CollectionMetadata* CollectionMetadata::cloneMerge( const BSONObj& minKey,
const BSONObj& maxKey,
const ChunkVersion& newShardVersion,
string* errMsg ) const {
if (newShardVersion <= _shardVersion) {
*errMsg = stream() << "cannot merge range " << rangeToString( minKey, maxKey )
<< ", new shard version " << newShardVersion.toString()
<< " is not greater than current version "
<< _shardVersion.toString();
warning() << *errMsg << endl;
return NULL;
}
RangeVector overlap;
getRangeMapOverlap( _chunksMap, minKey, maxKey, &overlap );
if ( overlap.empty() || overlap.size() == 1 ) {
*errMsg = stream() << "cannot merge range " << rangeToString( minKey, maxKey )
<< ( overlap.empty() ? ", no chunks found in this range" :
", only one chunk found in this range" );
warning() << *errMsg << endl;
return NULL;
}
bool validStartEnd = true;
bool validNoHoles = true;
if ( overlap.begin()->first.woCompare( minKey ) != 0 ) {
// First chunk doesn't start with minKey
validStartEnd = false;
}
else if ( overlap.rbegin()->second.woCompare( maxKey ) != 0 ) {
// Last chunk doesn't end with maxKey
validStartEnd = false;
}
else {
// Check that there are no holes
BSONObj prevMaxKey = minKey;
for ( RangeVector::iterator it = overlap.begin(); it != overlap.end(); ++it ) {
if ( it->first.woCompare( prevMaxKey ) != 0 ) {
validNoHoles = false;
break;
}
prevMaxKey = it->second;
}
}
if ( !validStartEnd || !validNoHoles ) {
*errMsg = stream() << "cannot merge range " << rangeToString( minKey, maxKey )
<< ", overlapping chunks " << overlapToString( overlap )
<< ( !validStartEnd ? " do not have the same min and max key" :
" are not all adjacent" );
warning() << *errMsg << endl;
return NULL;
}
auto_ptr<CollectionMetadata> metadata( new CollectionMetadata );
metadata->_keyPattern = this->_keyPattern;
metadata->_keyPattern.getOwned();
metadata->_pendingMap = this->_pendingMap;
metadata->_chunksMap = this->_chunksMap;
metadata->_rangesMap = this->_rangesMap;
metadata->_shardVersion = newShardVersion;
metadata->_collVersion =
newShardVersion > _collVersion ? newShardVersion : this->_collVersion;
for ( RangeVector::iterator it = overlap.begin(); it != overlap.end(); ++it ) {
metadata->_chunksMap.erase( it->first );
}
metadata->_chunksMap.insert( make_pair( minKey, maxKey ) );
dassert(metadata->isValid());
return metadata.release();
}
StatusWith<std::unique_ptr<CollectionMetadata>> CollectionMetadata::cloneMerge(
const BSONObj& minKey, const BSONObj& maxKey, const ChunkVersion& newShardVersion) const {
invariant(newShardVersion.epoch() == _shardVersion.epoch());
invariant(newShardVersion > _shardVersion);
RangeVector overlap;
getRangeMapOverlap(_chunksMap, minKey, maxKey, &overlap);
if (overlap.empty() || overlap.size() == 1) {
return {ErrorCodes::IllegalOperation,
stream() << "cannot merge range " << rangeToString(minKey, maxKey)
<< (overlap.empty() ? ", no chunks found in this range"
: ", only one chunk found in this range")};
}
bool validStartEnd = true;
bool validNoHoles = true;
if (overlap.begin()->first.woCompare(minKey) != 0) {
// First chunk doesn't start with minKey
validStartEnd = false;
} else if (overlap.rbegin()->second.woCompare(maxKey) != 0) {
// Last chunk doesn't end with maxKey
validStartEnd = false;
} else {
// Check that there are no holes
BSONObj prevMaxKey = minKey;
for (RangeVector::iterator it = overlap.begin(); it != overlap.end(); ++it) {
if (it->first.woCompare(prevMaxKey) != 0) {
validNoHoles = false;
break;
}
prevMaxKey = it->second;
}
}
if (!validStartEnd || !validNoHoles) {
return {ErrorCodes::IllegalOperation,
stream() << "cannot merge range " << rangeToString(minKey, maxKey)
<< ", overlapping chunks " << overlapToString(overlap)
<< (!validStartEnd ? " do not have the same min and max key"
: " are not all adjacent")};
}
unique_ptr<CollectionMetadata> metadata(stdx::make_unique<CollectionMetadata>());
metadata->_keyPattern = _keyPattern.getOwned();
metadata->fillKeyPatternFields();
metadata->_pendingMap = _pendingMap;
metadata->_chunksMap = _chunksMap;
metadata->_rangesMap = _rangesMap;
metadata->_shardVersion = newShardVersion;
metadata->_collVersion = newShardVersion > _collVersion ? newShardVersion : this->_collVersion;
for (RangeVector::iterator it = overlap.begin(); it != overlap.end(); ++it) {
metadata->_chunksMap.erase(it->first);
}
metadata->_chunksMap.insert(make_pair(minKey, maxKey));
invariant(metadata->isValid());
return std::move(metadata);
}
