SERVER-1752 Dedup DiskLocs in IntervalBtreeCursor using an unordered_set.

1 files changed, 53 insertions, 0 deletions

diff --git a/src/mongo/db/diskloc_test.cpp b/src/mongo/db/diskloc_test.cpp
new file mode 100644
index 00000000000..db3e0c8a65b
--- /dev/null
+++ b/src/mongo/db/diskloc_test.cpp
@@ -0,0 +1,53 @@
+/**
+ *    Copyright (C) 2012 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/>.
+ */
+
+/** Unit tests for DiskLoc. */
+
+#include "mongo/db/diskloc.h"
+
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+namespace {
+
+    TEST( DiskLoc, HashEqual ) {
+        DiskLoc locA( 1, 2 );
+        DiskLoc locB;
+        locB.set( 1, 2 );
+        ASSERT_EQUALS( locA, locB );
+        DiskLoc::Hasher hasher;
+        ASSERT_EQUALS( hasher( locA ), hasher( locB ) );
+    }
+
+    TEST( DiskLoc, HashNotEqual ) {
+        DiskLoc original( 1, 2 );
+        DiskLoc diffFile( 10, 2 );
+        DiskLoc diffOfs( 1, 20 );
+        DiskLoc diffBoth( 10, 20 );
+        ASSERT_NOT_EQUALS( original, diffFile );
+        ASSERT_NOT_EQUALS( original, diffOfs );
+        ASSERT_NOT_EQUALS( original, diffBoth );
+        
+        // Unequal DiskLocs need not produce unequal hashes.  But unequal hashes are likely, and
+        // assumed here for sanity checking of the custom hash implementation.
+        DiskLoc::Hasher hasher;
+        ASSERT_NOT_EQUALS( hasher( original ), hasher( diffFile ) );
+        ASSERT_NOT_EQUALS( hasher( original ), hasher( diffOfs ) );
+        ASSERT_NOT_EQUALS( hasher( original ), hasher( diffBoth ) );
+    }
+    
+} // namespace
+} // namespace mongo