1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
/**
* 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/db/clientcursor.h"
#include "mongo/db/query/canonical_query.h"
#include "mongo/db/query/lite_parsed_query.h"
#include "mongo/db/query/plan_cache.h"
#include "mongo/db/query/plan_executor.h"
#include "mongo/db/query/runner.h"
#include "mongo/db/query/stage_builder.h"
namespace mongo {
/**
* SingleSolutionRunner runs a plan that was the only possible solution to a query. It exists
* only to dump stats into the cache after running.
*/
class SingleSolutionRunner : public Runner {
public:
/**
* Takes ownership of both arguments.
*/
SingleSolutionRunner(CanonicalQuery* canonicalQuery, QuerySolution* soln,
PlanStage* root, WorkingSet* ws)
: _canonicalQuery(canonicalQuery), _solution(soln),
_exec(new PlanExecutor(ws, root)) { }
Runner::RunnerState getNext(BSONObj* objOut, DiskLoc* dlOut) {
return _exec->getNext(objOut, dlOut);
// TODO: I'm not convinced we want to cache this run. What if it's a collscan solution
// and the user adds an index later? We don't want to reach for this. But if solving
// the query is v. hard, we do want to cache it. Maybe we can remove single solution
// cache entries when we build an index?
}
virtual bool isEOF() { return _exec->isEOF(); }
virtual void saveState() { _exec->saveState(); }
virtual bool restoreState() { return _exec->restoreState(); }
virtual void setYieldPolicy(Runner::YieldPolicy policy) {
_exec->setYieldPolicy(policy);
}
virtual void invalidate(const DiskLoc& dl) { _exec->invalidate(dl); }
virtual const string& ns() { return _canonicalQuery->getParsed().ns(); }
virtual void kill() { _exec->kill(); }
private:
scoped_ptr<CanonicalQuery> _canonicalQuery;
scoped_ptr<QuerySolution> _solution;
scoped_ptr<PlanExecutor> _exec;
};
} // namespace mongo
|
