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/**
* 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.
*/
#pragma once
#include "mongo/base/status.h"
#include "mongo/db/dbmessage.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/matcher/expression.h"
#include "mongo/db/query/collation/collator_interface.h"
#include "mongo/db/query/parsed_projection.h"
#include "mongo/db/query/query_request.h"
namespace mongo {
class OperationContext;
class CanonicalQuery {
public:
/**
* If parsing succeeds, returns a std::unique_ptr<CanonicalQuery> representing the parsed
* query (which will never be NULL). If parsing fails, returns an error Status.
*
* 'txn' must point to a valid OperationContext, but 'txn' does not need to outlive the returned
* CanonicalQuery.
*
* Used for legacy find through the OP_QUERY message.
*/
static StatusWith<std::unique_ptr<CanonicalQuery>> canonicalize(
OperationContext* txn,
const QueryMessage& qm,
const ExtensionsCallback& extensionsCallback);
/**
* If parsing succeeds, returns a std::unique_ptr<CanonicalQuery> representing the parsed
* query (which will never be NULL). If parsing fails, returns an error Status.
*
* 'txn' must point to a valid OperationContext, but 'txn' does not need to outlive the returned
* CanonicalQuery.
*/
static StatusWith<std::unique_ptr<CanonicalQuery>> canonicalize(
OperationContext* txn, std::unique_ptr<QueryRequest> qr, const ExtensionsCallback&);
/**
* For testing or for internal clients to use.
*/
/**
* Used for creating sub-queries from an existing CanonicalQuery.
*
* 'root' must be an expression in baseQuery.root().
*
* Does not take ownership of 'root'.
*/
static StatusWith<std::unique_ptr<CanonicalQuery>> canonicalize(
OperationContext* txn,
const CanonicalQuery& baseQuery,
MatchExpression* root,
const ExtensionsCallback& extensionsCallback);
/**
* Returns true if "query" describes an exact-match query on _id, possibly with
* the $isolated/$atomic modifier.
*/
static bool isSimpleIdQuery(const BSONObj& query);
const NamespaceString& nss() const {
return _qr->nss();
}
const std::string& ns() const {
return _qr->nss().ns();
}
//
// Accessors for the query
//
MatchExpression* root() const {
return _root.get();
}
BSONObj getQueryObj() const {
return _qr->getFilter();
}
const QueryRequest& getQueryRequest() const {
return *_qr;
}
const ParsedProjection* getProj() const {
return _proj.get();
}
const CollatorInterface* getCollator() const {
return _collator.get();
}
// Debugging
std::string toString() const;
std::string toStringShort() const;
/**
* Validates match expression, checking for certain
* combinations of operators in match expression and
* query options in QueryRequest.
* Since 'root' is derived from 'filter' in QueryRequest,
* 'filter' is not validated.
*
* TODO: Move this to query_validator.cpp
*/
static Status isValid(MatchExpression* root, const QueryRequest& parsed);
/**
* Returns the normalized version of the subtree rooted at 'root'.
*
* Takes ownership of 'root'.
*/
static MatchExpression* normalizeTree(MatchExpression* root);
/**
* Traverses expression tree post-order.
* Sorts children at each non-leaf node by (MatchType, path(), children, number of children)
*/
static void sortTree(MatchExpression* tree);
/**
* Returns a count of 'type' nodes in expression tree.
*/
static size_t countNodes(const MatchExpression* root, MatchExpression::MatchType type);
/**
* Returns true if this canonical query converted extensions such as $where and $text into
* no-ops during parsing.
*
* Queries with a no-op extension context are special because they can be parsed and planned,
* but they cannot be executed.
*/
bool hasNoopExtensions() const {
return _hasNoopExtensions;
}
/**
* Returns true if the query this CanonicalQuery was parsed from included a $isolated/$atomic
* operator.
*/
bool isIsolated() const {
return _isIsolated;
}
private:
// You must go through canonicalize to create a CanonicalQuery.
CanonicalQuery() {}
Status init(std::unique_ptr<QueryRequest> qr,
const ExtensionsCallback& extensionsCallback,
MatchExpression* root,
std::unique_ptr<CollatorInterface> collator);
std::unique_ptr<QueryRequest> _qr;
// _root points into _qr->getFilter()
std::unique_ptr<MatchExpression> _root;
std::unique_ptr<ParsedProjection> _proj;
std::unique_ptr<CollatorInterface> _collator;
bool _hasNoopExtensions = false;
bool _isIsolated;
};
} // namespace mongo
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