path: root/src/mongo/db/query/cqf_command_utils.cpp

/**
 *    Copyright (C) 2022-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    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>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    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)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include "mongo/db/query/cqf_command_utils.h"

#include "mongo/db/commands/test_commands_enabled.h"
#include "mongo/db/exec/sbe/abt/abt_lower.h"
#include "mongo/db/matcher/expression_always_boolean.h"
#include "mongo/db/matcher/expression_array.h"
#include "mongo/db/matcher/expression_expr.h"
#include "mongo/db/matcher/expression_geo.h"
#include "mongo/db/matcher/expression_internal_bucket_geo_within.h"
#include "mongo/db/matcher/expression_internal_expr_comparison.h"
#include "mongo/db/matcher/expression_leaf.h"
#include "mongo/db/matcher/expression_text.h"
#include "mongo/db/matcher/expression_text_noop.h"
#include "mongo/db/matcher/expression_tree.h"
#include "mongo/db/matcher/expression_type.h"
#include "mongo/db/matcher/expression_visitor.h"
#include "mongo/db/matcher/expression_where.h"
#include "mongo/db/matcher/expression_where_noop.h"
#include "mongo/db/matcher/match_expression_walker.h"
#include "mongo/db/matcher/schema/expression_internal_schema_all_elem_match_from_index.h"
#include "mongo/db/matcher/schema/expression_internal_schema_allowed_properties.h"
#include "mongo/db/matcher/schema/expression_internal_schema_cond.h"
#include "mongo/db/matcher/schema/expression_internal_schema_eq.h"
#include "mongo/db/matcher/schema/expression_internal_schema_fmod.h"
#include "mongo/db/matcher/schema/expression_internal_schema_match_array_index.h"
#include "mongo/db/matcher/schema/expression_internal_schema_max_items.h"
#include "mongo/db/matcher/schema/expression_internal_schema_max_length.h"
#include "mongo/db/matcher/schema/expression_internal_schema_max_properties.h"
#include "mongo/db/matcher/schema/expression_internal_schema_min_items.h"
#include "mongo/db/matcher/schema/expression_internal_schema_min_length.h"
#include "mongo/db/matcher/schema/expression_internal_schema_min_properties.h"
#include "mongo/db/matcher/schema/expression_internal_schema_object_match.h"
#include "mongo/db/matcher/schema/expression_internal_schema_root_doc_eq.h"
#include "mongo/db/matcher/schema/expression_internal_schema_unique_items.h"
#include "mongo/db/matcher/schema/expression_internal_schema_xor.h"
#include "mongo/db/pipeline/abt/agg_expression_visitor.h"
#include "mongo/db/pipeline/abt/document_source_visitor.h"
#include "mongo/db/pipeline/abt/match_expression_visitor.h"
#include "mongo/db/pipeline/abt/utils.h"
#include "mongo/db/pipeline/document_source_bucket_auto.h"
#include "mongo/db/pipeline/document_source_coll_stats.h"
#include "mongo/db/pipeline/document_source_current_op.h"
#include "mongo/db/pipeline/document_source_cursor.h"
#include "mongo/db/pipeline/document_source_exchange.h"
#include "mongo/db/pipeline/document_source_facet.h"
#include "mongo/db/pipeline/document_source_geo_near.h"
#include "mongo/db/pipeline/document_source_geo_near_cursor.h"
#include "mongo/db/pipeline/document_source_graph_lookup.h"
#include "mongo/db/pipeline/document_source_group.h"
#include "mongo/db/pipeline/document_source_index_stats.h"
#include "mongo/db/pipeline/document_source_internal_inhibit_optimization.h"
#include "mongo/db/pipeline/document_source_internal_shard_filter.h"
#include "mongo/db/pipeline/document_source_internal_split_pipeline.h"
#include "mongo/db/pipeline/document_source_internal_unpack_bucket.h"
#include "mongo/db/pipeline/document_source_limit.h"
#include "mongo/db/pipeline/document_source_list_cached_and_active_users.h"
#include "mongo/db/pipeline/document_source_list_local_sessions.h"
#include "mongo/db/pipeline/document_source_list_sessions.h"
#include "mongo/db/pipeline/document_source_lookup.h"
#include "mongo/db/pipeline/document_source_match.h"
#include "mongo/db/pipeline/document_source_merge.h"
#include "mongo/db/pipeline/document_source_operation_metrics.h"
#include "mongo/db/pipeline/document_source_out.h"
#include "mongo/db/pipeline/document_source_plan_cache_stats.h"
#include "mongo/db/pipeline/document_source_queue.h"
#include "mongo/db/pipeline/document_source_redact.h"
#include "mongo/db/pipeline/document_source_replace_root.h"
#include "mongo/db/pipeline/document_source_sample.h"
#include "mongo/db/pipeline/document_source_sample_from_random_cursor.h"
#include "mongo/db/pipeline/document_source_sequential_document_cache.h"
#include "mongo/db/pipeline/document_source_single_document_transformation.h"
#include "mongo/db/pipeline/document_source_skip.h"
#include "mongo/db/pipeline/document_source_sort.h"
#include "mongo/db/pipeline/document_source_tee_consumer.h"
#include "mongo/db/pipeline/document_source_union_with.h"
#include "mongo/db/pipeline/document_source_unwind.h"
#include "mongo/db/pipeline/visitors/document_source_visitor.h"
#include "mongo/db/pipeline/visitors/document_source_walker.h"
#include "mongo/db/pipeline/visitors/transformer_interface_walker.h"
#include "mongo/db/query/projection_ast_path_tracking_visitor.h"
#include "mongo/db/query/query_feature_flags_gen.h"
#include "mongo/db/query/query_knobs_gen.h"
#include "mongo/db/query/query_planner_params.h"
#include "mongo/s/query/document_source_merge_cursors.h"

namespace mongo {

using namespace optimizer;

namespace {

/**
 * Visitor that is responsible for indicating whether a MatchExpression is eligible for Bonsai by
 * setting the '_eligible' member variable. Expressions which are "test-only" and not officially
 * supported should set _eligible to false.
 */
class ABTMatchExpressionVisitor : public MatchExpressionConstVisitor {
public:
    ABTMatchExpressionVisitor(bool& eligible) : _eligible(eligible) {}

    void visit(const LTEMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const LTMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const ElemMatchObjectMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const ElemMatchValueMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const EqualityMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const GTEMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const GTMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const InMatchExpression* expr) override {
        assertSupportedPathExpression(expr);

        // $in over a regex predicate is not supported.
        if (!expr->getRegexes().empty()) {
            _eligible = false;
        }
    }
    void visit(const ExistsMatchExpression* expr) override {
        assertSupportedPathExpression(expr);
    }
    void visit(const AndMatchExpression* expr) override {}
    void visit(const OrMatchExpression* expr) override {}

    void visit(const GeoMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const GeoNearMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalBucketGeoWithinMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalExprEqMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalExprGTMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalExprGTEMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalExprLTMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalExprLTEMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaAllElemMatchFromIndexMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaAllowedPropertiesMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaBinDataEncryptedTypeExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaBinDataFLE2EncryptedTypeExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaBinDataSubTypeExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaCondMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaEqMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaFmodMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaMatchArrayIndexMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaMaxItemsMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaMaxLengthMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaMaxPropertiesMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaMinItemsMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaMinLengthMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaMinPropertiesMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaObjectMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaRootDocEqMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaTypeExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaUniqueItemsMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const InternalSchemaXorMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const ModMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const NorMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const NotMatchExpression* expr) override {}

    void visit(const RegexMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const SizeMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const TextMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const TextNoOpMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const TwoDPtInAnnulusExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const WhereMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const WhereNoOpMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const BitsAllClearMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const BitsAllSetMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const BitsAnyClearMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const BitsAnySetMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const TypeMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const AlwaysFalseMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const AlwaysTrueMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const ExprMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

    void visit(const BetweenMatchExpression* expr) override {
        unsupportedExpression(expr);
    }

private:
    void unsupportedExpression(const MatchExpression* expr) {
        _eligible = false;
    }

    void assertSupportedPathExpression(const PathMatchExpression* expr) {
        if (FieldRef(expr->path()).hasNumericPathComponents())
            _eligible = false;
    }

    bool& _eligible;
};

class ABTProjectionVisitor final : public projection_ast::ProjectionASTConstVisitor {
public:
    ABTProjectionVisitor(projection_ast::PathTrackingVisitorContext<>* context, bool& eligible)
        : _context{context}, _eligible(eligible) {
        invariant(_context);
    }

    void visit(const projection_ast::ProjectionPositionalASTNode* node) final {
        unsupportedProjectionType();
    }

    void visit(const projection_ast::ProjectionSliceASTNode* node) final {
        unsupportedProjectionType();
    }

    void visit(const projection_ast::ProjectionElemMatchASTNode* node) final {
        unsupportedProjectionType();
    }

    void visit(const projection_ast::ExpressionASTNode* node) final {
        unsupportedProjectionType();
    }

    void visit(const projection_ast::BooleanConstantASTNode* node) final {
        const auto& path = _context->fullPath();
        assertSupportedPath(path.fullPath());
    }

    void visit(const projection_ast::ProjectionPathASTNode* node) final {}

    void visit(const projection_ast::MatchExpressionASTNode* node) final {
        unsupportedProjectionType();
    }

private:
    projection_ast::PathTrackingVisitorContext<>* _context;
    bool& _eligible;

    void assertSupportedPath(const std::string& path) {
        if (FieldRef(path).hasNumericPathComponents())
            _eligible = false;
    }

    void unsupportedProjectionType() {
        _eligible = false;
    }
};

/**
 * Visitor that is responsible for indicating whether a DocumentSource is eligible for Bonsai by
 * setting the 'eligible' member variable. Stages which are "test-only" and not officially supported
 * should set 'eligible' to false.
 */
class ABTUnsupportedDocumentSourceVisitor : public DocumentSourceConstVisitor {
public:
    void visit(const DocumentSourceInternalUnpackBucket* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceBucketAuto* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceCollStats* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceCurrentOp* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceCursor* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceExchange* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceFacet* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceGeoNear* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceGeoNearCursor* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceGraphLookUp* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceIndexStats* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceInternalShardFilter* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceInternalSplitPipeline* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceListCachedAndActiveUsers* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceListLocalSessions* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceListSessions* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceLookUp* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceMerge* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceMergeCursors* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceOperationMetrics* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceOut* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourcePlanCacheStats* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceQueue* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceRedact* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceSample* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceSampleFromRandomCursor* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceSequentialDocumentCache* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceTeeConsumer* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceGroup* source) override {
        unsupportedStage(source);
    }
    void visit(const DocumentSourceLimit* source) override {
        unsupportedStage(source);
    }
    void visit(const DocumentSourceSkip* source) override {
        unsupportedStage(source);
    }
    void visit(const DocumentSourceSort* source) override {
        unsupportedStage(source);
    }
    void visit(const DocumentSourceUnwind* source) override {
        unsupportedStage(source);
    }
    void visit(const DocumentSourceUnionWith* source) override {
        unsupportedStage(source);
    }

    void visit(const DocumentSourceInternalInhibitOptimization* source) override {
        // Can be ignored.
    }

    void visit(const DocumentSourceMatch* source) override {
        // Pass a reference to our local 'eligible' variable to allow the visitor to overwrite it.
        ABTMatchExpressionVisitor visitor(eligible);
        MatchExpressionWalker walker(nullptr /*preVisitor*/, nullptr /*inVisitor*/, &visitor);
        tree_walker::walk<true, MatchExpression>(source->getMatchExpression(), &walker);
    }

    void visit(const DocumentSourceSingleDocumentTransformation* source) override {
        switch (source->getType()) {
            case TransformerInterface::TransformerType::kComputedProjection:
            case TransformerInterface::TransformerType::kGroupFromFirstDocument:
            case TransformerInterface::TransformerType::kReplaceRoot:
                eligible = false;
                break;
            case TransformerInterface::TransformerType::kExclusionProjection:
            case TransformerInterface::TransformerType::kInclusionProjection: {
                tassert(6684602,
                        "Translating Inclusion or Exclusion projection but there's no AST in "
                        "DocumentSource",
                        source->hasProjectionAST());

                projection_ast::PathTrackingVisitorContext context;
                ABTProjectionVisitor visitor(&context, eligible);
                projection_ast::PathTrackingWalker walker{&context, {&visitor}, {}};
                tree_walker::walk<true, projection_ast::ASTNode>(source->getProjectionAST()->root(),
                                                                 &walker);
            }
        }
    }

    void unsupportedStage(const DocumentSource* source) {
        eligible = false;
    }

    bool eligible = true;
};

template <class RequestType>
bool isEligibleCommon(const RequestType& request,
                      OperationContext* opCtx,
                      const CollectionPtr& collection) {
    // The FindCommandRequest defaults some parameters to BSONObj() instead of boost::none.
    auto noneOrDefaultEmpty = [&](auto param) {
        if constexpr (std::is_same_v<decltype(param), boost::optional<BSONObj>>) {
            return param && !param->isEmpty();
        } else {
            return !param.isEmpty();
        }
    };
    bool unsupportedCmdOption = noneOrDefaultEmpty(request.getHint()) ||
        noneOrDefaultEmpty(request.getCollation()) || noneOrDefaultEmpty(request.getLet()) ||
        request.getLegacyRuntimeConstants();

    bool unsupportedIndexType = [&]() {
        if (collection == nullptr)
            return false;

        const IndexCatalog& indexCatalog = *collection->getIndexCatalog();
        auto indexIterator =
            indexCatalog.getIndexIterator(opCtx, IndexCatalog::InclusionPolicy::kReady);

        while (indexIterator->more()) {
            const IndexDescriptor& descriptor = *indexIterator->next()->descriptor();
            if (descriptor.hidden()) {
                // An index that is hidden will not be considered by the optimizer, so we don't need
                // to check its eligibility further.
                continue;
            }

            if (descriptor.isPartial() || descriptor.isSparse() ||
                descriptor.getIndexType() != IndexType::INDEX_BTREE ||
                !descriptor.collation().isEmpty()) {
                return true;
            }
        }
        return false;
    }();

    bool unsupportedCollectionType = [&]() {
        if (collection == nullptr)
            return false;

        if (collection->isClustered() || !collection->getCollectionOptions().collation.isEmpty() ||
            collection->getTimeseriesOptions()) {
            return true;
        }

        return false;
    }();

    return !unsupportedCmdOption && !unsupportedIndexType && !unsupportedCollectionType &&
        !storageGlobalParams.noTableScan.load();
}

boost::optional<bool> shouldForceEligibility() {
    // Without the feature flag set, no queries are eligible for Bonsai.
    if (!serverGlobalParams.featureCompatibility.isVersionInitialized() ||
        !feature_flags::gFeatureFlagCommonQueryFramework.isEnabled(
            serverGlobalParams.featureCompatibility)) {
        return false;
    }

    auto queryControl = ServerParameterSet::getNodeParameterSet()->get<QueryFrameworkControl>(
        "internalQueryFrameworkControl");

    switch (queryControl->_data.get()) {
        case QueryFrameworkControlEnum::kForceClassicEngine:
        case QueryFrameworkControlEnum::kTrySbeEngine:
            return false;
        case QueryFrameworkControlEnum::kTryBonsai:
            // Return boost::none to indicate that we should not force eligibility of bonsai nor the
            // classic engine.
            return boost::none;
        case QueryFrameworkControlEnum::kForceBonsai:
            // This option is only supported with test commands enabled.
            return getTestCommandsEnabled();
    }

    MONGO_UNREACHABLE;
}

}  // namespace

MONGO_FAIL_POINT_DEFINE(enableExplainInBonsai);

bool isEligibleForBonsai(const AggregateCommandRequest& request,
                         const Pipeline& pipeline,
                         OperationContext* opCtx,
                         const CollectionPtr& collection) {
    if (auto forceBonsai = shouldForceEligibility(); forceBonsai.has_value()) {
        return *forceBonsai;
    }

    // Explain is not currently supported but is allowed if the failpoint is set
    // for testing purposes.
    if (!MONGO_unlikely(enableExplainInBonsai.shouldFail()) && request.getExplain()) {
        return false;
    }

    bool commandOptionsEligible = isEligibleCommon(request, opCtx, collection) &&
        !request.getRequestReshardingResumeToken().has_value() && !request.getExchange();

    // Early return to avoid unnecessary work of walking the input pipeline.
    if (!commandOptionsEligible) {
        return false;
    }

    ABTUnsupportedDocumentSourceVisitor visitor;
    DocumentSourceWalker walker(nullptr /*preVisitor*/, &visitor);

    // The rudimentary walker may throw if it reaches a stage that it isn't aware about, so catch it
    // here and return ineligible.
    // TODO SERVER-62027 this should no longer be needed once all stages require a visit.
    try {
        walker.walk(pipeline);
    } catch (DBException&) {
        visitor.eligible = false;
    }

    return visitor.eligible;
}

bool isEligibleForBonsai(const CanonicalQuery& cq,
                         OperationContext* opCtx,
                         const CollectionPtr& collection) {
    if (auto forceBonsai = shouldForceEligibility(); forceBonsai.has_value()) {
        return *forceBonsai;
    }

    // Explain is not currently supported but is allowed if the failpoint is set
    // for testing purposes.
    if (!MONGO_unlikely(enableExplainInBonsai.shouldFail()) && cq.getExplain()) {
        return false;
    }

    auto request = cq.getFindCommandRequest();
    auto expression = cq.root();
    bool commandOptionsEligible = isEligibleCommon(request, opCtx, collection) &&
        request.getSort().isEmpty() && request.getMin().isEmpty() && request.getMax().isEmpty() &&
        !request.getReturnKey() && !request.getSingleBatch() && !request.getTailable() &&
        !request.getSkip() && !request.getLimit() && !request.getNoCursorTimeout() &&
        !request.getRequestResumeToken() && !request.getAllowPartialResults() &&
        !request.getAllowSpeculativeMajorityRead() && !request.getAwaitData() &&
        !request.getReadOnce() && !request.getShowRecordId() && !request.getTerm();

    // Early return to avoid unnecessary work of walking the input expression.
    if (!commandOptionsEligible) {
        return false;
    }

    bool eligible = true;
    ABTMatchExpressionVisitor visitor(eligible);
    MatchExpressionWalker walker(nullptr /*preVisitor*/, nullptr /*inVisitor*/, &visitor);
    tree_walker::walk<true, MatchExpression>(expression, &walker);

    if (cq.getProj()) {
        projection_ast::PathTrackingVisitorContext context;
        ABTProjectionVisitor visitor(&context, eligible);
        projection_ast::PathTrackingWalker walker{&context, {&visitor}, {}};
        tree_walker::walk<true, projection_ast::ASTNode>(cq.getProj()->root(), &walker);
    }

    return eligible;
}

}  // namespace mongo