git/fsmonitor--daemon.h
Štěpán Němec 97509a3497 doc: fix some typos, grammar and wording issues
Signed-off-by: Štěpán Němec <stepnem@smrk.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-05 12:55:38 -07:00

174 lines
5.7 KiB
C

#ifndef FSMONITOR_DAEMON_H
#define FSMONITOR_DAEMON_H
#ifdef HAVE_FSMONITOR_DAEMON_BACKEND
#include "dir.h"
#include "run-command.h"
#include "simple-ipc.h"
#include "thread-utils.h"
#include "fsmonitor-path-utils.h"
struct fsmonitor_batch;
struct fsmonitor_token_data;
/*
* Create a new batch of path(s). The returned batch is considered
* private and not linked into the fsmonitor daemon state. The caller
* should fill this batch with one or more paths and then publish it.
*/
struct fsmonitor_batch *fsmonitor_batch__new(void);
/*
* Free the list of batches starting with this one.
*/
void fsmonitor_batch__free_list(struct fsmonitor_batch *batch);
/*
* Add this path to this batch of modified files.
*
* The batch should be private and NOT (yet) linked into the fsmonitor
* daemon state and therefore not yet visible to worker threads and so
* no locking is required.
*/
void fsmonitor_batch__add_path(struct fsmonitor_batch *batch, const char *path);
struct fsm_listen_data; /* opaque platform-specific data for listener thread */
struct fsm_health_data; /* opaque platform-specific data for health thread */
struct fsmonitor_daemon_state {
pthread_t listener_thread;
pthread_t health_thread;
pthread_mutex_t main_lock;
struct strbuf path_worktree_watch;
struct strbuf path_gitdir_watch;
struct alias_info alias;
int nr_paths_watching;
struct fsmonitor_token_data *current_token_data;
struct strbuf path_cookie_prefix;
pthread_cond_t cookies_cond;
int cookie_seq;
struct hashmap cookies;
int listen_error_code;
int health_error_code;
struct fsm_listen_data *listen_data;
struct fsm_health_data *health_data;
struct ipc_server_data *ipc_server_data;
struct strbuf path_ipc;
};
/*
* 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 OSes 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);
/*
* Prepend the this batch of path(s) onto the list of batches associated
* with the current token. This makes the batch visible to worker threads.
*
* The caller no longer owns the batch and must not free it.
*
* Wake up the client threads waiting on these cookies.
*/
void fsmonitor_publish(struct fsmonitor_daemon_state *state,
struct fsmonitor_batch *batch,
const struct string_list *cookie_names);
/*
* If the platform-specific layer loses sync with the filesystem,
* it should call this to invalidate cached data and abort waiting
* threads.
*/
void fsmonitor_force_resync(struct fsmonitor_daemon_state *state);
#endif /* HAVE_FSMONITOR_DAEMON_BACKEND */
#endif /* FSMONITOR_DAEMON_H */