SERVER-27743: Implement LogicalTime

7 files changed, 437 insertions, 0 deletions

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index a5c8da3ddac..4cf0a47af5b 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -938,6 +938,37 @@ env.Library(
 )
 
 env.Library(
+    target='logical_time',
+    source=[
+        'logical_time.cpp',
+    ],
+    LIBDEPS=[
+        '$BUILD_DIR/mongo/base',
+    ],
+)
+
+env.Library(
+    target='signed_logical_time',
+    source=[
+        'signed_logical_time.cpp',
+    ],
+    LIBDEPS=[
+        'logical_time',
+    ],
+)
+
+env.CppUnitTest(
+    target='logical_time_test',
+    source=[
+        'logical_time_test.cpp',
+    ],
+    LIBDEPS=[
+        'logical_time',
+        'signed_logical_time',
+    ],
+)
+
+env.Library(
     target= 'op_observer_noop',
     source= [
         'op_observer_noop.cpp',
diff --git a/src/mongo/db/logical_time.cpp b/src/mongo/db/logical_time.cpp
new file mode 100644
index 00000000000..9d36a17a234
--- /dev/null
+++ b/src/mongo/db/logical_time.cpp
@@ -0,0 +1,52 @@
+/**
+ *    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/db/logical_time.h"
+
+#include "mongo/platform/basic.h"
+#include "mongo/util/mongoutils/str.h"
+
+namespace mongo {
+
+LogicalTime::LogicalTime(Timestamp ts) : _time(ts.asULL()) {}
+
+void LogicalTime::addTicks(uint64_t ticks) {
+    _time += ticks;
+}
+
+LogicalTime LogicalTime::addTicks(uint64_t ticks) const {
+    return LogicalTime(Timestamp(_time + ticks));
+}
+
+std::string LogicalTime::toString() const {
+    StringBuilder buf;
+    buf << asTimestamp().toString();
+    return buf.str();
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/logical_time.h b/src/mongo/db/logical_time.h
new file mode 100644
index 00000000000..6d3fb74a99b
--- /dev/null
+++ b/src/mongo/db/logical_time.h
@@ -0,0 +1,88 @@
+/**
+ *    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/timestamp.h"
+
+namespace mongo {
+
+/**
+ *  The LogicalTime class holds the cluster time of the cluster. It provides conversions to
+ *  a Timestamp to allow integration with opLog.
+ */
+class LogicalTime {
+public:
+    explicit LogicalTime(Timestamp);
+
+    Timestamp asTimestamp() const {
+        return Timestamp(_time);
+    }
+
+    /**
+     * Increases the _time by ticks.
+     */
+    void addTicks(uint64_t ticks);
+
+
+    /**
+     * Const version, returns the LogicalTime with increased _time by ticks.
+     */
+    LogicalTime addTicks(uint64_t ticks) const;
+
+    std::string toString() const;
+
+private:
+    uint64_t _time{0};
+};
+
+inline bool operator==(const LogicalTime& l, const LogicalTime& r) {
+    return l.asTimestamp() == r.asTimestamp();
+}
+
+inline bool operator!=(const LogicalTime& l, const LogicalTime& r) {
+    return !(l == r);
+}
+
+inline bool operator<(const LogicalTime& l, const LogicalTime& r) {
+    return l.asTimestamp() < r.asTimestamp();
+}
+
+inline bool operator<=(const LogicalTime& l, const LogicalTime& r) {
+    return (l < r || l == r);
+}
+
+inline bool operator>(const LogicalTime& l, const LogicalTime& r) {
+    return (r < l);
+}
+
+inline bool operator>=(const LogicalTime& l, const LogicalTime& r) {
+    return (l > r || l == r);
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/logical_time_test.cpp b/src/mongo/db/logical_time_test.cpp
new file mode 100644
index 00000000000..dbff22f8ce3
--- /dev/null
+++ b/src/mongo/db/logical_time_test.cpp
@@ -0,0 +1,101 @@
+/**
+ *    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/db/logical_time.h"
+#include "mongo/bson/timestamp.h"
+#include "mongo/db/signed_logical_time.h"
+#include "mongo/db/time_proof_service.h"
+#include "mongo/platform/basic.h"
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+namespace {
+
+TEST(LogicalTime, comparisons) {
+    Timestamp tX(1);
+    Timestamp tY(2);
+
+    ASSERT_TRUE(tX < tY);
+
+    ASSERT_TRUE(LogicalTime(tX) < LogicalTime(tY));
+    ASSERT_TRUE(LogicalTime(tX) <= LogicalTime(tY));
+    ASSERT_TRUE(LogicalTime(tY) > LogicalTime(tX));
+    ASSERT_TRUE(LogicalTime(tY) >= LogicalTime(tX));
+    ASSERT_TRUE(LogicalTime(tX) != LogicalTime(tY));
+    ASSERT_TRUE(LogicalTime(tX) == LogicalTime(tX));
+
+    ASSERT_FALSE(LogicalTime(tX) > LogicalTime(tY));
+    ASSERT_FALSE(LogicalTime(tX) >= LogicalTime(tY));
+    ASSERT_FALSE(LogicalTime(tY) < LogicalTime(tX));
+    ASSERT_FALSE(LogicalTime(tY) <= LogicalTime(tX));
+    ASSERT_FALSE(LogicalTime(tX) == LogicalTime(tY));
+    ASSERT_FALSE(LogicalTime(tX) != LogicalTime(tX));
+}
+
+TEST(LogicalTime, roundtrip) {
+    Timestamp tX(1);
+    auto tY = LogicalTime(tX).asTimestamp();
+
+    ASSERT_TRUE(tX == tY);
+}
+
+TEST(LogicalTime, addTicks) {
+    Timestamp tX(1);
+    Timestamp tY(2);
+
+    auto lT = LogicalTime(tX);
+    lT.addTicks(1);
+
+    ASSERT_TRUE(tY == lT.asTimestamp());
+}
+
+TEST(LogicalTime, addTicksConst) {
+    Timestamp tX(1);
+    Timestamp tY(2);
+
+    const auto lT = LogicalTime(tX);
+    auto lQ = lT.addTicks(1);
+
+    ASSERT_TRUE(tX == lT.asTimestamp());
+    ASSERT_TRUE(tY == lQ.asTimestamp());
+}
+
+TEST(SignedLogicalTime, roundtrip) {
+    Timestamp tX(1);
+    TimeProofService tps;
+    auto time = LogicalTime(tX);
+    auto proof = tps.getProof(time);
+
+    SignedLogicalTime signedTime(time, proof);
+    ASSERT_TRUE(time == signedTime.getTime());
+    ASSERT_TRUE(proof == signedTime.getProof());
+}
+
+}  // unnamed namespace
+}  // namespace mongo
diff --git a/src/mongo/db/signed_logical_time.cpp b/src/mongo/db/signed_logical_time.cpp
new file mode 100644
index 00000000000..bcfb89f027a
--- /dev/null
+++ b/src/mongo/db/signed_logical_time.cpp
@@ -0,0 +1,41 @@
+/**
+ *    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/db/signed_logical_time.h"
+
+#include "mongo/util/mongoutils/str.h"
+
+namespace mongo {
+
+std::string SignedLogicalTime::toString() const {
+    StringBuilder buf;
+    buf << _time.toString() << "|" << _proof;
+    return buf.str();
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/signed_logical_time.h b/src/mongo/db/signed_logical_time.h
new file mode 100644
index 00000000000..12c8d373d49
--- /dev/null
+++ b/src/mongo/db/signed_logical_time.h
@@ -0,0 +1,63 @@
+/**
+ *    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/db/logical_time.h"
+#include "mongo/db/time_proof_service.h"
+#include <string>
+
+namespace mongo {
+
+/**
+ * The SignedLogicalTime class is a pair of value i.e. time and a signature i.e. _proof
+ * The class is immutable and is used to hold the cryptogrphically protected LogicalTime.
+ */
+class SignedLogicalTime {
+public:
+    using TimeProof = TimeProofService::TimeProof;
+
+    explicit SignedLogicalTime(LogicalTime time, TimeProof proof)
+        : _time(std::move(time)), _proof(std::move(proof)) {}
+
+    LogicalTime getTime() const {
+        return _time;
+    }
+
+    const TimeProof& getProof() const {
+        return _proof;
+    }
+
+    std::string toString() const;
+
+private:
+    LogicalTime _time;
+    TimeProof _proof;
+};
+
+}  // namespace mongo
diff --git a/src/mongo/db/time_proof_service.h b/src/mongo/db/time_proof_service.h
new file mode 100644
index 00000000000..bc43e1ceee3
--- /dev/null
+++ b/src/mongo/db/time_proof_service.h
@@ -0,0 +1,61 @@
+/**
+ *    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/base/status.h"
+#include "mongo/db/logical_time.h"
+
+namespace mongo {
+
+/**
+ *  Mock of the TimeProofService class. The class when fully implemented will be self-contained. It
+ *  will provide key management and rotation, caching and other optimizations as needed.
+ */
+class TimeProofService {
+public:
+    // This type must be synchronized with the library that generates SHA1 or other proof.
+    using TimeProof = std::string;
+
+    /**
+     *  Returns the proof matching the time argument.
+     */
+    TimeProof getProof(LogicalTime time) {
+        TimeProof proof = "12345678901234567890";
+        return proof;
+    }
+
+    /**
+     *  Verifies that the proof is matching the time argument.
+     */
+    Status checkProof(LogicalTime time, const TimeProof& proof) {
+        return Status::OK();
+    }
+};
+
+}  // namespace mongo