Simplify cache API

Earlier, add_file_to_index() invalidated the path in the cache-tree
but remove_file_from_cache() did not, and the user of the latter
needed to invalidate the entry himself.  This led to a few bugs due to
missed invalidate calls already.  This patch makes the management of
cache-tree less error prone by making more invalidate calls from lower
level cache API functions.

The rules are:

 - If you are going to write the index, you should either maintain
   cache_tree correctly.

   - If you cannot, alternatively you can remove the entire cache_tree
     by calling cache_tree_free() before you call write_cache().

   - When you modify the index, cache_tree_invalidate_path() should be
     called with the path you are modifying, to discard the entry from
     the cache-tree structure.

 - The following cache API functions exported from read-cache.c (and
   the macro whose names have "cache" instead of "index")
   automatically call cache_tree_invalidate_path() for you:

   - remove_file_from_index();
   - add_file_to_index();
   - add_index_entry();

   You can modify the index bypassing the above API functions
   (e.g. find an existing cache entry from the index and modify it in
   place).  You need to call cache_tree_invalidate_path() yourself in
   such a case.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 0 insertions, 9 deletions

diff --git a/builtin-update-index.c b/builtin-update-index.c
index a7a4574..55fb679 100644
--- a/builtin-update-index.c
+++ b/builtin-update-index.c
@@ -195,11 +195,6 @@ static int process_path(const char *path)
 	int len;
 	struct stat st;
 
-	/* We probably want to do this in remove_file_from_cache() and
-	 * add_cache_entry() instead...
-	 */
-	cache_tree_invalidate_path(active_cache_tree, path);
-
 	/*
 	 * First things first: get the stat information, to decide
 	 * what to do about the pathname!
@@ -239,7 +234,6 @@ static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 		return error("%s: cannot add to the index - missing --add option?",
 			     path);
 	report("add '%s'", path);
-	cache_tree_invalidate_path(active_cache_tree, path);
 	return 0;
 }
 
@@ -284,7 +278,6 @@ static void update_one(const char *path, const char *prefix, int prefix_length)
 			die("Unable to mark file %s", path);
 		goto free_return;
 	}
-	cache_tree_invalidate_path(active_cache_tree, path);
 
 	if (force_remove) {
 		if (remove_file_from_cache(p))
@@ -367,7 +360,6 @@ static void read_index_info(int line_termination)
 				free(path_name);
 			continue;
 		}
-		cache_tree_invalidate_path(active_cache_tree, path_name);
 
 		if (!mode) {
 			/* mode == 0 means there is no such path -- remove */
@@ -474,7 +466,6 @@ static int unresolve_one(const char *path)
 		goto free_return;
 	}
 
-	cache_tree_invalidate_path(active_cache_tree, path);
 	remove_file_from_cache(path);
 	if (add_cache_entry(ce_2, ADD_CACHE_OK_TO_ADD)) {
 		error("%s: cannot add our version to the index.", path);