git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v2 3/9] ewah/bitmap: introduce bitmap_word_alloc()

From
Christian Couder <christian.couder@gmail.com>
Date
Oct 19, 2019, 10:35 UTC
Message-ID
<20191019103531.23274-4-chriscool@tuxfamily.org>
In-Reply-To
<20191019103531.23274-1-chriscool@tuxfamily.org>
From: Jeff King <peff@peff.net>

In a following commit we will need to allocate a variable number of bitmap words, instead of always 32, so let's add bitmap_word_alloc() for this purpose.

We will also always access at least one word for each bitmap, so we want to make sure that at least one is always allocated.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 ewah/bitmap.c | 13 +++++++++----
 ewah/ewok.h   |  1 +
 2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/ewah/bitmap.c b/ewah/bitmap.c
index 52f1178db4..b5fed9621f 100644
--- a/ewah/bitmap.c
+++ b/ewah/bitmap.c
@@ -22,21 +22,26 @@
 #define EWAH_MASK(x) ((eword_t)1 << (x % BITS_IN_EWORD))
 #define EWAH_BLOCK(x) (x / BITS_IN_EWORD)
 
-struct bitmap *bitmap_new(void)
+struct bitmap *bitmap_word_alloc(size_t word_alloc)
 {
 	struct bitmap *bitmap = xmalloc(sizeof(struct bitmap));
-	bitmap->words = xcalloc(32, sizeof(eword_t));
-	bitmap->word_alloc = 32;
+	bitmap->words = xcalloc(word_alloc, sizeof(eword_t));
+	bitmap->word_alloc = word_alloc;
 	return bitmap;
 }
 
+struct bitmap *bitmap_new(void)
+{
+	return bitmap_word_alloc(32);
+}
+
 void bitmap_set(struct bitmap *self, size_t pos)
 {
 	size_t block = EWAH_BLOCK(pos);
 
 	if (block >= self->word_alloc) {
 		size_t old_size = self->word_alloc;
-		self->word_alloc = block * 2;
+		self->word_alloc = block ? block * 2 : 1;
 		REALLOC_ARRAY(self->words, self->word_alloc);
 		memset(self->words + old_size, 0x0,
 			(self->word_alloc - old_size) * sizeof(eword_t));
diff --git a/ewah/ewok.h b/ewah/ewok.h
index 84b2a29faa..1b98b57c8b 100644
--- a/ewah/ewok.h
+++ b/ewah/ewok.h
@@ -172,6 +172,7 @@ struct bitmap {
 };
 
 struct bitmap *bitmap_new(void);
+struct bitmap *bitmap_word_alloc(size_t word_alloc);
 void bitmap_set(struct bitmap *self, size_t pos);
 int bitmap_get(struct bitmap *self, size_t pos);
 void bitmap_reset(struct bitmap *self);
-- 
2.24.0.rc0.9.gef620577e2
Previous: Christian CouderNext: Jonathan Tan
Message 4 of 22 in “Rewrite packfile reuse code”
  1. 0/9 Rewrite packfile reuse codeChristian Couder, Oct 19, 2019
  2. 1/9 builtin/pack-objects: report reused packfile objectsChristian Couder, Oct 19, 2019
  3. 2/9 packfile: expose get_delta_base()Christian Couder, Oct 19, 2019
  4. 3/9 ewah/bitmap: introduce bitmap_word_alloc()Christian Couder, Oct 19, 2019
  5. Jonathan TanOct 22, 2019
  6. Christian CouderOct 26, 2019
  7. 4/9 pack-bitmap: don't rely on bitmap_git->reuse_objectsChristian Couder, Oct 19, 2019
  8. 5/9 pack-bitmap: introduce bitmap_walk_contains()Christian Couder, Oct 19, 2019
  9. Philip OakleyOct 19, 2019
  10. Christian CouderOct 19, 2019
  11. Philip OakleyOct 19, 2019
  12. Jeff KingOct 19, 2019
  13. 6/9 csum-file: introduce hashfile_total()Christian Couder, Oct 19, 2019
  14. 7/9 pack-objects: introduce pack.allowPackReuseChristian Couder, Oct 19, 2019
  15. 8/9 builtin/pack-objects: introduce obj_is_packed()Christian Couder, Oct 19, 2019
  16. 9/9 pack-objects: improve partial packfile reuseChristian Couder, Oct 19, 2019
  17. Philip OakleyOct 19, 2019
  18. Christian CouderOct 19, 2019
  19. Jeff KingOct 19, 2019
  20. Philip OakleyOct 20, 2019
  21. Jonathan TanOct 22, 2019
  22. Christian CouderOct 26, 2019

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.