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From: Jeff King <peff@peff.net>
To: git@vger.kernel.org
Subject: [PATCH 5/6] pack-bitmap: save "have" bitmap from walk
Date: Tue, 21 Aug 2018 15:07:01 -0400	[thread overview]
Message-ID: <20180821190701.GE30764@sigill.intra.peff.net> (raw)
In-Reply-To: <20180821184140.GA24165@sigill.intra.peff.net>

When we do a bitmap walk, we save the result, which
represents (WANTs & ~HAVEs); i.e., every object we care
about visiting in our walk. However, we throw away the
haves bitmap, which can sometimes be useful, too. Save it
and provide an access function so code which has performed a
walk can query it.

A few notes on the accessor interface:

 - the bitmap code calls these "haves" because it grew out
   of the want/have negotiation for fetches. But really,
   these are simply the objects that would be flagged
   UNINTERESTING in a regular traversal. Let's use that
   more universal nomenclature for the external module
   interface. We may want to change the internal naming
   inside the bitmap code, but that's outside the scope of
   this patch.

 - it still uses a bare "sha1" rather than "oid". That's
   true of all of the bitmap code. And in this particular
   instance, our caller in pack-objects is dealing with the
   bare sha1 that comes from a packed REF_DELTA (we're
   pointing directly to the mmap'd pack on disk). That's
   something we'll have to deal with as we transition to a
   new hash, but we can wait and see how the caller ends up
   being fixed and adjust this interface accordingly.

Signed-off-by: Jeff King <peff@peff.net>
---
 pack-bitmap.c | 25 ++++++++++++++++++++++++-
 pack-bitmap.h |  7 +++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/pack-bitmap.c b/pack-bitmap.c
index f0a1937a1c..c3231ef9ef 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -86,6 +86,9 @@ struct bitmap_index {
 	/* Bitmap result of the last performed walk */
 	struct bitmap *result;
 
+	/* "have" bitmap from the last performed walk */
+	struct bitmap *haves;
+
 	/* Version of the bitmap index */
 	unsigned int version;
 
@@ -759,8 +762,8 @@ struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs)
 		bitmap_and_not(wants_bitmap, haves_bitmap);
 
 	bitmap_git->result = wants_bitmap;
+	bitmap_git->haves = haves_bitmap;
 
-	bitmap_free(haves_bitmap);
 	return bitmap_git;
 
 cleanup:
@@ -1114,5 +1117,25 @@ void free_bitmap_index(struct bitmap_index *b)
 	free(b->ext_index.objects);
 	free(b->ext_index.hashes);
 	bitmap_free(b->result);
+	bitmap_free(b->haves);
 	free(b);
 }
+
+int bitmap_has_sha1_in_uninteresting(struct bitmap_index *bitmap_git,
+				     const unsigned char *sha1)
+{
+	int pos;
+
+	if (!bitmap_git)
+		return 0; /* no bitmap loaded */
+	if (!bitmap_git->result)
+		BUG("failed to perform bitmap walk before querying");
+	if (!bitmap_git->haves)
+		return 0; /* walk had no "haves" */
+
+	pos = bitmap_position_packfile(bitmap_git, sha1);
+	if (pos < 0)
+		return 0;
+
+	return bitmap_get(bitmap_git->haves, pos);
+}
diff --git a/pack-bitmap.h b/pack-bitmap.h
index 8a04741e12..c633bf5238 100644
--- a/pack-bitmap.h
+++ b/pack-bitmap.h
@@ -53,6 +53,13 @@ int rebuild_existing_bitmaps(struct bitmap_index *, struct packing_data *mapping
 			     khash_sha1 *reused_bitmaps, int show_progress);
 void free_bitmap_index(struct bitmap_index *);
 
+/*
+ * After a traversal has been performed on the bitmap_index, this can be
+ * queried to see if a particular object was reachable from any of the
+ * objects flagged as UNINTERESTING.
+ */
+int bitmap_has_sha1_in_uninteresting(struct bitmap_index *, const unsigned char *sha1);
+
 void bitmap_writer_show_progress(int show);
 void bitmap_writer_set_checksum(unsigned char *sha1);
 void bitmap_writer_build_type_index(struct packing_data *to_pack,
-- 
2.19.0.rc0.398.g138a08f6f6


  parent reply	other threads:[~2018-08-21 19:07 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-21 18:41 [PATCH] test-tool.h: include git-compat-util.h Jeff King
2018-08-21 19:03 ` Junio C Hamano
2018-08-21 19:06 ` [PATCH 1/6] t/perf: factor boilerplate out of test_perf Jeff King
2018-08-21 19:06 ` [PATCH 2/6] t/perf: factor out percent calculations Jeff King
2018-08-21 19:06 ` [PATCH 3/6] t/perf: add infrastructure for measuring sizes Jeff King
2018-08-22 13:40   ` Derrick Stolee
2018-08-22 15:31     ` Jeff King
2018-08-21 19:06 ` [PATCH 4/6] t/perf: add perf tests for fetches from a bitmapped server Jeff King
2018-08-21 19:07 ` Jeff King [this message]
2018-08-21 19:47   ` [PATCH 5/6] pack-bitmap: save "have" bitmap from walk Derrick Stolee
2018-08-21 19:54     ` Jeff King
2018-08-31 15:23   ` Ævar Arnfjörð Bjarmason
2018-08-31 22:55     ` Jeff King
2018-09-01  7:41       ` [PATCH 0/4] un-breaking pack-objects with bitmaps Jeff King
2018-09-01  7:44         ` [PATCH 1/4] bitmap_has_sha1_in_uninteresting(): drop BUG check Jeff King
2018-09-01  7:48         ` [PATCH 2/4] t5310: test delta reuse with bitmaps Jeff King
2018-09-01  8:03           ` Jeff King
2018-09-01 20:29             ` Ævar Arnfjörð Bjarmason
2018-09-01 22:46               ` Ben Peart
2018-09-02  5:51               ` Jeff King
2018-09-04 19:05             ` Stefan Beller
2018-09-04 19:45               ` Junio C Hamano
2018-09-04 20:02               ` Jeff King
2018-09-01  7:49         ` [PATCH 3/4] traverse_bitmap_commit_list(): don't free result Jeff King
2018-09-01  7:50         ` [PATCH 4/4] pack-bitmap: drop "loaded" flag Jeff King
2018-09-04 19:30         ` [PATCH 0/4] un-breaking pack-objects with bitmaps Stefan Beller
2018-09-04 20:03           ` Jeff King
2018-09-08  6:43         ` Ævar Arnfjörð Bjarmason
2018-09-10 16:53           ` Junio C Hamano
2018-09-10 18:48             ` Jeff King
2018-09-10 19:23               ` Junio C Hamano
2018-08-21 19:07 ` [PATCH 6/6] pack-objects: reuse on-disk deltas for thin "have" objects Jeff King
2018-08-21 19:43   ` Junio C Hamano
2018-08-21 19:50     ` Junio C Hamano
2018-08-21 20:07       ` Jeff King
2018-08-21 20:14         ` Jeff King
2018-08-21 20:52           ` Junio C Hamano
2018-08-21 21:30             ` Jeff King
2018-08-21 20:57         ` Junio C Hamano
2018-08-21 21:32           ` Jeff King
2018-08-23  0:43           ` [PATCH 0/9] trailer-parsing false positives Jeff King
2018-08-23  0:44             ` [PATCH 1/9] trailer: use size_t for string offsets Jeff King
2018-08-23  0:45             ` [PATCH 2/9] trailer: use size_t for iterating trailer list Jeff King
2018-08-23  0:46             ` [PATCH 3/9] trailer: pass process_trailer_opts to trailer_info_get() Jeff King
2018-08-23  0:48             ` [PATCH 4/9] interpret-trailers: tighten check for "---" patch boundary Jeff King
2018-08-23  0:49             ` [PATCH 5/9] interpret-trailers: allow suppressing "---" divider Jeff King
2018-08-23  0:50             ` [PATCH 6/9] pretty, ref-filter: format %(trailers) with no_divider option Jeff King
2018-08-23  0:50             ` [PATCH 7/9] sequencer: ignore "---" divider when parsing trailers Jeff King
2018-08-23  0:50             ` [PATCH 8/9] append_signoff: use size_t for string offsets Jeff King
2018-08-23  0:51             ` [PATCH 9/9] sequencer: handle ignore_footer when parsing trailers Jeff King
2018-08-23 18:30             ` [PATCH 0/9] trailer-parsing false positives Junio C Hamano
2018-08-24  7:26               ` Jeff King
2018-08-21 20:00     ` [PATCH 6/6] pack-objects: reuse on-disk deltas for thin "have" objects Jeff King
  -- strict thread matches above, loose matches on Subject: below --
2018-08-17 20:54 [PATCH 0/6] reuse on-disk deltas for fetches with bitmaps Jeff King
2018-08-17 20:59 ` [PATCH 5/6] pack-bitmap: save "have" bitmap from walk Jeff King
2018-08-17 22:39   ` Stefan Beller
2018-08-17 22:45     ` Jeff King
2014-03-26  7:22 [PATCH/RFC 0/6] reuse deltas found by bitmaps Jeff King
2014-03-26  7:23 ` [PATCH 5/6] pack-bitmap: save "have" bitmap from walk Jeff King

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