diff options
| -rw-r--r-- | builtin/fsmonitor--daemon.c | 81 | ||||
| -rw-r--r-- | fsmonitor--daemon.h | 87 |
2 files changed, 168 insertions, 0 deletions
diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c index 69dd39121a..1ce00b7c15 100644 --- a/builtin/fsmonitor--daemon.c +++ b/builtin/fsmonitor--daemon.c @@ -134,6 +134,87 @@ static int handle_client(void *data, return result; } +#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))) + return IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX; + + return IS_INSIDE_DOT_GIT; +} + +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); +} + static void *fsm_listen__thread_proc(void *_state) { struct fsmonitor_daemon_state *state = _state; diff --git a/fsmonitor--daemon.h b/fsmonitor--daemon.h index 3009c1a83d..8c3a71a48b 100644 --- a/fsmonitor--daemon.h +++ b/fsmonitor--daemon.h @@ -30,5 +30,92 @@ struct fsmonitor_daemon_state { struct ipc_server_data *ipc_server_data; }; +/* + * 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 daemon only collects and reports on the set of modified paths + * within the working directory (proper). + * + * 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. + * + * Note that ".git" is usually a directory and is therefore inside + * the cone of the FS watch that we have on the working directory root, + * so we will also get FS events for disk activity on and within ".git/" + * that we need to respond to or filter from the client. + * + * But Git also allows ".git" to be a *file* that points to a GITDIR + * outside of the working directory. When this happens, we need to + * create FS watches on both the working directory root *and* on the + * (external) GITDIR root. (The latter is required because we put + * cookie files inside it and use them to sync with the FS event + * stream.) + * + * Note that in the context of this discussion, I'm using "GITDIR" + * to only mean an external GITDIR referenced by a ".git" file. + * + * The platform FS event backends will receive watch-specific + * relative paths (except for those OS's that always emit absolute + * paths). We use the following enum and routines to classify each + * path so that we know how to handle it. There is a slight asymmetry + * here because ".git/" is inside the working directory and the + * (external) GITDIR is not, and therefore how we handle events may + * vary slightly, so I have different enums for "IS...DOT_GIT..." and + * "IS...GITDIR...". + * + * The daemon uses the IS_DOT_GIT and IS_GITDIR internally to mean the + * exact ".git" file/directory or GITDIR directory. If the daemon + * receives a delete event for either of these paths, it will + * automatically shutdown, for example. + * + * Note that the daemon DOES NOT explicitly watch nor special case the + * index. The daemon does not read the index nor have any internal + * index-relative state, so there are no "IS...INDEX..." enum values. + */ +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 */ |