SERVER-61983 Create TenantNamespace class

3 files changed, 302 insertions, 0 deletions

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 5bf18e77cb8..2becfdb5dfc 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -2485,6 +2485,7 @@ if wiredtiger:
             'session_catalog_mongod_test.cpp',
             'session_catalog_test.cpp',
             'startup_warnings_mongod_test.cpp',
+            'tenant_namespace_test.cpp',
             'thread_client_test.cpp',
             'time_proof_service_test.cpp',
             'transaction_api_test.cpp',
@@ -2541,6 +2542,7 @@ if wiredtiger:
             'logical_session_id_helpers',
             'logical_time',
             'mirror_maestro',
+            'multitenancy_params',
             'namespace_string',
             'op_observer',
             'op_observer_impl',
@@ -2558,6 +2560,7 @@ if wiredtiger:
             'repl/storage_interface_impl',
             'rw_concern_d',
             's/shard_server_test_fixture',
+            'server_feature_flags',
             'server_options_core',
             'server_options_servers',
             'service_context',
diff --git a/src/mongo/db/tenant_namespace.h b/src/mongo/db/tenant_namespace.h
new file mode 100644
index 00000000000..080a12c5ead
--- /dev/null
+++ b/src/mongo/db/tenant_namespace.h
@@ -0,0 +1,161 @@
+/**
+ *    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.
+ */
+
+#pragma once
+
+#include <algorithm>
+#include <boost/optional.hpp>
+#include <iosfwd>
+#include <string>
+
+#include "mongo/base/string_data.h"
+#include "mongo/bson/util/builder.h"
+#include "mongo/db/multitenancy_gen.h"
+#include "mongo/db/namespace_string.h"
+#include "mongo/db/server_feature_flags_gen.h"
+#include "mongo/logv2/log_attr.h"
+
+namespace mongo {
+
+class TenantNamespace {
+public:
+    /**
+     * Constructs an empty TenantNamespace.
+     */
+    TenantNamespace() : _tenantId(boost::none), _nss(), _tenantNsStr() {}
+
+    /**
+     * Constructs a TenantNamespace from the given tenantId and NamespaceString.
+     *
+     * If featureFlagRequireTenantID is set, tenantId is required.
+     */
+    TenantNamespace(boost::optional<mongo::OID> tenantId, NamespaceString nss) {
+        // TODO SERVER-62114 Check instead if gMultitenancySupport is enabled.
+        if (gFeatureFlagRequireTenantID.isEnabledAndIgnoreFCV())
+            invariant(tenantId);
+
+        _tenantId = tenantId;
+        _nss = nss;
+        _tenantNsStr = _tenantId
+            ? boost::make_optional(_tenantId->toString() + "_" + _nss.toString())
+            : boost::none;
+    }
+
+    /**
+     * Constructs a TenantNamespace from the string "ns". When the server parameter
+     * "multitenancySupport” is enabled, the tenantId will be parsed separately from the database
+     * name. If it is disabled, the tenantId will be parsed as a prefix of the database name, and
+     * the tenantId field will be empty. For example:
+     * if “multitenancySupport” is enabled, "tenant1_dbA.collA" will be parsed as:
+     * _tenantId = tenant1
+     * _nss = NamespaceString(dbA.collA)
+     *
+     * if “multitenancySupport” is disabled, "tenant1_dbA.collA" will be parsed as:
+     * _tenantId = boost::none
+     * _nss = NamespaceString(tenant1_dbA.collA), and the _nss,db()
+     *
+     * This method should only be used when reading a namespace from disk. To construct a
+     * TenantNamespace otherwise, use the standard constructor above.
+     *
+     * If featureFlagRequireTenantID is set, tenantId is required.
+     */
+    static TenantNamespace parseTenantNamespaceFromDisk(StringData ns) {
+        if (!gMultitenancySupport) {
+            return TenantNamespace(boost::none, NamespaceString(ns));
+        }
+
+        auto tenantDelim = ns.find('_');
+        if (tenantDelim == std::string::npos)
+            return TenantNamespace(boost::none, NamespaceString(ns));
+
+        auto tenantId = OID(ns.substr(0, tenantDelim));
+        auto nss = NamespaceString(ns.substr(tenantDelim + 1, ns.size() - 1 - tenantDelim));
+        return TenantNamespace(tenantId, nss);
+    }
+
+    boost::optional<mongo::OID> tenantId() const {
+        return _tenantId;
+    }
+
+    StringData db() const {
+        return _nss.db();
+    }
+
+    StringData coll() const {
+        return _nss.coll();
+    }
+
+    NamespaceString getNss() const {
+        return _nss;
+    }
+
+    std::string toString() const {
+        if (_tenantNsStr)
+            return *_tenantNsStr;
+
+        invariant(!_tenantId);
+        return _nss.ns();
+    }
+
+    // Relops among `TenantNamespace`.
+    friend bool operator==(const TenantNamespace& a, const TenantNamespace& b) {
+        return a.toString() == b.toString();
+    }
+    friend bool operator!=(const TenantNamespace& a, const TenantNamespace& b) {
+        return a.toString() != b.toString();
+    }
+    friend bool operator<(const TenantNamespace& a, const TenantNamespace& b) {
+        return a.toString() < b.toString();
+    }
+    friend bool operator>(const TenantNamespace& a, const TenantNamespace& b) {
+        return a.toString() > b.toString();
+    }
+    friend bool operator<=(const TenantNamespace& a, const TenantNamespace& b) {
+        return a.toString() <= b.toString();
+    }
+    friend bool operator>=(const TenantNamespace& a, const TenantNamespace& b) {
+        return a.toString() >= b.toString();
+    }
+
+    template <typename H>
+    friend H AbslHashValue(H h, const TenantNamespace& tenantNs) {
+        return H::combine(std::move(h), tenantNs.toString());
+    }
+
+    friend auto logAttrs(const TenantNamespace& nss) {
+        return "tenantNamespace"_attr = nss;
+    }
+
+private:
+    boost::optional<mongo::OID> _tenantId;
+    NamespaceString _nss;
+    boost::optional<std::string> _tenantNsStr;  // Only set if _tenantId exists
+};
+
+}  // namespace mongo
diff --git a/src/mongo/db/tenant_namespace_test.cpp b/src/mongo/db/tenant_namespace_test.cpp
new file mode 100644
index 00000000000..d3f3f418ba5
--- /dev/null
+++ b/src/mongo/db/tenant_namespace_test.cpp
@@ -0,0 +1,138 @@
+/**
+ *    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/platform/basic.h"
+
+#include "mongo/db/multitenancy_gen.h"
+#include "mongo/db/server_feature_flags_gen.h"
+#include "mongo/db/tenant_namespace.h"
+#include "mongo/idl/server_parameter_test_util.h"
+#include "mongo/unittest/death_test.h"
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+namespace {
+
+TEST(TenantNamespaceTest, TenantNamespaceMultitenancySupportDisabledBasic) {
+    TenantNamespace tenantNs(boost::none, NamespaceString("a.b"));
+    ASSERT(!tenantNs.tenantId());
+    ASSERT_EQUALS(std::string("a"), tenantNs.db());
+    ASSERT_EQUALS(std::string("b"), tenantNs.coll());
+    ASSERT_EQUALS(std::string("a.b"), tenantNs.toString());
+}
+
+TEST(TenantNamespaceTest, TenantNamespaceParseFromDiskMultitenancySupportDisabled) {
+    TenantNamespace tenantNs = TenantNamespace::parseTenantNamespaceFromDisk("a.b");
+    ASSERT(!tenantNs.tenantId());
+    ASSERT_EQUALS(std::string("a"), tenantNs.db());
+    ASSERT_EQUALS(std::string("b"), tenantNs.coll());
+
+    mongo::OID tenantId = OID::gen();
+    std::string ns = tenantId.toString() + "_a.b";
+    TenantNamespace tenantNs2 = TenantNamespace::parseTenantNamespaceFromDisk(ns);
+    ASSERT(!tenantNs2.tenantId());
+    ASSERT_EQUALS(std::string(tenantId.toString() + "_a"), tenantNs2.db());
+    ASSERT_EQUALS(std::string("b"), tenantNs2.coll());
+}
+
+TEST(TenantNamespaceTest, TenantNamespaceMultitenancySupportEnabledFeatureFlagDisabledBasic) {
+    // TODO SERVER-62114 Remove this test case.
+    RAIIServerParameterControllerForTest multitenanyController("multitenancySupport", true);
+
+    // If the feature flag is disabled, it's acceptable for the tenantId not to exist.
+    TenantNamespace tenantNs(boost::none, NamespaceString("a.b"));
+    ASSERT(!tenantNs.tenantId());
+    ASSERT_EQUALS(std::string("a"), tenantNs.db());
+    ASSERT_EQUALS(std::string("b"), tenantNs.coll());
+    ASSERT_EQUALS(std::string("a.b"), tenantNs.toString());
+
+    // If the feature flag is disabled but a tenantId is given, the tenantId should be parsed
+    // separately from the db name.
+    mongo::OID tenantId = OID::gen();
+    TenantNamespace tenantNs2(tenantId, NamespaceString("a.b"));
+    ASSERT(tenantNs2.tenantId());
+    ASSERT_EQUALS(tenantId, *tenantNs2.tenantId());
+    ASSERT_EQUALS(std::string("a"), tenantNs2.db());
+    ASSERT_EQUALS(std::string("b"), tenantNs2.coll());
+    ASSERT_EQUALS(std::string(tenantId.toString() + "_a.b"), tenantNs2.toString());
+}
+
+DEATH_TEST(TenantNamespaceTest,
+           TenantNamespaceMultitenancySupportEnabledTenantIDRequired,
+           "invariant") {
+    RAIIServerParameterControllerForTest multitenanyController("multitenancySupport", true);
+    // TODO SERVER-62114 Remove enabling this feature flag.
+    RAIIServerParameterControllerForTest featureFlagController("featureFlagRequireTenantID", true);
+
+    // A tenantId is not included, so the server should crash
+    TenantNamespace(boost::none, NamespaceString("a.b"));
+}
+
+DEATH_TEST(TenantNamespaceTest,
+           TenantNamespaceParseFromDiskMultitenancySupportEnabledTenantIDRequired,
+           "invariant") {
+    RAIIServerParameterControllerForTest multitenanyController("multitenancySupport", true);
+    // TODO SERVER-62114 Remove enabling this feature flag.
+    RAIIServerParameterControllerForTest featureFlagController("featureFlagRequireTenantID", true);
+
+    // A tenantId is not included, so the server should crash
+    auto tenantNs = TenantNamespace::parseTenantNamespaceFromDisk("a.b");
+}
+
+TEST(TenantNamespaceTest, TenantNamespaceMultitenancySupportEnabledBasic) {
+    RAIIServerParameterControllerForTest multitenanyController("multitenancySupport", true);
+    // TODO SERVER-62114 Remove enabling this feature flag.
+    RAIIServerParameterControllerForTest featureFlagController("featureFlagRequireTenantID", true);
+
+    mongo::OID tenantId = OID::gen();
+    TenantNamespace tenantNs(tenantId, NamespaceString("a.b"));
+    ASSERT(tenantNs.tenantId());
+    ASSERT_EQUALS(tenantId, *tenantNs.tenantId());
+    ASSERT_EQUALS(std::string("a"), tenantNs.db());
+    ASSERT_EQUALS(std::string("b"), tenantNs.coll());
+    ASSERT_EQUALS(std::string(tenantId.toString() + "_a.b"), tenantNs.toString());
+}
+
+TEST(TenantNamespaceTest, TenantNamespaceParseFromDiskMultitenancySupportEnabled) {
+    RAIIServerParameterControllerForTest multitenanyController("multitenancySupport", true);
+    // TODO SERVER-62114 Remove enabling this feature flag.
+    RAIIServerParameterControllerForTest featureFlagController("featureFlagRequireTenantID", true);
+
+    mongo::OID tenantId = OID::gen();
+    std::string tenantNsStr = str::stream() << tenantId << "_a.b";
+
+    TenantNamespace tenantNs = TenantNamespace::parseTenantNamespaceFromDisk(tenantNsStr);
+    ASSERT(tenantNs.tenantId());
+    ASSERT_EQUALS(tenantId, *tenantNs.tenantId());
+    ASSERT_EQUALS(std::string("a"), tenantNs.db());
+    ASSERT_EQUALS(std::string("b"), tenantNs.coll());
+}
+
+}  // namespace
+}  // namespace mongo