@NotNull
@Override
public List<? extends VcsCommitMetadata> readFirstBlock(
@NotNull VirtualFile root, @NotNull Requirements requirements) throws VcsException {
if (!isRepositoryReady(root)) {
return Collections.emptyList();
}
int commitCount = requirements.getCommitCount();
if (requirements.isOrdered()) {
commitCount *=
2; // need to query more to sort them manually; this doesn't affect performance: it is
// equal for -1000 and -2000
}
String[] params =
new String[] {"HEAD", "--branches", "--remotes", "--max-count=" + commitCount};
// NB: not specifying --tags, because it introduces great slowdown if there are many tags,
// but makes sense only if there are heads without branch or HEAD labels (rare case). Such cases
// are partially handles below.
List<VcsCommitMetadata> firstBlock = GitHistoryUtils.loadMetadata(myProject, root, params);
if (requirements instanceof VcsLogProviderRequirementsEx) {
VcsLogProviderRequirementsEx rex = (VcsLogProviderRequirementsEx) requirements;
// on refresh: get new tags, which point to commits not from the first block; then get
// history, walking down just from these tags
// on init: just ignore such tagged-only branches. The price for speed-up.
if (!rex.isOrdered()) {
Collection<VcsRef> newTags = getNewTags(rex.getCurrentRefs(), rex.getPreviousRefs());
if (!newTags.isEmpty()) {
final Set<Hash> firstBlockHashes =
ContainerUtil.map2Set(
firstBlock,
new Function<VcsCommitMetadata, Hash>() {
@Override
public Hash fun(VcsCommitMetadata metadata) {
return metadata.getHash();
}
});
List<VcsRef> unmatchedHeads = getUnmatchedHeads(firstBlockHashes, newTags);
if (!unmatchedHeads.isEmpty()) {
List<VcsCommitMetadata> detailsFromTaggedBranches =
loadSomeCommitsOnTaggedBranches(root, commitCount, unmatchedHeads);
Collection<VcsCommitMetadata> unmatchedCommits =
getUnmatchedCommits(firstBlockHashes, detailsFromTaggedBranches);
firstBlock.addAll(unmatchedCommits);
}
}
}
}
if (requirements.isOrdered()) {
firstBlock = VcsLogSorter.sortByDateTopoOrder(firstBlock);
firstBlock =
new ArrayList<VcsCommitMetadata>(
firstBlock.subList(0, Math.min(firstBlock.size(), requirements.getCommitCount())));
}
return firstBlock;
}
