SERVER-10026 move 2d into stages, remove old query from 2d execution

1 files changed, 517 insertions, 0 deletions

diff --git a/src/mongo/db/exec/2dnear.cpp b/src/mongo/db/exec/2dnear.cpp
new file mode 100644
index 00000000000..29647b60e99
--- /dev/null
+++ b/src/mongo/db/exec/2dnear.cpp
@@ -0,0 +1,517 @@
+/**
+ *    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/2dnear.h"
+
+#include "mongo/db/exec/working_set_common.h"
+#include "mongo/db/index/catalog_hack.h"
+#include "mongo/db/jsobj.h"
+
+namespace mongo {
+
+    TwoDNear::TwoDNear(const TwoDNearParams& params, WorkingSet* ws) {
+        _params = params;
+        _workingSet = ws;
+        _initted = false;
+    }
+
+    TwoDNear::~TwoDNear() { }
+
+    bool TwoDNear::isEOF() {
+        return _initted && _results.empty();
+    }
+
+    PlanStage::StageState TwoDNear::work(WorkingSetID* out) {
+        if (!_initted) {
+            _initted = true;
+            NamespaceDetails* nsd = nsdetails(_params.ns);
+            if (NULL == nsd) { return PlanStage::IS_EOF; }
+            int idxNo = nsd->findIndexByKeyPattern(_params.indexKeyPattern);
+            if (-1 == idxNo) { return PlanStage::IS_EOF; }
+            auto_ptr<IndexDescriptor> desc(CatalogHack::getDescriptor(nsd, idxNo));
+            auto_ptr<TwoDAccessMethod> am(static_cast<TwoDAccessMethod*>(CatalogHack::getIndex(desc.get())));
+            auto_ptr<twod_exec::GeoSearch> search;
+            search.reset(new twod_exec::GeoSearch(am.get(),
+                                           _params.nearQuery.centroid.oldPoint,
+                                           _params.numWanted, 
+                                           _params.filter,
+                                           _params.nearQuery.maxDistance,
+                                           _params.nearQuery.isNearSphere ? twod_exec::GEO_SPHERE : twod_exec::GEO_PLANE,
+                                           _params.uniqueDocs,
+                                           false));
+            search->exec();
+            for (twod_exec::GeoHopper::Holder::iterator it = search->_points.begin(); it != search->_points.end(); it++) {
+                WorkingSetID id = _workingSet->allocate();
+                WorkingSetMember* member = _workingSet->get(id);
+                member->loc = it->_loc;
+                member->obj = member->loc.obj();
+                //cout << "points: " << member->obj.toString() << endl;
+                member->state = WorkingSetMember::LOC_AND_UNOWNED_OBJ;
+                _results.push(Result(id, it->_distance));
+                _invalidationMap.insert(pair<DiskLoc, WorkingSetID>(it->_loc, id));
+            }
+        }
+
+        if (isEOF()) { return PlanStage::IS_EOF; }
+
+        Result result = _results.top();
+        _results.pop();
+        *out = result.id;
+
+        // Remove from invalidation map.
+        WorkingSetMember* member = _workingSet->get(*out);
+        // XXX make sure this is ok
+        if (member->hasLoc()) {
+            typedef multimap<DiskLoc, WorkingSetID>::iterator MMIT;
+            pair<MMIT, MMIT> range = _invalidationMap.equal_range(member->loc);
+            for (MMIT it = range.first; it != range.second; ++it) {
+                if (it->second == *out) {
+                    _invalidationMap.erase(it);
+                    break;
+                }
+            }
+        }
+
+        ++_commonStats.advanced;
+        return PlanStage::ADVANCED;
+    }
+
+    void TwoDNear::prepareToYield() {
+        // Nothing to do here.
+    }
+
+    void TwoDNear::recoverFromYield() {
+        // Also nothing to do here.
+    }
+
+    void TwoDNear::invalidate(const DiskLoc& dl) {
+        // XXX make sure this is ok
+        typedef multimap<DiskLoc, WorkingSetID>::iterator MMIT;
+        pair<MMIT, MMIT> range = _invalidationMap.equal_range(dl);
+        for (MMIT it = range.first; it != range.second; ++it) {
+            WorkingSetMember* member = _workingSet->get(it->second);
+            verify(member->hasLoc());
+            WorkingSetCommon::fetchAndInvalidateLoc(member);
+            verify(!member->hasLoc());
+        }
+        _invalidationMap.erase(range.first, range.second);
+    }
+
+    PlanStageStats* TwoDNear::getStats() {
+        return NULL;
+    }
+
+}  // namespace mongo
+
+namespace mongo {
+namespace twod_exec {
+
+    //
+    // GeoHopper
+    //
+
+    GeoHopper::GeoHopper(TwoDAccessMethod* accessMethod,
+            unsigned max,
+            const Point& n,
+            MatchExpression* filter,
+            double maxDistance,
+            GeoDistType type,
+            bool uniqueDocs,
+            bool needDistance)
+        : GeoBrowse(accessMethod, "search", filter, uniqueDocs, needDistance),
+        _max(max),
+        _near(n),
+        _maxDistance(maxDistance),
+        _type(type),
+        _distError(type == GEO_PLANE
+                ? accessMethod->getParams().geoHashConverter->getError()
+                : accessMethod->getParams().geoHashConverter->getErrorSphere()),
+        _farthest(0) { }
+
+   GeoAccumulator:: KeyResult GeoHopper::approxKeyCheck(const Point& p, double& d) {
+        // Always check approximate distance, since it lets us avoid doing
+        // checks of the rest of the object if it succeeds
+        switch (_type) {
+            case GEO_PLANE:
+                d = distance(_near, p);
+                break;
+            case GEO_SPHERE:
+                checkEarthBounds(p);
+                d = spheredist_deg(_near, p);
+                break;
+            default: verify(false);
+        }
+        verify(d >= 0);
+
+        // If we need more points
+        double borderDist = (_points.size() < _max ? _maxDistance : farthest());
+
+        if (d >= borderDist - 2 * _distError && d <= borderDist + 2 * _distError) return BORDER;
+        else return d < borderDist ? GOOD : BAD;
+    }
+
+    bool GeoHopper::exactDocCheck(const Point& p, double& d){
+        bool within = false;
+
+        // Get the appropriate distance for the type
+        switch (_type) {
+            case GEO_PLANE:
+                d = distance(_near, p);
+                within = distanceWithin(_near, p, _maxDistance);
+                break;
+            case GEO_SPHERE:
+                checkEarthBounds(p);
+                d = spheredist_deg(_near, p);
+                within = (d <= _maxDistance);
+                break;
+            default: verify(false);
+        }
+
+        return within;
+    }
+
+
+    int GeoHopper::addSpecific(const GeoIndexEntry& node, const Point& keyP, bool onBounds,
+            double keyD, bool potentiallyNewDoc) {
+        // Unique documents
+        GeoPoint newPoint(node, keyD, false);
+        int prevSize = _points.size();
+
+        //cout << "uniquedocs: " << _uniqueDocs << endl;
+
+        // STEP 1 : Remove old duplicate points from the set if needed
+        if(_uniqueDocs){
+            // Lookup old point with same doc
+            map<DiskLoc, Holder::iterator>::iterator oldPointIt = _seenPts.find(newPoint.loc());
+
+            if(oldPointIt != _seenPts.end()){
+                const GeoPoint& oldPoint = *(oldPointIt->second);
+                // We don't need to care if we've already seen this same approx pt or better,
+                // or we've already gone to disk once for the point
+                if(oldPoint < newPoint){
+                    return 0;
+                }
+                _points.erase(oldPointIt->second);
+            }
+        }
+
+        //cout << "inserting point\n";
+        Holder::iterator newIt = _points.insert(newPoint);
+        if(_uniqueDocs) _seenPts[ newPoint.loc() ] = newIt;
+
+        verify(_max > 0);
+
+        Holder::iterator lastPtIt = _points.end();
+        lastPtIt--;
+        _farthest = lastPtIt->distance() + 2 * _distError;
+        return _points.size() - prevSize;
+    }
+
+    // Removes extra points from end of _points set.
+    // Check can be a bit costly if we have lots of exact points near borders,
+    // so we'll do this every once and awhile.
+    void GeoHopper::processExtraPoints(){
+        if(_points.size() == 0) return;
+        int prevSize = _points.size();
+
+        // Erase all points from the set with a position >= _max *and*
+        // whose distance isn't close to the _max - 1 position distance
+        int numToErase = _points.size() - _max;
+        if(numToErase < 0) numToErase = 0;
+
+        // Get the first point definitely in the _points array
+        Holder::iterator startErase = _points.end();
+        for(int i = 0; i < numToErase + 1; i++) startErase--;
+        _farthest = startErase->distance() + 2 * _distError;
+
+        startErase++;
+        while(numToErase > 0 && startErase->distance() <= _farthest){
+            numToErase--;
+            startErase++;
+            verify(startErase != _points.end() || numToErase == 0);
+        }
+
+        if(_uniqueDocs){
+            for(Holder::iterator i = startErase; i != _points.end(); ++i)
+                _seenPts.erase(i->loc());
+        }
+
+        _points.erase(startErase, _points.end());
+
+        int diff = _points.size() - prevSize;
+        if(diff > 0) _found += diff;
+        else _found -= -diff;
+    }
+
+    //
+    // GeoSearch
+    //
+
+    GeoSearch::GeoSearch(TwoDAccessMethod* accessMethod,
+            const Point& startPt,
+            int numWanted,
+            MatchExpression* filter,
+            double maxDistance,
+            GeoDistType type,
+            bool uniqueDocs,
+            bool needDistance)
+        : GeoHopper(accessMethod, numWanted, startPt, filter, maxDistance, type,
+                uniqueDocs, needDistance),
+        _start(accessMethod->getParams().geoHashConverter->hash(startPt.x, startPt.y)),
+        _numWanted(numWanted),
+        _type(type),
+        _params(accessMethod->getParams()) {
+
+            _nscanned = 0;
+            _found = 0;
+
+            if(_maxDistance < 0){
+                _scanDistance = numeric_limits<double>::max();
+            } else if (type == GEO_PLANE) {
+                _scanDistance = maxDistance + _params.geoHashConverter->getError();
+            } else if (type == GEO_SPHERE) {
+                checkEarthBounds(startPt);
+                // TODO: consider splitting into x and y scan distances
+                _scanDistance = computeXScanDistance(startPt.y,
+                        rad2deg(_maxDistance) + _params.geoHashConverter->getError());
+            }
+
+            verify(_scanDistance > 0);
+        }
+
+    void GeoSearch::exec() {
+        if(_numWanted == 0) return;
+
+        /*
+         * Search algorithm
+         * 1) use geohash prefix to find X items
+         * 2) compute max distance from want to an item
+         * 3) find optimal set of boxes that complete circle
+         * 4) use regular btree cursors to scan those boxes
+         */
+
+        // Part 1
+        {
+            do {
+                long long f = found();
+                verify(f <= 0x7fffffff);
+                fillStack(maxPointsHeuristic, _numWanted - static_cast<int>(f), true);
+                processExtraPoints();
+            } while(_state != DONE && _state != DONE_NEIGHBOR &&
+                    found() < _numWanted &&
+                    (!_prefix.constrains() ||
+                     _params.geoHashConverter->sizeEdge(_prefix) <= _scanDistance));
+
+            // If we couldn't scan or scanned everything, we're done
+            if(_state == DONE){
+                expandEndPoints();
+                return;
+            }
+        }
+
+        // Part 2
+        {
+            // Find farthest distance for completion scan
+            double farDist = farthest();
+            if(found() < _numWanted) {
+                // Not enough found in Phase 1
+                farDist = _scanDistance;
+            }
+            else if (_type == GEO_PLANE) {
+                // Enough found, but need to search neighbor boxes
+                farDist += _params.geoHashConverter->getError();
+            }
+            else if (_type == GEO_SPHERE) {
+                // Enough found, but need to search neighbor boxes
+                farDist = std::min(_scanDistance,
+                        computeXScanDistance(_near.y,
+                            rad2deg(farDist))
+                        + 2 * _params.geoHashConverter->getError());
+            }
+            verify(farDist >= 0);
+
+            // Find the box that includes all the points we need to return
+            _want = Box(_near.x - farDist, _near.y - farDist, farDist * 2);
+
+            // Remember the far distance for further scans
+            _scanDistance = farDist;
+
+            // Reset the search, our distances have probably changed
+            if(_state == DONE_NEIGHBOR){
+                _state = DOING_EXPAND;
+                _neighbor = -1;
+            }
+
+            // Do regular search in the full region
+            do {
+                fillStack(maxPointsHeuristic);
+                processExtraPoints();
+            }
+            while(_state != DONE);
+        }
+
+        expandEndPoints();
+    }
+
+    void GeoSearch::addExactPoints(const GeoPoint& pt, Holder& points, bool force){
+        int before, after;
+        addExactPoints(pt, points, before, after, force);
+    }
+
+    void GeoSearch::addExactPoints(const GeoPoint& pt, Holder& points, int& before, int& after,
+            bool force){
+        before = 0;
+        after = 0;
+
+        if(pt.isExact()){
+            if(force) points.insert(pt);
+            return;
+        }
+
+        vector<BSONObj> locs;
+        getPointsFor(pt.key(), pt.obj(), locs, _uniqueDocs);
+
+        GeoPoint nearestPt(pt, -1, true);
+
+        for(vector<BSONObj>::iterator i = locs.begin(); i != locs.end(); i++){
+            Point loc(*i);
+            double d;
+            if(! exactDocCheck(loc, d)) continue;
+
+            if(_uniqueDocs && (nearestPt.distance() < 0 || d < nearestPt.distance())){
+                nearestPt._distance = d;
+                nearestPt._pt = *i;
+                continue;
+            } else if(! _uniqueDocs){
+                GeoPoint exactPt(pt, d, true);
+                exactPt._pt = *i;
+                points.insert(exactPt);
+                exactPt < pt ? before++ : after++;
+            }
+        }
+
+        if(_uniqueDocs && nearestPt.distance() >= 0){
+            points.insert(nearestPt);
+            if(nearestPt < pt) before++;
+            else after++;
+        }
+    }
+
+    // TODO: Refactor this back into holder class, allow to run periodically when we are seeing
+    // a lot of pts
+    void GeoSearch::expandEndPoints(bool finish) {
+        processExtraPoints();
+        // All points in array *could* be in maxDistance
+
+        // Step 1 : Trim points to max size TODO:  This check will do little for now, but is
+        // skeleton for future work in incremental $near
+        // searches
+        if(_max > 0){
+            int numToErase = _points.size() - _max;
+            if(numToErase > 0){
+                Holder tested;
+                // Work backward through all points we're not sure belong in the set
+                Holder::iterator maybePointIt = _points.end();
+                maybePointIt--;
+                double approxMin = maybePointIt->distance() - 2 * _distError;
+
+                // Insert all
+                int erased = 0;
+                while(_points.size() > 0
+                        && (maybePointIt->distance() >= approxMin || erased < numToErase)){
+
+                    Holder::iterator current = maybePointIt;
+                    if (current != _points.begin())
+                        --maybePointIt;
+
+                    addExactPoints(*current, tested, true);
+                    _points.erase(current);
+                    erased++;
+
+                    if(tested.size())
+                        approxMin = tested.begin()->distance() - 2 * _distError;
+                }
+
+                int numToAddBack = erased - numToErase;
+                verify(numToAddBack >= 0);
+
+                Holder::iterator testedIt = tested.begin();
+                for(int i = 0; i < numToAddBack && testedIt != tested.end(); i++){
+                    _points.insert(*testedIt);
+                    testedIt++;
+                }
+            }
+        }
+
+        // We've now trimmed first set of unneeded points
+
+        // Step 2: iterate through all points and add as needed
+        unsigned expandedPoints = 0;
+        Holder::iterator it = _points.begin();
+        double expandWindowEnd = -1;
+
+        while(it != _points.end()){
+            const GeoPoint& currPt = *it;
+            // TODO: If one point is exact, maybe not 2 * _distError
+
+            // See if we're in an expand window
+            bool inWindow = currPt.distance() <= expandWindowEnd;
+            // If we're not, and we're done with points, break
+            if(! inWindow && expandedPoints >= _max) break;
+
+            bool expandApprox = !currPt.isExact() &&
+                (!_uniqueDocs || (finish && _needDistance) || inWindow);
+
+            if (expandApprox) {
+                // Add new point(s). These will only be added in a radius of 2 * _distError
+                // around the current point, so should not affect previously valid points.
+                int before, after;
+                addExactPoints(currPt, _points, before, after, false);
+                expandedPoints += before;
+
+                if(_max > 0 && expandedPoints < _max)
+                    expandWindowEnd = currPt.distance() + 2 * _distError;
+
+                // Iterate to the next point
+                Holder::iterator current = it++;
+                // Erase the current point
+                _points.erase(current);
+            } else{
+                expandedPoints++;
+                it++;
+            }
+        }
+
+        // Finish
+        // TODO:  Don't really need to trim?
+        for(; expandedPoints > _max; expandedPoints--) it--;
+        _points.erase(it, _points.end());
+    }
+
+}  // namespace twod_exec
+}  // namespace mongo