SERVER-27543 Create new metadata for oplog queries

(cherry picked from commit 8daf13374403272ace73340f25fce573fa36a55b)

4 files changed, 331 insertions, 0 deletions

diff --git a/src/mongo/rpc/SConscript b/src/mongo/rpc/SConscript
index afcfe2563e6..516e3a5f305 100644
--- a/src/mongo/rpc/SConscript
+++ b/src/mongo/rpc/SConscript
@@ -150,6 +150,7 @@ env.Library(
         'metadata/server_selection_metadata.cpp',
         'metadata/sharding_metadata.cpp',
         'metadata/repl_set_metadata.cpp',
+        'metadata/oplog_query_metadata.cpp',
         'metadata/tracking_metadata.cpp',
     ],
     LIBDEPS=[
@@ -204,6 +205,14 @@ env.CppUnitTest(
 )
 
 env.CppUnitTest(
+    target='oplog_query_metadata_test',
+    source=[
+        'metadata/oplog_query_metadata_test.cpp',
+    ],
+    LIBDEPS=['metadata']
+)
+
+env.CppUnitTest(
     target='config_server_metadata_test',
     source=[
         'metadata/config_server_metadata_test.cpp',
diff --git a/src/mongo/rpc/metadata/oplog_query_metadata.cpp b/src/mongo/rpc/metadata/oplog_query_metadata.cpp
new file mode 100644
index 00000000000..6ac3f91ea00
--- /dev/null
+++ b/src/mongo/rpc/metadata/oplog_query_metadata.cpp
@@ -0,0 +1,117 @@
+/**
+ *    Copyright (C) 2017 MongoDB 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/rpc/metadata/oplog_query_metadata.h"
+
+#include "mongo/bson/util/bson_check.h"
+#include "mongo/bson/util/bson_extract.h"
+#include "mongo/db/jsobj.h"
+#include "mongo/db/repl/bson_extract_optime.h"
+#include "mongo/rpc/metadata.h"
+
+namespace mongo {
+namespace rpc {
+
+using repl::OpTime;
+
+const char kOplogQueryMetadataFieldName[] = "$oplogQueryData";
+
+namespace {
+
+const char kLastOpCommittedFieldName[] = "lastOpCommitted";
+const char kLastOpAppliedFieldName[] = "lastOpApplied";
+const char kPrimaryIndexFieldName[] = "primaryIndex";
+const char kSyncSourceIndexFieldName[] = "syncSourceIndex";
+const char kRBIDFieldName[] = "rbid";
+
+}  // unnamed namespace
+
+const int OplogQueryMetadata::kNoPrimary;
+
+OplogQueryMetadata::OplogQueryMetadata(OpTime lastOpCommitted,
+                                       OpTime lastOpApplied,
+                                       int rbid,
+                                       int currentPrimaryIndex,
+                                       int currentSyncSourceIndex)
+    : _lastOpCommitted(std::move(lastOpCommitted)),
+      _lastOpApplied(std::move(lastOpApplied)),
+      _rbid(rbid),
+      _currentPrimaryIndex(currentPrimaryIndex),
+      _currentSyncSourceIndex(currentSyncSourceIndex) {}
+
+StatusWith<OplogQueryMetadata> OplogQueryMetadata::readFromMetadata(const BSONObj& metadataObj) {
+    BSONElement oqMetadataElement;
+
+    Status status = bsonExtractTypedField(
+        metadataObj, rpc::kOplogQueryMetadataFieldName, Object, &oqMetadataElement);
+    if (!status.isOK())
+        return status;
+    BSONObj oqMetadataObj = oqMetadataElement.Obj();
+
+    long long primaryIndex;
+    status = bsonExtractIntegerField(oqMetadataObj, kPrimaryIndexFieldName, &primaryIndex);
+    if (!status.isOK())
+        return status;
+
+    long long syncSourceIndex;
+    status = bsonExtractIntegerField(oqMetadataObj, kSyncSourceIndexFieldName, &syncSourceIndex);
+    if (!status.isOK())
+        return status;
+
+    long long rbid;
+    status = bsonExtractIntegerField(oqMetadataObj, kRBIDFieldName, &rbid);
+    if (!status.isOK())
+        return status;
+
+    repl::OpTime lastOpCommitted;
+    status = bsonExtractOpTimeField(oqMetadataObj, kLastOpCommittedFieldName, &lastOpCommitted);
+    if (!status.isOK())
+        return status;
+
+    repl::OpTime lastOpApplied;
+    status = bsonExtractOpTimeField(oqMetadataObj, kLastOpAppliedFieldName, &lastOpApplied);
+    if (!status.isOK())
+        return status;
+
+    return OplogQueryMetadata(lastOpCommitted, lastOpApplied, rbid, primaryIndex, syncSourceIndex);
+}
+
+Status OplogQueryMetadata::writeToMetadata(BSONObjBuilder* builder) const {
+    BSONObjBuilder oqMetadataBuilder(builder->subobjStart(kOplogQueryMetadataFieldName));
+    _lastOpCommitted.append(&oqMetadataBuilder, kLastOpCommittedFieldName);
+    _lastOpApplied.append(&oqMetadataBuilder, kLastOpAppliedFieldName);
+    oqMetadataBuilder.append(kRBIDFieldName, _rbid);
+    oqMetadataBuilder.append(kPrimaryIndexFieldName, _currentPrimaryIndex);
+    oqMetadataBuilder.append(kSyncSourceIndexFieldName, _currentSyncSourceIndex);
+    oqMetadataBuilder.doneFast();
+
+    return Status::OK();
+}
+
+}  // namespace rpc
+}  // namespace mongo
diff --git a/src/mongo/rpc/metadata/oplog_query_metadata.h b/src/mongo/rpc/metadata/oplog_query_metadata.h
new file mode 100644
index 00000000000..b95970a7d38
--- /dev/null
+++ b/src/mongo/rpc/metadata/oplog_query_metadata.h
@@ -0,0 +1,119 @@
+/**
+ *    Copyright (C) 2017 MongoDB 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/bson/oid.h"
+#include "mongo/db/repl/optime.h"
+
+namespace mongo {
+
+class BSONObj;
+class BSONObjBuilder;
+
+namespace rpc {
+
+extern const char kOplogQueryMetadataFieldName[];
+
+/**
+ * Represents the metadata information for $oplogQueryData.
+ */
+class OplogQueryMetadata {
+public:
+    /**
+     * Default primary index. Also used to indicate in metadata that there is no
+     * primary.
+     */
+    static const int kNoPrimary = -1;
+
+    OplogQueryMetadata(repl::OpTime lastOpCommitted,
+                       repl::OpTime lastOpApplied,
+                       int rbid,
+                       int currentPrimaryIndex,
+                       int currentSyncSourceIndex);
+
+    /**
+     * format:
+     * {
+     *     lastOpCommitted: {ts: Timestamp(0, 0), term: 0},
+     *     lastOpApplied: {ts: Timestamp(0, 0), term: 0},
+     *     rbid: 0
+     *     primaryIndex: 0,
+     *     syncSourceIndex: 0
+     * }
+     */
+    static StatusWith<OplogQueryMetadata> readFromMetadata(const BSONObj& doc);
+    Status writeToMetadata(BSONObjBuilder* builder) const;
+
+    /**
+     * Returns the OpTime of the most recently committed op of which the sender was aware.
+     */
+    repl::OpTime getLastOpCommitted() const {
+        return _lastOpCommitted;
+    }
+
+    /**
+     * Returns the OpTime of the most recent operation to be applied by the sender.
+     */
+    repl::OpTime getLastOpApplied() const {
+        return _lastOpApplied;
+    }
+
+    /**
+     * Returns the index of the current primary from the perspective of the sender.
+     * Returns kNoPrimary if there is no primary.
+     */
+    int getPrimaryIndex() const {
+        return _currentPrimaryIndex;
+    }
+
+    /**
+     * Returns the index of the sync source of the sender.
+     * Returns -1 if it has no sync source.
+     */
+    int getSyncSourceIndex() const {
+        return _currentSyncSourceIndex;
+    }
+
+    /**
+     * Returns the current rbid of the sender.
+     */
+    int getRBID() const {
+        return _rbid;
+    }
+
+private:
+    repl::OpTime _lastOpCommitted;
+    repl::OpTime _lastOpApplied;
+    int _rbid = -1;
+    int _currentPrimaryIndex = kNoPrimary;
+    int _currentSyncSourceIndex = -1;
+};
+
+}  // namespace rpc
+}  // namespace mongo
diff --git a/src/mongo/rpc/metadata/oplog_query_metadata_test.cpp b/src/mongo/rpc/metadata/oplog_query_metadata_test.cpp
new file mode 100644
index 00000000000..cc08bf832fb
--- /dev/null
+++ b/src/mongo/rpc/metadata/oplog_query_metadata_test.cpp
@@ -0,0 +1,86 @@
+/**
+ *    Copyright (C) 2017 MongoDB 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/platform/basic.h"
+
+#include "mongo/db/jsobj.h"
+#include "mongo/rpc/metadata/oplog_query_metadata.h"
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+namespace rpc {
+namespace {
+
+using repl::OpTime;
+
+TEST(ReplResponseMetadataTest, OplogQueryMetadataRoundtrip) {
+    OpTime opTime1(Timestamp(1234, 100), 5);
+    OpTime opTime2(Timestamp(7777, 101), 6);
+    OplogQueryMetadata metadata(opTime1, opTime2, 6, 12, -1);
+
+    ASSERT_EQ(opTime1, metadata.getLastOpCommitted());
+    ASSERT_EQ(opTime2, metadata.getLastOpApplied());
+
+    BSONObjBuilder builder;
+    metadata.writeToMetadata(&builder);
+
+    BSONObj expectedObj(BSON(kOplogQueryMetadataFieldName << BSON(
+                                 "lastOpCommitted"
+                                 << BSON("ts" << opTime1.getTimestamp() << "t" << opTime1.getTerm())
+                                 << "lastOpApplied"
+                                 << BSON("ts" << opTime2.getTimestamp() << "t" << opTime2.getTerm())
+                                 << "rbid"
+                                 << 6
+                                 << "primaryIndex"
+                                 << 12
+                                 << "syncSourceIndex"
+                                 << -1)));
+
+    BSONObj serializedObj = builder.obj();
+    ASSERT_BSONOBJ_EQ(expectedObj, serializedObj);
+
+    auto cloneStatus = OplogQueryMetadata::readFromMetadata(serializedObj);
+    ASSERT_OK(cloneStatus.getStatus());
+
+    const auto& clonedMetadata = cloneStatus.getValue();
+    ASSERT_EQ(opTime1, clonedMetadata.getLastOpCommitted());
+    ASSERT_EQ(opTime2, clonedMetadata.getLastOpApplied());
+    ASSERT_EQ(metadata.getRBID(), clonedMetadata.getRBID());
+    ASSERT_EQ(metadata.getPrimaryIndex(), clonedMetadata.getPrimaryIndex());
+    ASSERT_EQ(metadata.getSyncSourceIndex(), clonedMetadata.getSyncSourceIndex());
+
+    BSONObjBuilder clonedBuilder;
+    clonedMetadata.writeToMetadata(&clonedBuilder);
+
+    BSONObj clonedSerializedObj = clonedBuilder.obj();
+    ASSERT_BSONOBJ_EQ(expectedObj, clonedSerializedObj);
+}
+
+}  // unnamed namespace
+}  // namespace rpc
+}  // namespace mongo