Author: stsp
Date: Mon Nov 21 11:11:25 2011
New Revision: 1204445
URL: http://svn.apache.org/viewvc?rev=1204445&view=rev
Log:
On the moves-scan-log branch:
* subversion/libsvn_client/update.c
(scan_moves_log_receiver_baton): Explain the 'moves' hash in detail,
based on the log message of r1204035.
Suggested by: philip
Modified:
subversion/branches/moves-scan-log/subversion/libsvn_client/update.c
Modified: subversion/branches/moves-scan-log/subversion/libsvn_client/update.c
URL:
http://svn.apache.org/viewvc/subversion/branches/moves-scan-log/subversion/libsvn_client/update.c?rev=1204445&r1=1204444&r2=1204445&view=diff
==============================================================================
--- subversion/branches/moves-scan-log/subversion/libsvn_client/update.c
(original)
+++ subversion/branches/moves-scan-log/subversion/libsvn_client/update.c Mon
Nov 21 11:11:25 2011
@@ -168,8 +168,34 @@ struct scan_moves_log_receiver_baton {
svn_ra_session_t *ra_session;
/* The moved nodes hash to be populated.
- * Maps a revision number to an array of repos_move_info_t describing
- * moves which happened in the revision. */
+ * Maps a revision number to an array of svn_wc_repos_move_info_t
+ * objects describing moves which happened in the revision.
+ *
+ * Given a sequence of moves which happened in given revisions, such as:
+ * rA: mv x->z
+ * rA: mv a->b
+ * rB: mv b->c
+ * rC: mv c->d
+ * we map each revision number to all moves which happened in the
+ * revision, which looks as follows:
+ * rA : [(rA, x->z), (rA, a->b)]
+ * rB : [(rB, b->c)]
+ * rC : [(rC, c->d)]
+ * This allows an update to find relevant moves based on the base
+ * revision of a node (during updates the base revision of each node
+ * in the working copy is arbitrary so we might not know the nodes 'a'
+ * and 'x' under these names).
+ * Additionally, all moves pertaining to the same node are chained into a
+ * doubly-linked list via 'next' and 'prev' pointers (see definition of
+ * svn_wc_repos_move_info_t).
+ * This way, an update can look up all moves relevant to a node, forwards
+ * or backwards in history, once it has located a relevant move in the chain.
+ * This can be visualized as follows:
+ * rA : [(rA, x->z, prev=>NULL, next=>NULL),
+ * (rA, a->b, prev=>NULL, next=>(rB, b->c))]
+ * rB : [(rB, b->c), prev=>(rA, a->b), next=>(rC, c->d)]
+ * rC : [(rC, c->d), prev=>(rB, c->d), next=>NULL]
+ */
apr_hash_t *moves;
/* Temporary map of move-target paths to repos_move_info_t.
