Author: stefan2
Date: Sun Apr 13 09:45:03 2014
New Revision: 1586947
URL: http://svn.apache.org/r1586947
Log:
Improve MT scalability of the FSFS DAG traversal code.
Error objects are a very expensive way to control the control flow
as they carry their own pools, created from a thread-safe root pool.
dag_open should not return an error to open_path if the dirent
cannot be found, pass a NULL node back instead. This eliminates
about 50% of all transitional error objects during log-y operations.
As there are only 2 callers of dag_open, they are easy to adapt.
* subversion/libsvn_fs_fs/dag.h
(svn_fs_fs__dag_clone_root): Document the new error behavior.
* subversion/libsvn_fs_fs/dag.c
(svn_fs_fs__dag_clone_child): This caller actually wants an error,
thus we create it here.
(svn_fs_fs__dag_open): Return NULL if entry cannot be found.
* subversion/libsvn_fs_fs/tree.c
(open_path): Replace error meddling with a check for NULL.
Modified:
subversion/trunk/subversion/libsvn_fs_fs/dag.c
subversion/trunk/subversion/libsvn_fs_fs/dag.h
subversion/trunk/subversion/libsvn_fs_fs/tree.c
Modified: subversion/trunk/subversion/libsvn_fs_fs/dag.c
URL:
http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/dag.c?rev=1586947&r1=1586946&r2=1586947&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_fs_fs/dag.c (original)
+++ subversion/trunk/subversion/libsvn_fs_fs/dag.c Sun Apr 13 09:45:03 2014
@@ -685,6 +685,10 @@ svn_fs_fs__dag_clone_child(dag_node_t **
/* Find the node named NAME in PARENT's entries list if it exists. */
SVN_ERR(svn_fs_fs__dag_open(&cur_entry, parent, name, pool, subpool));
+ if (! cur_entry)
+ return svn_error_createf
+ (SVN_ERR_FS_NOT_FOUND, NULL,
+ "Attempted to open non-existent child node '%s'", name);
/* Check for mutability in the node we found. If it's mutable, we
don't need to clone it. */
@@ -1174,9 +1178,10 @@ svn_fs_fs__dag_open(dag_node_t **child_p
SVN_ERR(dir_entry_id_from_node(&node_id, parent, name,
scratch_pool, scratch_pool));
if (! node_id)
- return svn_error_createf
- (SVN_ERR_FS_NOT_FOUND, NULL,
- "Attempted to open non-existent child node '%s'", name);
+ {
+ *child_p = NULL;
+ return SVN_NO_ERROR;
+ }
/* Make sure that NAME is a single path component. */
if (! svn_path_is_single_path_component(name))
Modified: subversion/trunk/subversion/libsvn_fs_fs/dag.h
URL:
http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/dag.h?rev=1586947&r1=1586946&r2=1586947&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_fs_fs/dag.h (original)
+++ subversion/trunk/subversion/libsvn_fs_fs/dag.h Sun Apr 13 09:45:03 2014
@@ -254,7 +254,8 @@ svn_error_t *svn_fs_fs__dag_clone_root(d
/* Open the node named NAME in the directory PARENT. Set *CHILD_P to
the new node, allocated in RESULT_POOL. NAME must be a single path
- component; it cannot be a slash-separated directory path.
+ component; it cannot be a slash-separated directory path. If NAME does
+ not exist within PARENT, set *CHILD_P to NULL.
*/
svn_error_t *
svn_fs_fs__dag_open(dag_node_t **child_p,
Modified: subversion/trunk/subversion/libsvn_fs_fs/tree.c
URL:
http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/tree.c?rev=1586947&r1=1586946&r2=1586947&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_fs_fs/tree.c (original)
+++ subversion/trunk/subversion/libsvn_fs_fs/tree.c Sun Apr 13 09:45:03 2014
@@ -1033,7 +1033,6 @@ open_path(parent_path_t **parent_path_p,
{
copy_id_inherit_t inherit;
const char *copy_path = NULL;
- svn_error_t *err = SVN_NO_ERROR;
dag_node_t *cached_node = NULL;
/* If we found a directory entry, follow it. First, we
@@ -1047,17 +1046,15 @@ open_path(parent_path_t **parent_path_p,
if (cached_node)
child = cached_node;
else
- err = svn_fs_fs__dag_open(&child, here, entry, pool, iterpool);
+ SVN_ERR(svn_fs_fs__dag_open(&child, here, entry, pool, iterpool));
/* "file not found" requires special handling. */
- if (err && err->apr_err == SVN_ERR_FS_NOT_FOUND)
+ if (child == NULL)
{
/* If this was the last path component, and the caller
said it was optional, then don't return an error;
just put a NULL node pointer in the path. */
- svn_error_clear(err);
-
if ((flags & open_path_last_optional)
&& (! next || *next == '\0'))
{
@@ -1073,9 +1070,6 @@ open_path(parent_path_t **parent_path_p,
}
}
- /* Other errors we return normally. */
- SVN_ERR(err);
-
if (flags & open_path_node_only)
{
/* Shortcut: the caller only wan'ts the final DAG node. */
