Andrew's git - gitweb.git/blob

   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
  21struct progress_data {
  22        unsigned long n;
  23        struct progress *progress;
  24        pthread_mutex_t mutex;
  25};
  26
  27struct 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
  35static 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
  93void 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
 149int 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}