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-rw-r--r--src/timedata.cpp91
1 files changed, 91 insertions, 0 deletions
diff --git a/src/timedata.cpp b/src/timedata.cpp
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+++ b/src/timedata.cpp
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+// Copyright (c) 2014 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "timedata.h"
+
+#include "netbase.h"
+#include "sync.h"
+#include "ui_interface.h"
+#include "util.h"
+
+#include <boost/foreach.hpp>
+
+using namespace std;
+
+static CCriticalSection cs_nTimeOffset;
+static int64_t nTimeOffset = 0;
+
+//
+// "Never go to sea with two chronometers; take one or three."
+// Our three time sources are:
+// - System clock
+// - Median of other nodes clocks
+// - The user (asking the user to fix the system clock if the first two disagree)
+//
+//
+int64_t GetTimeOffset()
+{
+ LOCK(cs_nTimeOffset);
+ return nTimeOffset;
+}
+
+int64_t GetAdjustedTime()
+{
+ return GetTime() + GetTimeOffset();
+}
+
+void AddTimeData(const CNetAddr& ip, int64_t nTime)
+{
+ int64_t nOffsetSample = nTime - GetTime();
+
+ LOCK(cs_nTimeOffset);
+ // Ignore duplicates
+ static set<CNetAddr> setKnown;
+ if (!setKnown.insert(ip).second)
+ return;
+
+ // Add data
+ static CMedianFilter<int64_t> vTimeOffsets(200,0);
+ vTimeOffsets.input(nOffsetSample);
+ LogPrintf("Added time data, samples %d, offset %+d (%+d minutes)\n", vTimeOffsets.size(), nOffsetSample, nOffsetSample/60);
+ if (vTimeOffsets.size() >= 5 && vTimeOffsets.size() % 2 == 1)
+ {
+ int64_t nMedian = vTimeOffsets.median();
+ std::vector<int64_t> vSorted = vTimeOffsets.sorted();
+ // Only let other nodes change our time by so much
+ if (abs64(nMedian) < 70 * 60)
+ {
+ nTimeOffset = nMedian;
+ }
+ else
+ {
+ nTimeOffset = 0;
+
+ static bool fDone;
+ if (!fDone)
+ {
+ // If nobody has a time different than ours but within 5 minutes of ours, give a warning
+ bool fMatch = false;
+ BOOST_FOREACH(int64_t nOffset, vSorted)
+ if (nOffset != 0 && abs64(nOffset) < 5 * 60)
+ fMatch = true;
+
+ if (!fMatch)
+ {
+ fDone = true;
+ string strMessage = _("Warning: Please check that your computer's date and time are correct! If your clock is wrong Bitcoin will not work properly.");
+ strMiscWarning = strMessage;
+ LogPrintf("*** %s\n", strMessage);
+ uiInterface.ThreadSafeMessageBox(strMessage, "", CClientUIInterface::MSG_WARNING);
+ }
+ }
+ }
+ if (fDebug) {
+ BOOST_FOREACH(int64_t n, vSorted)
+ LogPrintf("%+d ", n);
+ LogPrintf("| ");
+ }
+ LogPrintf("nTimeOffset = %+d (%+d minutes)\n", nTimeOffset, nTimeOffset/60);
+ }
+}