SERVER-17311 Ensure BSONObj, RecordData, and SharedBuffer are noexcept moveable

1 files changed, 135 insertions, 0 deletions

diff --git a/src/mongo/dbtests/shared_buffer_test.cpp b/src/mongo/dbtests/shared_buffer_test.cpp
new file mode 100644
index 00000000000..37d259114d6
--- /dev/null
+++ b/src/mongo/dbtests/shared_buffer_test.cpp
@@ -0,0 +1,135 @@
+/**
+ *    Copyright (C) 2019-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/util/shared_buffer.h"
+
+#include "mongo/base/string_data.h"
+
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+namespace {
+
+using SharedBufferTest = unittest::Test;
+
+TEST_F(SharedBufferTest, ReallocOrCopyNull) {
+    SharedBuffer buf;
+    ASSERT_EQ(buf.capacity(), 0u);
+    ASSERT(!buf);
+    ASSERT(!buf.isShared());
+    buf.reallocOrCopy(10);
+    ASSERT(buf);
+    ASSERT(!buf.isShared());
+    ASSERT_EQ(buf.capacity(), 10u);
+}
+
+TEST_F(SharedBufferTest, ReallocOrCopyNullShared) {
+    // null SharedBuffers are never considered "shared", even when copied.
+    SharedBuffer buf;
+    const SharedBuffer sharer = buf;
+    ASSERT_EQ(buf.capacity(), 0u);
+    ASSERT(!buf);
+    ASSERT(!buf.isShared());
+    buf.reallocOrCopy(10);
+    ASSERT(buf);
+    ASSERT(!buf.isShared());
+    ASSERT_EQ(buf.capacity(), 10u);
+    ASSERT_EQ(sharer.capacity(), 0u);
+}
+
+SharedBuffer makeBuffer() {
+    SharedBuffer buf = SharedBuffer::allocate(4);
+    memcpy(buf.get(), "foo", 4);
+    return buf;
+}
+
+TEST_F(SharedBufferTest, ReallocOrCopyGrow) {
+    SharedBuffer buf = makeBuffer();
+    ASSERT_EQ(buf.capacity(), 4u);
+    ASSERT(buf);
+    ASSERT(!buf.isShared());
+    buf.reallocOrCopy(10);
+    ASSERT(buf);
+    ASSERT(!buf.isShared());
+    ASSERT_EQ(buf.capacity(), 10u);
+    ASSERT_EQ("foo"_sd, buf.get());
+}
+
+TEST_F(SharedBufferTest, ReallocOrCopyGrowShared) {
+    SharedBuffer buf = makeBuffer();
+    const SharedBuffer sharer = buf;
+    ASSERT_EQ(buf.capacity(), 4u);
+    ASSERT(buf);
+    ASSERT(buf.isShared());
+    buf.reallocOrCopy(10);
+    ASSERT(buf);
+    ASSERT(!buf.isShared());
+    ASSERT_EQ(buf.capacity(), 10u);
+    ASSERT_EQ(sharer.capacity(), 4u);
+    ASSERT_EQ("foo"_sd, buf.get());
+    ASSERT_EQ("foo"_sd, sharer.get());
+    ASSERT_NE(buf.get(), sharer.get());
+}
+
+TEST_F(SharedBufferTest, ReallocOrCopyShrink) {
+    SharedBuffer buf = makeBuffer();
+    ASSERT_EQ(buf.capacity(), 4u);
+    ASSERT(buf);
+    ASSERT(!buf.isShared());
+    // The buffer is already at least 1 byte.
+    buf.reallocOrCopy(1);
+    ASSERT(buf);
+    // We copy it anyway.
+    ASSERT(!buf.isShared());
+    ASSERT_EQ(buf.capacity(), 1u);
+    ASSERT_EQ('f', buf.get()[0]);
+}
+
+TEST_F(SharedBufferTest, ReallocOrCopyShrinkShared) {
+    SharedBuffer buf = makeBuffer();
+    const SharedBuffer sharer = buf;
+    ASSERT_EQ(buf.capacity(), 4u);
+    ASSERT(buf);
+    ASSERT(buf.isShared());
+    // The buffer is already at least 1 byte.
+    buf.reallocOrCopy(1);
+    ASSERT(buf);
+    // We copy it anyway.
+    ASSERT(!buf.isShared());
+    ASSERT_EQ(buf.capacity(), 1u);
+    ASSERT_EQ(sharer.capacity(), 4u);
+    ASSERT_EQ('f', buf.get()[0]);
+    ASSERT_EQ("foo"_sd, sharer.get());
+    ASSERT_NE(buf.get(), sharer.get());
+}
+
+}  // namespace
+}  // namespace mongo