Author: toad
Date: 2008-03-20 18:19:26 +0000 (Thu, 20 Mar 2008)
New Revision: 18655
Modified:
trunk/freenet/src/freenet/node/SSKInsertSender.java
Log:
Handle collisions with new messages.
Modified: trunk/freenet/src/freenet/node/SSKInsertSender.java
===================================================================
--- trunk/freenet/src/freenet/node/SSKInsertSender.java 2008-03-20 17:29:27 UTC
(rev 18654)
+++ trunk/freenet/src/freenet/node/SSKInsertSender.java 2008-03-20 18:19:26 UTC
(rev 18655)
@@ -428,6 +428,54 @@
continue;
}
+ if(msg.getSpec() == DMT.FNPSSKDataFoundHeaders)
{
+ /**
+ * Data was already on node, and was
NOT equal to what we sent. COLLISION!
+ *
+ * We can either accept the old data or
the new data.
+ * OLD DATA:
+ * - KSK-based stuff is usable. Well,
somewhat; a node could spoof KSKs on
+ * receiving an insert, (if it knows
them in advance), but it cannot just
+ * start inserts to overwrite old SSKs.
+ * - You cannot "update" an SSK.
+ * NEW DATA:
+ * - KSK-based stuff not usable. (Some
people think this is a good idea!).
+ * - Illusion of updatability. (VERY
BAD IMHO, because it's not really
+ * updatable... FIXME implement TUKs;
would determine latest version based
+ * on version number, and propagate on
request with a certain probability or
+ * according to time. However there are
good arguments to do updating at a
+ * higher level (e.g. key bottleneck
argument), and TUKs should probably be
+ * distinct from SSKs.
+ *
+ * For now, accept the "old" i.e.
preexisting data.
+ */
+ Logger.normal(this, "Got collision on
"+myKey+" ("+uid+") sending to "+next.getPeer());
+
+ headers = ((ShortBuffer)
msg.getObject(DMT.BLOCK_HEADERS)).getData();
+ // Wait for the data
+ MessageFilter mfData =
MessageFilter.create().setSource(next).setField(DMT.UID,
uid).setTimeout(RequestSender.FETCH_TIMEOUT).setType(DMT.FNPSSKDataFoundData);
+ Message dataMessage;
+ try {
+ dataMessage =
node.usm.waitFor(mfData, this);
+ } catch (DisconnectedException e) {
+ if(logMINOR)
+ Logger.minor(this,
"Disconnected: "+next+" getting datareply for "+this);
+ break;
+ }
+ if(dataMessage == null) {
+ Logger.error(this, "Got headers but not
data for datareply for insert from "+this);
+ break;
+ }
+ data = ((ShortBuffer)
dataMessage.getObject(DMT.DATA)).getData();
+
+ synchronized(this) {
+ hasRecentlyCollided = true;
+ hasCollided = true;
+ notifyAll();
+ }
+ continue; // The node will now
propagate the new data. There is no need to move to the next node yet.
+ }
+
if (msg.getSpec() != DMT.FNPInsertReply) {
Logger.error(this, "Unknown reply: " +
msg);
finish(INTERNAL_ERROR, next);
