Author: stefan2
Date: Mon Aug 25 15:55:11 2014
New Revision: 1620358
URL: http://svn.apache.org/r1620358
Log:
On the revprop-caching-ng branch:
Update FSFS structure doc. No functional change.
* subversion/libsvn_fs_fs/structure
(Layout): Add revprop-generation file.
(Revision property generation): New section describing the file contents.
Modified:
subversion/branches/revprop-caching-ng/subversion/libsvn_fs_fs/structure
Modified:
subversion/branches/revprop-caching-ng/subversion/libsvn_fs_fs/structure
URL:
http://svn.apache.org/viewvc/subversion/branches/revprop-caching-ng/subversion/libsvn_fs_fs/structure?rev=1620358&r1=1620357&r2=1620358&view=diff
==============================================================================
--- subversion/branches/revprop-caching-ng/subversion/libsvn_fs_fs/structure
(original)
+++ subversion/branches/revprop-caching-ng/subversion/libsvn_fs_fs/structure
Mon Aug 25 15:55:11 2014
@@ -68,6 +68,7 @@ repository) is:
min-unpacked-rev File containing the oldest revision not in a pack file
min-unpacked-revprop File containing the oldest revision of unpacked revprop
rep-cache.db SQLite database mapping rep checksums to locations
+ revprop-generation File containing the current revprop generation (f. 7+)
Files in the revprops directory are in the hash dump format used by
svn_hash_write.
@@ -414,6 +415,25 @@ Writing to packed revprops
file deletions.
+Revision property generation
+----------------------------
+
+Since format 7, revision properties can be cached. To detect updates,
+the revision property generation number gets incremented twice during
+each revprop change - once immediately before and once immediately
+after the change became active. Hence, odd generation numbers indicate
+a revprop modification in progress and must only appear in open
+repositories.
+
+The revprop generation file format is as follows:
+
+ <MD5> ' ' <generation> '\n'
+
+where <generation> is the decimal ASCII value of the revision property
+generation and <MD5> is the hexadecimal MD5 digest of that decimal
+string.
+
+
Node-revision IDs
-----------------
