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+/* Copyright (C) 2021 Free Software Foundation, Inc.
+ Contributed by Oracle.
+
+ This file is part of GNU Binutils.
+
+ 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 3, 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, 51 Franklin Street - Fifth Floor, Boston,
+ MA 02110-1301, USA. */
+
+/*
+ * Dbe Cache Map implementation.
+ *
+ * Simple Cache Map makes the following assumptions:
+ * - Cache Map is used for very fast but not guaranteed mapping;
+ * - No Relations can be used;
+ * - all objects used as keys or values has to be managed
+ * outside CacheMap (f.e. deletion);
+ */
+
+#ifndef _DbeCacheMap_h
+#define _DbeCacheMap_h
+
+#include <Map.h>
+
+template <typename Key_t, class ITEM>
+class DbeCacheMap : public Map<Key_t, ITEM *>
+{
+public:
+
+ DbeCacheMap (int _size = DefaultSize)
+ { // _size should be 2 ** N
+ size = _size;
+ table = new DbeCache_T[size];
+ memset (table, 0, size * sizeof (DbeCache_T));
+ };
+
+ ~DbeCacheMap ()
+ {
+ delete[] table;
+ };
+
+ void
+ put (Key_t key, ITEM *val)
+ {
+ int ind = get_hash (key);
+ table[ind].key = key;
+ table[ind].value = val;
+ };
+
+ ITEM *
+ get (Key_t key)
+ {
+ int ind = get_hash (key);
+ if (table[ind].key == key)
+ return table[ind].value;
+ return (ITEM *) NULL;
+ };
+
+ ITEM *
+ remove (Key_t key)
+ {
+ int ind = get_hash (key);
+ ITEM *v = table[ind].value;
+ table[ind].value = (ITEM *) NULL;
+ return v;
+ };
+
+ ITEM *
+ get (Key_t /* key */, typename Map<Key_t, ITEM *>::Relation /* rel */)
+ {
+ return (ITEM *) NULL;
+ };
+
+private:
+
+ enum
+ {
+ DefaultSize = (1 << 13)
+ };
+
+ typedef struct DbeCache_S
+ {
+ Key_t key;
+ ITEM *value;
+ } DbeCache_T;
+ DbeCache_T *table;
+ int size;
+
+ int
+ get_hash (Key_t key)
+ {
+ unsigned long long h = (unsigned long long) key;
+ h ^= (h >> 20) ^ (h >> 12);
+ return (h ^ (h >> 7) ^ (h >> 4)) & (size - 1);
+ }
+};
+
+#endif