Merge branch 'ab/range-diff-no-patch'
[git] / preload-index.c
1 /*
2  * Copyright (C) 2008 Linus Torvalds
3  */
4 #include "cache.h"
5 #include "pathspec.h"
6 #include "dir.h"
7 #include "fsmonitor.h"
8 #include "config.h"
9 #include "progress.h"
10 #include "thread-utils.h"
11
12 /*
13  * Mostly randomly chosen maximum thread counts: we
14  * cap the parallelism to 20 threads, and we want
15  * to have at least 500 lstat's per thread for it to
16  * be worth starting a thread.
17  */
18 #define MAX_PARALLEL (20)
19 #define THREAD_COST (500)
20
21 struct progress_data {
22         unsigned long n;
23         struct progress *progress;
24         pthread_mutex_t mutex;
25 };
26
27 struct thread_data {
28         pthread_t pthread;
29         struct index_state *index;
30         struct pathspec pathspec;
31         struct progress_data *progress;
32         int offset, nr;
33 };
34
35 static void *preload_thread(void *_data)
36 {
37         int nr, last_nr;
38         struct thread_data *p = _data;
39         struct index_state *index = p->index;
40         struct cache_entry **cep = index->cache + p->offset;
41         struct cache_def cache = CACHE_DEF_INIT;
42
43         nr = p->nr;
44         if (nr + p->offset > index->cache_nr)
45                 nr = index->cache_nr - p->offset;
46         last_nr = nr;
47
48         do {
49                 struct cache_entry *ce = *cep++;
50                 struct stat st;
51
52                 if (ce_stage(ce))
53                         continue;
54                 if (S_ISGITLINK(ce->ce_mode))
55                         continue;
56                 if (ce_uptodate(ce))
57                         continue;
58                 if (ce_skip_worktree(ce))
59                         continue;
60                 if (ce->ce_flags & CE_FSMONITOR_VALID)
61                         continue;
62                 if (p->progress && !(nr & 31)) {
63                         struct progress_data *pd = p->progress;
64
65                         pthread_mutex_lock(&pd->mutex);
66                         pd->n += last_nr - nr;
67                         display_progress(pd->progress, pd->n);
68                         pthread_mutex_unlock(&pd->mutex);
69                         last_nr = nr;
70                 }
71                 if (!ce_path_match(index, ce, &p->pathspec, NULL))
72                         continue;
73                 if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
74                         continue;
75                 if (lstat(ce->name, &st))
76                         continue;
77                 if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
78                         continue;
79                 ce_mark_uptodate(ce);
80                 mark_fsmonitor_valid(ce);
81         } while (--nr > 0);
82         if (p->progress) {
83                 struct progress_data *pd = p->progress;
84
85                 pthread_mutex_lock(&pd->mutex);
86                 display_progress(pd->progress, pd->n + last_nr);
87                 pthread_mutex_unlock(&pd->mutex);
88         }
89         cache_def_clear(&cache);
90         return NULL;
91 }
92
93 void preload_index(struct index_state *index,
94                    const struct pathspec *pathspec,
95                    unsigned int refresh_flags)
96 {
97         int threads, i, work, offset;
98         struct thread_data data[MAX_PARALLEL];
99         struct progress_data pd;
100
101         if (!HAVE_THREADS || !core_preload_index)
102                 return;
103
104         threads = index->cache_nr / THREAD_COST;
105         if ((index->cache_nr > 1) && (threads < 2) && git_env_bool("GIT_TEST_PRELOAD_INDEX", 0))
106                 threads = 2;
107         if (threads < 2)
108                 return;
109         trace_performance_enter();
110         if (threads > MAX_PARALLEL)
111                 threads = MAX_PARALLEL;
112         offset = 0;
113         work = DIV_ROUND_UP(index->cache_nr, threads);
114         memset(&data, 0, sizeof(data));
115
116         memset(&pd, 0, sizeof(pd));
117         if (refresh_flags & REFRESH_PROGRESS && isatty(2)) {
118                 pd.progress = start_delayed_progress(_("Refreshing index"), index->cache_nr);
119                 pthread_mutex_init(&pd.mutex, NULL);
120         }
121
122         for (i = 0; i < threads; i++) {
123                 struct thread_data *p = data+i;
124                 int err;
125
126                 p->index = index;
127                 if (pathspec)
128                         copy_pathspec(&p->pathspec, pathspec);
129                 p->offset = offset;
130                 p->nr = work;
131                 if (pd.progress)
132                         p->progress = &pd;
133                 offset += work;
134                 err = pthread_create(&p->pthread, NULL, preload_thread, p);
135
136                 if (err)
137                         die(_("unable to create threaded lstat: %s"), strerror(err));
138         }
139         for (i = 0; i < threads; i++) {
140                 struct thread_data *p = data+i;
141                 if (pthread_join(p->pthread, NULL))
142                         die("unable to join threaded lstat");
143         }
144         stop_progress(&pd.progress);
145
146         trace_performance_leave("preload index");
147 }
148
149 int read_index_preload(struct index_state *index,
150                        const struct pathspec *pathspec,
151                        unsigned int refresh_flags)
152 {
153         int retval = read_index(index);
154
155         preload_index(index, pathspec, refresh_flags);
156         return retval;
157 }