From 296236412f311de7e889a4c37c3ee545b358dd12 Mon Sep 17 00:00:00 2001
From: Pedro Pinheiro <pdpinheiro@gmail.com>
Date: Mon, 22 Feb 2016 14:15:19 +0000
Subject: [PATCH] Add hard fork information to getblockchaininfo RPC endpoint

---
 src/main.h            |  1 +
 src/rpcblockchain.cpp | 46 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/src/main.h b/src/main.h
index 93b412b08db..7ae8eec4df0 100644
--- a/src/main.h
+++ b/src/main.h
@@ -124,6 +124,7 @@ struct BlockHasher
 extern CScript COINBASE_FLAGS;
 extern CCriticalSection cs_main;
 extern CTxMemPool mempool;
+extern boost::atomic<uint32_t> sizeForkTime;
 typedef boost::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
 extern BlockMap mapBlockIndex;
 extern uint64_t nLastBlockTx;
diff --git a/src/rpcblockchain.cpp b/src/rpcblockchain.cpp
index f5b16bc7c49..1c6d25cdf28 100644
--- a/src/rpcblockchain.cpp
+++ b/src/rpcblockchain.cpp
@@ -16,6 +16,8 @@
 #include "streams.h"
 #include "sync.h"
 #include "txmempool.h"
+#include "txdb.h"
+#include "timedata.h"
 #include "util.h"
 #include "utilstrencodings.h"
 
@@ -604,6 +606,46 @@ static UniValue SoftForkDesc(const std::string &name, int version, CBlockIndex*
     return rv;
 }
 
+static UniValue HardForkMajorityDesc(int minVersion, CBlockIndex* pindex, int nRequired, const Consensus::Params& consensusParams)
+{
+    uint32_t forkTime = sizeForkTime.load();
+    bool isHardForkActive = forkTime < std::numeric_limits<uint32_t>::max();
+    int nFound = 0;
+    UniValue gracePeriodEnds;
+    UniValue triggeredAtBlock;
+    CBlockIndex* pstart = pindex;
+    if (isHardForkActive) {
+        // Always report blocks found as over the threshold once the fork is active
+        nFound = nRequired + 1;
+        gracePeriodEnds = static_cast<uint64_t>(forkTime);
+        triggeredAtBlock = pblocktree->ForkBitActivated(FORK_BIT_2MB).GetHex();
+    } else {
+        for (int i = 0; i < consensusParams.nMajorityWindow && pstart != NULL; i++)
+        {
+            if (pstart->nVersion >= minVersion)
+                ++nFound;
+            pstart = pstart->pprev;
+        }
+    }
+
+    UniValue rv(UniValue::VOBJ);
+    rv.push_back(Pair("triggeredatblock", triggeredAtBlock));
+    rv.push_back(Pair("earliestforktime", gracePeriodEnds));
+    rv.push_back(Pair("found", nFound));
+    rv.push_back(Pair("required", nRequired));
+    rv.push_back(Pair("window", consensusParams.nMajorityWindow));
+    return rv;
+}
+
+static UniValue HardForkDesc(const std::string &name, int version, CBlockIndex* pindex, const Consensus::Params& consensusParams)
+{
+    UniValue rv(UniValue::VOBJ);
+    rv.push_back(Pair("id", name));
+    rv.push_back(Pair("version", version));
+    rv.push_back(Pair("status", HardForkMajorityDesc(version, pindex, consensusParams.nMajorityEnforceBlockUpgrade, consensusParams)));
+    return rv;
+}
+
 UniValue getblockchaininfo(const UniValue& params, bool fHelp)
 {
     if (fHelp || params.size() != 0)
@@ -662,6 +704,10 @@ UniValue getblockchaininfo(const UniValue& params, bool fHelp)
     softforks.push_back(SoftForkDesc("bip65", 4, tip, consensusParams));
     obj.push_back(Pair("softforks",             softforks));
 
+    UniValue hardforks(UniValue::VARR);
+    hardforks.push_back(HardForkDesc("bip109", 0x01000000, tip, consensusParams));
+    obj.push_back(Pair("hardforks", hardforks));
+
     if (fPruneMode)
     {
         CBlockIndex *block = chainActive.Tip();