[Refactor] Introduce CyclingVector class

random-zebra · random-zebra · commit ddf63feac801 · 2020-10-19T11:18:02.000+02:00
diff --git a/src/Makefile.am b/src/Makefile.am
@@ -179,6 +179,7 @@ BITCOIN_CORE_H = \
   core_io.h \
   cuckoocache.h \
   crypter.h \
+  cyclingvector.h \
   pairresult.h \
   addressbook.h \
   denomination_functions.h \
diff --git a/src/cyclingvector.h b/src/cyclingvector.h
@@ -0,0 +1,36 @@
+// Copyright (c) 2020 The PIVX developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef PIVX_CYCLINGVECTOR_H
+#define PIVX_CYCLINGVECTOR_H
+
+#include <sync.h>
+#include <vector>
+
+/*
+ * Vector container that keeps only MAX_SIZE elements.
+ * Initialized with empty objects.
+ * Exposes only atomic getter and setter
+ * (which cycles the vector index modulo MAX_SIZE)
+ */
+template <typename T>
+class CyclingVector
+{
+private:
+    mutable RecursiveMutex cs;
+    unsigned int MAX_SIZE;
+    std::vector<T> vec;
+
+public:
+    CyclingVector(unsigned int _MAX_SIZE, const T& defaultVal):
+        MAX_SIZE(_MAX_SIZE),
+        vec(_MAX_SIZE, defaultVal)
+    {}
+
+    T Get(int idx) const { LOCK(cs); return vec[idx % MAX_SIZE]; }
+    void Set(int idx, const T& value) { LOCK(cs); vec[idx % MAX_SIZE] = value; }
+    std::vector<T> GetCache() const { LOCK(cs); return vec; }
+};
+
+#endif // PIVX_CYCLINGVECTOR_H
