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#include "repository.h"
  12
  13/*
  14 * Mostly randomly chosen maximum thread counts: we
  15 * cap the parallelism to 20 threads, and we want
  16 * to have at least 500 lstat's per thread for it to
  17 * be worth starting a thread.
  18 */
  19#define MAX_PARALLEL (20)
  20#define THREAD_COST (500)
  21
  22struct progress_data {
  23        unsigned long n;
  24        struct progress *progress;
  25        pthread_mutex_t mutex;
  26};
  27
  28struct thread_data {
  29        pthread_t pthread;
  30        struct index_state *index;
  31        struct pathspec pathspec;
  32        struct progress_data *progress;
  33        int offset, nr;
  34};
  35
  36static void *preload_thread(void *_data)
  37{
  38        int nr, last_nr;
  39        struct thread_data *p = _data;
  40        struct index_state *index = p->index;
  41        struct cache_entry **cep = index->cache + p->offset;
  42        struct cache_def cache = CACHE_DEF_INIT;
  43
  44        nr = p->nr;
  45        if (nr + p->offset > index->cache_nr)
  46                nr = index->cache_nr - p->offset;
  47        last_nr = nr;
  48
  49        do {
  50                struct cache_entry *ce = *cep++;
  51                struct stat st;
  52
  53                if (ce_stage(ce))
  54                        continue;
  55                if (S_ISGITLINK(ce->ce_mode))
  56                        continue;
  57                if (ce_uptodate(ce))
  58                        continue;
  59                if (ce_skip_worktree(ce))
  60                        continue;
  61                if (ce->ce_flags & CE_FSMONITOR_VALID)
  62                        continue;
  63                if (p->progress && !(nr & 31)) {
  64                        struct progress_data *pd = p->progress;
  65
  66                        pthread_mutex_lock(&pd->mutex);
  67                        pd->n += last_nr - nr;
  68                        display_progress(pd->progress, pd->n);
  69                        pthread_mutex_unlock(&pd->mutex);
  70                        last_nr = nr;
  71                }
  72                if (!ce_path_match(index, ce, &p->pathspec, NULL))
  73                        continue;
  74                if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
  75                        continue;
  76                if (lstat(ce->name, &st))
  77                        continue;
  78                if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
  79                        continue;
  80                ce_mark_uptodate(ce);
  81                mark_fsmonitor_valid(index, ce);
  82        } while (--nr > 0);
  83        if (p->progress) {
  84                struct progress_data *pd = p->progress;
  85
  86                pthread_mutex_lock(&pd->mutex);
  87                display_progress(pd->progress, pd->n + last_nr);
  88                pthread_mutex_unlock(&pd->mutex);
  89        }
  90        cache_def_clear(&cache);
  91        return NULL;
  92}
  93
  94void preload_index(struct index_state *index,
  95                   const struct pathspec *pathspec,
  96                   unsigned int refresh_flags)
  97{
  98        int threads, i, work, offset;
  99        struct thread_data data[MAX_PARALLEL];
 100        struct progress_data pd;
 101
 102        if (!HAVE_THREADS || !core_preload_index)
 103                return;
 104
 105        threads = index->cache_nr / THREAD_COST;
 106        if ((index->cache_nr > 1) && (threads < 2) && git_env_bool("GIT_TEST_PRELOAD_INDEX", 0))
 107                threads = 2;
 108        if (threads < 2)
 109                return;
 110        trace_performance_enter();
 111        if (threads > MAX_PARALLEL)
 112                threads = MAX_PARALLEL;
 113        offset = 0;
 114        work = DIV_ROUND_UP(index->cache_nr, threads);
 115        memset(&data, 0, sizeof(data));
 116
 117        memset(&pd, 0, sizeof(pd));
 118        if (refresh_flags & REFRESH_PROGRESS && isatty(2)) {
 119                pd.progress = start_delayed_progress(_("Refreshing index"), index->cache_nr);
 120                pthread_mutex_init(&pd.mutex, NULL);
 121        }
 122
 123        for (i = 0; i < threads; i++) {
 124                struct thread_data *p = data+i;
 125                int err;
 126
 127                p->index = index;
 128                if (pathspec)
 129                        copy_pathspec(&p->pathspec, pathspec);
 130                p->offset = offset;
 131                p->nr = work;
 132                if (pd.progress)
 133                        p->progress = &pd;
 134                offset += work;
 135                err = pthread_create(&p->pthread, NULL, preload_thread, p);
 136
 137                if (err)
 138                        die(_("unable to create threaded lstat: %s"), strerror(err));
 139        }
 140        for (i = 0; i < threads; i++) {
 141                struct thread_data *p = data+i;
 142                if (pthread_join(p->pthread, NULL))
 143                        die("unable to join threaded lstat");
 144        }
 145        stop_progress(&pd.progress);
 146
 147        trace_performance_leave("preload index");
 148}
 149
 150int repo_read_index_preload(struct repository *repo,
 151                            const struct pathspec *pathspec,
 152                            unsigned int refresh_flags)
 153{
 154        int retval = repo_read_index(repo);
 155
 156        preload_index(repo->index, pathspec, refresh_flags);
 157        return retval;
 158}