/**
* returns in order from branch root to head for a non-empty BranchChain, shall return modifiable
* list
*/
public List<Nodeid> visitBranches(BranchChain bc) throws HgRemoteConnectionException {
if (bc == null) {
return Collections.emptyList();
}
List<Nodeid> mine = completeBranch(bc.branchRoot, bc.branchHead);
if (bc.isTerminal() || bc.isRepoStart()) {
return mine;
}
List<Nodeid> parentBranch1 = visitBranches(bc.p1);
List<Nodeid> parentBranch2 = visitBranches(bc.p2);
// merge
LinkedList<Nodeid> merged = new LinkedList<Nodeid>();
ListIterator<Nodeid> i1 = parentBranch1.listIterator(), i2 = parentBranch2.listIterator();
while (i1.hasNext() && i2.hasNext()) {
Nodeid n1 = i1.next();
Nodeid n2 = i2.next();
if (n1.equals(n2)) {
merged.addLast(n1);
} else {
// first different => add both, and continue adding both tails sequentially
merged.add(n2);
merged.add(n1);
break;
}
}
// copy rest of second parent branch
while (i2.hasNext()) {
merged.add(i2.next());
}
// copy rest of first parent branch
while (i1.hasNext()) {
merged.add(i1.next());
}
//
ArrayList<Nodeid> rv = new ArrayList<Nodeid>(mine.size() + merged.size());
rv.addAll(merged);
rv.addAll(mine);
return rv;
}
// somewhat similar to Outgoing.findCommonWithRemote()
public List<BranchChain> calculateMissingBranches() throws HgRemoteConnectionException {
List<Nodeid> remoteHeads = remoteRepo.heads();
LinkedList<Nodeid> common = new LinkedList<Nodeid>(); // these remotes are known in local
LinkedHashSet<Nodeid> toQuery =
new LinkedHashSet<Nodeid>(); // these need further queries to find common
for (Nodeid rh : remoteHeads) {
if (localRepo.knownNode(rh)) {
common.add(rh);
} else {
toQuery.add(rh);
}
}
if (toQuery.isEmpty()) {
return Collections.emptyList(); // no incoming changes
}
LinkedList<BranchChain> branches2load = new LinkedList<BranchChain>(); // return value
// detailed comments are in Outgoing.findCommonWithRemote
LinkedList<RemoteBranch> checkUp2Head = new LinkedList<RemoteBranch>();
// records relation between branch head and its parent branch, if any
HashMap<Nodeid, BranchChain> head2chain = new HashMap<Nodeid, BranchChain>();
while (!toQuery.isEmpty()) {
List<RemoteBranch> remoteBranches =
remoteRepo.branches(
new ArrayList<Nodeid>(toQuery)); // head, root, first parent, second parent
toQuery.clear();
while (!remoteBranches.isEmpty()) {
RemoteBranch rb = remoteBranches.remove(0);
BranchChain chainElement = head2chain.get(rb.head);
if (chainElement == null) {
chainElement = new BranchChain(rb.head);
// record this unknown branch to download later
branches2load.add(chainElement);
// the only chance we'll need chainElement in the head2chain is when we know this branch's
// root
head2chain.put(rb.head, chainElement);
}
if (localRepo.knownNode(rb.root)) {
// we known branch start, common head is somewhere in its descendants line
checkUp2Head.add(rb);
} else {
chainElement.branchRoot = rb.root;
// dig deeper in the history, if necessary
boolean hasP1 = !rb.p1.isNull(), hasP2 = !rb.p2.isNull();
if (hasP1 && !localRepo.knownNode(rb.p1)) {
toQuery.add(rb.p1);
// we might have seen parent node already, and recorded it as a branch chain
// we shall reuse existing BC to get it completely initialized (head2chain map
// on second put with the same key would leave first BC uninitialized.
// It seems there's no reason to be afraid (XXX although shall double-check)
// that BC's chain would get corrupt (its p1 and p2 fields assigned twice with different
// values)
// as parents are always the same (and likely, BC that is common would be the last
// unknown)
BranchChain bc = head2chain.get(rb.p1);
if (bc == null) {
head2chain.put(rb.p1, bc = new BranchChain(rb.p1));
}
chainElement.p1 = bc;
}
if (hasP2 && !localRepo.knownNode(rb.p2)) {
toQuery.add(rb.p2);
BranchChain bc = head2chain.get(rb.p2);
if (bc == null) {
head2chain.put(rb.p2, bc = new BranchChain(rb.p2));
}
chainElement.p2 = bc;
}
if (!hasP1 && !hasP2) {
// special case, when we do incoming against blank repository, chainElement.branchRoot
// is first unknown element (revision 0). We need to add another fake BranchChain
// to fill the promise that terminal BranchChain has branchRoot that is known both
// locally and remotely
BranchChain fake = new BranchChain(NULL);
fake.branchRoot = NULL;
chainElement.p1 = chainElement.p2 = fake;
}
}
}
}
for (RemoteBranch rb : checkUp2Head) {
Nodeid h = rb.head;
Nodeid r = rb.root;
int watchdog = 1000;
assert head2chain.containsKey(h);
BranchChain bc = head2chain.get(h);
assert bc != null : h.toString();
// if we know branch root locally, there could be no parent branch chain elements.
assert bc.p1 == null;
assert bc.p2 == null;
do {
List<Nodeid> between = remoteRepo.between(h, r);
if (between.isEmpty()) {
bc.branchRoot = r;
break;
} else {
Collections.reverse(between);
for (Nodeid n : between) {
if (localRepo.knownNode(n)) {
r = n;
} else {
h = n;
break;
}
}
Nodeid lastInBetween = between.get(between.size() - 1);
if (r.equals(lastInBetween)) {
bc.branchRoot = r;
break;
} else if (h.equals(
lastInBetween)) { // the only chance for current head pointer to point to the sequence
// tail
// is when r is second from the between list end (iow, head,1,[2],4,8...,root)
bc.branchRoot = r;
break;
}
}
} while (--watchdog > 0);
if (watchdog == 0) {
throw new HgInvalidStateException(
String.format(
"Can't narrow down branch [%s, %s]",
rb.head.shortNotation(), rb.root.shortNotation()));
}
}
if (debug) {
System.out.println("calculateMissingBranches:");
for (BranchChain bc : branches2load) {
bc.dump();
}
}
return branches2load;
}
