shard_filterer_impl.cpp

/**
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 *
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 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
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 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
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 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
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 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
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#include "mongo/platform/basic.h"

#include "mongo/db/exec/shard_filterer_impl.h"

#include "mongo/db/exec/filter.h"
#include "mongo/db/matcher/matchable.h"

namespace mongo {

std::unique_ptr<ShardFilterer> ShardFiltererImpl::clone() const {
    return std::make_unique<ShardFiltererImpl>(_collectionFilter);
}

ShardFiltererImpl::ShardFiltererImpl(ScopedCollectionFilter cf) : _collectionFilter(std::move(cf)) {
    if (_collectionFilter.isSharded()) {
        _keyPattern = ShardKeyPattern(_collectionFilter.getKeyPattern());
    }
}

ShardFilterer::DocumentBelongsResult ShardFiltererImpl::keyBelongsToMeHelper(
    const BSONObj& shardKey) const {
    if (shardKey.isEmpty()) {
        return DocumentBelongsResult::kNoShardKey;
    }

    return keyBelongsToMe(shardKey) ? DocumentBelongsResult::kBelongs
                                    : DocumentBelongsResult::kDoesNotBelong;
}

ShardFilterer::DocumentBelongsResult ShardFiltererImpl::documentBelongsToMe(
    const WorkingSetMember& wsm) const {
    if (!_collectionFilter.isSharded()) {
        return DocumentBelongsResult::kBelongs;
    }

    if (wsm.hasObj()) {
        return keyBelongsToMeHelper(_keyPattern->extractShardKeyFromDoc(wsm.doc.value().toBson()));
    }
    // Transform 'IndexKeyDatum' provided by 'wsm' into 'IndexKeyData' to call
    // extractShardKeyFromIndexKeyData().
    invariant(!wsm.keyData.empty());
    std::vector<ShardKeyPattern::IndexKeyData> indexKeyDataVector;
    indexKeyDataVector.resize(wsm.keyData.size());
    for (auto&& indexKeyData : wsm.keyData) {
        indexKeyDataVector.push_back({indexKeyData.keyData, indexKeyData.indexKeyPattern});
    }
    return keyBelongsToMeHelper(_keyPattern->extractShardKeyFromIndexKeyData(indexKeyDataVector));
}

ShardFilterer::DocumentBelongsResult ShardFiltererImpl::documentBelongsToMe(
    const BSONObj& doc) const {
    if (!_collectionFilter.isSharded()) {
        return DocumentBelongsResult::kBelongs;
    }
    return keyBelongsToMeHelper(_keyPattern->extractShardKeyFromDoc(doc));
}

const KeyPattern& ShardFiltererImpl::getKeyPattern() const {
    invariant(_keyPattern);
    return _keyPattern->getKeyPattern();
}

size_t ShardFiltererImpl::getApproximateSize() const {
    // _collectionFilter contains a shared_ptr to metadata, but it does not own this metadata,
    // so we don't account for the size of the metadata here.
    auto size = sizeof(ShardFiltererImpl);
    size += _keyPattern ? _keyPattern->getApproximateSize() - sizeof(ShardKeyPattern) : 0;
    return 0;
}
}  // namespace mongo