Re: [PATCH 10/23] fsmonitor--daemon: add pathname classification

> +#define FSMONITOR_COOKIE_PREFIX ".fsmonitor-daemon-"
> +
> +enum fsmonitor_path_type fsmonitor_classify_path_workdir_relative(
> +	const char *rel)
> +{
> +	if (fspathncmp(rel, ".git", 4))
> +		return IS_WORKDIR_PATH;
> +	rel += 4;
> +
> +	if (!*rel)
> +		return IS_DOT_GIT;
> +	if (*rel != '/')
> +		return IS_WORKDIR_PATH; /* e.g. .gitignore */
> +	rel++;
> +
> +	if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX,
> +			strlen(FSMONITOR_COOKIE_PREFIX)))

> +enum fsmonitor_path_type fsmonitor_classify_path_gitdir_relative(
> +	const char *rel)
> +{
> +	if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX,
> +			strlen(FSMONITOR_COOKIE_PREFIX)))
> +		return IS_INSIDE_GITDIR_WITH_COOKIE_PREFIX;
> +
> +	return IS_INSIDE_GITDIR;
> +}

> +static enum fsmonitor_path_type try_classify_workdir_abs_path(
> +	struct fsmonitor_daemon_state *state,
> +	const char *path)
> +{
> +	const char *rel;
> +
> +	if (fspathncmp(path, state->path_worktree_watch.buf,
> +		       state->path_worktree_watch.len))
> +		return IS_OUTSIDE_CONE;
> +
> +	rel = path + state->path_worktree_watch.len;
> +
> +	if (!*rel)
> +		return IS_WORKDIR_PATH; /* it is the root dir exactly */
> +	if (*rel != '/')
> +		return IS_OUTSIDE_CONE;
> +	rel++;
> +
> +	return fsmonitor_classify_path_workdir_relative(rel);
> +}
> +
> +enum fsmonitor_path_type fsmonitor_classify_path_absolute(
> +	struct fsmonitor_daemon_state *state,
> +	const char *path)
> +{
> +	const char *rel;
> +	enum fsmonitor_path_type t;
> +
> +	t = try_classify_workdir_abs_path(state, path);
> +	if (state->nr_paths_watching == 1)
> +		return t;
> +	if (t != IS_OUTSIDE_CONE)
> +		return t;
> +
> +	if (fspathncmp(path, state->path_gitdir_watch.buf,
> +		       state->path_gitdir_watch.len))
> +		return IS_OUTSIDE_CONE;
> +
> +	rel = path + state->path_gitdir_watch.len;
> +
> +	if (!*rel)
> +		return IS_GITDIR; /* it is the <gitdir> exactly */
> +	if (*rel != '/')
> +		return IS_OUTSIDE_CONE;
> +	rel++;
> +
> +	return fsmonitor_classify_path_gitdir_relative(rel);
> +}

> +/*
> + * Pathname classifications.
> + *
> + * The daemon classifies the pathnames that it receives from file
> + * system notification events into the following categories and uses
> + * that to decide whether clients are told about them.  (And to watch
> + * for file system synchronization events.)
> + *
> + * The client should only care about paths within the working
> + * directory proper (inside the working directory and not ".git" nor
> + * inside of ".git/").  That is, the client has read the index and is
> + * asking for a list of any paths in the working directory that have
> + * been modified since the last token.  The client does not care about
> + * file system changes within the .git directory (such as new loose
> + * objects or packfiles).  So the client will only receive paths that
> + * are classified as IS_WORKDIR_PATH.
> + *
> + * The daemon uses the IS_DOT_GIT and IS_GITDIR internally to mean the
> + * exact ".git" directory or GITDIR.  If the daemon receives a delete
> + * event for either of these directories, it will automatically
> + * shutdown, for example.
> + *
> + * Note that the daemon DOES NOT explicitly watch nor special case the
> + * ".git/index" file.  The daemon does not read the index and does not
> + * have any internal index-relative state.  The daemon only collects
> + * the set of modified paths within the working directory.
> + */
> +enum fsmonitor_path_type {
> +	IS_WORKDIR_PATH = 0,
> +
> +	IS_DOT_GIT,
> +	IS_INSIDE_DOT_GIT,
> +	IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX,
> +
> +	IS_GITDIR,
> +	IS_INSIDE_GITDIR,
> +	IS_INSIDE_GITDIR_WITH_COOKIE_PREFIX,
> +
> +	IS_OUTSIDE_CONE,
> +};
> +
> +/*
> + * Classify a pathname relative to the root of the working directory.
> + */
> +enum fsmonitor_path_type fsmonitor_classify_path_workdir_relative(
> +	const char *relative_path);
> +
> +/*
> + * Classify a pathname relative to a <gitdir> that is external to the
> + * worktree directory.
> + */
> +enum fsmonitor_path_type fsmonitor_classify_path_gitdir_relative(
> +	const char *relative_path);
> +
> +/*
> + * Classify an absolute pathname received from a filesystem event.
> + */
> +enum fsmonitor_path_type fsmonitor_classify_path_absolute(
> +	struct fsmonitor_daemon_state *state,
> +	const char *path);
> +
>  #endif /* HAVE_FSMONITOR_DAEMON_BACKEND */
>  #endif /* FSMONITOR_DAEMON_H */