git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
blob aae6e4a042bff58eb06a78be80595e52fc1e6854 4114 bytes (raw)
name: preload-index.c 	 # note: path name is non-authoritative(*)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
 
/*
 * Copyright (C) 2008 Linus Torvalds
 */
#include "cache.h"
#include "pathspec.h"
#include "dir.h"
#include "fsmonitor.h"
#include "config.h"
#include "progress.h"
#include "thread-utils.h"
#include "repository.h"

/*
 * Mostly randomly chosen maximum thread counts: we
 * cap the parallelism to 20 threads, and we want
 * to have at least 500 lstat's per thread for it to
 * be worth starting a thread.
 */
#define MAX_PARALLEL (20)
#define THREAD_COST (500)

struct progress_data {
	unsigned long n;
	struct progress *progress;
	pthread_mutex_t mutex;
};

struct thread_data {
	pthread_t pthread;
	struct index_state *index;
	struct pathspec pathspec;
	struct progress_data *progress;
	int offset, nr;
	int t2_nr_lstat;
};

static void *preload_thread(void *_data)
{
	int nr, last_nr;
	struct thread_data *p = _data;
	struct index_state *index = p->index;
	struct cache_entry **cep = index->cache + p->offset;
	struct cache_def cache = CACHE_DEF_INIT;

	nr = p->nr;
	if (nr + p->offset > index->cache_nr)
		nr = index->cache_nr - p->offset;
	last_nr = nr;

	do {
		struct cache_entry *ce = *cep++;
		struct stat st;

		if (ce_stage(ce))
			continue;
		if (S_ISGITLINK(ce->ce_mode))
			continue;
		if (ce_uptodate(ce))
			continue;
		if (ce_skip_worktree(ce))
			continue;
		if (ce->ce_flags & CE_FSMONITOR_VALID)
			continue;
		if (p->progress && !(nr & 31)) {
			struct progress_data *pd = p->progress;

			pthread_mutex_lock(&pd->mutex);
			pd->n += last_nr - nr;
			display_progress(pd->progress, pd->n);
			pthread_mutex_unlock(&pd->mutex);
			last_nr = nr;
		}
		if (!ce_path_match(index, ce, &p->pathspec, NULL))
			continue;
		if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
			continue;
		p->t2_nr_lstat++;
		if (lstat(ce->name, &st))
			continue;
		if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
			continue;
		ce_mark_uptodate(ce);
		mark_fsmonitor_valid(index, ce);
	} while (--nr > 0);
	if (p->progress) {
		struct progress_data *pd = p->progress;

		pthread_mutex_lock(&pd->mutex);
		display_progress(pd->progress, pd->n + last_nr);
		pthread_mutex_unlock(&pd->mutex);
	}
	cache_def_clear(&cache);
	return NULL;
}

void preload_index(struct index_state *index,
		   const struct pathspec *pathspec,
		   unsigned int refresh_flags)
{
	int threads, i, work, offset;
	struct thread_data data[MAX_PARALLEL];
	struct progress_data pd;
	int t2_sum_lstat = 0;

	if (!HAVE_THREADS || !core_preload_index)
		return;

	threads = index->cache_nr / THREAD_COST;
	if ((index->cache_nr > 1) && (threads < 2) && git_env_bool("GIT_TEST_PRELOAD_INDEX", 0))
		threads = 2;
	if (threads < 2)
		return;

	trace2_region_enter("index", "preload", NULL);

	trace_performance_enter();
	if (threads > MAX_PARALLEL)
		threads = MAX_PARALLEL;
	offset = 0;
	work = DIV_ROUND_UP(index->cache_nr, threads);
	memset(&data, 0, sizeof(data));

	memset(&pd, 0, sizeof(pd));
	pd.progress = start_delayed_progress_if_tty(_("Refreshing index"),index->cache_nr,
						   refresh_flags & REFRESH_PROGRESS ? -1 : 0);
	pthread_mutex_init(&pd.mutex, NULL);

	for (i = 0; i < threads; i++) {
		struct thread_data *p = data+i;
		int err;

		p->index = index;
		if (pathspec)
			copy_pathspec(&p->pathspec, pathspec);
		p->offset = offset;
		p->nr = work;
		if (pd.progress)
			p->progress = &pd;
		offset += work;
		err = pthread_create(&p->pthread, NULL, preload_thread, p);

		if (err)
			die(_("unable to create threaded lstat: %s"), strerror(err));
	}
	for (i = 0; i < threads; i++) {
		struct thread_data *p = data+i;
		if (pthread_join(p->pthread, NULL))
			die("unable to join threaded lstat");
		t2_sum_lstat += p->t2_nr_lstat;
	}
	stop_progress(&pd.progress);

	trace_performance_leave("preload index");

	trace2_data_intmax("index", NULL, "preload/sum_lstat", t2_sum_lstat);
	trace2_region_leave("index", "preload", NULL);
}

int repo_read_index_preload(struct repository *repo,
			    const struct pathspec *pathspec,
			    unsigned int refresh_flags)
{
	int retval = repo_read_index(repo);

	preload_index(repo->index, pathspec, refresh_flags);
	return retval;
}

debug log:

solving aae6e4a042 ...
found aae6e4a042 in https://public-inbox.org/git/20210623215736.8279-2-szeder.dev@gmail.com/
found e5529a5863 in https://80x24.org/mirrors/git.git
preparing index
index prepared:
100644 e5529a586366d4031a5300d7ab0dfa6ec97489b8	preload-index.c

applying [1/1] https://public-inbox.org/git/20210623215736.8279-2-szeder.dev@gmail.com/
diff --git a/preload-index.c b/preload-index.c
index e5529a5863..aae6e4a042 100644

Checking patch preload-index.c...
Applied patch preload-index.c cleanly.

index at:
100644 aae6e4a042bff58eb06a78be80595e52fc1e6854	preload-index.c

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).