_ro, self->key_ro);
        self->serial = current_serial;
    }
    c = self->evaluate(self);

    pthread_mutex_unlock(&self->lock);

    return c;
}

char android_log_timestamp()
{
    static struct cache r_time_cache = { NULL, -1, 0 };
    static struct cache p_time_cache = { NULL, -1, 0 };
    char retval;

    if (pthread_mutex_trylock(&lock_timestamp)) {
        /* We are willing to accept some race in this context */
        if (!(retval = p_time_cache.c)) {
            retval = r_time_cache.c;
        }
    } else {
        static uint32_t serial;
        uint32_t current_serial = __system_property_area_serial();
        if (current_serial != serial) {
            refresh_cache(&r_time_cache, "ro.logd.timestamp");
            refresh_cache(&p_time_cache, "persist.logd.timestamp");
            serial = current_serial;
        }
        if (!(retval = p_time_cache.c)) {
            retval = r_time_cache.c;
        }

        pthread_mutex_unlock(&lock_timestamp);
    }

    return tolower(retval ?: 'r');
}

static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
{
	unsigned char result_tree[20], result_commit[20];
	struct commit_list *parents, **pptr = &parents;
	static struct lock_file lock;

	hold_locked_index(&lock, 1);
	refresh_cache(REFRESH_QUIET);
	if (active_cache_changed &&
	    write_locked_index(&the_index, &lock, COMMIT_LOCK))
		return error(_("Unable to write index."));
	rollback_lock_file(&lock);

	write_tree_trivial(result_tree);
	printf(_("Wonderful.\n"));
	pptr = commit_list_append(head, pptr);
	pptr = commit_list_append(remoteheads->item, pptr);
	prepare_to_commit(remoteheads);
	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
			result_commit, NULL, sign_commit))
		die(_("failed to write commit object"));
	finish(head, remoteheads, result_commit, "In-index merge");
	drop_save();
	return 0;
}

/**
 * If the work tree has unstaged or uncommitted changes, dies with the
 * appropriate message.
 */
static void die_on_unclean_work_tree(const char *prefix)
{
	struct lock_file *lock_file = xcalloc(1, sizeof(*lock_file));
	int do_die = 0;

	hold_locked_index(lock_file, 0);
	refresh_cache(REFRESH_QUIET);
	update_index_if_able(&the_index, lock_file);
	rollback_lock_file(lock_file);

	if (has_unstaged_changes(prefix)) {
		error(_("Cannot pull with rebase: You have unstaged changes."));
		do_die = 1;
	}

	if (has_uncommitted_changes(prefix)) {
		if (do_die)
			error(_("Additionally, your index contains uncommitted changes."));
		else
			error(_("Cannot pull with rebase: Your index contains uncommitted changes."));
		do_die = 1;
	}

	if (do_die)
		exit(1);
}

static int refresh(struct refresh_params *o, unsigned int flag)
{
	setup_work_tree();
	read_cache_preload(NULL);
	*o->has_errors |= refresh_cache(o->flags | flag);
	return 0;
}

static int try_merge_strategy(const char *strategy, struct commit_list *common,
			      const char *head_arg)
{
	int index_fd;
	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));

	index_fd = hold_locked_index(lock, 1);
	refresh_cache(REFRESH_QUIET);
	if (active_cache_changed &&
			(write_cache(index_fd, active_cache, active_nr) ||
			 commit_locked_index(lock)))
		return error(_("Unable to write index."));
	rollback_lock_file(lock);

	if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
		int clean, x;
		struct commit *result;
		struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
		int index_fd;
		struct commit_list *reversed = NULL;
		struct merge_options o;
		struct commit_list *j;

		if (remoteheads->next) {
			error(_("Not handling anything other than two heads merge."));
			return 2;
		}

		init_merge_options(&o);
		if (!strcmp(strategy, "subtree"))
			o.subtree_shift = "";

		o.renormalize = option_renormalize;
		o.show_rename_progress =
			show_progress == -1 ? isatty(2) : show_progress;

		for (x = 0; x < xopts_nr; x++)
			if (parse_merge_opt(&o, xopts[x]))
				die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);

		o.branch1 = head_arg;
		o.branch2 = remoteheads->item->util;

		for (j = common; j; j = j->next)
			commit_list_insert(j->item, &reversed);

		index_fd = hold_locked_index(lock, 1);
		clean = merge_recursive(&o, lookup_commit(head),
				remoteheads->item, reversed, &result);
		if (active_cache_changed &&
				(write_cache(index_fd, active_cache, active_nr) ||
				 commit_locked_index(lock)))
			die (_("unable to write %s"), get_index_file());
		rollback_lock_file(lock);
		return clean ? 0 : 1;
	} else {
		return try_merge_command(strategy, xopts_nr, xopts,
						common, head_arg, remoteheads);
	}
}

static void refresh_cache_or_die(int refresh_flags)
{
	/*
	 * refresh_flags contains REFRESH_QUIET, so the only errors
	 * are for unmerged entries.
	 */
	if (refresh_cache(refresh_flags | REFRESH_IN_PORCELAIN))
		die_resolve_conflict("commit");
}

static void refresh_index_quietly(void)
{
	struct lock_file lock_file = LOCK_INIT;
	int fd;

	fd = hold_locked_index(&lock_file, 0);
	if (fd < 0)
		return;
	discard_cache();
	read_cache();
	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
	update_index_if_able(&the_index, &lock_file);
}

int checkout_fast_forward(const unsigned char *head,
			  const unsigned char *remote,
			  int overwrite_ignore)
{
	struct tree *trees[MAX_UNPACK_TREES];
	struct unpack_trees_options opts;
	struct tree_desc t[MAX_UNPACK_TREES];
	int i, nr_trees = 0;
	struct dir_struct dir;
	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));

	refresh_cache(REFRESH_QUIET);

	hold_locked_index(lock_file, 1);

	memset(&trees, 0, sizeof(trees));
	memset(&opts, 0, sizeof(opts));
	memset(&t, 0, sizeof(t));
	if (overwrite_ignore) {
		memset(&dir, 0, sizeof(dir));
		dir.flags |= DIR_SHOW_IGNORED;
		setup_standard_excludes(&dir);
		opts.dir = &dir;
	}

	opts.head_idx = 1;
	opts.src_index = &the_index;
	opts.dst_index = &the_index;
	opts.update = 1;
	opts.verbose_update = 1;
	opts.merge = 1;
	opts.fn = twoway_merge;
	setup_unpack_trees_porcelain(&opts, "merge");

	trees[nr_trees] = parse_tree_indirect(head);
	if (!trees[nr_trees++])
		return -1;
	trees[nr_trees] = parse_tree_indirect(remote);
	if (!trees[nr_trees++])
		return -1;
	for (i = 0; i < nr_trees; i++) {
		parse_tree(trees[i]);
		init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
	}
	if (unpack_trees(nr_trees, t, &opts))
		return -1;
	if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
		die(_("unable to write new index file"));
	return 0;
}

static void refresh_index_quietly(void)
{
	struct lock_file *lock_file;
	int fd;

	lock_file = xcalloc(1, sizeof(struct lock_file));
	fd = hold_locked_index(lock_file, 0);
	if (fd < 0)
		return;
	discard_cache();
	read_cache();
	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
	update_index_if_able(&the_index, lock_file);
}

static int checkout_fast_forward(unsigned char *head, unsigned char *remote)
{
	struct tree *trees[MAX_UNPACK_TREES];
	struct unpack_trees_options opts;
	struct tree_desc t[MAX_UNPACK_TREES];
	int i, fd, nr_trees = 0;
	struct dir_struct dir;
	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));

	refresh_cache(REFRESH_QUIET);

	fd = hold_locked_index(lock_file, 1);

	memset(&trees, 0, sizeof(trees));
	memset(&opts, 0, sizeof(opts));
	memset(&t, 0, sizeof(t));
	memset(&dir, 0, sizeof(dir));
	dir.flags |= DIR_SHOW_IGNORED;
	dir.exclude_per_dir = ".gitignore";
	opts.dir = &dir;

	opts.head_idx = 1;
	opts.src_index = &the_index;
	opts.dst_index = &the_index;
	opts.update = 1;
	opts.verbose_update = 1;
	opts.merge = 1;
	opts.fn = twoway_merge;
	opts.msgs = get_porcelain_error_msgs();

	trees[nr_trees] = parse_tree_indirect(head);
	if (!trees[nr_trees++])
		return -1;
	trees[nr_trees] = parse_tree_indirect(remote);
	if (!trees[nr_trees++])
		return -1;
	for (i = 0; i < nr_trees; i++) {
		parse_tree(trees[i]);
		init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
	}
	if (unpack_trees(nr_trees, t, &opts))
		return -1;
	if (write_cache(fd, active_cache, active_nr) ||
		commit_locked_index(lock_file))
		die("unable to write new index file");
	return 0;
}

static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
{
	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(flags) ? 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 refresh_index_quietly(void)
{
	struct lock_file *lock_file;
	int fd;

	lock_file = xcalloc(1, sizeof(struct lock_file));
	fd = hold_locked_index(lock_file, 0);
	if (fd < 0)
		return;
	discard_cache();
	read_cache();
	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);

	if (active_cache_changed &&
	    !write_cache(fd, active_cache, active_nr))
		commit_locked_index(lock_file);

	rollback_lock_file(lock_file);
}

static void restore_state(void)
{
	struct strbuf sb = STRBUF_INIT;
	const char *args[] = { "stash", "apply", NULL, NULL };

	if (is_null_sha1(stash))
		return;

	reset_hard(head, 1);

	args[2] = sha1_to_hex(stash);

	/*
	 * It is OK to ignore error here, for example when there was
	 * nothing to restore.
	 */
	run_command_v_opt(args, RUN_GIT_CMD);

	strbuf_release(&sb);
	refresh_cache(REFRESH_QUIET);
}

static int reset_tree(struct object_id *i_tree, int update, int reset)
{
	int nr_trees = 1;
	struct unpack_trees_options opts;
	struct tree_desc t[MAX_UNPACK_TREES];
	struct tree *tree;
	struct lock_file lock_file = LOCK_INIT;

	read_cache_preload(NULL);
	if (refresh_cache(REFRESH_QUIET))
		return -1;

	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);

	memset(&opts, 0, sizeof(opts));

	tree = parse_tree_indirect(i_tree);
	if (parse_tree(tree))
		return -1;

	init_tree_desc(t, tree->buffer, tree->size);

	opts.head_idx = 1;
	opts.src_index = &the_index;
	opts.dst_index = &the_index;
	opts.merge = 1;
	opts.reset = reset;
	opts.update = update;
	opts.fn = oneway_merge;

	if (unpack_trees(nr_trees, t, &opts))
		return -1;

	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
		return error(_("unable to write new index file"));

	return 0;
}