From 3da6dc7302899e95a811377c0517836f735c56fe Mon Sep 17 00:00:00 2001
From: coblee <chocobo@alum.mit.edu>
Date: Fri, 17 May 2013 00:57:05 -1000
Subject: [PATCH] Litecoin: getnetworkhashps

---
 src/bitcoinrpc.cpp |  2 ++
 src/bitcoinrpc.h   |  1 +
 src/rpcmining.cpp  | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/src/bitcoinrpc.cpp b/src/bitcoinrpc.cpp
index 44102e5a50..9741b3389f 100644
--- a/src/bitcoinrpc.cpp
+++ b/src/bitcoinrpc.cpp
@@ -207,6 +207,7 @@ static const CRPCCommand vRPCCommands[] =
     { "addnode",                &addnode,                true,      true },
     { "getaddednodeinfo",       &getaddednodeinfo,       true,      true },
     { "getdifficulty",          &getdifficulty,          true,      false },
+    { "getnetworkhashps",       &getnetworkhashps,       true,      false },
     { "getgenerate",            &getgenerate,            true,      false },
     { "setgenerate",            &setgenerate,            true,      false },
     { "gethashespersec",        &gethashespersec,        true,      false },
@@ -1145,6 +1146,7 @@ Array RPCConvertValues(const std::string &strMethod, const std::vector<std::stri
     if (strMethod == "getaddednodeinfo"       && n > 0) ConvertTo<bool>(params[0]);
     if (strMethod == "setgenerate"            && n > 0) ConvertTo<bool>(params[0]);
     if (strMethod == "setgenerate"            && n > 1) ConvertTo<boost::int64_t>(params[1]);
+    if (strMethod == "getnetworkhashps"       && n > 0) ConvertTo<boost::int64_t>(params[0]);
     if (strMethod == "sendtoaddress"          && n > 1) ConvertTo<double>(params[1]);
     if (strMethod == "settxfee"               && n > 0) ConvertTo<double>(params[0]);
     if (strMethod == "getreceivedbyaddress"   && n > 1) ConvertTo<boost::int64_t>(params[1]);
diff --git a/src/bitcoinrpc.h b/src/bitcoinrpc.h
index cf5b137988..5c0cae66e3 100644
--- a/src/bitcoinrpc.h
+++ b/src/bitcoinrpc.h
@@ -142,6 +142,7 @@ extern json_spirit::Value importprivkey(const json_spirit::Array& params, bool f
 
 extern json_spirit::Value getgenerate(const json_spirit::Array& params, bool fHelp); // in rpcmining.cpp
 extern json_spirit::Value setgenerate(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value getnetworkhashps(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value gethashespersec(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getmininginfo(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getwork(const json_spirit::Array& params, bool fHelp);
diff --git a/src/rpcmining.cpp b/src/rpcmining.cpp
index b8b7459634..33dcf22387 100644
--- a/src/rpcmining.cpp
+++ b/src/rpcmining.cpp
@@ -11,6 +11,42 @@
 using namespace json_spirit;
 using namespace std;
 
+// Litecoin: Return average network hashes per second based on last number of blocks.
+Value GetNetworkHashPS(int lookup) {
+    if (pindexBest == NULL)
+        return 0;
+
+    // If lookup is -1, then use blocks since last difficulty change.
+    if (lookup <= 0)
+        lookup = pindexBest->nHeight % 2016 + 1;
+
+    // If lookup is larger than chain, then set it to chain length.
+    if (lookup > pindexBest->nHeight)
+        lookup = pindexBest->nHeight;
+
+    CBlockIndex* pindexPrev = pindexBest;
+    double sum = 0.0;
+    for (int i = 0; i < lookup; i++)
+    {
+        sum += (pindexPrev->GetBlockTime() - pindexPrev->pprev->GetBlockTime()) / GetDifficulty(pindexPrev);
+        pindexPrev = pindexPrev->pprev;
+    }
+
+    return (boost::int64_t)(pow(2.0, 32) / (sum / lookup));
+}
+
+Value getnetworkhashps(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() > 1)
+        throw runtime_error(
+            "getnetworkhashps [blocks]\n"
+            "Returns the estimated network hashes per second based on the last 120 blocks.\n"
+            "Pass in [blocks] to override # of blocks, -1 specifies since last difficulty change.");
+
+    return GetNetworkHashPS(params.size() > 0 ? params[0].get_int() : 120);
+}
+
+
 Value getgenerate(const Array& params, bool fHelp)
 {
     if (fHelp || params.size() != 0)
@@ -77,6 +113,7 @@ Value getmininginfo(const Array& params, bool fHelp)
     obj.push_back(Pair("generate",      GetBoolArg("-gen")));
     obj.push_back(Pair("genproclimit",  (int)GetArg("-genproclimit", -1)));
     obj.push_back(Pair("hashespersec",  gethashespersec(params, false)));
+    obj.push_back(Pair("networkhashps", getnetworkhashps(params, false)));
     obj.push_back(Pair("pooledtx",      (uint64_t)mempool.size()));
     obj.push_back(Pair("testnet",       fTestNet));
     return obj;