Added option 'checkpoint-days'

Configure how old blocks must be before we skip script validation

src/init.cpp

@@ -371,7 +371,8 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageGroup(_("Debugging/Testing options:"));
     if (showDebug)
     {
-        strUsage += HelpMessageOpt("-checkpoints", strprintf("Only accept block chain matching built-in checkpoints (default: %u)", 1));
+        strUsage += HelpMessageOpt("-checkpoints", strprintf("Skip validating scripts for old blocks with valid PoW (default: %u)", 1));
+        strUsage += HelpMessageOpt("-checkpoint-days", strprintf("Minimum age of blocks (in days) to skip validation for (default: %u)", DEFAULT_CHECKPOINT_DAYS));
         strUsage += HelpMessageOpt("-dblogsize=<n>", strprintf("Flush database activity from memory pool to disk log every <n> megabytes (default: %u)", 100));
         strUsage += HelpMessageOpt("-disablesafemode", strprintf("Disable safemode, override a real safe mode event (default: %u)", 0));
         strUsage += HelpMessageOpt("-testsafemode", strprintf("Force safe mode (default: %u)", 0));

src/main.cpp

@@ -2152,7 +2152,7 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
         return true;
     }
 
-    const int64_t timeBarrier = GetTime() - 24 * 3600 * std::max(1, nScriptCheckThreads);
+    const int64_t timeBarrier = GetTime() - 24 * 3600 * Opt().CheckpointDays();
     // Blocks that have varius days of POW behind them makes them secure in
     // that actually online nodes checked the scripts, so during initial sync we
     // don't need to check the scripts.

src/options.cpp

@@ -64,6 +64,11 @@ int Opt::ScriptCheckThreads() {
     return nScriptCheckThreads;
 }
 
+int64_t Opt::CheckpointDays() {
+    int64_t def = DEFAULT_CHECKPOINT_DAYS * std::max(1, ScriptCheckThreads());
+    return std::max(int64_t(1), Args->GetArg("-checkpoint-days", def));
+}
+
 std::auto_ptr<ArgReset> SetDummyArgGetter(std::auto_ptr<ArgGetter> getter) {
     Args.reset(getter.release());
     return std::auto_ptr<ArgReset>(new ArgReset);

src/options.h

@@ -13,13 +13,15 @@ struct Opt {
     bool HidePlatform();
     std::vector<std::string> UAComment(bool validate = false);
     int ScriptCheckThreads();
+    int64_t CheckpointDays();
 };
 
 /** Maximum number of script-checking threads allowed */
 static const int MAX_SCRIPTCHECK_THREADS = 16;
 /** -par default (number of script-checking threads, 0 = auto) */
 static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
-
+// Blocks newer than n days will have their script validated during sync.
+static const int DEFAULT_CHECKPOINT_DAYS = 30;
 
 //
 // For unit testing

src/test/options_tests.cpp

@@ -5,11 +5,25 @@
 #include <boost/test/unit_test.hpp>
 
 #include "options.h"
+#include <limits.h>
+
+const int NOT_SET = std::numeric_limits<int>::min();
 
 struct DummyArgGetter : public ArgGetter {
+
+    DummyArgGetter() : ArgGetter(),
+        par(NOT_SET), checkpdays(NOT_SET)
+    {
+    }
+
     virtual int64_t GetArg(const std::string& strArg, int64_t nDefault) {
-        assert(strArg == "-par");
-        return par;
+        if (strArg == "-par")
+            return par == NOT_SET ? nDefault : par;
+
+        if (strArg == "-checkpoint-days")
+            return checkpdays == NOT_SET ? nDefault : checkpdays;
+
+        assert(false);
     }
     virtual std::vector<std::string> GetMultiArgs(const std::string& arg) {
         assert(false);
@@ -18,6 +32,7 @@ struct DummyArgGetter : public ArgGetter {
         assert(false);
     }
     int par;
+    int checkpdays;
 };
 
 BOOST_AUTO_TEST_SUITE(options_tests);
@@ -38,4 +53,27 @@ BOOST_AUTO_TEST_CASE(scripthreads) {
     BOOST_CHECK_EQUAL(3, Opt().ScriptCheckThreads());
 }
 
+BOOST_AUTO_TEST_CASE(checkpointdays) {
+    std::auto_ptr<DummyArgGetter> arg(new DummyArgGetter);
+    DummyArgGetter* argPtr = arg.get();
+    std::auto_ptr<ArgReset> argraii
+        = SetDummyArgGetter(std::auto_ptr<ArgGetter>(arg.release()));
+
+    // No multiplier
+    argPtr->par = 1;
+    BOOST_CHECK_EQUAL(DEFAULT_CHECKPOINT_DAYS, Opt().CheckpointDays());
+
+    // x3 multiplier (3 script threads)
+    argPtr->par = 3;
+    BOOST_CHECK_EQUAL(3 * DEFAULT_CHECKPOINT_DAYS, Opt().CheckpointDays());
+
+    // Explicitly set days overrides default and multipliers
+    argPtr->checkpdays = 1;
+    BOOST_CHECK_EQUAL(1, Opt().CheckpointDays());
+
+     // Can't have less than 1 day
+    argPtr->checkpdays = 0;
+    BOOST_CHECK_EQUAL(1, Opt().CheckpointDays());
+}
+
 BOOST_AUTO_TEST_SUITE_END()