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[PATCH 02/16] sha1_file: refactor into `find_pack_object_pos`

From
Vicent Marti <tanoku@gmail.com>
Date
Jun 24, 2013, 23:22 UTC
Message-ID
<1372116193-32762-3-git-send-email-tanoku@gmail.com>
In-Reply-To
<1372116193-32762-1-git-send-email-tanoku@gmail.com>

Looking up the offset in the packfile for a given SHA1 involves the following:

	- Finding the position in the index for the given SHA1
	- Accessing the offset cache in the index for the found position

There are cases however where we'd like to find the position of a SHA1 in the index without looking up the packfile offset (e.g. when accessing information that has been indexed based on index offsets).

This refactoring implements `find_pack_object_pos`, returning the
position in the index, and re-implements `find_pack_entry_one`(returning
the actual offset in the packfile) to use the new function.
---
 cache.h     |    1 +
 sha1_file.c |   27 +++++++++++++++++----------
 2 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/cache.h b/cache.h
index ec8240f..a29645e 100644
--- a/cache.h
+++ b/cache.h
@@ -1101,6 +1101,7 @@ extern void clear_delta_base_cache(void);
 extern struct packed_git *add_packed_git(const char *, int, int);
 extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t);
 extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t);
+extern int find_pack_entry_pos(const unsigned char *sha1, struct packed_git *p);
 extern off_t find_pack_entry_one(const unsigned char *, struct packed_git *);
 extern int is_pack_valid(struct packed_git *);
 extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
diff --git a/sha1_file.c b/sha1_file.c
index 0af19c0..371e295 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2205,8 +2205,7 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 	}
 }
 
-off_t find_pack_entry_one(const unsigned char *sha1,
-				  struct packed_git *p)
+int find_pack_entry_pos(const unsigned char *sha1, struct packed_git *p)
 {
 	const uint32_t *level1_ofs = p->index_data;
 	const unsigned char *index = p->index_data;
@@ -2219,7 +2218,7 @@ off_t find_pack_entry_one(const unsigned char *sha1,
 
 	if (!index) {
 		if (open_pack_index(p))
-			return 0;
+			return -1;
 		level1_ofs = p->index_data;
 		index = p->index_data;
 	}
@@ -2243,12 +2242,9 @@ off_t find_pack_entry_one(const unsigned char *sha1,
 
 	if (use_lookup < 0)
 		use_lookup = !!getenv("GIT_USE_LOOKUP");
+
 	if (use_lookup) {
-		int pos = sha1_entry_pos(index, stride, 0,
-					 lo, hi, p->num_objects, sha1);
-		if (pos < 0)
-			return 0;
-		return nth_packed_object_offset(p, pos);
+		return sha1_entry_pos(index, stride, 0, lo, hi, p->num_objects, sha1);
 	}
 
 	do {
@@ -2259,13 +2255,24 @@ off_t find_pack_entry_one(const unsigned char *sha1,
 			printf("lo %u hi %u rg %u mi %u\n",
 			       lo, hi, hi - lo, mi);
 		if (!cmp)
-			return nth_packed_object_offset(p, mi);
+			return mi;
 		if (cmp > 0)
 			hi = mi;
 		else
 			lo = mi+1;
 	} while (lo < hi);
-	return 0;
+
+	return -1;
+}
+
+off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *p)
+{
+	int pos;
+
+	if ((pos = find_pack_entry_pos(sha1, p)) < 0)
+		return 0;
+
+	return nth_packed_object_offset(p, (uint32_t)pos);
 }
 
 int is_pack_valid(struct packed_git *p)
-- 
1.7.9.5
Previous: Vicent MartiNext: Thomas Rast
Message 3 of 64 in “Speed up Counting Objects with bitmap data”
  1. 00/16 Speed up Counting Objects with bitmap dataVicent Marti, Jun 24, 2013
  2. 01/16 list-objects: mark tree as unparsed when we free its bufferVicent Marti, Jun 24, 2013
  3. 02/16 sha1_file: refactor into `find_pack_object_pos`Vicent Marti, Jun 24, 2013
  4. Thomas RastJun 25, 2013
  5. 03/16 pack-objects: use a faster hash tableVicent Marti, Jun 24, 2013
  6. Thomas RastJun 25, 2013
  7. Jeff KingJun 26, 2013
  8. Jeff KingJun 26, 2013
  9. Ramkumar RamachandraJun 25, 2013
  10. Junio C HamanoJun 25, 2013
  11. Vicent MartíJun 25, 2013
  12. 04/16 pack-objects: make `pack_name_hash` globalVicent Marti, Jun 24, 2013
  13. 05/16 revision: allow setting custom limiter functionVicent Marti, Jun 24, 2013
  14. 06/16 sha1_file: export `git_open_noatime`Vicent Marti, Jun 24, 2013
  15. 07/16 compat: add endinanness helpersVicent Marti, Jun 24, 2013
  16. Peter KreftingJun 25, 2013
  17. Vicent MartíJun 25, 2013
  18. Peter KreftingJun 27, 2013
  19. 08/16 ewah: compressed bitmap implementationVicent Marti, Jun 24, 2013
  20. Junio C HamanoJun 25, 2013
  21. Junio C HamanoJun 25, 2013
  22. Thomas RastJun 25, 2013
  23. 09/16 documentation: add documentation for the bitmap formatVicent Marti, Jun 24, 2013
  24. Shawn PearceJun 25, 2013
  25. Vicent MartíJun 25, 2013
  26. Junio C HamanoJun 25, 2013
  27. Vicent MartíJun 25, 2013
  28. Shawn PearceJun 27, 2013
  29. Vicent MartíJun 27, 2013
  30. Jeff KingJun 27, 2013
  31. Shawn PearceJun 27, 2013
  32. Jeff KingJun 27, 2013
  33. Colby RangerJul 1, 2013
  34. Shawn PearceJul 1, 2013
  35. Jeff KingJul 7, 2013
  36. Shawn PearceJul 7, 2013
  37. Jeff KingJun 26, 2013
  38. Colby RangerJun 26, 2013
  39. Colby RangerJun 26, 2013
  40. Colby RangerJun 27, 2013
  41. Shawn PearceJun 27, 2013
  42. Shawn PearceJun 27, 2013
  43. Thomas RastJun 25, 2013
  44. Vicent MartíJun 25, 2013
  45. Thomas RastJun 26, 2013
  46. Thomas RastJun 26, 2013
  47. 10/16 pack-objects: use bitmaps when packing objectsVicent Marti, Jun 24, 2013
  48. Ramkumar RamachandraJun 25, 2013
  49. Thomas RastJun 25, 2013
  50. Junio C HamanoJun 25, 2013
  51. Vicent MartíJun 25, 2013
  52. 11/16 rev-list: add bitmap mode to speed up listsVicent Marti, Jun 24, 2013
  53. Thomas RastJun 25, 2013
  54. Vicent MartíJun 26, 2013
  55. Thomas RastJun 26, 2013
  56. Jeff KingJun 26, 2013
  57. 12/16 pack-objects: implement bitmap writingVicent Marti, Jun 24, 2013
  58. 13/16 repack: consider bitmaps when performing repacksVicent Marti, Jun 24, 2013
  59. Junio C HamanoJun 25, 2013
  60. Vicent MartíJun 25, 2013
  61. 14/16 sha1_file: implement `nth_packed_object_info`Vicent Marti, Jun 24, 2013
  62. 15/16 write-bitmap: implement new git command to write bitmapsVicent Marti, Jun 24, 2013
  63. 16/16 rev-list: Optimize --count using bitmaps tooVicent Marti, Jun 24, 2013
  64. Thomas RastJun 25, 2013

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