blockfilter: Use unordered_set instead of set in blockfilter.

2 files changed, 44 insertions, 0 deletions

diff --git a/src/util/bytevectorhash.cpp b/src/util/bytevectorhash.cpp
new file mode 100644
index 0000000000..f87d0e04b3
--- /dev/null
+++ b/src/util/bytevectorhash.cpp
@@ -0,0 +1,18 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/siphash.h>
+#include <random.h>
+#include <util/bytevectorhash.h>
+
+ByteVectorHash::ByteVectorHash()
+{
+    GetRandBytes(reinterpret_cast<unsigned char*>(&m_k0), sizeof(m_k0));
+    GetRandBytes(reinterpret_cast<unsigned char*>(&m_k1), sizeof(m_k1));
+}
+
+size_t ByteVectorHash::operator()(const std::vector<unsigned char>& input) const
+{
+    return CSipHasher(m_k0, m_k1).Write(input.data(), input.size()).Finalize();
+}
diff --git a/src/util/bytevectorhash.h b/src/util/bytevectorhash.h
new file mode 100644
index 0000000000..b88c17460b
--- /dev/null
+++ b/src/util/bytevectorhash.h
@@ -0,0 +1,26 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_BYTEVECTORHASH_H
+#define BITCOIN_UTIL_BYTEVECTORHASH_H
+
+#include <stdint.h>
+#include <vector>
+
+/**
+ * Implementation of Hash named requirement for types that internally store a byte array. This may
+ * be used as the hash function in std::unordered_set or std::unordered_map over such types.
+ * Internally, this uses a random instance of SipHash-2-4.
+ */
+class ByteVectorHash final
+{
+private:
+    uint64_t m_k0, m_k1;
+
+public:
+    ByteVectorHash();
+    size_t operator()(const std::vector<unsigned char>& input) const;
+};
+
+#endif // BITCOIN_UTIL_BYTEVECTORHASH_H