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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/**
* Copyright (C) 2021-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/pipeline/change_stream_helpers_legacy.h"
#include "mongo/db/pipeline/change_stream_filter_helpers.h"
#include "mongo/db/pipeline/document_source_change_stream_add_post_image.h"
#include "mongo/db/pipeline/document_source_change_stream_add_pre_image.h"
#include "mongo/db/pipeline/document_source_change_stream_check_invalidate.h"
#include "mongo/db/pipeline/document_source_change_stream_check_resumability.h"
#include "mongo/db/pipeline/document_source_change_stream_check_topology_change.h"
#include "mongo/db/pipeline/document_source_change_stream_ensure_resume_token_present.h"
#include "mongo/db/pipeline/document_source_change_stream_handle_topology_change.h"
#include "mongo/db/pipeline/document_source_change_stream_oplog_match.h"
#include "mongo/db/pipeline/document_source_change_stream_transform.h"
#include "mongo/db/pipeline/document_source_change_stream_unwind_transaction.h"
#include "mongo/db/pipeline/expression.h"
#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kCommand
namespace mongo {
namespace change_stream_legacy {
std::list<boost::intrusive_ptr<DocumentSource>> buildPipeline(
const boost::intrusive_ptr<ExpressionContext>& expCtx, DocumentSourceChangeStreamSpec spec) {
// The only case where we expect to build a legacy pipeline is if we are a shard which has
// received a $changeStream request from an older mongoS.
tassert(5565900,
"Unexpected {needsMerge:false} request for a legacy change stream pipeline",
expCtx->needsMerge);
std::list<boost::intrusive_ptr<DocumentSource>> stages;
const auto userRequestedResumePoint =
spec.getResumeAfter() || spec.getStartAfter() || spec.getStartAtOperationTime();
if (!userRequestedResumePoint) {
// Make sure we update the 'resumeAfter' in the 'spec' so that we serialize the
// correct resume token when sending it to the shards.
auto clusterTime = DocumentSourceChangeStream::getStartTimeForNewStream(expCtx);
spec.setResumeAfter(
ResumeToken::makeHighWaterMarkToken(clusterTime, expCtx->changeStreamTokenVersion));
}
// Unfold the $changeStream into its constituent stages and add them to the pipeline.
stages.push_back(DocumentSourceChangeStreamOplogMatch::create(expCtx, spec));
stages.push_back(DocumentSourceChangeStreamUnwindTransaction::create(expCtx));
stages.push_back(DocumentSourceChangeStreamTransform::create(expCtx, spec));
tassert(5467606,
"'DocumentSourceChangeStreamTransform' stage should populate "
"'initialPostBatchResumeToken' field",
!expCtx->initialPostBatchResumeToken.isEmpty());
// The resume stage must come after the check invalidate stage so that the former can determine
// whether the event that matches the resume token should be followed by an "invalidate" event.
stages.push_back(DocumentSourceChangeStreamCheckInvalidate::create(expCtx, spec));
// We must always check that the shard is capable of resuming from the specified point.
stages.push_back(DocumentSourceChangeStreamCheckResumability::create(expCtx, spec));
// If 'showExpandedEvents' is NOT set, add a filter that returns only classic change events.
if (!spec.getShowExpandedEvents()) {
stages.push_back(DocumentSourceMatch::create(
change_stream_filter::getMatchFilterForClassicOperationTypes(), expCtx));
}
return stages;
}
boost::optional<Document> legacyLookupPreImage(boost::intrusive_ptr<ExpressionContext> pExpCtx,
const Document& preImageId) {
// We need the oplog's UUID for lookup, so obtain the collection info via MongoProcessInterface.
auto localOplogInfo = pExpCtx->mongoProcessInterface->getCollectionOptions(
pExpCtx->opCtx, NamespaceString::kRsOplogNamespace);
// Extract the UUID from the collection information. We should always have a valid uuid here.
auto oplogUUID = invariantStatusOK(UUID::parse(localOplogInfo["uuid"]));
// Look up the pre-image oplog entry using the opTime as the query filter.
const auto opTime = repl::OpTime::parse(preImageId.toBson());
auto lookedUpDoc =
pExpCtx->mongoProcessInterface->lookupSingleDocument(pExpCtx,
NamespaceString::kRsOplogNamespace,
oplogUUID,
Document{opTime.asQuery()},
boost::none);
// Return boost::none to signify that we failed to find the pre-image.
if (!lookedUpDoc) {
return boost::none;
}
// If we had an optime to look up, and we found an oplog entry with that timestamp, then we
// should always have a valid no-op entry containing a valid, non-empty pre-image document.
auto opLogEntry = uassertStatusOK(repl::OplogEntry::parse(lookedUpDoc->toBson()));
tassert(5868901,
"Oplog entry type must be a no-op",
opLogEntry.getOpType() == repl::OpTypeEnum::kNoop);
tassert(5868902,
"Oplog entry must contait a non-empty pre-image document",
!opLogEntry.getObject().isEmpty());
return Document{opLogEntry.getObject().getOwned()};
}
// TODO SERVER-66138: This function can be removed after we branch for 7.0.
void populateInternalOperationFilter(const boost::intrusive_ptr<ExpressionContext>& expCtx,
BSONArrayBuilder* orBuilder) {
std::vector<StringData> opTypes = {"reshardBegin"_sd, "reshardDoneCatchUp"_sd};
// Noop change events that are only applicable when merging results on mongoS:
// - migrateChunkToNewShard: A chunk migrated to a shard that didn't have any chunks.
if (expCtx->inMongos || expCtx->needsMerge) {
opTypes.push_back("migrateChunkToNewShard"_sd);
}
for (const auto& eventName : opTypes) {
// Legacy oplog messages used the "o2.type" field to indicate the message type.
orBuilder->append(BSON("o2.type" << eventName));
}
}
// TODO SERVER-66138: This function can be removed after we branch for 7.0.
Document convertFromLegacyOplogFormat(const Document& o2Entry, const NamespaceString& nss) {
auto type = o2Entry["type"];
if (type.missing()) {
return o2Entry;
}
MutableDocument doc(o2Entry);
doc.remove("type");
// This field would be the first field in the new format, but the current change stream code
// does not depend on the field order.
doc.addField(type.getString(), Value(nss.toString()));
return doc.freeze();
}
// TODO SERVER-66138: This function can be removed after we branch for 7.0.
StringData getNewShardDetectedOpName(const boost::intrusive_ptr<ExpressionContext>& expCtx) {
// The op name on 6.0 and older versions.
const StringData kNewShardDetectedOpTypeLegacyName = "kNewShardDetected"_sd;
return (expCtx->changeStreamTokenVersion == ResumeTokenData::kDefaultTokenVersion)
? DocumentSourceChangeStream::kNewShardDetectedOpType
: kNewShardDetectedOpTypeLegacyName;
}
} // namespace change_stream_legacy
} // namespace mongo
|
