SERVER-38694 Allow specializing ServerParameter class in IDL

4 files changed, 450 insertions, 0 deletions

diff --git a/src/mongo/idl/SConscript b/src/mongo/idl/SConscript
index 09f0d7d6dc8..ac53fb52393 100644
--- a/src/mongo/idl/SConscript
+++ b/src/mongo/idl/SConscript
@@ -47,6 +47,8 @@ env.CppUnitTest(
         env.Idlc('server_parameter_test.idl')[0],
         'server_parameter_with_storage_test.cpp',
         env.Idlc('server_parameter_with_storage_test.idl')[0],
+        'server_parameter_specialized_test.cpp',
+        env.Idlc('server_parameter_specialized_test.idl')[0],
     ],
     LIBDEPS=[
         'server_parameter',
diff --git a/src/mongo/idl/server_parameter_specialized_test.cpp b/src/mongo/idl/server_parameter_specialized_test.cpp
new file mode 100644
index 00000000000..07ce7e4dc8c
--- /dev/null
+++ b/src/mongo/idl/server_parameter_specialized_test.cpp
@@ -0,0 +1,316 @@
+/**
+ *    Copyright (C) 2018-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/bson/unordered_fields_bsonobj_comparator.h"
+#include "mongo/idl/server_parameter_specialized_test_gen.h"
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+namespace test {
+
+template <typename T = ServerParameter>
+T* getServerParameter(StringData name) {
+    auto* sp = ServerParameterSet::getGlobal()->get<T>(name);
+    ASSERT(sp);
+    return sp;
+}
+
+template <typename Validator>
+void ASSERT_APPENDED_VALUE(ServerParameter* sp, Validator validator) {
+    BSONObjBuilder b;
+    sp->append(nullptr, b, sp->name());
+    auto obj = b.obj();
+
+    ASSERT_EQ(obj.nFields(), 1);
+    auto elem = obj[sp->name()];
+    ASSERT_FALSE(elem.eoo());
+    validator(elem);
+}
+
+void ASSERT_APPENDED_INT(ServerParameter* sp, long exp) {
+    ASSERT_APPENDED_VALUE(sp, [&exp](const BSONElement& elem) {
+        if (elem.type() == NumberInt) {
+            ASSERT_EQ(elem.Int(), exp);
+        } else {
+            ASSERT_EQ(elem.type(), NumberLong);
+            ASSERT_EQ(elem.Long(), exp);
+        }
+    });
+}
+
+void ASSERT_APPENDED_STRING(ServerParameter* sp, StringData exp) {
+    ASSERT_APPENDED_VALUE(sp, [&exp](const BSONElement& elem) {
+        ASSERT_EQ(elem.type(), String);
+        ASSERT_EQ(elem.String(), exp);
+    });
+}
+
+void ASSERT_APPENDED_OBJECT(ServerParameter* sp, const BSONObj& exp) {
+    ASSERT_APPENDED_VALUE(sp, [&exp](const BSONElement& elem) {
+        ASSERT_EQ(elem.type(), Object);
+
+        UnorderedFieldsBSONObjComparator comparator;
+        ASSERT(comparator.evaluate(elem.Obj() == exp));
+    });
+}
+
+// specializedDummy
+
+void SpecializedDummyServerParameter::append(OperationContext*,
+                                             BSONObjBuilder& b,
+                                             const std::string& name) {
+    b << name << "Dummy Value";
+}
+
+Status SpecializedDummyServerParameter::setFromString(const std::string& value) {
+    return Status::OK();
+}
+
+TEST(SpecializedServerParameter, dummy) {
+    auto* dsp = getServerParameter("specializedDummy");
+    ASSERT_APPENDED_STRING(dsp, "Dummy Value");
+    ASSERT_OK(dsp->setFromString("new value"));
+    ASSERT_NOT_OK(dsp->set(BSON("" << BSON_ARRAY("bar")).firstElement()));
+    ASSERT_OK(dsp->set(BSON(""
+                            << "bar")
+                           .firstElement()));
+}
+
+// specializedWithCtor
+
+namespace {
+std::string gSCSP("Initial Value");
+}  // namespace
+
+SpecializedConstructorServerParameter::SpecializedConstructorServerParameter(
+    StringData name, ServerParameterType spt)
+    : ServerParameter(name, spt) {
+    gSCSP = "Value from ctor";
+}
+
+void SpecializedConstructorServerParameter::append(OperationContext*,
+                                                   BSONObjBuilder& b,
+                                                   const std::string& name) {
+    b << name << gSCSP;
+}
+
+Status SpecializedConstructorServerParameter::setFromString(const std::string& value) {
+    gSCSP = value;
+    return Status::OK();
+}
+
+TEST(SpecializedServerParameter, withCtor) {
+    auto* csp = getServerParameter("specializedWithCtor");
+    ASSERT_APPENDED_STRING(csp, "Value from ctor");
+    ASSERT_OK(csp->setFromString("Updated Value"));
+    ASSERT_EQ(gSCSP, "Updated Value");
+    ASSERT_APPENDED_STRING(csp, "Updated Value");
+}
+
+// specializedWithValue
+
+void SpecializedWithValueServerParameter::append(OperationContext*,
+                                                 BSONObjBuilder& b,
+                                                 const std::string& name) {
+    b << name << _data;
+}
+
+Status SpecializedWithValueServerParameter::setFromString(const std::string& value) {
+    return parseNumberFromString(value, &_data);
+}
+
+TEST(SpecializedServerParameter, withValue) {
+    using cls = SpecializedWithValueServerParameter;
+    ASSERT_EQ(cls::kDataDefault, 43);
+
+    auto* wv = getServerParameter<cls>("specializedWithValue");
+    ASSERT_EQ(wv->_data, cls::kDataDefault);
+    ASSERT_APPENDED_INT(wv, cls::kDataDefault);
+    ASSERT_OK(wv->setFromString("102"));
+    ASSERT_APPENDED_INT(wv, 102);
+    ASSERT_EQ(wv->_data, 102);
+}
+
+// specializedWithStringValue
+
+void SpecializedWithStringValueServerParameter::append(OperationContext*,
+                                                       BSONObjBuilder& b,
+                                                       const std::string& name) {
+    b << name << _data;
+}
+
+Status SpecializedWithStringValueServerParameter::setFromString(const std::string& value) {
+    _data = value;
+    return Status::OK();
+}
+
+TEST(SpecializedServerParameter, withStringValue) {
+    using cls = SpecializedWithStringValueServerParameter;
+    ASSERT_EQ(cls::kDataDefault, "Hello World"_sd);
+
+    auto* wsv = getServerParameter<cls>("specializedWithStringValue");
+    ASSERT_EQ(wsv->_data, cls::kDataDefault);
+    ASSERT_APPENDED_STRING(wsv, cls::kDataDefault);
+    ASSERT_OK(wsv->setFromString("Goodbye Land"));
+    ASSERT_APPENDED_STRING(wsv, "Goodbye Land");
+    ASSERT_EQ(wsv->_data, "Goodbye Land");
+}
+
+// specializedWithAtomicValue
+
+void SpecializedWithAtomicValueServerParameter::append(OperationContext*,
+                                                       BSONObjBuilder& b,
+                                                       const std::string& name) {
+    b << name << _data.load();
+}
+
+Status SpecializedWithAtomicValueServerParameter::setFromString(const std::string& value) {
+    std::uint32_t val;
+
+    auto status = parseNumberFromString(value, &val);
+    if (!status.isOK()) {
+        return status;
+    }
+
+    _data.store(val);
+    return Status::OK();
+}
+
+TEST(SpecializedServerParameter, withAtomicValue) {
+    using cls = SpecializedWithAtomicValueServerParameter;
+    ASSERT_EQ(cls::kDataDefault, 42);
+
+    auto* wv = getServerParameter<cls>("specializedWithAtomicValue");
+    ASSERT_EQ(wv->_data.load(), cls::kDataDefault);
+    ASSERT_APPENDED_INT(wv, cls::kDataDefault);
+    ASSERT_OK(wv->setFromString("101"));
+    ASSERT_APPENDED_INT(wv, 101);
+    ASSERT_EQ(wv->_data.load(), 101);
+}
+
+// specializedWithMultiValue
+
+void SpecializedMultiValueServerParameter::append(OperationContext*,
+                                                  BSONObjBuilder& b,
+                                                  const std::string& name) {
+    b << name << BSON("value" << _data.value << "flag" << _data.flag);
+}
+
+Status SpecializedMultiValueServerParameter::set(const BSONElement& value) try {
+    auto obj = value.Obj();
+    _data.value = obj["value"].String();
+    _data.flag = obj["flag"].Bool();
+    return Status::OK();
+} catch (const AssertionException&) {
+    return {ErrorCodes::BadValue, "Failed parsing extra data"};
+}
+
+Status SpecializedMultiValueServerParameter::setFromString(const std::string& value) {
+    return set(BSON("" << BSON("value" << value << "flag" << false)).firstElement());
+}
+
+TEST(SpecializedServerParameter, multiValue) {
+    auto* edsp = getServerParameter("specializedWithMultiValue");
+    ASSERT_APPENDED_OBJECT(edsp,
+                           BSON("value"
+                                << "start value"
+                                << "flag"
+                                << true));
+    ASSERT_OK(edsp->setFromString("second value"));
+    ASSERT_APPENDED_OBJECT(edsp,
+                           BSON("value"
+                                << "second value"
+                                << "flag"
+                                << false));
+    ASSERT_OK(edsp->set(BSON("" << BSON("value"
+                                        << "third value"
+                                        << "flag"
+                                        << true))
+                            .firstElement()));
+    ASSERT_APPENDED_OBJECT(edsp,
+                           BSON("value"
+                                << "third value"
+                                << "flag"
+                                << true));
+}
+
+// specializedWithCtorAndValue
+
+SpecializedWithCtorAndValueServerParameter::SpecializedWithCtorAndValueServerParameter(
+    StringData name, ServerParameterType spt)
+    : ServerParameter(name, spt) {}
+
+void SpecializedWithCtorAndValueServerParameter::append(OperationContext*,
+                                                        BSONObjBuilder& b,
+                                                        const std::string& name) {
+    b << name << _data;
+}
+
+Status SpecializedWithCtorAndValueServerParameter::setFromString(const std::string& value) {
+    return parseNumberFromString(value, &_data);
+}
+
+TEST(SpecializedServerParameter, withCtorAndValue) {
+    using cls = SpecializedWithCtorAndValueServerParameter;
+    auto* cvsp = getServerParameter<cls>("specializedWithCtorAndValue");
+    ASSERT_APPENDED_INT(cvsp, cls::kDataDefault);
+    ASSERT_OK(cvsp->setFromString(std::to_string(cls::kDataDefault + 1)));
+    ASSERT_EQ(cvsp->_data, cls::kDataDefault + 1);
+    ASSERT_APPENDED_INT(cvsp, cls::kDataDefault + 1);
+}
+
+// specializedWithOptions
+
+namespace {
+std::string gSWO = "Initial Value";
+}  // namespace
+
+Status SpecializedWithOptions::setFromString(const std::string& value) {
+    gSWO = value;
+    return Status::OK();
+}
+
+TEST(SpecializedServerParameter, withOptions) {
+    auto* swo = getServerParameter("specializedWithOptions");
+    ASSERT_APPENDED_STRING(swo, "###");
+    ASSERT_OK(swo->setFromString("second value"));
+    ASSERT_EQ(gSWO, "second value");
+    ASSERT_APPENDED_STRING(swo, "###");
+
+    auto* dswo = getServerParameter("deprecatedWithOptions");
+    ASSERT_APPENDED_STRING(dswo, "###");
+    ASSERT_OK(dswo->setFromString("third value"));
+    ASSERT_EQ(gSWO, "third value");
+    ASSERT_APPENDED_STRING(dswo, "###");
+}
+
+}  // namespace test
+}  // namespace mongo
diff --git a/src/mongo/idl/server_parameter_specialized_test.h b/src/mongo/idl/server_parameter_specialized_test.h
new file mode 100644
index 00000000000..b5b255e0453
--- /dev/null
+++ b/src/mongo/idl/server_parameter_specialized_test.h
@@ -0,0 +1,43 @@
+/**
+ *    Copyright (C) 2018-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 "mongo/platform/basic.h"
+
+namespace mongo {
+namespace test {
+
+struct ExtraDataForServerParameter {
+    std::string value = "start value";
+    bool flag = true;
+};
+
+}  // namespace test
+}  // namespace mongo
diff --git a/src/mongo/idl/server_parameter_specialized_test.idl b/src/mongo/idl/server_parameter_specialized_test.idl
new file mode 100644
index 00000000000..7596a4a7fef
--- /dev/null
+++ b/src/mongo/idl/server_parameter_specialized_test.idl
@@ -0,0 +1,89 @@
+#    Copyright (C) 2018-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.
+#
+
+global:
+    cpp_namespace: "mongo::test"
+    cpp_includes:
+    - "mongo/idl/server_parameter_specialized_test.h"
+    - "mongo/platform/atomic_word.h"
+
+server_parameters:
+    specializedDummy:
+        description: "Specialized server parameter with dummy value."
+        set_at: [ startup, runtime ]
+        cpp_class: SpecializedDummyServerParameter
+    specializedWithCtor:
+        description: "Provide a custom constructor implementation."
+        set_at: startup
+        cpp_class:
+            name: SpecializedConstructorServerParameter
+            override_ctor: true
+    specializedWithValue:
+        description: "Attach a simple value."
+        set_at: startup
+        cpp_class:
+            name: SpecializedWithValueServerParameter
+            data: std::int32_t
+        default: 43
+    specializedWithStringValue:
+        description: "Attach a string."
+        set_at: startup
+        cpp_class:
+            name: SpecializedWithStringValueServerParameter
+            data: std::string
+        default: 'Hello World'
+    specializedWithAtomicValue:
+        description: "Attach a thread safe value."
+        set_at: [ startup, runtime ]
+        cpp_class:
+            name: SpecializedWithAtomicValueServerParameter
+            data: AtomicWord<std::int32_t>
+        default: 42
+    specializedWithMultiValue:
+        description: "Attach a struct."
+        set_at: startup
+        cpp_class:
+            name: SpecializedMultiValueServerParameter
+            data: ExtraDataForServerParameter
+            override_set: true
+    specializedWithCtorAndValue:
+        description: "Attach a simple value and a constum constructor."
+        set_at: startup
+        cpp_class:
+            name: SpecializedWithCtorAndValueServerParameter
+            data: std::int32_t
+            override_ctor: true
+        default: 44
+    specializedWithOptions:
+        description: "Use optional attributes."
+        set_at: startup
+        cpp_class: SpecializedWithOptions
+        redact: true
+        test_only: false
+        condition: { expr: true }
+        deprecated_name: deprecatedWithOptions