SERVER-18438/SERVER-18435 Add RemoteCommandTargeter and runner to grid

* Implement a RemoteCommandTargeterFactory to dispense targeters based on
the connection string.

* Implement replica set monitor-based remote command targeter factory.

* Hook these with the global grid object.

* Switch the Shard::runCommand call to build on those.

1 files changed, 65 insertions, 0 deletions

diff --git a/src/mongo/client/remote_command_targeter_factory_impl.cpp b/src/mongo/client/remote_command_targeter_factory_impl.cpp
new file mode 100644
index 00000000000..191b5a4dfa7
--- /dev/null
+++ b/src/mongo/client/remote_command_targeter_factory_impl.cpp
@@ -0,0 +1,65 @@
+/**
+ *    Copyright (C) 2015 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/platform/basic.h"
+
+#include "mongo/client/remote_command_targeter_factory_impl.h"
+
+#include "mongo/base/status_with.h"
+#include "mongo/client/connection_string.h"
+#include "mongo/client/remote_command_targeter_rs.h"
+#include "mongo/client/remote_command_targeter_standalone.h"
+#include "mongo/stdx/memory.h"
+#include "mongo/util/assert_util.h"
+
+namespace mongo {
+
+    RemoteCommandTargeterFactoryImpl::RemoteCommandTargeterFactoryImpl() = default;
+
+    RemoteCommandTargeterFactoryImpl::~RemoteCommandTargeterFactoryImpl() = default;
+
+    std::unique_ptr<RemoteCommandTargeter>
+    RemoteCommandTargeterFactoryImpl::create(const ConnectionString& connStr) {
+        switch (connStr.type()) {
+        case ConnectionString::MASTER:
+        case ConnectionString::CUSTOM:
+            invariant(connStr.getServers().size() == 1);
+            return stdx::make_unique<RemoteCommandTargeterStandalone>(connStr.getServers().front());
+        case ConnectionString::SET:
+            return stdx::make_unique<RemoteCommandTargeterRS>(connStr.getSetName(),
+                                                             connStr.getServers());
+        case ConnectionString::INVALID:
+        case ConnectionString::SYNC:
+            // These connections should never be seen
+            break;
+        }
+
+        MONGO_UNREACHABLE;
+    }
+
+} // namespace mongo