1 files changed, 70 insertions, 0 deletions
diff --git a/src/mongo/db/index/hash_key_generator.cpp b/src/mongo/db/index/hash_key_generator.cpp
new file mode 100644
index 00000000000..2e891701fba
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+++ b/src/mongo/db/index/hash_key_generator.cpp
@@ -0,0 +1,70 @@
+/**
+*    Copyright (C) 2013 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/>.
+*
+*    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/db/structure/btree/btree.h"
+#include "mongo/db/hasher.h"
+#include "mongo/db/index/expression_params.h"
+#include "mongo/db/index/hash_access_method.h"
+#include "mongo/db/index/hash_key_generator.h"
+
+namespace mongo {
+
+    HashKeyGenerator::HashKeyGenerator( const std::string& hashedField,
+                                        HashSeed seed,
+                                        int hashVersion,
+                                        bool isSparse )
+        : _hashedField( hashedField ),
+          _seed( seed ),
+          _hashVersion( hashVersion ),
+          _isSparse( isSparse ) {
+    }
+
+    void HashKeyGenerator::getKeys( const BSONObj& obj, BSONObjSet* keys ) const {
+        const char* cstr = _hashedField.c_str();
+        BSONElement fieldVal = obj.getFieldDottedOrArray(cstr);
+        uassert(16766, "Error: hashed indexes do not currently support array values",
+                fieldVal.type() != Array );
+
+        if (!fieldVal.eoo()) {
+            BSONObj key = BSON( "" << makeSingleHashKey(fieldVal, _seed, _hashVersion));
+            keys->insert(key);
+        }
+        else if (!_isSparse) {
+            BSONObj nullObj = BSON("" << BSONNULL);
+            keys->insert(BSON("" << makeSingleHashKey(nullObj.firstElement(), _seed, _hashVersion)));
+        }
+
+    }
+
+    long long int HashKeyGenerator::makeSingleHashKey(const BSONElement& e, HashSeed seed, int v) {
+        massert(16767, "Only HashVersion 0 has been defined" , v == 0 );
+        return BSONElementHasher::hash64(e, seed);
+    }
+
+
+}  // namespace mongo