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
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
/**
* 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/fetch.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/exec/filter.h"
#include "mongo/db/exec/working_set_common.h"
#include "mongo/db/pdfile.h"
#include "mongo/util/fail_point_service.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
FetchStage::FetchStage(WorkingSet* ws,
PlanStage* child,
const MatchExpression* filter,
const Collection* collection)
: _collection(collection),
_ws(ws),
_child(child),
_filter(filter) { }
FetchStage::~FetchStage() { }
bool FetchStage::isEOF() {
return _child->isEOF();
}
PlanStage::StageState FetchStage::work(WorkingSetID* out) {
++_commonStats.works;
if (isEOF()) { return PlanStage::IS_EOF; }
// If we're here, we're not waiting for a DiskLoc to be fetched. Get another to-be-fetched
// result from our child.
WorkingSetID id = WorkingSet::INVALID_ID;
StageState status = _child->work(&id);
if (PlanStage::ADVANCED == status) {
WorkingSetMember* member = _ws->get(id);
// If there's an obj there, there is no fetching to perform.
if (member->hasObj()) {
++_specificStats.alreadyHasObj;
}
else {
// We need a valid loc to fetch from and this is the only state that has one.
verify(WorkingSetMember::LOC_AND_IDX == member->state);
verify(member->hasLoc());
// Don't need index data anymore as we have an obj.
member->keyData.clear();
member->obj = _collection->docFor(member->loc);
member->state = WorkingSetMember::LOC_AND_UNOWNED_OBJ;
}
return returnIfMatches(member, id, out);
}
else if (PlanStage::FAILURE == status) {
*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 << "fetch stage failed to read in results from child";
Status status(ErrorCodes::InternalError, ss);
*out = WorkingSetCommon::allocateStatusMember( _ws, status);
}
return status;
}
else {
if (PlanStage::NEED_TIME == status) {
++_commonStats.needTime;
}
return status;
}
}
void FetchStage::prepareToYield() {
++_commonStats.yields;
_child->prepareToYield();
}
void FetchStage::recoverFromYield() {
++_commonStats.unyields;
_child->recoverFromYield();
}
void FetchStage::invalidate(const DiskLoc& dl, InvalidationType type) {
++_commonStats.invalidates;
_child->invalidate(dl, type);
}
PlanStage::StageState FetchStage::returnIfMatches(WorkingSetMember* member,
WorkingSetID memberID,
WorkingSetID* out) {
if (Filter::passes(member, _filter)) {
if (NULL != _filter) {
++_specificStats.matchTested;
}
*out = memberID;
++_commonStats.advanced;
return PlanStage::ADVANCED;
}
else {
_ws->free(memberID);
++_commonStats.needTime;
return PlanStage::NEED_TIME;
}
}
PlanStageStats* FetchStage::getStats() {
_commonStats.isEOF = isEOF();
auto_ptr<PlanStageStats> ret(new PlanStageStats(_commonStats, STAGE_FETCH));
ret->specific.reset(new FetchStats(_specificStats));
ret->children.push_back(_child->getStats());
return ret.release();
}
} // namespace mongo
|
