svn commit: r1574128 - /subversion/trunk/subversion/libsvn_subr/cache-membuffer.c

[br...@apache.org]

Author: breser
Date: Tue Mar  4 16:37:45 2014
New Revision: 1574128

URL: http://svn.apache.org/r1574128
Log:
Fix compiler errors regarding index values for membuffer cache.

The maximum entries in a membuffer cache is limited to the max value of an
apr_uint32_t.  But does pointer arithmatic to calculate indexes into the
cache.  On 64-bit platforms the pointers are going to be 64-bits wide, so
the calculation will be 64-bits wide.  The results will stay within the
range of the apr_uint32_t so it's safe to just cast these calculations.

* subversion/libsvn_subr/cache-membuffer.c
  (free_spare_group): Cast to apr_uint32_t when calculating first_spare_group.
  (drop_entry): Cast to apr_uint32_t when calculating last_in_group.
  (find_entry): Cast to apr_uint32_t when calculating previous and next on
    group headers.



Modified:
    subversion/trunk/subversion/libsvn_subr/cache-membuffer.c

Modified: subversion/trunk/subversion/libsvn_subr/cache-membuffer.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_subr/cache-membuffer.c?rev=1574128&r1=1574127&r2=1574128&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_subr/cache-membuffer.c (original)
+++ subversion/trunk/subversion/libsvn_subr/cache-membuffer.c Tue Mar  4 16:37:45 2014
@@ -811,7 +811,7 @@ free_spare_group(svn_membuffer_t *cache,
 
   /* add to chain of spares */
   group->header.next = cache->first_spare_group;
-  cache->first_spare_group = group - cache->directory;
+  cache->first_spare_group = (apr_uint32_t) (group - cache->directory);
 }
 
 /* Follow the group chain from GROUP in CACHE to its end and return the last
@@ -966,8 +966,8 @@ drop_entry(svn_membuffer_t *cache, entry
   entry_group_t *last_group
     = last_group_in_chain(cache, &cache->directory[group_index]);
   apr_uint32_t last_in_group
-    = (last_group - cache->directory) * GROUP_SIZE
-    + last_group->header.used - 1;
+    = (apr_uint32_t) ((last_group - cache->directory) * GROUP_SIZE
+    + last_group->header.used - 1);
 
   cache_level_t *level = get_cache_level(cache, entry);
 
@@ -1204,9 +1204,11 @@ find_entry(svn_membuffer_t *cache,
               /* chain groups
                */
               new_group->header.chain_length = group->header.chain_length + 1;
-              new_group->header.previous = group - cache->directory;
+              new_group->header.previous = (apr_uint32_t) (group -
+                                                           cache->directory);
               new_group->header.next = NO_INDEX;
-              group->header.next = new_group - cache->directory;
+              group->header.next = (apr_uint32_t) (new_group -
+                                                   cache->directory);
               group = new_group;
             }
         }