From 236982c2b6de619f0744c9c17ea7208b64a4afb3 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Sun, 29 Jun 2014 15:26:58 +0200
Subject: [PATCH] Add skiplist unit tests

---
 src/Makefile.test.include   |  1 +
 src/test/skiplist_tests.cpp | 45 +++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 src/test/skiplist_tests.cpp

diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index 4dab1773f4..8685452c7b 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -47,6 +47,7 @@ BITCOIN_TESTS =\
   test/script_tests.cpp \
   test/serialize_tests.cpp \
   test/sigopcount_tests.cpp \
+  test/skiplist_tests.cpp \
   test/test_bitcoin.cpp \
   test/transaction_tests.cpp \
   test/uint256_tests.cpp \
diff --git a/src/test/skiplist_tests.cpp b/src/test/skiplist_tests.cpp
new file mode 100644
index 0000000000..ea301685c9
--- /dev/null
+++ b/src/test/skiplist_tests.cpp
@@ -0,0 +1,45 @@
+// Copyright (c) 2014 The Bitcoin Core developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <boost/test/unit_test.hpp>
+#include <vector>
+#include "main.h"
+#include "util.h"
+
+
+#define SKIPLIST_LENGTH 300000
+
+BOOST_AUTO_TEST_SUITE(skiplist_tests)
+
+BOOST_AUTO_TEST_CASE(skiplist_test)
+{
+    std::vector<CBlockIndex> vIndex(SKIPLIST_LENGTH);
+
+    for (int i=0; i<SKIPLIST_LENGTH; i++) {
+        vIndex[i].nHeight = i;
+        vIndex[i].pprev = (i == 0) ? NULL : &vIndex[i - 1];
+        vIndex[i].BuildSkip();
+    }
+
+    for (int i=0; i<SKIPLIST_LENGTH; i++) {
+        if (i > 0) {
+            BOOST_CHECK(vIndex[i].pskip == &vIndex[vIndex[i].pskip->nHeight]);
+            BOOST_CHECK(vIndex[i].pskip->nHeight < i);
+        } else {
+            BOOST_CHECK(vIndex[i].pskip == NULL);
+        }
+    }
+
+    for (int i=0; i < 1000; i++) {
+        int from = insecure_rand() % (SKIPLIST_LENGTH - 1);
+        int to = insecure_rand() % (from + 1);
+
+        BOOST_CHECK(vIndex[SKIPLIST_LENGTH - 1].GetAncestor(from) == &vIndex[from]);
+        BOOST_CHECK(vIndex[from].GetAncestor(to) == &vIndex[to]);
+        BOOST_CHECK(vIndex[from].GetAncestor(0) == &vIndex[0]);
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+