C++ DatabaseType::getPrimary方法代码示例

Status CatalogManagerReplicaSet::shardCollection(OperationContext* txn,
                                                 const string& ns,
                                                 const ShardKeyPattern& fieldsAndOrder,
                                                 bool unique,
                                                 const vector<BSONObj>& initPoints,
                                                 const set<ShardId>& initShardIds) {
    // Lock the collection globally so that no other mongos can try to shard or drop the collection
    // at the same time.
    auto scopedDistLock = getDistLockManager()->lock(ns, "shardCollection");
    if (!scopedDistLock.isOK()) {
        return scopedDistLock.getStatus();
    }

    StatusWith<DatabaseType> status = getDatabase(nsToDatabase(ns));
    if (!status.isOK()) {
        return status.getStatus();
    }

    DatabaseType dbt = status.getValue();
    ShardId dbPrimaryShardId = dbt.getPrimary();
    const auto primaryShard = grid.shardRegistry()->getShard(dbPrimaryShardId);

    {
        // In 3.0 and prior we include this extra safety check that the collection is not getting
        // sharded concurrently by two different mongos instances. It is not 100%-proof, but it
        // reduces the chance that two invocations of shard collection will step on each other's
        // toes.  Now we take the distributed lock so going forward this check won't be necessary
        // but we leave it around for compatibility with other mongoses from 3.0.
        // TODO(spencer): Remove this after 3.2 ships.
        const auto configShard = grid.shardRegistry()->getShard("config");
        const auto readHost = configShard->getTargeter()->findHost(kConfigReadSelector);
        if (!readHost.isOK()) {
            return readHost.getStatus();
        }

        auto countStatus = _runCountCommand(
            readHost.getValue(), NamespaceString(ChunkType::ConfigNS), BSON(ChunkType::ns(ns)));
        if (!countStatus.isOK()) {
            return countStatus.getStatus();
        }
        if (countStatus.getValue() > 0) {
            return Status(ErrorCodes::AlreadyInitialized,
                          str::stream() << "collection " << ns << " already sharded with "
                                        << countStatus.getValue() << " chunks.");
        }
    }

    // Record start in changelog
    {
        BSONObjBuilder collectionDetail;
        collectionDetail.append("shardKey", fieldsAndOrder.toBSON());
        collectionDetail.append("collection", ns);
        collectionDetail.append("primary", primaryShard->toString());

        {
            BSONArrayBuilder initialShards(collectionDetail.subarrayStart("initShards"));
            for (const ShardId& shardId : initShardIds) {
                initialShards.append(shardId);
            }
        }

        collectionDetail.append("numChunks", static_cast<int>(initPoints.size() + 1));

        logChange(txn->getClient()->clientAddress(true),
                  "shardCollection.start",
                  ns,
                  collectionDetail.obj());
    }

    ChunkManagerPtr manager(new ChunkManager(ns, fieldsAndOrder, unique));
    manager->createFirstChunks(dbPrimaryShardId, &initPoints, &initShardIds);
    manager->loadExistingRanges(nullptr);

    CollectionInfo collInfo;
    collInfo.useChunkManager(manager);
    collInfo.save(ns);
    manager->reload(true);

    // TODO(spencer) SERVER-19319: Send setShardVersion to primary shard so it knows to start
    // rejecting unversioned writes.

    BSONObj finishDetail = BSON("version"
                                << "");  // TODO(spencer) SERVER-19319 Report actual version used

    logChange(txn->getClient()->clientAddress(true), "shardCollection", ns, finishDetail);

    return Status::OK();
}

DBConfig::DBConfig(std::string name, const DatabaseType& dbt, repl::OpTime configOpTime)
    : _name(name), _configOpTime(std::move(configOpTime)) {
    invariant(_name == dbt.getName());
    _primaryId = dbt.getPrimary();
    _shardingEnabled = dbt.getSharded();
}