SERVER-32206 timestamp catalog change to declare index multikey

1 files changed, 94 insertions, 0 deletions

diff --git a/src/mongo/db/multi_key_path_tracker.h b/src/mongo/db/multi_key_path_tracker.h
new file mode 100644
index 00000000000..781ec9924cc
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+++ b/src/mongo/db/multi_key_path_tracker.h
@@ -0,0 +1,94 @@
+/**
+ *    Copyright (C) 2018 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 <string>
+
+#include "mongo/db/index/multikey_paths.h"
+#include "mongo/db/operation_context.h"
+
+namespace mongo {
+
+struct MultikeyPathInfo {
+    NamespaceString nss;
+    std::string indexName;
+    MultikeyPaths multikeyPaths;
+};
+
+/**
+ * An OperationContext decoration that tracks which indexes should be made multikey. This is used
+ * by IndexCatalogEntryImpl::setMultikey() to track what indexes should be set as multikey during
+ * secondary oplog application. This both marks if the multikey path information should be tracked
+ * instead of set immediately and saves the multikey path information for later if needed.
+ */
+class MultikeyPathTracker {
+public:
+    static const OperationContext::Decoration<MultikeyPathTracker> get;
+
+    // Decoration requires a default constructor.
+    MultikeyPathTracker() = default;
+
+    /**
+     * Appends the provided multikey path information to the list of indexes to set as multikey
+     * after the current replication batch finishes.
+     * Must call startTrackingMultikeyPathInfo() first.
+     */
+    void addMultikeyPathInfo(MultikeyPathInfo info);
+
+    /**
+     * Returns the multikey path information that has been saved.
+     */
+    const std::vector<MultikeyPathInfo>& getMultikeyPathInfo() const;
+
+    /**
+     * Specifies that we should track multikey path information on this MultikeyPathTracker. This is
+     * only expected to be called during oplog application on secondaries. We cannot simply check
+     * 'canAcceptWritesFor' because background index builds use their own OperationContext and
+     * cannot store their multikey path info here.
+     */
+    void startTrackingMultikeyPathInfo();
+
+    /**
+     * Specifies to stop tracking multikey path information.
+     */
+    void stopTrackingMultikeyPathInfo();
+
+    /**
+     * Returns if we've called startTrackingMultikeyPathInfo() and not yet called
+     * stopTrackingMultikeyPathInfo().
+     */
+    bool isTrackingMultikeyPathInfo() const;
+
+
+private:
+    std::vector<MultikeyPathInfo> _multikeyPathInfo;
+    bool _trackMultikeyPathInfo = false;
+};
+
+}  // namespace mongo