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Diffstat (limited to 'src/mongo/db/exec/or.cpp')
| -rw-r--r-- | src/mongo/db/exec/or.cpp | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/mongo/db/exec/or.cpp b/src/mongo/db/exec/or.cpp new file mode 100644 index 00000000000..83a441d3896 --- /dev/null +++ b/src/mongo/db/exec/or.cpp @@ -0,0 +1,184 @@ +/** + * Copyright (C) 2013 10gen Inc. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License, version 3, + * as published by the Free Software Foundation. + * + * 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 + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * 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 GNU Affero General 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/exec/or.h" +#include "mongo/db/exec/filter.h" +#include "mongo/db/exec/working_set_common.h" +#include "mongo/util/mongoutils/str.h" + +namespace mongo { + + OrStage::OrStage(WorkingSet* ws, bool dedup, const MatchExpression* filter) + : _ws(ws), _filter(filter), _currentChild(0), _dedup(dedup) { } + + OrStage::~OrStage() { + for (size_t i = 0; i < _children.size(); ++i) { + delete _children[i]; + } + } + + void OrStage::addChild(PlanStage* child) { _children.push_back(child); } + + bool OrStage::isEOF() { return _currentChild >= _children.size(); } + + PlanStage::StageState OrStage::work(WorkingSetID* out) { + ++_commonStats.works; + + if (isEOF()) { return PlanStage::IS_EOF; } + + if (0 == _specificStats.matchTested.size()) { + _specificStats.matchTested = vector<size_t>(_children.size(), 0); + } + + WorkingSetID id = WorkingSet::INVALID_ID; + StageState childStatus = _children[_currentChild]->work(&id); + + if (PlanStage::ADVANCED == childStatus) { + WorkingSetMember* member = _ws->get(id); + + // If we're deduping (and there's something to dedup by) + if (_dedup && member->hasLoc()) { + ++_specificStats.dupsTested; + + // ...and we've seen the DiskLoc before + if (_seen.end() != _seen.find(member->loc)) { + // ...drop it. + ++_specificStats.dupsDropped; + _ws->free(id); + ++_commonStats.needTime; + return PlanStage::NEED_TIME; + } + else { + // Otherwise, note that we've seen it. + _seen.insert(member->loc); + } + } + + if (Filter::passes(member, _filter)) { + if (NULL != _filter) { + ++_specificStats.matchTested[_currentChild]; + } + // Match! return it. + *out = id; + ++_commonStats.advanced; + return PlanStage::ADVANCED; + } + else { + // Does not match, try again. + _ws->free(id); + ++_commonStats.needTime; + return PlanStage::NEED_TIME; + } + } + else if (PlanStage::IS_EOF == childStatus) { + // Done with _currentChild, move to the next one. + ++_currentChild; + + // Maybe we're out of children. + if (isEOF()) { + return PlanStage::IS_EOF; + } + else { + ++_commonStats.needTime; + return PlanStage::NEED_TIME; + } + } + else if (PlanStage::FAILURE == childStatus) { + *out = id; + // If a stage fails, it may create a status WSM to indicate why it + // failed, in which case 'id' is valid. If ID is invalid, we + // create our own error message. + if (WorkingSet::INVALID_ID == id) { + mongoutils::str::stream ss; + ss << "OR stage failed to read in results from child " << _currentChild; + Status status(ErrorCodes::InternalError, ss); + *out = WorkingSetCommon::allocateStatusMember( _ws, status); + } + return childStatus; + } + else { + if (PlanStage::NEED_FETCH == childStatus) { + *out = id; + ++_commonStats.needFetch; + } + else if (PlanStage::NEED_TIME == childStatus) { + ++_commonStats.needTime; + } + + // NEED_TIME, ERROR, NEED_YIELD, pass them up. + return childStatus; + } + } + + void OrStage::prepareToYield() { + ++_commonStats.yields; + for (size_t i = 0; i < _children.size(); ++i) { + _children[i]->prepareToYield(); + } + } + + void OrStage::recoverFromYield() { + ++_commonStats.unyields; + for (size_t i = 0; i < _children.size(); ++i) { + _children[i]->recoverFromYield(); + } + } + + void OrStage::invalidate(const DiskLoc& dl, InvalidationType type) { + ++_commonStats.invalidates; + + if (isEOF()) { return; } + + for (size_t i = 0; i < _children.size(); ++i) { + _children[i]->invalidate(dl, type); + } + + // If we see DL again it is not the same record as it once was so we still want to + // return it. + if (_dedup && INVALIDATION_DELETION == type) { + unordered_set<DiskLoc, DiskLoc::Hasher>::iterator it = _seen.find(dl); + if (_seen.end() != it) { + ++_specificStats.locsForgotten; + _seen.erase(dl); + } + } + } + + PlanStageStats* OrStage::getStats() { + _commonStats.isEOF = isEOF(); + + auto_ptr<PlanStageStats> ret(new PlanStageStats(_commonStats, STAGE_OR)); + ret->specific.reset(new OrStats(_specificStats)); + for (size_t i = 0; i < _children.size(); ++i) { + ret->children.push_back(_children[i]->getStats()); + } + + return ret.release(); + } + +} // namespace mongo |