SERVER-32607 Implement a DatabaseVersion type class and add it to the DatabaseType

9 files changed, 163 insertions, 4 deletions

diff --git a/src/mongo/s/SConscript b/src/mongo/s/SConscript
index ec341c87500..2c4b0bee9f8 100644
--- a/src/mongo/s/SConscript
+++ b/src/mongo/s/SConscript
@@ -91,6 +91,8 @@ env.Library(
         'move_chunk_request.cpp',
         'set_shard_version_request.cpp',
         'shard_key_pattern.cpp',
+        env.Idlc('database_version.idl')[0],
+        'versioning.cpp',
     ],
     LIBDEPS=[
         'shard_id',
diff --git a/src/mongo/s/catalog/sharding_catalog_test.cpp b/src/mongo/s/catalog/sharding_catalog_test.cpp
index 636838dd11e..c460b66c93a 100644
--- a/src/mongo/s/catalog/sharding_catalog_test.cpp
+++ b/src/mongo/s/catalog/sharding_catalog_test.cpp
@@ -53,6 +53,7 @@
 #include "mongo/s/catalog/type_tags.h"
 #include "mongo/s/chunk_version.h"
 #include "mongo/s/client/shard_registry.h"
+#include "mongo/s/versioning.h"
 #include "mongo/s/write_ops/batched_command_response.h"
 #include "mongo/stdx/future.h"
 #include "mongo/util/log.h"
@@ -161,6 +162,7 @@ TEST_F(ShardingCatalogClientTest, GetDatabaseExisting) {
     expectedDb.setName("bigdata");
     expectedDb.setPrimary(ShardId("shard0000"));
     expectedDb.setSharded(true);
+    expectedDb.setVersion(Versioning::newDatabaseVersion());
 
     const OpTime newOpTime(Timestamp(7, 6), 5);
 
@@ -208,6 +210,7 @@ TEST_F(ShardingCatalogClientTest, GetDatabaseStaleSecondaryRetrySuccess) {
     expectedDb.setName("bigdata");
     expectedDb.setPrimary(ShardId("shard0000"));
     expectedDb.setSharded(true);
+    expectedDb.setVersion(Versioning::newDatabaseVersion());
 
     auto future = launchAsync([this, &expectedDb] {
         return assertGet(
@@ -1096,6 +1099,7 @@ TEST_F(ShardingCatalogClientTest, UpdateDatabase) {
     dbt.setName("test");
     dbt.setPrimary(ShardId("shard0000"));
     dbt.setSharded(true);
+    dbt.setVersion(Versioning::newDatabaseVersion());
 
     auto future = launchAsync([this, dbt] {
         auto status = catalogClient()->updateDatabase(operationContext(), dbt.getName(), dbt);
diff --git a/src/mongo/s/catalog/type_database.cpp b/src/mongo/s/catalog/type_database.cpp
index 9ccf117ea87..492077a9337 100644
--- a/src/mongo/s/catalog/type_database.cpp
+++ b/src/mongo/s/catalog/type_database.cpp
@@ -34,6 +34,7 @@
 #include "mongo/bson/bsonobj.h"
 #include "mongo/bson/bsonobjbuilder.h"
 #include "mongo/bson/util/bson_extract.h"
+#include "mongo/s/versioning.h"
 #include "mongo/util/assert_util.h"
 
 namespace mongo {
@@ -45,6 +46,7 @@ const std::string DatabaseType::ConfigNS = "config.databases";
 const BSONField<std::string> DatabaseType::name("_id");
 const BSONField<std::string> DatabaseType::primary("primary");
 const BSONField<bool> DatabaseType::sharded("partitioned");
+const BSONField<BSONObj> DatabaseType::version("version");
 
 
 StatusWith<DatabaseType> DatabaseType::fromBSON(const BSONObj& source) {
@@ -78,6 +80,15 @@ StatusWith<DatabaseType> DatabaseType::fromBSON(const BSONObj& source) {
         dbt._sharded = dbtSharded;
     }
 
+    {
+        BSONObj versionField = source.getObjectField("version");
+        // TODO: parse this unconditionally after v4.0.
+        if (!versionField.isEmpty()) {
+            dbt._version =
+                DatabaseVersion::parse(IDLParserErrorContext("DatabaseType"), versionField);
+        }
+    }
+
     return StatusWith<DatabaseType>(dbt);
 }
 
@@ -103,6 +114,11 @@ BSONObj DatabaseType::toBSON() const {
     builder.append(primary.name(), _primary.get_value_or(ShardId()).toString());
     builder.append(sharded.name(), _sharded.get_value_or(false));
 
+    BSONObjBuilder versionBuilder;
+    DatabaseVersion defaultDbv;
+    _version.get_value_or(Versioning::newDatabaseVersion()).serialize(&versionBuilder);
+    builder.append(version.name(), versionBuilder.obj());
+
     return builder.obj();
 }
 
diff --git a/src/mongo/s/catalog/type_database.h b/src/mongo/s/catalog/type_database.h
index c1948f1132c..9525263a151 100644
--- a/src/mongo/s/catalog/type_database.h
+++ b/src/mongo/s/catalog/type_database.h
@@ -32,6 +32,7 @@
 #include <string>
 
 #include "mongo/db/jsobj.h"
+#include "mongo/s/database_version_gen.h"
 #include "mongo/s/shard_id.h"
 
 namespace mongo {
@@ -55,7 +56,7 @@ public:
     static const BSONField<std::string> name;
     static const BSONField<std::string> primary;
     static const BSONField<bool> sharded;
-
+    static const BSONField<BSONObj> version;
 
     /**
      * Constructs a new DatabaseType object from BSON. Also does validation of the contents.
@@ -95,6 +96,14 @@ public:
         _sharded = sharded;
     }
 
+    DatabaseVersion getVersion() const {
+        return _version.get();
+    }
+
+    void setVersion(DatabaseVersion version) {
+        _version = std::move(version);
+    }
+
 private:
     // Requred database name
     boost::optional<std::string> _name;
@@ -106,6 +115,8 @@ private:
     // Required whether sharding is enabled for this database. Even though this field is of
     // type optional, it is only used as an indicator that the value was explicitly set.
     boost::optional<bool> _sharded;
+
+    boost::optional<DatabaseVersion> _version;
 };
 
 }  // namespace mongo
diff --git a/src/mongo/s/catalog/type_database_test.cpp b/src/mongo/s/catalog/type_database_test.cpp
index f038ee65bb4..08f13f2e576 100644
--- a/src/mongo/s/catalog/type_database_test.cpp
+++ b/src/mongo/s/catalog/type_database_test.cpp
@@ -32,6 +32,7 @@
 #include "mongo/db/jsobj.h"
 #include "mongo/s/catalog/type_database.h"
 #include "mongo/unittest/unittest.h"
+#include "mongo/util/uuid.h"
 
 namespace {
 
@@ -44,15 +45,20 @@ TEST(DatabaseType, Empty) {
 }
 
 TEST(DatabaseType, Basic) {
-    StatusWith<DatabaseType> status =
-        DatabaseType::fromBSON(BSON(DatabaseType::name("mydb") << DatabaseType::primary("shard")
-                                                               << DatabaseType::sharded(true)));
+    UUID uuid = UUID::gen();
+    StatusWith<DatabaseType> status = DatabaseType::fromBSON(
+        BSON(DatabaseType::name("mydb")
+             << DatabaseType::primary("shard")
+             << DatabaseType::sharded(true)
+             << DatabaseType::version(BSON("uuid" << uuid << "version" << 0))));
     ASSERT_TRUE(status.isOK());
 
     DatabaseType db = status.getValue();
     ASSERT_EQUALS(db.getName(), "mydb");
     ASSERT_EQUALS(db.getPrimary(), "shard");
     ASSERT_TRUE(db.getSharded());
+    ASSERT_EQUALS(db.getVersion().getUuid(), uuid);
+    ASSERT_EQUALS(db.getVersion().getVersion(), 0);
 }
 
 TEST(DatabaseType, BadType) {
diff --git a/src/mongo/s/database_version.idl b/src/mongo/s/database_version.idl
new file mode 100644
index 00000000000..3875144b6bb
--- /dev/null
+++ b/src/mongo/s/database_version.idl
@@ -0,0 +1,33 @@
+# 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/>.
+#
+
+# DatabaseVersion type
+
+global:
+    cpp_namespace: "mongo"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+
+structs:
+    DatabaseVersion:
+        description: "A type to represent DatabaseVersions"
+        fields:
+            uuid:
+                type: uuid
+                description: "UUID, indicating the incarnation of the database"
+            version:
+                type: int
+                description: "Int32, which is bumped whenever movePrimary is called"
diff --git a/src/mongo/s/versioning.cpp b/src/mongo/s/versioning.cpp
new file mode 100644
index 00000000000..52dbc2cfa80
--- /dev/null
+++ b/src/mongo/s/versioning.cpp
@@ -0,0 +1,47 @@
+/**
+ *    Copyright (C) 2018 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/s/versioning.h"
+#include "mongo/s/database_version_gen.h"
+
+namespace mongo {
+
+DatabaseVersion Versioning::increment(const DatabaseVersion& v) {
+    DatabaseVersion dbv;
+    dbv.setVersion(v.getVersion() + 1);
+    dbv.setUuid(v.getUuid());
+    return dbv;
+}
+
+DatabaseVersion Versioning::newDatabaseVersion() {
+    DatabaseVersion dbv;
+    dbv.setVersion(0);
+    dbv.setUuid(UUID::gen());
+    return dbv;
+}
+}
diff --git a/src/mongo/s/versioning.h b/src/mongo/s/versioning.h
new file mode 100644
index 00000000000..ebd7b8a3760
--- /dev/null
+++ b/src/mongo/s/versioning.h
@@ -0,0 +1,39 @@
+/**
+ *    Copyright (C) 2018 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/s/database_version_gen.h"
+
+namespace mongo {
+
+class Versioning {
+public:
+    static DatabaseVersion increment(const DatabaseVersion& v);
+
+    static DatabaseVersion newDatabaseVersion();
+};
+}
diff --git a/src/mongo/util/uuid.h b/src/mongo/util/uuid.h
index 3eedf7db04f..bc0db1257d0 100644
--- a/src/mongo/util/uuid.h
+++ b/src/mongo/util/uuid.h
@@ -60,6 +60,7 @@ class UUID {
 
     // Make the IDL generated parser a friend
     friend class ConfigsvrShardCollectionResponse;
+    friend class DatabaseVersion;
     friend class DbCheckOplogCollection;
     friend class idl::import::One_UUID;
     friend class LogicalSessionId;