Improve code quality

Sources/NBitcoin/Utils/DeStreamTxInListExtensions.cs

@@ -14,5 +14,10 @@ namespace NBitcoin
         {
             return txInList.Where(p => p.PrevOut.Hash == uint256.Zero).Select(p => p.PrevOut.N);
         }
+
+        public static bool IsChangePointer(this TxIn txInList)
+        {
+            return txInList.PrevOut.Hash == uint256.Zero;
+        }
     }
 }
\ No newline at end of file

Sources/Stratis.Bitcoin.Features.Consensus/ConsensusErrors.cs

@@ -5,7 +5,7 @@ namespace Stratis.Bitcoin.Features.Consensus
     /// <summary>
     /// A class that holds consensus errors.
     /// </summary>
-    public static class ConsensusErrors
+    public static partial class ConsensusErrors
     {
         public static readonly ConsensusError InvalidPrevTip = new ConsensusError("invalid-prev-tip", "invalid previous tip");
         public static readonly ConsensusError HighHash = new ConsensusError("high-hash", "proof of work failed");

Sources/Stratis.Bitcoin.Features.Consensus/ConsensusOptions.cs

@@ -28,7 +28,6 @@ namespace Stratis.Bitcoin.Features.Consensus
         /// <param name="network">The network.</param>
         public virtual int GetStakeMinConfirmations(int height, Network network)
         {
-            return 0;
             if (network.IsTest())
                 return height < CoinstakeMinConfirmationActivationHeightTestnet ? 10 : 20;
 

Sources/Stratis.Bitcoin.Features.Consensus/DeStreamConsensusErrors.cs

+using Stratis.Bitcoin.Consensus;
+
+namespace Stratis.Bitcoin.Features.Consensus
+{
+    public static partial class ConsensusErrors
+    {
+        public static readonly ConsensusError BadBlockNoFeeOutput = new ConsensusError("bad-blk-feeoutput", "no fee output in coinbase or coinstake transactions");
+    }
+}
\ No newline at end of file

Sources/Stratis.Bitcoin.Features.Consensus/DeStreamRuleContextOverrides.cs

@@ -4,25 +4,41 @@ using Stratis.Bitcoin.Consensus;
 
 namespace Stratis.Bitcoin.Features.Consensus
 {
-    /// <inheritdoc />
-    public class DeStreamPosRuleContext : PosRuleContext
+    public interface IDeStreamRuleContext
     {
-        internal DeStreamPosRuleContext()
+        /// <summary>
+        ///     ScriptPubKeys of inputs spent in transaction
+        /// </summary>
+        List<Script> InputScriptPubKeys { get; set; }
+
+        /// <summary>
+        ///     Sum of inputs spent in transaction
+        /// </summary>
+        Money TotalIn { get; set; }
+    }
+
+    /// <inheritdoc cref="PosRuleContext" />
+    public class DeStreamRuleContext : PosRuleContext, IDeStreamRuleContext
+    {
+        internal DeStreamRuleContext()
         {
         }
 
-        public DeStreamPosRuleContext(ValidationContext validationContext, NBitcoin.Consensus consensus,
+        public DeStreamRuleContext(ValidationContext validationContext, NBitcoin.Consensus consensus,
             ChainedHeader consensusTip) : base(validationContext, consensus, consensusTip)
         {
         }
 
+        /// <inheritdoc />
         public List<Script> InputScriptPubKeys { get; set; }
 
+
+        /// <inheritdoc />
         public Money TotalIn { get; set; }
     }
 
-    /// <inheritdoc />
-    public class DeStreamPowRuleContext : PowRuleContext
+    /// <inheritdoc cref="PowRuleContext" />
+    public class DeStreamPowRuleContext : PowRuleContext, IDeStreamRuleContext
     {
         internal DeStreamPowRuleContext()
         {
@@ -33,8 +49,10 @@ namespace Stratis.Bitcoin.Features.Consensus
         {
         }
 
+        /// <inheritdoc />
         public List<Script> InputScriptPubKeys { get; set; }
 
+        /// <inheritdoc />
         public Money TotalIn { get; set; }
     }
 }
\ No newline at end of file

Sources/Stratis.Bitcoin.Features.Consensus/Rules/CommonRules/DeStreamBlockFeeRule.cs

@@ -7,12 +7,18 @@ using Stratis.Bitcoin.Consensus.Rules;
 
 namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
 {
+    /// <summary>
+    /// A rule that verifies fee is charged from all spent funds and transferred to <see cref="Network.DeStreamWallet"/>
+    /// </summary>
     [ExecutionRule]
     public class DeStreamBlockFeeRule : ConsensusRule
     {
         public override Task RunAsync(RuleContext context)
         {
+            // Actual fee is funds that are transferred to fee wallet in mined/staked block
             long actualFee = this.GetActualFee(context.ValidationContext.Block);
+            
+            // Expected fee is charged from all moved funds (not change)
             long expectedFee;
             switch (context)
             {
@@ -20,16 +26,17 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                     expectedFee = this.GetExpectedFee(context.ValidationContext.Block, deStreamPowRuleContext.TotalIn,
                         deStreamPowRuleContext.InputScriptPubKeys);
                     break;
-                case DeStreamPosRuleContext deStreamPosRuleContext:
+                case DeStreamRuleContext deStreamPosRuleContext:
                     expectedFee = this.GetExpectedFee(context.ValidationContext.Block, deStreamPosRuleContext.TotalIn,
                         deStreamPosRuleContext.InputScriptPubKeys);
                     break;
                 default:
-                    throw new Exception();
+                    throw new NotSupportedException(
+                        $"Rule context must be {nameof(DeStreamPowRuleContext)} or {nameof(DeStreamRuleContext)}");
             }
 
             if (Math.Abs(actualFee - expectedFee) > Money.CENT)
-                throw new Exception();
+                ConsensusErrors.BadTransactionFeeOutOfRange.Throw();
 
             return Task.CompletedTask;
         }
@@ -40,32 +47,21 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                 .Where(p => this.Parent.Network.IsDeStreamAddress(p.ScriptPubKey
                     .GetDestinationAddress(this.Parent.Network)?.ToString())).ToList();
 
-            if (outputsToFeeWallet.Count() != 1)
-                throw new Exception();
+            if (outputsToFeeWallet.Count != 1)
+                ConsensusErrors.BadBlockNoFeeOutput.Throw();
 
             return outputsToFeeWallet.Single().Value;
         }
 
         private long GetExpectedFee(Block block, Money totalIn, ICollection<Script> inputScriptPubKeys)
         {
-            long totalFee = 0;
-            foreach (Transaction transaction in block.Transactions.Where(p => !p.IsCoinBase && !p.IsCoinStake))
-            {
-                IList<Script> changeScriptPubKeys = transaction.Outputs
-                    .Select(q =>
-                        q.ScriptPubKey)
-                    .Intersect(inputScriptPubKeys)
-                    .Concat(transaction.Inputs.GetChangePointers()
-                        .Select(p => transaction.Outputs[p].ScriptPubKey))
+            return block.Transactions.Where(p => !p.IsCoinBase && !p.IsCoinStake).Sum(p => this.GetFeeInTransaction(p,
+                totalIn, p.Outputs
+                    .Select(q => q.ScriptPubKey).Intersect(inputScriptPubKeys)
+                    .Concat(p.Inputs.GetChangePointers()
+                        .Select(q => p.Outputs[q].ScriptPubKey))
                     .Distinct()
-                    .ToList();
-
-                long feeInTransaction = this.GetFeeInTransaction(transaction, totalIn, changeScriptPubKeys);
-
-                totalFee += feeInTransaction;
-            }
-
-            return totalFee;
+                    .ToList()));
         }
 
         private long GetFeeInTransaction(Transaction transaction, Money totalIn,
@@ -75,7 +71,7 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                                           .Where(p => !changeScriptPubKeys.Contains(p.ScriptPubKey))
                                           .Sum(p => p.Value) * this.Parent.Network.FeeRate;
             if (Math.Abs(totalIn.Satoshi - transaction.TotalOut.Satoshi - feeInTransaction) > Money.CENT)
-                throw new Exception();
+                ConsensusErrors.BadTransactionFeeOutOfRange.Throw();
 
             return (long) (feeInTransaction * this.Parent.Network.DeStreamFeePart);
         }

Sources/Stratis.Bitcoin.Features.Consensus/Rules/CommonRules/DeStreamCoinviewRule.cs

-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
@@ -9,6 +10,9 @@ using Stratis.Bitcoin.Utilities;
 
 namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
 {
+    /// <summary>
+    /// CoinViewRule that prevents verifing ChangePointer input
+    /// </summary>
     public abstract class DeStreamCoinViewRule : CoinViewRule
     {
         public override async Task RunAsync(RuleContext context)
@@ -45,7 +49,7 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                         // be in ConnectBlock because they require the UTXO set.
                         for (int j = 0; j < tx.Inputs.Count; j++)
                         {
-                            prevheights[j] = tx.Inputs[j].PrevOut.Hash == uint256.Zero
+                            prevheights[j] = tx.Inputs[j].IsChangePointer()
                                 ? 0
                                 : (int) view.AccessCoins(tx.Inputs[j].PrevOut.Hash).Height;
                         }
@@ -75,7 +79,7 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                         var txData = new PrecomputedTransactionData(tx);
                         for (int inputIndex = 0; inputIndex < tx.Inputs.Count; inputIndex++)
                         {
-                            if (tx.Inputs[inputIndex].PrevOut.Hash == uint256.Zero)
+                            if (tx.Inputs[inputIndex].IsChangePointer())
                                 continue;
 
                             this.Parent.PerformanceCounter.AddProcessedInputs(1);
@@ -126,6 +130,7 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
             this.Logger.LogTrace("(-)");
         }
 
+        /// <inheritdoc />
         public override void CheckInputs(Transaction transaction, UnspentOutputSet inputs, int spendHeight)
         {
             this.Logger.LogTrace("({0}:{1})", nameof(spendHeight), spendHeight);
@@ -175,6 +180,7 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
             this.Logger.LogTrace("(-)");
         }
 
+        /// <inheritdoc />
         public override long GetTransactionSignatureOperationCost(Transaction transaction, UnspentOutputSet inputs,
             DeploymentFlags flags)
         {
@@ -185,8 +191,10 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                 return signatureOperationCost;
 
             if (flags.ScriptFlags.HasFlag(ScriptVerify.P2SH))
+            {
                 signatureOperationCost += this.GetP2SHSignatureOperationsCount(transaction, inputs) *
                                           this.PowConsensusOptions.WitnessScaleFactor;
+            }
 
             signatureOperationCost += (from t in transaction.Inputs.RemoveChangePointer()
                 let prevout = inputs.GetOutputFor(t)
@@ -195,6 +203,7 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
             return signatureOperationCost;
         }
 
+        /// <inheritdoc />
         protected override uint GetP2SHSignatureOperationsCount(Transaction transaction, UnspentOutputSet inputs)
         {
             if (transaction.IsCoinBase)
@@ -211,8 +220,11 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
             return sigOps;
         }
 
+        ///<inheritdoc />
         protected override void UpdateUTXOSet(RuleContext context, Transaction transaction)
         {
+            // Saves script pub keys and total amount of spent inputs to context
+            
             this.Logger.LogTrace("()");
 
             ChainedHeader index = context.ValidationContext.ChainedHeader;
@@ -225,11 +237,14 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                         .Select(p => view.GetOutputFor(p).ScriptPubKey));
                     deStreamPowRuleContext.TotalIn = view.GetValueIn(transaction);
                     break;
-                case DeStreamPosRuleContext deStreamPosRuleContext:
+                case DeStreamRuleContext deStreamPosRuleContext:
                     deStreamPosRuleContext.InputScriptPubKeys.AddRange(transaction.Inputs.RemoveChangePointer()
                         .Select(p => view.GetOutputFor(p).ScriptPubKey));
                     deStreamPosRuleContext.TotalIn = view.GetValueIn(transaction);
                     break;
+                default:
+                    throw new NotSupportedException(
+                        $"Rule context must be {nameof(DeStreamPowRuleContext)} or {nameof(DeStreamRuleContext)}");
             }
 
             view.Update(transaction, index.Height);

Sources/Stratis.Bitcoin.Features.Consensus/Rules/CommonRules/DeStreamLoadCoinviewRule.cs

-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using NBitcoin;
@@ -25,9 +26,12 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules.CommonRules
                 case DeStreamPowRuleContext deStreamPowRuleContext:
                     deStreamPowRuleContext.InputScriptPubKeys = new List<Script>();
                     break;
-                case DeStreamPosRuleContext deStreamPosRuleContext:
+                case DeStreamRuleContext deStreamPosRuleContext:
                     deStreamPosRuleContext.InputScriptPubKeys = new List<Script>();
                     break;
+                default:
+                    throw new NotSupportedException(
+                        $"Rule context must be {nameof(DeStreamPowRuleContext)} or {nameof(DeStreamRuleContext)}");
             }
 
             using (new StopwatchDisposable(o => this.Parent.PerformanceCounter.AddUTXOFetchingTime(o)))

Sources/Stratis.Bitcoin.Features.Consensus/Rules/DeStreamConsensusRules.cs

@@ -40,7 +40,7 @@ namespace Stratis.Bitcoin.Features.Consensus.Rules
 
         public override RuleContext CreateRuleContext(ValidationContext validationContext, ChainedHeader consensusTip)
         {
-            return new DeStreamPosRuleContext(validationContext, this.Network.Consensus, consensusTip);
+            return new DeStreamRuleContext(validationContext, this.Network.Consensus, consensusTip);
         }
     }
 }
\ No newline at end of file

Sources/Stratis.Bitcoin.Features.MemoryPool/DeStreamMempoolCoinView.cs

@@ -10,6 +10,9 @@ using Stratis.Bitcoin.Utilities;
 
 namespace Stratis.Bitcoin.Features.MemoryPool
 {
+    /// <summary>
+    /// Creates <see cref="DeStreamUnspentOutputSet"/> and ChangePointer input
+    /// </summary>
     public class DeStreamMempoolCoinView : MempoolCoinView
     {
         public DeStreamMempoolCoinView(CoinView inner, ITxMempool memPool, SchedulerLock mempoolLock, IMempoolValidator mempoolValidator) : base(inner, memPool, mempoolLock, mempoolValidator)

Sources/Stratis.Bitcoin.Features.MemoryPool/DeStreamMempoolManager.cs

@@ -7,6 +7,9 @@ using Stratis.Bitcoin.Utilities;
 
 namespace Stratis.Bitcoin.Features.MemoryPool
 {
+    /// <summary>
+    /// Creates <see cref="DeStreamMempoolCoinView"/>
+    /// </summary>
     public class DeStreamMempoolManager : MempoolManager
     {
         public DeStreamMempoolManager(MempoolSchedulerLock mempoolLock, ITxMempool memPool, IMempoolValidator validator, IDateTimeProvider dateTimeProvider, MempoolSettings mempoolSettings, IMempoolPersistence mempoolPersistence, CoinView coinView, ILoggerFactory loggerFactory, Network network) : base(mempoolLock, memPool, validator, dateTimeProvider, mempoolSettings, mempoolPersistence, coinView, loggerFactory, network)

Sources/Stratis.Bitcoin.Features.MemoryPool/DeStreamMempoolValidator.cs

@@ -12,6 +12,9 @@ using Stratis.Bitcoin.Utilities;
 
 namespace Stratis.Bitcoin.Features.MemoryPool
 {
+    /// <summary>
+    /// Creates <see cref="DeStreamMempoolCoinView"/> and prevents verifing ChangePointer input
+    /// </summary>
     public class DeStreamMempoolValidator : MempoolValidator
     {
         public DeStreamMempoolValidator(ITxMempool memPool, MempoolSchedulerLock mempoolLock,