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Diffstat (limited to 'src/mongo/db/exec/projection_exec.cpp')
| -rw-r--r-- | src/mongo/db/exec/projection_exec.cpp | 489 |
1 files changed, 0 insertions, 489 deletions
diff --git a/src/mongo/db/exec/projection_exec.cpp b/src/mongo/db/exec/projection_exec.cpp deleted file mode 100644 index bf212a0b44b..00000000000 --- a/src/mongo/db/exec/projection_exec.cpp +++ /dev/null @@ -1,489 +0,0 @@ -/** - * Copyright (C) 2018-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/exec/projection_exec.h" - -#include "mongo/bson/mutable/document.h" -#include "mongo/db/matcher/expression.h" -#include "mongo/db/matcher/expression_parser.h" -#include "mongo/db/query/collation/collator_interface.h" -#include "mongo/db/query/query_request.h" -#include "mongo/db/update/path_support.h" -#include "mongo/util/decimal_counter.h" -#include "mongo/util/str.h" - -namespace mongo { - -using std::string; - -namespace mmb = mongo::mutablebson; - -ProjectionExec::ProjectionExec(OperationContext* opCtx, - const BSONObj& spec, - const MatchExpression* queryExpression, - const CollatorInterface* collator) - : _source(spec), _queryExpression(queryExpression), _collator(collator) { - // Whether we're including or excluding fields. - enum class IncludeExclude { kUninitialized, kInclude, kExclude }; - IncludeExclude includeExclude = IncludeExclude::kUninitialized; - - BSONObjIterator it(_source); - while (it.more()) { - BSONElement e = it.next(); - - if (Object == e.type()) { - BSONObj obj = e.embeddedObject(); - invariant(1 == obj.nFields()); - - BSONElement e2 = obj.firstElement(); - if (e2.fieldNameStringData() == "$slice") { - if (e2.isNumber()) { - int i = e2.numberInt(); - if (i < 0) { - add(e.fieldName(), i, -i); // limit is now positive - } else { - add(e.fieldName(), 0, i); - } - } else { - invariant(e2.type() == Array); - BSONObj arr = e2.embeddedObject(); - invariant(2 == arr.nFields()); - - BSONObjIterator it(arr); - int skip = it.next().numberInt(); - int limit = it.next().numberInt(); - - invariant(limit > 0); - - add(e.fieldName(), skip, limit); - } - } else if (e2.fieldNameStringData() == "$elemMatch") { - _arrayOpType = ARRAY_OP_ELEM_MATCH; - - // Create a MatchExpression for the elemMatch. - BSONObj elemMatchObj = e.wrap(); - invariant(elemMatchObj.isOwned()); - _elemMatchObjs.push_back(elemMatchObj); - boost::intrusive_ptr<ExpressionContext> expCtx( - new ExpressionContext(opCtx, _collator)); - StatusWithMatchExpression statusWithMatcher = - MatchExpressionParser::parse(elemMatchObj, std::move(expCtx)); - invariant(statusWithMatcher.isOK()); - // And store it in _matchers. - _matchers[str::before(e.fieldNameStringData(), '.')] = - statusWithMatcher.getValue().release(); - - add(e.fieldName(), true); - } else if (e2.fieldNameStringData() == "$meta") { - invariant(String == e2.type()); - if (e2.valuestr() == QueryRequest::metaTextScore) { - _meta[e.fieldName()] = META_TEXT_SCORE; - _needsTextScore = true; - } else if (e2.valuestr() == QueryRequest::metaSortKey) { - _meta[e.fieldName()] = META_SORT_KEY; - _needsSortKey = true; - } else if (e2.valuestr() == QueryRequest::metaRecordId) { - _meta[e.fieldName()] = META_RECORDID; - } else if (e2.valuestr() == QueryRequest::metaGeoNearPoint) { - _meta[e.fieldName()] = META_GEONEAR_POINT; - _needsGeoNearPoint = true; - } else if (e2.valuestr() == QueryRequest::metaGeoNearDistance) { - _meta[e.fieldName()] = META_GEONEAR_DIST; - _needsGeoNearDistance = true; - } else { - // This shouldn't happen, should be caught by parsing. - MONGO_UNREACHABLE; - } - } else { - MONGO_UNREACHABLE; - } - } else if ((e.fieldNameStringData() == "_id") && !e.trueValue()) { - _includeID = false; - } else { - add(e.fieldName(), e.trueValue()); - - // If we haven't specified an include/exclude, initialize includeExclude. - if (includeExclude == IncludeExclude::kUninitialized) { - includeExclude = - e.trueValue() ? IncludeExclude::kInclude : IncludeExclude::kExclude; - _include = !e.trueValue(); - } - } - - if (str::contains(e.fieldName(), ".$")) { - _arrayOpType = ARRAY_OP_POSITIONAL; - } - } -} - -ProjectionExec::~ProjectionExec() { - for (FieldMap::const_iterator it = _fields.begin(); it != _fields.end(); ++it) { - delete it->second; - } - - for (Matchers::const_iterator it = _matchers.begin(); it != _matchers.end(); ++it) { - delete it->second; - } -} - -void ProjectionExec::add(const string& field, bool include) { - if (field.empty()) { // this is the field the user referred to - _include = include; - } else { - _include = !include; - - const size_t dot = field.find('.'); - const string subfield = field.substr(0, dot); - const string rest = (dot == string::npos ? "" : field.substr(dot + 1, string::npos)); - - ProjectionExec*& fm = _fields[subfield.c_str()]; - - if (nullptr == fm) { - fm = new ProjectionExec(); - } - - fm->add(rest, include); - } -} - -void ProjectionExec::add(const string& field, int skip, int limit) { - _special = true; // can't include or exclude whole object - - if (field.empty()) { // this is the field the user referred to - _skip = skip; - _limit = limit; - } else { - const size_t dot = field.find('.'); - const string subfield = field.substr(0, dot); - const string rest = (dot == string::npos ? "" : field.substr(dot + 1, string::npos)); - - ProjectionExec*& fm = _fields[subfield.c_str()]; - - if (nullptr == fm) { - fm = new ProjectionExec(); - } - - fm->add(rest, skip, limit); - } -} - -// -// Execution -// - -StatusWith<BSONObj> ProjectionExec::project(const BSONObj& in, - const boost::optional<const double> geoDistance, - Value geoNearPoint, - const BSONObj& sortKey, - const boost::optional<const double> textScore, - const int64_t recordId) const { - BSONObjBuilder bob; - MatchDetails matchDetails; - - // If it's a positional projection we need a MatchDetails. - if (projectRequiresQueryExpression()) { - matchDetails.requestElemMatchKey(); - invariant(nullptr != _queryExpression); - invariant(_queryExpression->matchesBSON(in, &matchDetails)); - } - - Status projStatus = projectHelper(in, &bob, &matchDetails); - if (!projStatus.isOK()) - return projStatus; - else - return {addMeta(std::move(bob), geoDistance, geoNearPoint, sortKey, textScore, recordId)}; -} - -StatusWith<BSONObj> ProjectionExec::projectCovered(const std::vector<IndexKeyDatum>& keyData, - const boost::optional<const double> geoDistance, - Value geoNearPoint, - const BSONObj& sortKey, - const boost::optional<const double> textScore, - const int64_t recordId) const { - invariant(!_include); - BSONObjBuilder bob; - // Go field by field. - if (_includeID) { - boost::optional<BSONElement> elt; - // Sometimes the _id field doesn't exist... - if ((elt = IndexKeyDatum::getFieldDotted(keyData, "_id")) && !elt->eoo()) { - bob.appendAs(elt.get(), "_id"); - } - } - - mmb::Document projectedDoc; - - for (auto&& specElt : _source) { - if (specElt.fieldNameStringData() == "_id") { - continue; - } - - // $meta sortKey is the only meta-projection which is allowed to operate on index keys - // rather than the full document. - auto metaIt = _meta.find(specElt.fieldName()); - if (metaIt != _meta.end()) { - invariant(metaIt->second == META_SORT_KEY); - continue; - } - - // $meta sortKey is also the only element with an Object value in the projection spec - // that can operate on index keys rather than the full document. - invariant(BSONType::Object != specElt.type()); - - boost::optional<BSONElement> keyElt; - // We can project a field that doesn't exist. We just ignore it. - if ((keyElt = IndexKeyDatum::getFieldDotted(keyData, specElt.fieldName())) && - !keyElt->eoo()) { - FieldRef projectedFieldPath{specElt.fieldNameStringData()}; - auto setElementStatus = - pathsupport::setElementAtPath(projectedFieldPath, keyElt.get(), &projectedDoc); - if (!setElementStatus.isOK()) { - return setElementStatus; - } - } - } - - bob.appendElements(projectedDoc.getObject()); - return {addMeta(std::move(bob), geoDistance, geoNearPoint, sortKey, textScore, recordId)}; -} - -BSONObj ProjectionExec::addMeta(BSONObjBuilder bob, - const boost::optional<const double> geoDistance, - Value geoNearPoint, - const BSONObj& sortKey, - const boost::optional<const double> textScore, - const int64_t recordId) const { - for (MetaMap::const_iterator it = _meta.begin(); it != _meta.end(); ++it) { - switch (it->second) { - case META_GEONEAR_DIST: - invariant(geoDistance); - bob.append(it->first, geoDistance.get()); - break; - case META_GEONEAR_POINT: { - invariant(!geoNearPoint.missing()); - geoNearPoint.addToBsonObj(&bob, it->first); - break; - } - case META_TEXT_SCORE: - invariant(textScore); - bob.append(it->first, textScore.get()); - break; - case META_SORT_KEY: { - invariant(!sortKey.isEmpty()); - bob.append(it->first, sortKey); - break; - } - case META_RECORDID: - invariant(recordId != 0); - bob.append(it->first, recordId); - } - } - return bob.obj(); -} - -Status ProjectionExec::projectHelper(const BSONObj& in, - BSONObjBuilder* bob, - const MatchDetails* details) const { - const ArrayOpType& arrayOpType = _arrayOpType; - - BSONObjIterator it(in); - while (it.more()) { - BSONElement elt = it.next(); - - // Case 1: _id - if ("_id" == elt.fieldNameStringData()) { - if (_includeID) { - bob->append(elt); - } - continue; - } - - // Case 2: no array projection for this field. - Matchers::const_iterator matcher = _matchers.find(elt.fieldName()); - if (_matchers.end() == matcher) { - Status s = append(bob, elt, details, arrayOpType); - if (!s.isOK()) { - return s; - } - continue; - } - - // Case 3: field has array projection with $elemMatch specified. - if (ARRAY_OP_ELEM_MATCH != arrayOpType) { - return Status(ErrorCodes::BadValue, "Matchers are only supported for $elemMatch"); - } - - MatchDetails arrayDetails; - arrayDetails.requestElemMatchKey(); - - if (matcher->second->matchesBSON(in, &arrayDetails)) { - FieldMap::const_iterator fieldIt = _fields.find(elt.fieldName()); - if (_fields.end() == fieldIt) { - return Status(ErrorCodes::BadValue, - "$elemMatch specified, but projection field not found."); - } - - BSONArrayBuilder arrBuilder; - BSONObjBuilder subBob; - - if (in.getField(elt.fieldName()).eoo()) { - return Status(ErrorCodes::InternalError, - "$elemMatch called on document element with eoo"); - } - - if (in.getField(elt.fieldName()).Obj().getField(arrayDetails.elemMatchKey()).eoo()) { - return Status(ErrorCodes::InternalError, - "$elemMatch called on array element with eoo"); - } - - arrBuilder.append( - in.getField(elt.fieldName()).Obj().getField(arrayDetails.elemMatchKey())); - subBob.appendArray(matcher->first, arrBuilder.arr()); - Status status = append(bob, subBob.done().firstElement(), details, arrayOpType); - if (!status.isOK()) { - return status; - } - } - } - - return Status::OK(); -} - -void ProjectionExec::appendArray(BSONObjBuilder* bob, const BSONObj& array, bool nested) const { - int skip = nested ? 0 : _skip; - int limit = nested ? -1 : _limit; - - if (skip < 0) { - skip = std::max(0, skip + array.nFields()); - } - - DecimalCounter<size_t> index; - BSONObjIterator it(array); - while (it.more()) { - BSONElement elt = it.next(); - - if (skip) { - skip--; - continue; - } - - if (limit != -1 && (limit-- == 0)) { - break; - } - - switch (elt.type()) { - case Array: { - BSONObjBuilder subBob; - appendArray(&subBob, elt.embeddedObject(), true); - bob->appendArray(StringData{index}, subBob.obj()); - ++index; - break; - } - case Object: { - BSONObjBuilder subBob; - BSONObjIterator jt(elt.embeddedObject()); - while (jt.more()) { - append(&subBob, jt.next()).transitional_ignore(); - } - bob->append(StringData{index}, subBob.obj()); - ++index; - break; - } - default: - if (_include) { - bob->appendAs(elt, StringData{index}); - ++index; - } - } - } -} - -Status ProjectionExec::append(BSONObjBuilder* bob, - const BSONElement& elt, - const MatchDetails* details, - const ArrayOpType arrayOpType) const { - // Skip if the field name matches a computed $meta field. - // $meta projection fields can exist at the top level of - // the result document and the field names cannot be dotted. - if (_meta.find(elt.fieldName()) != _meta.end()) { - return Status::OK(); - } - - FieldMap::const_iterator field = _fields.find(elt.fieldName()); - if (field == _fields.end()) { - if (_include) { - bob->append(elt); - } - return Status::OK(); - } - - ProjectionExec& subfm = *field->second; - if ((subfm._fields.empty() && !subfm._special) || - !(elt.type() == Object || elt.type() == Array)) { - // field map empty, or element is not an array/object - if (subfm._include) { - bob->append(elt); - } - } else if (elt.type() == Object) { - BSONObjBuilder subBob; - BSONObjIterator it(elt.embeddedObject()); - while (it.more()) { - subfm.append(&subBob, it.next(), details, arrayOpType).transitional_ignore(); - } - bob->append(elt.fieldName(), subBob.obj()); - } else { - // Array - BSONObjBuilder matchedBuilder; - if (details && arrayOpType == ARRAY_OP_POSITIONAL) { - // $ positional operator specified - if (!details->hasElemMatchKey()) { - str::stream error; - error << "positional operator (" << elt.fieldName() - << ".$) requires corresponding field" - << " in query specifier"; - return Status(ErrorCodes::BadValue, error); - } - - if (elt.embeddedObject()[details->elemMatchKey()].eoo()) { - return Status(ErrorCodes::BadValue, "positional operator element mismatch"); - } - - // append as the first and only element in the projected array - matchedBuilder.appendAs(elt.embeddedObject()[details->elemMatchKey()], "0"); - } else { - // append exact array; no subarray matcher specified - subfm.appendArray(&matchedBuilder, elt.embeddedObject()); - } - bob->appendArray(elt.fieldName(), matchedBuilder.obj()); - } - - return Status::OK(); -} - -} // namespace mongo |