1 files changed, 101 insertions, 0 deletions
diff --git a/src/mongo/db/pipeline/builder.h b/src/mongo/db/pipeline/builder.h
new file mode 100755
index 00000000000..6b6a265aeea
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+++ b/src/mongo/db/pipeline/builder.h
@@ -0,0 +1,101 @@
+/**
+ * Copyright (c) 2011 10gen 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/>.
+ */
+
+#pragma once
+
+#include "mongo/pch.h"
+
+namespace mongo {
+
+    class BSONArrayBuilder;
+    class BSONObjBuilder;
+
+    /*
+      Generic Builder.
+
+      The methods to append items to an object (on BSONObjBuilder) and an array
+      (on BSONArrayBuilder) differ only by their inclusion of a field name. 
+      For more complicated implementations of addToBsonObj() and
+      addToBsonArray(), it makes sense to abstract that out and use
+      this generic builder that always looks the same, and then implement
+      addToBsonObj() and addToBsonArray() by using a common method.
+    */
+    class Builder :
+        boost::noncopyable {
+    public:
+        virtual ~Builder() {};
+
+        virtual void append() = 0; // append a null
+        virtual void appendUndefined() = 0;
+        virtual void append(bool b) = 0;
+        virtual void append(int i) = 0;
+        virtual void append(long long ll) = 0;
+        virtual void append(double d) = 0;
+        virtual void append(string s) = 0;
+        virtual void append(const OID &o) = 0;
+        virtual void append(const Date_t &d) = 0;
+        virtual void append(const OpTime& ot) = 0;
+        virtual void append(BSONObjBuilder *pDone) = 0;
+        virtual void append(BSONArrayBuilder *pDone) = 0;
+    };
+
+    class BuilderObj :
+        public Builder {
+    public:
+        // virtuals from Builder
+        virtual void append();
+        virtual void appendUndefined();
+        virtual void append(bool b);
+        virtual void append(int i);
+        virtual void append(long long ll);
+        virtual void append(double d);
+        virtual void append(string s);
+        virtual void append(const OID &o);
+        virtual void append(const Date_t &d);
+        virtual void append(const OpTime& ot);
+        virtual void append(BSONObjBuilder *pDone);
+        virtual void append(BSONArrayBuilder *pDone);
+
+        BuilderObj(BSONObjBuilder *pBuilder, string fieldName);
+
+    private:
+        BSONObjBuilder *pBuilder;
+        string fieldName;
+    };
+
+    class BuilderArray :
+        public Builder {
+    public:
+        // virtuals from Builder
+        virtual void append();
+        virtual void appendUndefined();
+        virtual void append(bool b);
+        virtual void append(int i);
+        virtual void append(long long ll);
+        virtual void append(double d);
+        virtual void append(string s);
+        virtual void append(const OID &o);
+        virtual void append(const Date_t &d);
+        virtual void append(const OpTime& ot);
+        virtual void append(BSONObjBuilder *pDone);
+        virtual void append(BSONArrayBuilder *pDone);
+
+        BuilderArray(BSONArrayBuilder *pBuilder);
+
+    private:
+        BSONArrayBuilder *pBuilder;
+    };
+}