Move network-time related functions to timedata.cpp/h

The network time-offset-mangement functions from util.cpp are moved to
timedata.(cpp|h). This breaks the dependency of util on netbase.

Author: laanwj

src/Makefile.am

@@ -80,6 +80,7 @@ BITCOIN_CORE_H = \
   serialize.h \
   sync.h \
   threadsafety.h \
+  timedata.h \
   tinyformat.h \
   txdb.h \
   txmempool.h \
@@ -129,6 +130,7 @@ libbitcoin_server_a_SOURCES = \
   rpcnet.cpp \
   rpcrawtransaction.cpp \
   rpcserver.cpp \
+  timedata.cpp \
   txdb.cpp \
   txmempool.cpp \
   $(JSON_H) \

src/addrman.h

@@ -8,6 +8,7 @@
 #include "netbase.h"
 #include "protocol.h"
 #include "sync.h"
+#include "timedata.h"
 #include "util.h"
 
 #include <map>

src/alert.cpp

@@ -8,6 +8,7 @@
 #include "chainparams.h"
 #include "key.h"
 #include "net.h"
+#include "timedata.h"
 #include "ui_interface.h"
 #include "util.h"
 

src/qt/transactiondesc.cpp

@@ -12,6 +12,7 @@
 #include "main.h"
 #include "paymentserver.h"
 #include "transactionrecord.h"
+#include "timedata.h"
 #include "ui_interface.h"
 #include "wallet.h"
 

src/qt/transactionrecord.cpp

@@ -5,6 +5,7 @@
 #include "transactionrecord.h"
 
 #include "base58.h"
+#include "timedata.h"
 #include "wallet.h"
 
 #include <stdint.h>

src/rpcmisc.cpp

@@ -9,6 +9,7 @@
 #include "net.h"
 #include "netbase.h"
 #include "rpcserver.h"
+#include "timedata.h"
 #include "util.h"
 #ifdef ENABLE_WALLET
 #include "wallet.h"

src/rpcnet.cpp

@@ -9,6 +9,7 @@
 #include "netbase.h"
 #include "protocol.h"
 #include "sync.h"
+#include "timedata.h"
 #include "util.h"
 
 #include <boost/foreach.hpp>

src/rpcwallet.cpp

@@ -8,6 +8,7 @@
 #include "init.h"
 #include "net.h"
 #include "netbase.h"
+#include "timedata.h"
 #include "util.h"
 #include "wallet.h"
 #include "walletdb.h"

src/timedata.cpp

@@ -0,0 +1,91 @@
+// 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);
+    }
+}

src/timedata.h

@@ -0,0 +1,17 @@
+// 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.
+
+#ifndef BITCOIN_TIMEDATA_H
+#define BITCOIN_TIMEDATA_H
+
+#include <stdint.h>
+
+class CNetAddr;
+
+/* Functions to keep track of adjusted P2P time */
+int64_t GetTimeOffset();
+int64_t GetAdjustedTime();
+void AddTimeData(const CNetAddr& ip, int64_t nTime);
+
+#endif