Add MurmurHash3() unit test

Useful as a source of test vectors to anyone re-implementing bloom
filters.

src/test/hash_tests.cpp

@@ -0,0 +1,44 @@
+#include <boost/test/unit_test.hpp>
+#include <vector>
+
+#include "util.h"
+#include "hash.h"
+
+using namespace std;
+
+BOOST_AUTO_TEST_SUITE(hash_tests)
+
+BOOST_AUTO_TEST_CASE(murmurhash3)
+{
+
+#define T(expected, seed, data) BOOST_CHECK_EQUAL(MurmurHash3(seed, ParseHex(data)), expected)
+
+    // Test MurmurHash3 with various inputs. Of course this is retested in the
+    // bloom filter tests - they would fail if MurmurHash3() had any problems -
+    // but is useful for those trying to implement Bitcoin libraries as a
+    // source of test data for their MurmurHash3() primitive during
+    // development.
+    //
+    // The magic number 0xFBA4C795 comes from CBloomFilter::Hash()
+
+    T(0x00000000, 0x00000000, "");
+    T(0x6a396f08, 0xFBA4C795, "");
+    T(0x81f16f39, 0xffffffff, "");
+
+    T(0x514e28b7, 0x00000000, "00");
+    T(0xea3f0b17, 0xFBA4C795, "00");
+    T(0xfd6cf10d, 0x00000000, "ff");
+
+    T(0x16c6b7ab, 0x00000000, "0011");
+    T(0x8eb51c3d, 0x00000000, "001122");
+    T(0xb4471bf8, 0x00000000, "00112233");
+    T(0xe2301fa8, 0x00000000, "0011223344");
+    T(0xfc2e4a15, 0x00000000, "001122334455");
+    T(0xb074502c, 0x00000000, "00112233445566");
+    T(0x8034d2a0, 0x00000000, "0011223344556677");
+    T(0xb4698def, 0x00000000, "001122334455667788");
+
+#undef T
+}
+
+BOOST_AUTO_TEST_SUITE_END()