Hi,
Stefan Sperling asked me to post some details in respect of a suggestion I wanted to make for issue 3830
http://subversion.tigris.org/issues/show_bug.cgi?id=3830
It took me some time to understand that it is _not_ possible for the svn client to display the future of an object in some revision when it no longer resists on the initial path or was replaced by another object on the same path.
Well, here is the pseudo code of my algorithm to determine the forward history & backward history of a svn path_at_peg in logarithmic time (it should terminate quickly in most real world situations):
log[] getFullRemoteLog(urlOfObject, revOfObject)
url = urlOfObject
peg = revOfObject
// start to fetch complete forward & backward log of url_at_peg
endRev = repsitory.getLastChangedRevision()
try
// first try the regular way
// using HEAD instead of HEAD's rev number as endRev produces wrong results in svn 1.6.
// see http://subversion.tigris.org/issues/show_bug.cgi?id=3931
return svn log url_at_peg -r endRev:1
catch exception
// OK, no problem. Remote file does no longer exist on HEAD. Proceed.
startRev = peg
youngestRev = determineYoungestRevision(url, startRev.number(), endRev.number(), false)
return svn log url_at_peg -r youngestRev:1
rev determineYoungestRevision(url, startRev, endRev, objectFound)
if startRev == endRev
return startRev
testRev = startRev + (endRev - startRev) / 2
if objectFound
try
svn info url_at_testRev -r startRev
// test revision exists => proceed forward in history
determineYoungestRevision(url, testRev, endRev, true)
catch exception
// test revision does not exist => go backward in history
determineYoungestRevision(url, startRev, testRev - 1 , true)
// right object not yet found
try
log[] = svn log url_at_testRev -r testRev:1
// object hit! But is it the right one?
for i:log.length // no need to improve as svn requests dominate Running time
if log[i - 1].getRevision() >= startRev && log[i].getRevision() <= startRev
// right object found! Now find youngest object revision.
return determineYoungestRevision(url, log[0].getRevision(), endRev, true)
// not the right object!
return determineYoungestRevision(url, startRev, log[log.length - 1].getRevision() - 2, false)
catch exception
// no object hit!
return determineLastYoungestRevision(url, startRev, testRev.getNumber() - 1, false)
Greetings,
Julian
p.s. please cc me. I am not subscribed
Received on 2012-03-02 15:13:11 CET