git.oblomov.eu Git - git/blob - 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 "progress.h"
   9
  10 #ifdef NO_PTHREADS
  11 static void preload_index(struct index_state *index,
  12                           const struct pathspec *pathspec,
  13                           unsigned int refresh_flags)
  14 {
  15         ; /* nothing */
  16 }
  17 #else
  18
  19 #include <pthread.h>
  20
  21 /*
  22  * Mostly randomly chosen maximum thread counts: we
  23  * cap the parallelism to 20 threads, and we want
  24  * to have at least 500 lstat's per thread for it to
  25  * be worth starting a thread.
  26  */
  27 #define MAX_PARALLEL (20)
  28 #define THREAD_COST (500)
  29
  30 struct progress_data {
  31         unsigned long n;
  32         struct progress *progress;
  33         pthread_mutex_t mutex;
  34 };
  35
  36 struct thread_data {
  37         pthread_t pthread;
  38         struct index_state *index;
  39         struct pathspec pathspec;
  40         struct progress_data *progress;
  41         int offset, nr;
  42 };
  43
  44 static void *preload_thread(void *_data)
  45 {
  46         int nr, last_nr;
  47         struct thread_data *p = _data;
  48         struct index_state *index = p->index;
  49         struct cache_entry **cep = index->cache + p->offset;
  50         struct cache_def cache = CACHE_DEF_INIT;
  51
  52         nr = p->nr;
  53         if (nr + p->offset > index->cache_nr)
  54                 nr = index->cache_nr - p->offset;
  55         last_nr = nr;
  56
  57         do {
  58                 struct cache_entry *ce = *cep++;
  59                 struct stat st;
  60
  61                 if (ce_stage(ce))
  62                         continue;
  63                 if (S_ISGITLINK(ce->ce_mode))
  64                         continue;
  65                 if (ce_uptodate(ce))
  66                         continue;
  67                 if (ce_skip_worktree(ce))
  68                         continue;
  69                 if (ce->ce_flags & CE_FSMONITOR_VALID)
  70                         continue;
  71                 if (p->progress && !(nr & 31)) {
  72                         struct progress_data *pd = p->progress;
  73
  74                         pthread_mutex_lock(&pd->mutex);
  75                         pd->n += last_nr - nr;
  76                         display_progress(pd->progress, pd->n);
  77                         pthread_mutex_unlock(&pd->mutex);
  78                         last_nr = nr;
  79                 }
  80                 if (!ce_path_match(index, ce, &p->pathspec, NULL))
  81                         continue;
  82                 if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
  83                         continue;
  84                 if (lstat(ce->name, &st))
  85                         continue;
  86                 if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
  87                         continue;
  88                 ce_mark_uptodate(ce);
  89                 mark_fsmonitor_valid(ce);
  90         } while (--nr > 0);
  91         if (p->progress) {
  92                 struct progress_data *pd = p->progress;
  93
  94                 pthread_mutex_lock(&pd->mutex);
  95                 display_progress(pd->progress, pd->n + last_nr);
  96                 pthread_mutex_unlock(&pd->mutex);
  97         }
  98         cache_def_clear(&cache);
  99         return NULL;
 100 }
 101
 102 static void preload_index(struct index_state *index,
 103                           const struct pathspec *pathspec,
 104                           unsigned int refresh_flags)
 105 {
 106         int threads, i, work, offset;
 107         struct thread_data data[MAX_PARALLEL];
 108         uint64_t start = getnanotime();
 109         struct progress_data pd;
 110
 111         if (!core_preload_index)
 112                 return;
 113
 114         threads = index->cache_nr / THREAD_COST;
 115         if ((index->cache_nr > 1) && (threads < 2) && getenv("GIT_FORCE_PRELOAD_TEST"))
 116                 threads = 2;
 117         if (threads < 2)
 118                 return;
 119         if (threads > MAX_PARALLEL)
 120                 threads = MAX_PARALLEL;
 121         offset = 0;
 122         work = DIV_ROUND_UP(index->cache_nr, threads);
 123         memset(&data, 0, sizeof(data));
 124
 125         memset(&pd, 0, sizeof(pd));
 126         if (refresh_flags & REFRESH_PROGRESS && isatty(2)) {
 127                 pd.progress = start_delayed_progress(_("Refreshing index"), index->cache_nr);
 128                 pthread_mutex_init(&pd.mutex, NULL);
 129         }
 130
 131         for (i = 0; i < threads; i++) {
 132                 struct thread_data *p = data+i;
 133                 p->index = index;
 134                 if (pathspec)
 135                         copy_pathspec(&p->pathspec, pathspec);
 136                 p->offset = offset;
 137                 p->nr = work;
 138                 if (pd.progress)
 139                         p->progress = &pd;
 140                 offset += work;
 141                 if (pthread_create(&p->pthread, NULL, preload_thread, p))
 142                         die("unable to create threaded lstat");
 143         }
 144         for (i = 0; i < threads; i++) {
 145                 struct thread_data *p = data+i;
 146                 if (pthread_join(p->pthread, NULL))
 147                         die("unable to join threaded lstat");
 148         }
 149         stop_progress(&pd.progress);
 150
 151         trace_performance_since(start, "preload index");
 152 }
 153 #endif
 154
 155 int read_index_preload(struct index_state *index,
 156                        const struct pathspec *pathspec,
 157                        unsigned int refresh_flags)
 158 {
 159         int retval = read_index(index);
 160
 161         preload_index(index, pathspec, refresh_flags);
 162         return retval;
 163 }