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[PATCH v3 17/24] read-cache: read cache-tree in index-v5

From
Thomas Gummerer <t.gummerer@gmail.com>
Date
Aug 18, 2013, 19:42 UTC
Message-ID
<1376854933-31241-18-git-send-email-t.gummerer@gmail.com>
In-Reply-To
<1376854933-31241-1-git-send-email-t.gummerer@gmail.com>

Since the cache-tree data is saved as part of the directory data, we already read it at the beginning of the index. The cache-tree is only converted from this directory data.

The cache-tree data is arranged in a tree, with the children sorted by pathlen at each node, while the ondisk format is sorted lexically. So we have to rebuild this format from the on-disk directory list.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
---
 cache-tree.c    |  2 +-
 cache-tree.h    |  1 +
 read-cache-v5.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+), 1 deletion(-)
diff --git a/cache-tree.c b/cache-tree.c
index 0bbec43..1209732 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -31,7 +31,7 @@ void cache_tree_free(struct cache_tree **it_p)
 	*it_p = NULL;
 }
 
-static int subtree_name_cmp(const char *one, int onelen,
+int subtree_name_cmp(const char *one, int onelen,
 			    const char *two, int twolen)
 {
 	if (onelen < twolen)
diff --git a/cache-tree.h b/cache-tree.h
index f1923ad..9818926 100644
--- a/cache-tree.h
+++ b/cache-tree.h
@@ -25,6 +25,7 @@ struct cache_tree *cache_tree(void);
 void cache_tree_free(struct cache_tree **);
 void cache_tree_invalidate_path(struct cache_tree *, const char *);
 struct cache_tree_sub *cache_tree_sub(struct cache_tree *, const char *);
+int subtree_name_cmp(const char *, int, const char *, int);
 
 void cache_tree_write(struct strbuf *, struct cache_tree *root);
 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
diff --git a/read-cache-v5.c b/read-cache-v5.c
index 85a2069..b14505a 100644
--- a/read-cache-v5.c
+++ b/read-cache-v5.c
@@ -471,6 +471,83 @@ static int convert_resolve_undo(struct index_state *istate,
 	return 0;
 }
 
+static struct cache_tree *convert_one(struct directory_entry *de)
+{
+	int i;
+	struct cache_tree *it;
+
+	it = cache_tree();
+	it->entry_count = de->de_nentries;
+	if (0 <= it->entry_count)
+		hashcpy(it->sha1, de->sha1);
+
+	/*
+	 * Just a heuristic -- we do not add directories that often but
+	 * we do not want to have to extend it immediately when we do,
+	 * hence +2.
+	 */
+	it->subtree_alloc = de->de_nsubtrees + 2;
+	it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
+	for (i = 0; i < de->de_nsubtrees; i++) {
+		struct cache_tree *sub;
+		struct cache_tree_sub *subtree;
+		char *buf, *name;
+
+		sub = convert_one(de->sub[i]);
+		if(!sub)
+			goto free_return;
+
+		name = "";
+		buf = strtok(de->sub[i]->pathname, "/");
+		while (buf) {
+			name = buf;
+			buf = strtok(NULL, "/");
+		}
+		subtree = cache_tree_sub(it, name);
+		subtree->cache_tree = sub;
+	}
+	if (de->de_nsubtrees != it->subtree_nr)
+		die("cache-tree: internal error");
+	return it;
+ free_return:
+	cache_tree_free(&it);
+	return NULL;
+}
+
+static int compare_cache_tree_elements(const void *a, const void *b)
+{
+	const struct directory_entry *de1, *de2;
+
+	de1 = (const struct directory_entry *) a;
+	de2 = (const struct directory_entry *) b;
+	return subtree_name_cmp(de1->pathname, de1->de_pathlen,
+				de2->pathname, de2->de_pathlen);
+}
+
+static void sort_directories(struct directory_entry *de)
+{
+	int i;
+
+	for (i = 0; i < de->de_nsubtrees; i++) {
+		if (de->sub[i]->de_nsubtrees)
+			sort_directories(de->sub[i]);
+	}
+	qsort(de->sub, de->de_nsubtrees, sizeof(struct directory_entry *),
+	      compare_cache_tree_elements);
+}
+
+/*
+ * This function modifies the directory argument that is given to it.
+ * Don't use it if the directory entries are still needed after.
+ */
+static struct cache_tree *cache_tree_convert_v5(struct directory_entry *de)
+{
+	if (!de->de_nentries)
+		return NULL;
+	sort_directories(de);
+	return convert_one(de);
+}
+
 static int read_entries(struct index_state *istate, struct directory_entry *de,
 			unsigned int first_entry_offset, void *mmap,
 			unsigned long mmap_size, unsigned int *nr,
@@ -591,6 +668,7 @@ static int read_index_v5(struct index_state *istate, void *mmap,
 		}
 		de = de->next;
 	}
+	istate->cache_tree = cache_tree_convert_v5(root_directory);
 	istate->cache_nr = nr;
 	return 0;
 }
-- 
1.8.3.4.1231.g9fbf354.dirty
Previous: Eric SunshineNext: Duy Nguyen
Message 36 of 55 in “Index-v5”
  1. 00/24 Index-v5Thomas Gummerer, Aug 18, 2013
  2. 01/24 t2104: Don't fail for index versions other than [23]Thomas Gummerer, Aug 18, 2013
  3. 02/24 read-cache: use fixed width integer typesThomas Gummerer, Aug 18, 2013
  4. Eric SunshineAug 18, 2013
  5. Junio C HamanoAug 20, 2013
  6. Thomas GummererAug 21, 2013
  7. 03/24 read-cache: split index file version specific functionalityThomas Gummerer, Aug 18, 2013
  8. 04/24 read-cache: clear version in discard_index()Thomas Gummerer, Aug 18, 2013
  9. Junio C HamanoAug 20, 2013
  10. Thomas GummererAug 21, 2013
  11. 05/24 read-cache: move index v2 specific functions to their own fileThomas Gummerer, Aug 18, 2013
  12. 06/24 read-cache: Don't compare uid, gid and ino on cygwinThomas Gummerer, Aug 18, 2013
  13. Ramsay JonesAug 18, 2013
  14. Thomas GummererAug 20, 2013
  15. 07/24 read-cache: Re-read index if index file changedThomas Gummerer, Aug 18, 2013
  16. 08/24 add documentation for the index apiThomas Gummerer, Aug 18, 2013
  17. Eric SunshineAug 18, 2013
  18. 09/24 read-cache: add index reading apiThomas Gummerer, Aug 18, 2013
  19. 10/24 make sure partially read index is not changedThomas Gummerer, Aug 18, 2013
  20. Eric SunshineAug 18, 2013
  21. Thomas GummererAug 20, 2013
  22. 11/24 grep.c: use index apiThomas Gummerer, Aug 18, 2013
  23. 12/24 ls-files.c: use index apiThomas Gummerer, Aug 18, 2013
  24. 13/24 documentation: add documentation of the index-v5 file formatThomas Gummerer, Aug 18, 2013
  25. 14/24 read-cache: make in-memory format aware of stat_crcThomas Gummerer, Aug 18, 2013
  26. 15/24 read-cache: read index-v5Thomas Gummerer, Aug 18, 2013
  27. Eric SunshineAug 19, 2013
  28. Duy NguyenAug 20, 2013
  29. Thomas GummererAug 20, 2013
  30. Duy NguyenAug 21, 2013
  31. Duy NguyenAug 20, 2013
  32. Thomas GummererAug 20, 2013
  33. Duy NguyenAug 23, 2013
  34. 16/24 read-cache: read resolve-undo dataThomas Gummerer, Aug 18, 2013
  35. Eric SunshineAug 19, 2013
  36. 17/24 read-cache: read cache-tree in index-v5Thomas Gummerer, Aug 18, 2013
  37. Duy NguyenAug 24, 2013
  38. Thomas GummererNov 25, 2013
  39. 18/24 read-cache: write index-v5Thomas Gummerer, Aug 18, 2013
  40. Duy NguyenAug 24, 2013
  41. Thomas GummererNov 25, 2013
  42. Duy NguyenAug 24, 2013
  43. Duy NguyenAug 24, 2013
  44. 19/24 read-cache: write index-v5 cache-tree dataThomas Gummerer, Aug 18, 2013
  45. 20/24 read-cache: write resolve-undo data for index-v5Thomas Gummerer, Aug 18, 2013
  46. 21/24 update-index.c: rewrite index when index-version is givenThomas Gummerer, Aug 18, 2013
  47. 22/24 p0003-index.sh: add perf test for the index formatsThomas Gummerer, Aug 18, 2013
  48. 23/24 introduce GIT_INDEX_VERSION environment variableThomas Gummerer, Aug 18, 2013
  49. Duy NguyenAug 21, 2013
  50. Thomas GummererAug 21, 2013
  51. 24/24 test-lib: allow setting the index format versionThomas Gummerer, Aug 18, 2013
  52. Duy NguyenAug 24, 2013
  53. Junio C HamanoAug 25, 2013
  54. Duy NguyenAug 25, 2013
  55. Thomas GummererAug 31, 2013

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