Add xxhash

third_party/xxhash/tests/collisions/sort.cc

@@ -0,0 +1,59 @@
+/*
+ * sort.cc - C++ sort functions
+ * Copyright (C) 2019-2021 Yann Collet
+ * GPL v2 License
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * You can contact the author at:
+ *   - xxHash homepage: https://www.xxhash.com
+ *   - xxHash source repository: https://github.com/Cyan4973/xxHash
+ */
+
+/*
+ * C++ sort functions tend to run faster than C ones due to templates allowing
+ * inline optimizations.
+ * Also, glibc's qsort() seems to inflate memory usage, resulting in OOM
+ * crashes on the test server.
+ */
+
+#include <algorithm>  // std::sort
+#define XXH_INLINE_ALL  // XXH128_cmp
+#include <xxhash.h>
+
+#include "sort.hh"
+
+void sort64(uint64_t* table, size_t size)
+{
+    std::sort(table, table + size);
+}
+
+#include <stdlib.h>  // qsort
+
+void sort128(XXH128_hash_t* table, size_t size)
+{
+#if 0
+    // C++ sort using a custom function object
+    struct {
+        bool operator()(XXH128_hash_t a, XXH128_hash_t b) const
+        {
+            return XXH128_cmp(&a, &b);
+        }
+    } customLess;
+    std::sort(table, table + size, customLess);
+#else
+    qsort(table, size, sizeof(*table), XXH128_cmp);
+#endif
+}