Merge branch 'nd/ita-wt-renames-in-status' into maint
[git] / fsmonitor.c
1 #include "cache.h"
2 #include "config.h"
3 #include "dir.h"
4 #include "ewah/ewok.h"
5 #include "fsmonitor.h"
6 #include "run-command.h"
7 #include "strbuf.h"
8
9 #define INDEX_EXTENSION_VERSION (1)
10 #define HOOK_INTERFACE_VERSION  (1)
11
12 struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR);
13
14 static void fsmonitor_ewah_callback(size_t pos, void *is)
15 {
16         struct index_state *istate = (struct index_state *)is;
17         struct cache_entry *ce = istate->cache[pos];
18
19         ce->ce_flags &= ~CE_FSMONITOR_VALID;
20 }
21
22 int read_fsmonitor_extension(struct index_state *istate, const void *data,
23         unsigned long sz)
24 {
25         const char *index = data;
26         uint32_t hdr_version;
27         uint32_t ewah_size;
28         struct ewah_bitmap *fsmonitor_dirty;
29         int ret;
30
31         if (sz < sizeof(uint32_t) + sizeof(uint64_t) + sizeof(uint32_t))
32                 return error("corrupt fsmonitor extension (too short)");
33
34         hdr_version = get_be32(index);
35         index += sizeof(uint32_t);
36         if (hdr_version != INDEX_EXTENSION_VERSION)
37                 return error("bad fsmonitor version %d", hdr_version);
38
39         istate->fsmonitor_last_update = get_be64(index);
40         index += sizeof(uint64_t);
41
42         ewah_size = get_be32(index);
43         index += sizeof(uint32_t);
44
45         fsmonitor_dirty = ewah_new();
46         ret = ewah_read_mmap(fsmonitor_dirty, index, ewah_size);
47         if (ret != ewah_size) {
48                 ewah_free(fsmonitor_dirty);
49                 return error("failed to parse ewah bitmap reading fsmonitor index extension");
50         }
51         istate->fsmonitor_dirty = fsmonitor_dirty;
52
53         trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful");
54         return 0;
55 }
56
57 void fill_fsmonitor_bitmap(struct index_state *istate)
58 {
59         int i;
60         istate->fsmonitor_dirty = ewah_new();
61         for (i = 0; i < istate->cache_nr; i++)
62                 if (!(istate->cache[i]->ce_flags & CE_FSMONITOR_VALID))
63                         ewah_set(istate->fsmonitor_dirty, i);
64 }
65
66 void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
67 {
68         uint32_t hdr_version;
69         uint64_t tm;
70         uint32_t ewah_start;
71         uint32_t ewah_size = 0;
72         int fixup = 0;
73
74         put_be32(&hdr_version, INDEX_EXTENSION_VERSION);
75         strbuf_add(sb, &hdr_version, sizeof(uint32_t));
76
77         put_be64(&tm, istate->fsmonitor_last_update);
78         strbuf_add(sb, &tm, sizeof(uint64_t));
79         fixup = sb->len;
80         strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */
81
82         ewah_start = sb->len;
83         ewah_serialize_strbuf(istate->fsmonitor_dirty, sb);
84         ewah_free(istate->fsmonitor_dirty);
85         istate->fsmonitor_dirty = NULL;
86
87         /* fix up size field */
88         put_be32(&ewah_size, sb->len - ewah_start);
89         memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
90
91         trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful");
92 }
93
94 /*
95  * Call the query-fsmonitor hook passing the time of the last saved results.
96  */
97 static int query_fsmonitor(int version, uint64_t last_update, struct strbuf *query_result)
98 {
99         struct child_process cp = CHILD_PROCESS_INIT;
100         char ver[64];
101         char date[64];
102         const char *argv[4];
103
104         if (!(argv[0] = core_fsmonitor))
105                 return -1;
106
107         snprintf(ver, sizeof(version), "%d", version);
108         snprintf(date, sizeof(date), "%" PRIuMAX, (uintmax_t)last_update);
109         argv[1] = ver;
110         argv[2] = date;
111         argv[3] = NULL;
112         cp.argv = argv;
113         cp.use_shell = 1;
114         cp.dir = get_git_work_tree();
115
116         return capture_command(&cp, query_result, 1024);
117 }
118
119 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
120 {
121         int pos = index_name_pos(istate, name, strlen(name));
122
123         if (pos >= 0) {
124                 struct cache_entry *ce = istate->cache[pos];
125                 ce->ce_flags &= ~CE_FSMONITOR_VALID;
126         }
127
128         /*
129          * Mark the untracked cache dirty even if it wasn't found in the index
130          * as it could be a new untracked file.
131          */
132         trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
133         untracked_cache_invalidate_path(istate, name);
134 }
135
136 void refresh_fsmonitor(struct index_state *istate)
137 {
138         static int has_run_once = 0;
139         struct strbuf query_result = STRBUF_INIT;
140         int query_success = 0;
141         size_t bol; /* beginning of line */
142         uint64_t last_update;
143         char *buf;
144         int i;
145
146         if (!core_fsmonitor || has_run_once)
147                 return;
148         has_run_once = 1;
149
150         trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
151         /*
152          * This could be racy so save the date/time now and query_fsmonitor
153          * should be inclusive to ensure we don't miss potential changes.
154          */
155         last_update = getnanotime();
156
157         /*
158          * If we have a last update time, call query_fsmonitor for the set of
159          * changes since that time, else assume everything is possibly dirty
160          * and check it all.
161          */
162         if (istate->fsmonitor_last_update) {
163                 query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION,
164                         istate->fsmonitor_last_update, &query_result);
165                 trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
166                 trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
167                         core_fsmonitor, query_success ? "success" : "failure");
168         }
169
170         /* a fsmonitor process can return '/' to indicate all entries are invalid */
171         if (query_success && query_result.buf[0] != '/') {
172                 /* Mark all entries returned by the monitor as dirty */
173                 buf = query_result.buf;
174                 bol = 0;
175                 for (i = 0; i < query_result.len; i++) {
176                         if (buf[i] != '\0')
177                                 continue;
178                         fsmonitor_refresh_callback(istate, buf + bol);
179                         bol = i + 1;
180                 }
181                 if (bol < query_result.len)
182                         fsmonitor_refresh_callback(istate, buf + bol);
183         } else {
184                 /* Mark all entries invalid */
185                 for (i = 0; i < istate->cache_nr; i++)
186                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
187
188                 if (istate->untracked)
189                         istate->untracked->use_fsmonitor = 0;
190         }
191         strbuf_release(&query_result);
192
193         /* Now that we've updated istate, save the last_update time */
194         istate->fsmonitor_last_update = last_update;
195 }
196
197 void add_fsmonitor(struct index_state *istate)
198 {
199         int i;
200
201         if (!istate->fsmonitor_last_update) {
202                 trace_printf_key(&trace_fsmonitor, "add fsmonitor");
203                 istate->cache_changed |= FSMONITOR_CHANGED;
204                 istate->fsmonitor_last_update = getnanotime();
205
206                 /* reset the fsmonitor state */
207                 for (i = 0; i < istate->cache_nr; i++)
208                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
209
210                 /* reset the untracked cache */
211                 if (istate->untracked) {
212                         add_untracked_cache(istate);
213                         istate->untracked->use_fsmonitor = 1;
214                 }
215
216                 /* Update the fsmonitor state */
217                 refresh_fsmonitor(istate);
218         }
219 }
220
221 void remove_fsmonitor(struct index_state *istate)
222 {
223         if (istate->fsmonitor_last_update) {
224                 trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
225                 istate->cache_changed |= FSMONITOR_CHANGED;
226                 istate->fsmonitor_last_update = 0;
227         }
228 }
229
230 void tweak_fsmonitor(struct index_state *istate)
231 {
232         int i;
233         int fsmonitor_enabled = git_config_get_fsmonitor();
234
235         if (istate->fsmonitor_dirty) {
236                 if (fsmonitor_enabled) {
237                         /* Mark all entries valid */
238                         for (i = 0; i < istate->cache_nr; i++) {
239                                 istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
240                         }
241
242                         /* Mark all previously saved entries as dirty */
243                         ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
244
245                         /* Now mark the untracked cache for fsmonitor usage */
246                         if (istate->untracked)
247                                 istate->untracked->use_fsmonitor = 1;
248                 }
249
250                 ewah_free(istate->fsmonitor_dirty);
251                 istate->fsmonitor_dirty = NULL;
252         }
253
254         switch (fsmonitor_enabled) {
255         case -1: /* keep: do nothing */
256                 break;
257         case 0: /* false */
258                 remove_fsmonitor(istate);
259                 break;
260         case 1: /* true */
261                 add_fsmonitor(istate);
262                 break;
263         default: /* unknown value: do nothing */
264                 break;
265         }
266 }