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1#ifndef FSMONITOR_DAEMON_H
2#define FSMONITOR_DAEMON_H
3
4#ifdef HAVE_FSMONITOR_DAEMON_BACKEND
5
6#include "hashmap.h"
7#include "thread-utils.h"
8#include "fsmonitor-path-utils.h"
9
10struct fsmonitor_batch;
11struct fsmonitor_token_data;
12
13/*
14 * Create a new batch of path(s). The returned batch is considered
15 * private and not linked into the fsmonitor daemon state. The caller
16 * should fill this batch with one or more paths and then publish it.
17 */
18struct fsmonitor_batch *fsmonitor_batch__new(void);
19
20/*
21 * Free the list of batches starting with this one.
22 */
23void fsmonitor_batch__free_list(struct fsmonitor_batch *batch);
24
25/*
26 * Add this path to this batch of modified files.
27 *
28 * The batch should be private and NOT (yet) linked into the fsmonitor
29 * daemon state and therefore not yet visible to worker threads and so
30 * no locking is required.
31 */
32void fsmonitor_batch__add_path(struct fsmonitor_batch *batch, const char *path);
33
34struct fsm_listen_data; /* opaque platform-specific data for listener thread */
35struct fsm_health_data; /* opaque platform-specific data for health thread */
36
37struct fsmonitor_daemon_state {
38 pthread_t listener_thread;
39 pthread_t health_thread;
40 pthread_mutex_t main_lock;
41
42 struct strbuf path_worktree_watch;
43 struct strbuf path_gitdir_watch;
44 struct alias_info alias;
45 int nr_paths_watching;
46
47 struct fsmonitor_token_data *current_token_data;
48
49 struct strbuf path_cookie_prefix;
50 pthread_cond_t cookies_cond;
51 int cookie_seq;
52 struct hashmap cookies;
53
54 int listen_error_code;
55 int health_error_code;
56 struct fsm_listen_data *listen_data;
57 struct fsm_health_data *health_data;
58
59 struct ipc_server_data *ipc_server_data;
60 struct strbuf path_ipc;
61
62};
63
64/*
65 * Pathname classifications.
66 *
67 * The daemon classifies the pathnames that it receives from file
68 * system notification events into the following categories and uses
69 * that to decide whether clients are told about them. (And to watch
70 * for file system synchronization events.)
71 *
72 * The daemon only collects and reports on the set of modified paths
73 * within the working directory (proper).
74 *
75 * The client should only care about paths within the working
76 * directory proper (inside the working directory and not ".git" nor
77 * inside of ".git/"). That is, the client has read the index and is
78 * asking for a list of any paths in the working directory that have
79 * been modified since the last token. The client does not care about
80 * file system changes within the ".git/" directory (such as new loose
81 * objects or packfiles). So the client will only receive paths that
82 * are classified as IS_WORKDIR_PATH.
83 *
84 * Note that ".git" is usually a directory and is therefore inside
85 * the cone of the FS watch that we have on the working directory root,
86 * so we will also get FS events for disk activity on and within ".git/"
87 * that we need to respond to or filter from the client.
88 *
89 * But Git also allows ".git" to be a *file* that points to a GITDIR
90 * outside of the working directory. When this happens, we need to
91 * create FS watches on both the working directory root *and* on the
92 * (external) GITDIR root. (The latter is required because we put
93 * cookie files inside it and use them to sync with the FS event
94 * stream.)
95 *
96 * Note that in the context of this discussion, I'm using "GITDIR"
97 * to only mean an external GITDIR referenced by a ".git" file.
98 *
99 * The platform FS event backends will receive watch-specific
100 * relative paths (except for those OSes that always emit absolute
101 * paths). We use the following enum and routines to classify each
102 * path so that we know how to handle it. There is a slight asymmetry
103 * here because ".git/" is inside the working directory and the
104 * (external) GITDIR is not, and therefore how we handle events may
105 * vary slightly, so I have different enums for "IS...DOT_GIT..." and
106 * "IS...GITDIR...".
107 *
108 * The daemon uses the IS_DOT_GIT and IS_GITDIR internally to mean the
109 * exact ".git" file/directory or GITDIR directory. If the daemon
110 * receives a delete event for either of these paths, it will
111 * automatically shutdown, for example.
112 *
113 * Note that the daemon DOES NOT explicitly watch nor special case the
114 * index. The daemon does not read the index nor have any internal
115 * index-relative state, so there are no "IS...INDEX..." enum values.
116 */
117enum fsmonitor_path_type {
118 IS_WORKDIR_PATH = 0,
119
120 IS_DOT_GIT,
121 IS_INSIDE_DOT_GIT,
122 IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX,
123
124 IS_GITDIR,
125 IS_INSIDE_GITDIR,
126 IS_INSIDE_GITDIR_WITH_COOKIE_PREFIX,
127
128 IS_OUTSIDE_CONE,
129};
130
131/*
132 * Classify a pathname relative to the root of the working directory.
133 */
134enum fsmonitor_path_type fsmonitor_classify_path_workdir_relative(
135 const char *relative_path);
136
137/*
138 * Classify a pathname relative to a <gitdir> that is external to the
139 * worktree directory.
140 */
141enum fsmonitor_path_type fsmonitor_classify_path_gitdir_relative(
142 const char *relative_path);
143
144/*
145 * Classify an absolute pathname received from a filesystem event.
146 */
147enum fsmonitor_path_type fsmonitor_classify_path_absolute(
148 struct fsmonitor_daemon_state *state,
149 const char *path);
150
151/*
152 * Prepend the this batch of path(s) onto the list of batches associated
153 * with the current token. This makes the batch visible to worker threads.
154 *
155 * The caller no longer owns the batch and must not free it.
156 *
157 * Wake up the client threads waiting on these cookies.
158 */
159void fsmonitor_publish(struct fsmonitor_daemon_state *state,
160 struct fsmonitor_batch *batch,
161 const struct string_list *cookie_names);
162
163/*
164 * If the platform-specific layer loses sync with the filesystem,
165 * it should call this to invalidate cached data and abort waiting
166 * threads.
167 */
168void fsmonitor_force_resync(struct fsmonitor_daemon_state *state);
169
170#endif /* HAVE_FSMONITOR_DAEMON_BACKEND */
171#endif /* FSMONITOR_DAEMON_H */