Merge branch 'jc/cache-tree' into jc/dirwalk-n-cache-tree

* jc/cache-tree: (24 commits)
  Fix crash when reading the empty tree
  fsck-objects: do not segfault on missing tree in cache-tree
  cache-tree: a bit more debugging support.
  read-tree: invalidate cache-tree entry when a new index entry is added.
  Fix test-dump-cache-tree in one-tree disappeared case.
  fsck-objects: mark objects reachable from cache-tree
  cache-tree: replace a sscanf() by two strtol() calls
  cache-tree.c: typefix
  test-dump-cache-tree: validate the cached data as well.
  cache_tree_update: give an option to update cache-tree only.
  read-tree: teach 1-way merege and plain read to prime cache-tree.
  read-tree: teach 1 and 2 way merges about cache-tree.
  update-index: when --unresolve, smudge the relevant cache-tree entries.
  test-dump-cache-tree: report number of subtrees.
  cache-tree: sort the subtree entries.
  Teach fsck-objects about cache-tree.
  index: make the index file format extensible.
  cache-tree: protect against "git prune".
  Add test-dump-cache-tree
  Use cache-tree in update-index.
  ...

1 files changed, 31 insertions, 0 deletions

diff --git a/cache-tree.h b/cache-tree.h
new file mode 100644
index 0000000000..72c64801f5
--- /dev/null
+++ b/cache-tree.h
@@ -0,0 +1,31 @@
+#ifndef CACHE_TREE_H
+#define CACHE_TREE_H
+
+struct cache_tree;
+struct cache_tree_sub {
+	struct cache_tree *cache_tree;
+	int namelen;
+	int used;
+	char name[FLEX_ARRAY];
+};
+
+struct cache_tree {
+	int entry_count; /* negative means "invalid" */
+	unsigned char sha1[20];
+	int subtree_nr;
+	int subtree_alloc;
+	struct cache_tree_sub **down;
+};
+
+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 *);
+
+void *cache_tree_write(struct cache_tree *root, unsigned long *size_p);
+struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
+
+int cache_tree_fully_valid(struct cache_tree *);
+int cache_tree_update(struct cache_tree *, struct cache_entry **, int, int, int);
+
+#endif