commit-graph: collapse parameters into flags
[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
101         if (!core_fsmonitor)
102                 return -1;
103
104         argv_array_push(&cp.args, core_fsmonitor);
105         argv_array_pushf(&cp.args, "%d", version);
106         argv_array_pushf(&cp.args, "%" PRIuMAX, (uintmax_t)last_update);
107         cp.use_shell = 1;
108         cp.dir = get_git_work_tree();
109
110         return capture_command(&cp, query_result, 1024);
111 }
112
113 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
114 {
115         int pos = index_name_pos(istate, name, strlen(name));
116
117         if (pos >= 0) {
118                 struct cache_entry *ce = istate->cache[pos];
119                 ce->ce_flags &= ~CE_FSMONITOR_VALID;
120         }
121
122         /*
123          * Mark the untracked cache dirty even if it wasn't found in the index
124          * as it could be a new untracked file.
125          */
126         trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
127         untracked_cache_invalidate_path(istate, name, 0);
128 }
129
130 void refresh_fsmonitor(struct index_state *istate)
131 {
132         static int has_run_once = 0;
133         struct strbuf query_result = STRBUF_INIT;
134         int query_success = 0;
135         size_t bol; /* beginning of line */
136         uint64_t last_update;
137         char *buf;
138         int i;
139
140         if (!core_fsmonitor || has_run_once)
141                 return;
142         has_run_once = 1;
143
144         trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
145         /*
146          * This could be racy so save the date/time now and query_fsmonitor
147          * should be inclusive to ensure we don't miss potential changes.
148          */
149         last_update = getnanotime();
150
151         /*
152          * If we have a last update time, call query_fsmonitor for the set of
153          * changes since that time, else assume everything is possibly dirty
154          * and check it all.
155          */
156         if (istate->fsmonitor_last_update) {
157                 query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION,
158                         istate->fsmonitor_last_update, &query_result);
159                 trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
160                 trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
161                         core_fsmonitor, query_success ? "success" : "failure");
162         }
163
164         /* a fsmonitor process can return '/' to indicate all entries are invalid */
165         if (query_success && query_result.buf[0] != '/') {
166                 /* Mark all entries returned by the monitor as dirty */
167                 buf = query_result.buf;
168                 bol = 0;
169                 for (i = 0; i < query_result.len; i++) {
170                         if (buf[i] != '\0')
171                                 continue;
172                         fsmonitor_refresh_callback(istate, buf + bol);
173                         bol = i + 1;
174                 }
175                 if (bol < query_result.len)
176                         fsmonitor_refresh_callback(istate, buf + bol);
177         } else {
178                 /* Mark all entries invalid */
179                 for (i = 0; i < istate->cache_nr; i++)
180                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
181
182                 /* If we're going to check every file, ensure we save the results */
183                 istate->cache_changed |= FSMONITOR_CHANGED;
184
185                 if (istate->untracked)
186                         istate->untracked->use_fsmonitor = 0;
187         }
188         strbuf_release(&query_result);
189
190         /* Now that we've updated istate, save the last_update time */
191         istate->fsmonitor_last_update = last_update;
192 }
193
194 void add_fsmonitor(struct index_state *istate)
195 {
196         int i;
197
198         if (!istate->fsmonitor_last_update) {
199                 trace_printf_key(&trace_fsmonitor, "add fsmonitor");
200                 istate->cache_changed |= FSMONITOR_CHANGED;
201                 istate->fsmonitor_last_update = getnanotime();
202
203                 /* reset the fsmonitor state */
204                 for (i = 0; i < istate->cache_nr; i++)
205                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
206
207                 /* reset the untracked cache */
208                 if (istate->untracked) {
209                         add_untracked_cache(istate);
210                         istate->untracked->use_fsmonitor = 1;
211                 }
212
213                 /* Update the fsmonitor state */
214                 refresh_fsmonitor(istate);
215         }
216 }
217
218 void remove_fsmonitor(struct index_state *istate)
219 {
220         if (istate->fsmonitor_last_update) {
221                 trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
222                 istate->cache_changed |= FSMONITOR_CHANGED;
223                 istate->fsmonitor_last_update = 0;
224         }
225 }
226
227 void tweak_fsmonitor(struct index_state *istate)
228 {
229         int i;
230         int fsmonitor_enabled = git_config_get_fsmonitor();
231
232         if (istate->fsmonitor_dirty) {
233                 if (fsmonitor_enabled) {
234                         /* Mark all entries valid */
235                         for (i = 0; i < istate->cache_nr; i++) {
236                                 istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
237                         }
238
239                         /* Mark all previously saved entries as dirty */
240                         ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
241
242                         /* Now mark the untracked cache for fsmonitor usage */
243                         if (istate->untracked)
244                                 istate->untracked->use_fsmonitor = 1;
245                 }
246
247                 ewah_free(istate->fsmonitor_dirty);
248                 istate->fsmonitor_dirty = NULL;
249         }
250
251         switch (fsmonitor_enabled) {
252         case -1: /* keep: do nothing */
253                 break;
254         case 0: /* false */
255                 remove_fsmonitor(istate);
256                 break;
257         case 1: /* true */
258                 add_fsmonitor(istate);
259                 break;
260         default: /* unknown value: do nothing */
261                 break;
262         }
263 }