1 files changed, 22 insertions, 3 deletions
diff --git a/src/mongo/base/string_data.cpp b/src/mongo/base/string_data.cpp
index 31ab21f1144..51f05fb6839 100644
--- a/src/mongo/base/string_data.cpp
+++ b/src/mongo/base/string_data.cpp
@@ -20,14 +20,33 @@
 
 namespace mongo {
 
+    namespace {
+
+        template <int SizeofSizeT>
+        size_t murmur3(const StringData& str);
+
+        template <>
+        size_t murmur3<4>(const StringData& str) {
+            uint32_t hash;
+            MurmurHash3_x86_32(str.rawData(), str.size(), 0, &hash);
+            return hash;
+        }
+
+        template <>
+        size_t murmur3<8>(const StringData& str) {
+            uint64_t hash[2];
+            MurmurHash3_x64_128(str.rawData(), str.size(), 0, hash);
+            return static_cast<size_t>(hash[0]);
+        }
+
+    }  // namespace
+
     std::ostream& operator<<(std::ostream& stream, const StringData& value) {
         return stream.write(value.rawData(), value.size());
     }
 
     size_t StringData::Hasher::operator() (const StringData& str) const {
-        unsigned out;
-        MurmurHash3_x86_32(str.rawData(), str.size(), 0, &out);
-        return out;
+        return murmur3<sizeof(size_t)>(str);
     }
 
 } // namespace mongo