SERVER-30015 Create the interface for ChunkSplitter

1 files changed, 60 insertions, 0 deletions

diff --git a/src/mongo/db/s/chunk_splitter.h b/src/mongo/db/s/chunk_splitter.h
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+++ b/src/mongo/db/s/chunk_splitter.h
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+/**
+ *    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/util/concurrency/thread_pool.h"
+
+namespace mongo {
+
+class ChunkRange;
+class NamespaceString;
+class OperationContext;
+class ThreadPool;
+
+/**
+ * Handles asynchronous auto-splitting of chunks.
+ */
+class ChunkSplitter {
+public:
+    ChunkSplitter();
+    ~ChunkSplitter();
+
+    /**
+     * Schedules an autosplit task. Returns whether or not the task was successfully scheduled.
+     */
+    bool trySplitting(OperationContext* opCtx,
+                      const NamespaceString& nss,
+                      const ChunkRange& chunkRange);
+
+private:
+    // Thread pool for parallelizing splits.
+    ThreadPool _threadPool;
+};
+
+}  // namespace mongo