From 865b61b503157ac5dff9ad682a92d3590c8a5712 Mon Sep 17 00:00:00 2001
From: UdjinM6 <UdjinM6@users.noreply.github.com>
Date: Fri, 1 Dec 2017 08:15:11 +0300
Subject: [PATCH] Unify GetNextWorkRequired (#1737)

* unify GetNextWorkRequired

* drop enum
---
 src/chainparams.cpp    |  6 ++++++
 src/consensus/params.h |  2 ++
 src/pow.cpp            | 31 +++++++------------------------
 src/pow.h              |  7 -------
 4 files changed, 15 insertions(+), 31 deletions(-)

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 80466e055..21177b528 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -96,6 +96,8 @@ public:
         consensus.nPowTargetSpacing = 2.5 * 60; // Dash: 2.5 minutes
         consensus.fPowAllowMinDifficultyBlocks = false;
         consensus.fPowNoRetargeting = false;
+        consensus.nPowKGWHeight = 15200;
+        consensus.nPowDGWHeight = 34140;
         consensus.nRuleChangeActivationThreshold = 1916; // 95% of 2016
         consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
@@ -235,6 +237,8 @@ public:
         consensus.nPowTargetSpacing = 2.5 * 60; // Dash: 2.5 minutes
         consensus.fPowAllowMinDifficultyBlocks = true;
         consensus.fPowNoRetargeting = false;
+        consensus.nPowKGWHeight = 4001; // nPowKGWHeight >= nPowDGWHeight means "no KGW"
+        consensus.nPowDGWHeight = 4001;
         consensus.nRuleChangeActivationThreshold = 1512; // 75% for testchains
         consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
@@ -352,6 +356,8 @@ public:
         consensus.nPowTargetSpacing = 2.5 * 60; // Dash: 2.5 minutes
         consensus.fPowAllowMinDifficultyBlocks = true;
         consensus.fPowNoRetargeting = true;
+        consensus.nPowKGWHeight = 15200; // same as mainnet
+        consensus.nPowDGWHeight = 34140; // same as mainnet
         consensus.nRuleChangeActivationThreshold = 108; // 75% for testchains
         consensus.nMinerConfirmationWindow = 144; // Faster than normal for regtest (144 instead of 2016)
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
diff --git a/src/consensus/params.h b/src/consensus/params.h
index a759e0c26..e85949fe0 100644
--- a/src/consensus/params.h
+++ b/src/consensus/params.h
@@ -79,6 +79,8 @@ struct Params {
     bool fPowNoRetargeting;
     int64_t nPowTargetSpacing;
     int64_t nPowTargetTimespan;
+    int nPowKGWHeight;
+    int nPowDGWHeight;
     int64_t DifficultyAdjustmentInterval() const { return nPowTargetTimespan / nPowTargetSpacing; }
     uint256 nMinimumChainWork;
     uint256 defaultAssumeValid;
diff --git a/src/pow.cpp b/src/pow.cpp
index 785451c82..307759a46 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -171,33 +171,16 @@ unsigned int GetNextWorkRequiredBTC(const CBlockIndex* pindexLast, const CBlockH
 
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
 {
-    unsigned int retarget = DIFF_DGW;
-
-    // mainnet/regtest share a configuration
-    if (Params().NetworkIDString() == CBaseChainParams::MAIN || Params().NetworkIDString() == CBaseChainParams::REGTEST) {
-        if (pindexLast->nHeight + 1 >= 34140) retarget = DIFF_DGW;
-        else if (pindexLast->nHeight + 1 >= 15200) retarget = DIFF_KGW;
-        else retarget = DIFF_BTC;
-    // testnet -- we want a lot of coins in existance early on
-    } else {
-        if (pindexLast->nHeight + 1 >= 4001) retarget = DIFF_DGW;
-        else retarget = DIFF_BTC;
+    // Most recent algo first
+    if (pindexLast->nHeight + 1 >= params.nPowDGWHeight) {
+        return DarkGravityWave(pindexLast, params);
     }
-
-    // Bitcoin style retargeting
-    if (retarget == DIFF_BTC)
-    {
-        return GetNextWorkRequiredBTC(pindexLast, pblock, params);
-    }
-
-    // Retarget using Kimoto Gravity Wave
-    else if (retarget == DIFF_KGW)
-    {
+    else if (pindexLast->nHeight + 1 >= params.nPowKGWHeight) {
         return KimotoGravityWell(pindexLast, params);
     }
-
-    // Retarget using Dark Gravity Wave 3 by default
-    return DarkGravityWave(pindexLast, params);
+    else {
+        return GetNextWorkRequiredBTC(pindexLast, pblock, params);
+    }
 }
 
 // for DIFF_BTC only!
diff --git a/src/pow.h b/src/pow.h
index 864be944a..62939b979 100644
--- a/src/pow.h
+++ b/src/pow.h
@@ -15,13 +15,6 @@ class CBlockIndex;
 class uint256;
 class arith_uint256;
 
-// Define difficulty retarget algorithms
-enum DiffMode {
-    DIFF_DEFAULT = 0, // Default to invalid 0
-    DIFF_BTC     = 1, // Retarget every x blocks (Bitcoin style)
-    DIFF_KGW     = 2, // Retarget using Kimoto Gravity Well
-    DIFF_DGW     = 3, // Retarget using Dark Gravity Wave v3
-};
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params&);
 unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params&);