[SVN-2256] make fs_base's auto-merging more efficient

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: trunk
• Fix Version/s: 1.3.0
• Component/s: libsvn_fs_base
• Labels: perf
• Assignee: Unassigned
• Reporter: Ben Collins-Sussman
• Created: 28/Mar/05 19:47
• Updated: 27/Oct/18 16:36
• Resolved: 10/Mar/09 15:22

Description

In svn 1.2, libsvn_fs_fs had it's auto-merging algorithm changed to avoid expensive predecessor walks.  
See revisions 13222, 13223, 13232.

This logic needs to be ported to libsvn_fs_base as well.   This issue should be marked with a 
"performance" keyword.  Specifically, it will make things more efficient when a new HEAD revision 
comes in during a commit that's the process of finalization.  It doesn't happen very often, but when it 
does, the current auto-merging algorithm is very expensive.