1 files changed, 53 insertions, 0 deletions
diff --git a/src/mongo/db/btreebuilder.h b/src/mongo/db/btreebuilder.h
new file mode 100644
index 00000000000..6de55d89299
--- /dev/null
+++ b/src/mongo/db/btreebuilder.h
@@ -0,0 +1,53 @@
+#pragma once
+
+#include "btree.h"
+
+namespace mongo {
+
+    /**
+     * build btree from the bottom up
+     */
+    template< class V >
+    class BtreeBuilder {
+        typedef typename V::KeyOwned KeyOwned;
+        typedef typename V::Key Key;
+        
+        bool dupsAllowed;
+        IndexDetails& idx;
+        /** Number of keys added to btree. */
+        unsigned long long n;
+        /** Last key passed to addKey(). */
+        auto_ptr< typename V::KeyOwned > keyLast;
+        BSONObj order;
+        Ordering ordering;
+        /** true iff commit() completed successfully. */
+        bool committed;
+
+        DiskLoc cur, first;
+        BtreeBucket<V> *b;
+
+        void newBucket();
+        void buildNextLevel(DiskLoc);
+        void mayCommitProgressDurably();
+
+    public:
+        ~BtreeBuilder();
+
+        BtreeBuilder(bool _dupsAllowed, IndexDetails& _idx);
+
+        /**
+         * Preconditions: 'key' is > or >= last key passed to this function (depends on _dupsAllowed)
+         * Postconditions: 'key' is added to intermediate storage.
+         */
+        void addKey(BSONObj& key, DiskLoc loc);
+
+        /**
+         * commit work.  if not called, destructor will clean up partially completed work
+         *  (in case exception has happened).
+         */
+        void commit();
+
+        unsigned long long getn() { return n; }
+    };
+
+}