C++ QuerySolutionNode::toString方法代码示例

    bool SubplanRunner::runSubplans() {
        // This is what we annotate with the index selections and then turn into a solution.
        auto_ptr<OrMatchExpression> theOr(
            static_cast<OrMatchExpression*>(_query->root()->shallowClone()));

        // This is the skeleton of index selections that is inserted into the cache.
        auto_ptr<PlanCacheIndexTree> cacheData(new PlanCacheIndexTree());

        for (size_t i = 0; i < theOr->numChildren(); ++i) {
            MatchExpression* orChild = theOr->getChild(i);

            auto_ptr<CanonicalQuery> orChildCQ(_cqs.front());
            _cqs.pop();

            // 'solutions' is owned by the SubplanRunner instance until
            // it is popped from the queue.
            vector<QuerySolution*> solutions = _solutions.front();
            _solutions.pop();

            // We already checked for zero solutions in planSubqueries(...).
            invariant(!solutions.empty());

            if (1 == solutions.size()) {
                // There is only one solution. Transfer ownership to an auto_ptr.
                auto_ptr<QuerySolution> autoSoln(solutions[0]);

                // We want a well-formed *indexed* solution.
                if (NULL == autoSoln->cacheData.get()) {
                    // For example, we don't cache things for 2d indices.
                    QLOG() << "Subplanner: No cache data for subchild " << orChild->toString();
                    return false;
                }

                if (SolutionCacheData::USE_INDEX_TAGS_SOLN != autoSoln->cacheData->solnType) {
                    QLOG() << "Subplanner: No indexed cache data for subchild "
                           << orChild->toString();
                    return false;
                }

                // Add the index assignments to our original query.
                Status tagStatus = QueryPlanner::tagAccordingToCache(
                    orChild, autoSoln->cacheData->tree.get(), _indexMap);

                if (!tagStatus.isOK()) {
                    QLOG() << "Subplanner: Failed to extract indices from subchild "
                           << orChild->toString();
                    return false;
                }

                // Add the child's cache data to the cache data we're creating for the main query.
                cacheData->children.push_back(autoSoln->cacheData->tree->clone());
            }
            else {
                // N solutions, rank them.  Takes ownership of orChildCQ.

                // the working set will be shared by the candidate plans and owned by the runner
                WorkingSet* sharedWorkingSet = new WorkingSet();

                MultiPlanStage* multiPlanStage = new MultiPlanStage(_collection,
                                                                    orChildCQ.get());

                // Dump all the solutions into the MPR.
                for (size_t ix = 0; ix < solutions.size(); ++ix) {
                    PlanStage* nextPlanRoot;
                    verify(StageBuilder::build(_txn,
                                               _collection,
                                               *solutions[ix],
                                               sharedWorkingSet,
                                               &nextPlanRoot));

                    // Owns first two arguments
                    multiPlanStage->addPlan(solutions[ix], nextPlanRoot, sharedWorkingSet);
                }

                multiPlanStage->pickBestPlan();
                if (! multiPlanStage->bestPlanChosen()) {
                    QLOG() << "Subplanner: Failed to pick best plan for subchild "
                           << orChildCQ->toString();
                    return false;
                }

                Runner* mpr = new SingleSolutionRunner(_collection,
                                                       orChildCQ.release(),
                                                       multiPlanStage->bestSolution(),
                                                       multiPlanStage,
                                                       sharedWorkingSet);

                _underlyingRunner.reset(mpr);

                if (_killed) {
                    QLOG() << "Subplanner: Killed while picking best plan for subchild "
                           << orChild->toString();
                    return false;
                }

                QuerySolution* bestSoln = multiPlanStage->bestSolution();

                if (SolutionCacheData::USE_INDEX_TAGS_SOLN != bestSoln->cacheData->solnType) {
                    QLOG() << "Subplanner: No indexed cache data for subchild "
                           << orChild->toString();
//.........这里部分代码省略.........

    Status SubplanStage::choosePlanForSubqueries(PlanYieldPolicy* yieldPolicy) {
        // This is what we annotate with the index selections and then turn into a solution.
        auto_ptr<OrMatchExpression> orExpr(
            static_cast<OrMatchExpression*>(_query->root()->shallowClone()));

        // This is the skeleton of index selections that is inserted into the cache.
        auto_ptr<PlanCacheIndexTree> cacheData(new PlanCacheIndexTree());

        for (size_t i = 0; i < orExpr->numChildren(); ++i) {
            MatchExpression* orChild = orExpr->getChild(i);
            BranchPlanningResult* branchResult = _branchResults[i];

            if (branchResult->cachedSolution.get()) {
                // We can get the index tags we need out of the cache.
                Status tagStatus = tagOrChildAccordingToCache(
                    cacheData.get(),
                    branchResult->cachedSolution->plannerData[0],
                    orChild,
                    _indexMap);
                if (!tagStatus.isOK()) {
                    return tagStatus;
                }
            }
            else if (1 == branchResult->solutions.size()) {
                QuerySolution* soln = branchResult->solutions.front();
                Status tagStatus = tagOrChildAccordingToCache(cacheData.get(),
                                                              soln->cacheData.get(),
                                                              orChild,
                                                              _indexMap);
                if (!tagStatus.isOK()) {
                    return tagStatus;
                }
            }
            else {
                // N solutions, rank them.

                // We already checked for zero solutions in planSubqueries(...).
                invariant(!branchResult->solutions.empty());

                _ws->clear();

                _child.reset(new MultiPlanStage(_txn, _collection,
                                                branchResult->canonicalQuery.get()));
                MultiPlanStage* multiPlanStage = static_cast<MultiPlanStage*>(_child.get());

                // Dump all the solutions into the MPS.
                for (size_t ix = 0; ix < branchResult->solutions.size(); ++ix) {
                    PlanStage* nextPlanRoot;
                    invariant(StageBuilder::build(_txn,
                                                  _collection,
                                                  *branchResult->solutions[ix],
                                                  _ws,
                                                  &nextPlanRoot));

                    // Takes ownership of solution with index 'ix' and 'nextPlanRoot'.
                    multiPlanStage->addPlan(branchResult->solutions.releaseAt(ix),
                                            nextPlanRoot,
                                            _ws);
                }

                Status planSelectStat = multiPlanStage->pickBestPlan(yieldPolicy);
                if (!planSelectStat.isOK()) {
                    return planSelectStat;
                }

                if (!multiPlanStage->bestPlanChosen()) {
                    mongoutils::str::stream ss;
                    ss << "Failed to pick best plan for subchild "
                       << branchResult->canonicalQuery->toString();
                    return Status(ErrorCodes::BadValue, ss);
                }

                QuerySolution* bestSoln = multiPlanStage->bestSolution();

                // Check that we have good cache data. For example, we don't cache things
                // for 2d indices.
                if (NULL == bestSoln->cacheData.get()) {
                    mongoutils::str::stream ss;
                    ss << "No cache data for subchild " << orChild->toString();
                    return Status(ErrorCodes::BadValue, ss);
                }

                if (SolutionCacheData::USE_INDEX_TAGS_SOLN != bestSoln->cacheData->solnType) {
                    mongoutils::str::stream ss;
                    ss << "No indexed cache data for subchild "
                       << orChild->toString();
                    return Status(ErrorCodes::BadValue, ss);
                }

                // Add the index assignments to our original query.
                Status tagStatus = QueryPlanner::tagAccordingToCache(
                    orChild, bestSoln->cacheData->tree.get(), _indexMap);

                if (!tagStatus.isOK()) {
                    mongoutils::str::stream ss;
                    ss << "Failed to extract indices from subchild "
                       << orChild->toString();
                    return Status(ErrorCodes::BadValue, ss);
                }

//.........这里部分代码省略.........

Status SubplanStage::choosePlanForSubqueries(PlanYieldPolicy* yieldPolicy) {
    // This is the skeleton of index selections that is inserted into the cache.
    std::unique_ptr<PlanCacheIndexTree> cacheData(new PlanCacheIndexTree());

    for (size_t i = 0; i < _orExpression->numChildren(); ++i) {
        MatchExpression* orChild = _orExpression->getChild(i);
        BranchPlanningResult* branchResult = _branchResults[i];

        if (branchResult->cachedSolution.get()) {
            // We can get the index tags we need out of the cache.
            Status tagStatus = tagOrChildAccordingToCache(
                cacheData.get(), branchResult->cachedSolution->plannerData[0], orChild, _indexMap);
            if (!tagStatus.isOK()) {
                return tagStatus;
            }
        } else if (1 == branchResult->solutions.size()) {
            QuerySolution* soln = branchResult->solutions.front();
            Status tagStatus = tagOrChildAccordingToCache(
                cacheData.get(), soln->cacheData.get(), orChild, _indexMap);
            if (!tagStatus.isOK()) {
                return tagStatus;
            }
        } else {
            // N solutions, rank them.

            // We already checked for zero solutions in planSubqueries(...).
            invariant(!branchResult->solutions.empty());

            _ws->clear();

            // We pass the SometimesCache option to the MPS because the SubplanStage currently does
            // not use the CachedPlanStage's eviction mechanism. We therefore are more conservative
            // about putting a potentially bad plan into the cache in the subplan path.
            // We temporarily add the MPS to _children to ensure that we pass down all
            // save/restore/invalidate messages that can be generated if pickBestPlan yields.
            invariant(_children.empty());
            _children.emplace_back(
                stdx::make_unique<MultiPlanStage>(getOpCtx(),
                                                  _collection,
                                                  branchResult->canonicalQuery.get(),
                                                  MultiPlanStage::CachingMode::SometimesCache));
            ON_BLOCK_EXIT([&] {
                invariant(_children.size() == 1);  // Make sure nothing else was added to _children.
                _children.pop_back();
            });
            MultiPlanStage* multiPlanStage = static_cast<MultiPlanStage*>(child().get());

            // Dump all the solutions into the MPS.
            for (size_t ix = 0; ix < branchResult->solutions.size(); ++ix) {
                PlanStage* nextPlanRoot;
                invariant(StageBuilder::build(getOpCtx(),
                                              _collection,
                                              *branchResult->canonicalQuery,
                                              *branchResult->solutions[ix],
                                              _ws,
                                              &nextPlanRoot));

                // Takes ownership of solution with index 'ix' and 'nextPlanRoot'.
                multiPlanStage->addPlan(branchResult->solutions.releaseAt(ix), nextPlanRoot, _ws);
            }

            Status planSelectStat = multiPlanStage->pickBestPlan(yieldPolicy);
            if (!planSelectStat.isOK()) {
                return planSelectStat;
            }

            if (!multiPlanStage->bestPlanChosen()) {
                mongoutils::str::stream ss;
                ss << "Failed to pick best plan for subchild "
                   << branchResult->canonicalQuery->toString();
                return Status(ErrorCodes::BadValue, ss);
            }

            QuerySolution* bestSoln = multiPlanStage->bestSolution();

            // Check that we have good cache data. For example, we don't cache things
            // for 2d indices.
            if (NULL == bestSoln->cacheData.get()) {
                mongoutils::str::stream ss;
                ss << "No cache data for subchild " << orChild->toString();
                return Status(ErrorCodes::BadValue, ss);
            }

            if (SolutionCacheData::USE_INDEX_TAGS_SOLN != bestSoln->cacheData->solnType) {
                mongoutils::str::stream ss;
                ss << "No indexed cache data for subchild " << orChild->toString();
                return Status(ErrorCodes::BadValue, ss);
            }

            // Add the index assignments to our original query.
            Status tagStatus = QueryPlanner::tagAccordingToCache(
                orChild, bestSoln->cacheData->tree.get(), _indexMap);

            if (!tagStatus.isOK()) {
                mongoutils::str::stream ss;
                ss << "Failed to extract indices from subchild " << orChild->toString();
                return Status(ErrorCodes::BadValue, ss);
            }

            cacheData->children.push_back(bestSoln->cacheData->tree->clone());
//.........这里部分代码省略.........