On Fri, Jun 21, 2013 at 2:11 AM, <stef...@apache.org> wrote: > Author: stefan2 > Date: Thu Jun 20 22:11:31 2013 > New Revision: 1495209 > > URL: http://svn.apache.org/r1495209 > Log: > Make the hash function used by the FSFS DAG node cache > platform-independent. That should help us reproducing issues > detected on "exotic" platforms. > > * subversion/libsvn_fs_fs/tree.c > (cache_lookup): normalize chunked calculation to big endian > > Patch by: stsp > > Modified: > subversion/trunk/subversion/libsvn_fs_fs/tree.c > > Modified: subversion/trunk/subversion/libsvn_fs_fs/tree.c > URL: > http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_fs_fs/tree.c?rev=1495209&r1=1495208&r2=1495209&view=diff > ============================================================================== > --- subversion/trunk/subversion/libsvn_fs_fs/tree.c (original) > +++ subversion/trunk/subversion/libsvn_fs_fs/tree.c Thu Jun 20 22:11:31 2013 > @@ -355,14 +355,15 @@ cache_lookup( fs_fs_dag_cache_t *cache > (HASH_VALUE has been initialized to REVISION). */ > for (i = 0; i + 4 <= path_len; i += 4) > #if SVN_UNALIGNED_ACCESS_IS_OK > - hash_value = hash_value * 0xd1f3da69 + *(const apr_uint32_t*)(path + i); > + hash_value = hash_value * 0xd1f3da69 > + + ntohl(*(const apr_uint32_t*)(path + i)); ntohl() is real function, not inline function or macro on Windows [1]. So most likely your change make hash calculation significantly slower on Windows due function call for each four bytes.
[1] http://msdn.microsoft.com/en-us/library/windows/desktop/ms740069%28v=vs.85%29.aspx -- Ivan Zhakov CTO | VisualSVN | http://www.visualsvn.com
