SERVER-20266 Use ConstDataCursor to read buffer in Checksum::gen

1 files changed, 7 insertions, 8 deletions

diff --git a/src/mongo/util/checksum.h b/src/mongo/util/checksum.h
index fb45bd5546c..7b04b38bdc1 100644
--- a/src/mongo/util/checksum.h
+++ b/src/mongo/util/checksum.h
@@ -28,6 +28,7 @@
 
 #pragma once
 
+#include "mongo/base/data_cursor.h"
 #include "mongo/platform/basic.h"
 
 namespace mongo {
@@ -42,18 +43,16 @@ struct Checksum {
     void gen(const void* buf, unsigned len) {
         wassert(((size_t)buf) % 8 == 0);  // performance warning
         unsigned n = len / 8 / 2;
-        const unsigned long long* p = (const unsigned long long*)buf;
-        unsigned long long a = 0;
+        ConstDataCursor cdc(static_cast<const char*>(buf));
+        uint64_t a = 0;
         for (unsigned i = 0; i < n; i++) {
-            a += (*p ^ i);
-            p++;
+            a += (cdc.readAndAdvance<LittleEndian<uint64_t>>() ^ i);
         }
-        unsigned long long b = 0;
+        uint64_t b = 0;
         for (unsigned i = 0; i < n; i++) {
-            b += (*p ^ i);
-            p++;
+            b += (cdc.readAndAdvance<LittleEndian<uint64_t>>() ^ i);
         }
-        unsigned long long c = 0;
+        uint64_t c = 0;
         for (unsigned i = n * 2 * 8; i < len; i++) {  // 0-7 bytes left
             c = (c << 8) | ((const signed char*)buf)[i];
         }