1 files changed, 88 insertions, 2 deletions
diff --git a/src/main.cpp b/src/main.cpp
index f0c08d273f..8d53e3be43 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -158,8 +158,6 @@ void static ResendWalletTransactions()
         pwallet->ResendWalletTransactions();
 }
 
-
-
 //////////////////////////////////////////////////////////////////////////////
 //
 // Registration of network node signals.
@@ -177,7 +175,95 @@ void UnregisterNodeSignals(CNodeSignals& nodeSignals)
     nodeSignals.SendMessages.disconnect(&SendMessages);
 }
 
+//////////////////////////////////////////////////////////////////////////////
+//
+// CBlockLocator implementation
+//
+
+CBlockLocator::CBlockLocator(uint256 hashBlock)
+{
+    std::map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hashBlock);
+    if (mi != mapBlockIndex.end())
+        Set((*mi).second);
+}
+
+void CBlockLocator::Set(const CBlockIndex* pindex)
+{
+    vHave.clear();
+    int nStep = 1;
+    while (pindex)
+    {
+        vHave.push_back(pindex->GetBlockHash());
+
+        // Exponentially larger steps back
+        for (int i = 0; pindex && i < nStep; i++)
+            pindex = pindex->pprev;
+        if (vHave.size() > 10)
+            nStep *= 2;
+    }
+    vHave.push_back(hashGenesisBlock);
+}
+
+int CBlockLocator::GetDistanceBack()
+{
+    // Retrace how far back it was in the sender's branch
+    int nDistance = 0;
+    int nStep = 1;
+    BOOST_FOREACH(const uint256& hash, vHave)
+    {
+        std::map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hash);
+        if (mi != mapBlockIndex.end())
+        {
+            CBlockIndex* pindex = (*mi).second;
+            if (pindex->IsInMainChain())
+                return nDistance;
+        }
+        nDistance += nStep;
+        if (nDistance > 10)
+            nStep *= 2;
+    }
+    return nDistance;
+}
+
+CBlockIndex *CBlockLocator::GetBlockIndex()
+{
+    // Find the first block the caller has in the main chain
+    BOOST_FOREACH(const uint256& hash, vHave)
+    {
+        std::map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hash);
+        if (mi != mapBlockIndex.end())
+        {
+            CBlockIndex* pindex = (*mi).second;
+            if (pindex->IsInMainChain())
+                return pindex;
+        }
+    }
+    return pindexGenesisBlock;
+}
+
+uint256 CBlockLocator::GetBlockHash()
+{
+    // Find the first block the caller has in the main chain
+    BOOST_FOREACH(const uint256& hash, vHave)
+    {
+        std::map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hash);
+        if (mi != mapBlockIndex.end())
+        {
+            CBlockIndex* pindex = (*mi).second;
+            if (pindex->IsInMainChain())
+                return hash;
+        }
+    }
+    return hashGenesisBlock;
+}
 
+int CBlockLocator::GetHeight()
+{
+    CBlockIndex* pindex = GetBlockIndex();
+    if (!pindex)
+        return 0;
+    return pindex->nHeight;
+}
 
 //////////////////////////////////////////////////////////////////////////////
 //