🧹 Remove mining

CHANGES.md

@@ -55,6 +55,9 @@ To be released.
  -  (Libplanet.Extensions.Cocona) Changed signature of
     `ApvCommand.Verify(string?, string[]?, bool)` method to
     `ApvCommand.Verify(string?, PublicKey[]?, bool)`.  [[#3044]]
+ -  Removed `PreEvaluationBlock<T>.Mine()` and `BlockMetadata.MineNonce()`
+    methods.  [[#3067]]
+ -  Removed `HashCash` class.  [[#3067]]
 
 ### Backward-incompatible network protocol changes
 
@@ -140,6 +143,7 @@ To be released.
 [#3044]: https://github.com/planetarium/libplanet/pull/3044
 [#3054]: https://github.com/planetarium/libplanet/issues/3054
 [#3060]: https://github.com/planetarium/libplanet/pull/3060
+[#3067]: https://github.com/planetarium/libplanet/pull/3067
 
 
 Version 0.53.4

Libplanet.Tests/Blockchain/BlockChainTest.MineBlock.cs

@@ -496,7 +496,7 @@ public void IgnoreDuplicatedNonceTxs()
         [SkippableFact]
         public void GatherTransactionsToPropose()
         {
-            // TODO: We test more properties of GatherTransactionsToMine() method:
+            // TODO: We test more properties of GatherTransactionsToPropose() method:
             //       - if transactions are cut off if they exceed GetMaxTransactionsBytes()
             //       - if transactions with already consumed nonces are excluded
             //       - if transactions with greater nonces than unconsumed nonces are excluded

Libplanet.Tests/Blocks/BlockMetadataTest.cs

@@ -329,20 +329,6 @@ public void ValidateLastCommit()
                 lastCommit: validLastCommit);
         }
 
-        [Fact]
-        public void MineNonce()
-        {
-            var codec = new Codec();
-            var difficulty = 5000L;
-
-            (Nonce nonce, HashDigest<SHA256> preEvalHash) =
-                GenesisMetadata.MineNonce(difficulty);
-            Assert.True(Satisfies(preEvalHash.ByteArray, difficulty));
-            HashDigest<SHA256> actual = HashDigest<SHA256>.DeriveFrom(
-                    codec.Encode(GenesisMetadata.MakeCandidateData(nonce)));
-            AssertBytesEqual(actual.ByteArray, preEvalHash.ByteArray);
-        }
-
         private static Vote GenerateVote(BlockHash? hash, long height, int round, VoteFlag flag)
         {
             var key = new PrivateKey();

Libplanet.Tests/TestUtils.cs

@@ -402,30 +402,6 @@ public static byte[] GetRandomBytes(int size)
                 height, round, blockHash, votes);
         }
 
-        public static PreEvaluationBlock<T> MineGenesis<T>(
-            PublicKey miner = null,
-            IReadOnlyList<Transaction<T>> transactions = null,
-            DateTimeOffset? timestamp = null,
-            int protocolVersion = Block<T>.CurrentProtocolVersion
-        )
-            where T : IAction, new()
-        {
-            var txs = transactions?.OrderBy(tx => tx.Id).ToList() ?? new List<Transaction<T>>();
-            var content = new BlockContent<T>(
-                new BlockMetadata(
-                    protocolVersion: protocolVersion,
-                    index: 0,
-                    timestamp: timestamp ??
-                        new DateTimeOffset(2018, 11, 29, 0, 0, 0, TimeSpan.Zero),
-                    miner: (miner ?? GenesisProposer.PublicKey).ToAddress(),
-                    publicKey: protocolVersion >= 2 ? miner ?? GenesisProposer.PublicKey : null,
-                    previousHash: null,
-                    txHash: BlockContent<T>.DeriveTxHash(txs.OrderBy(tx => tx.Id).ToList()),
-                    lastCommit: null),
-                transactions: txs);
-            return content.Mine(0L, default);
-        }
-
         public static PreEvaluationBlock<T> ProposeGenesis<T>(
             PublicKey proposer = null,
             IReadOnlyList<Transaction<T>> transactions = null,
@@ -466,26 +442,6 @@ public static byte[] GetRandomBytes(int size)
             return content.Propose();
         }
 
-        public static Block<T> MineGenesisBlock<T>(
-            PrivateKey miner,
-            IReadOnlyList<Transaction<T>> transactions = null,
-            DateTimeOffset? timestamp = null,
-            int protocolVersion = Block<T>.CurrentProtocolVersion,
-            HashDigest<SHA256> stateRootHash = default
-        )
-            where T : IAction, new()
-        {
-            PreEvaluationBlock<T> preEval = MineGenesis(
-                miner?.PublicKey,
-                transactions,
-                timestamp,
-                protocolVersion);
-            var hash = preEval.Header.DeriveBlockHash(stateRootHash, null);
-            return protocolVersion < 2
-                ? new Block<T>(preEval, (stateRootHash, null, hash))
-                : preEval.Sign(miner, stateRootHash);
-        }
-
         public static Block<T> ProposeGenesisBlock<T>(
             PrivateKey miner,
             IReadOnlyList<Transaction<T>> transactions = null,

Libplanet/Blocks/BlockContent.cs

@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Security.Cryptography;
-using System.Threading;
 using Libplanet.Action;
 using Libplanet.Crypto;
 using Libplanet.Tx;
@@ -196,26 +195,6 @@ public BlockContent(IBlockMetadata metadata, IEnumerable<Transaction<T>> transac
             return new HashDigest<SHA256>(hasher.Hash);
         }
 
-        /// <summary>
-        /// Mines the PoW (proof-of-work) nonce satisfying <paramref name="difficulty"/>
-        /// for <see cref="PreEvaluationBlockHeader.PreEvaluationHash"/>
-        /// and returns a valid <see cref="PreEvaluationBlock{T}"/> instance.
-        /// </summary>
-        /// <param name="difficulty">The difficulty to target when mining
-        /// <see cref="PreEvaluationBlockHeader.PreEvaluationHash"/>.</param>
-        /// <param name="cancellationToken">An optional cancellation token used to propagate signal
-        /// that this operation should be cancelled.</param>
-        /// <returns>A <see cref="PreEvaluationBlock{T}"/> instance with a valid proof-of-work.
-        /// </returns>
-        /// <exception cref="OperationCanceledException">Thrown when the specified
-        /// <paramref name="cancellationToken"/> received a cancellation request.</exception>
-        public PreEvaluationBlock<T> Mine(
-            long difficulty,
-            CancellationToken cancellationToken = default) =>
-                new PreEvaluationBlock<T>(
-                    this,
-                    _blockMetadata.MineNonce(difficulty, cancellationToken).PreEvaluationHash);
-
         public PreEvaluationBlock<T> Propose()
         {
             return new PreEvaluationBlock<T>(

Libplanet/Blocks/BlockMetadata.cs

@@ -1,11 +1,7 @@
 using System;
 using System.Globalization;
-using System.Linq;
 using System.Security.Cryptography;
-using System.Text;
-using System.Threading;
 using Bencodex;
-using Bencodex.Types;
 using Libplanet.Crypto;
 
 namespace Libplanet.Blocks
@@ -311,62 +307,5 @@ public Bencodex.Types.Dictionary MakeCandidateData(Nonce nonce)
         /// <returns>A pre-evaluation block hash.</returns>
         public HashDigest<SHA256> DerivePreEvaluationHash(Nonce nonce) =>
             HashDigest<SHA256>.DeriveFrom(Codec.Encode(MakeCandidateData(nonce)));
-
-        /// <summary>
-        /// Mines the PoW (proof-of-work) nonce satisfying <paramref name="difficulty"/>.
-        /// </summary>
-        /// <param name="difficulty">The difficulty to target when mining
-        /// <see cref="PreEvaluationBlockHeader.PreEvaluationHash"/>.</param>
-        /// <param name="cancellationToken">An optional cancellation token used to propagate signal
-        /// that this operation should be cancelled.</param>
-        /// <returns>A pair of the mined nonce and the pre-evaluation hash that satisfy the
-        /// block <paramref name="difficulty"/>.</returns>
-        /// <exception cref="OperationCanceledException">Thrown when the specified
-        /// <paramref name="cancellationToken"/> received a cancellation request.</exception>
-        public (Nonce Nonce, HashDigest<SHA256> PreEvaluationHash) MineNonce(
-            long difficulty,
-            CancellationToken cancellationToken = default)
-        {
-            Hashcash.Stamp stamp = GetStampFunction();
-            var random = new Random();
-            int seed = random.Next();
-            return Hashcash.Answer(
-                stamp, difficulty, seed, cancellationToken);
-        }
-
-        private Hashcash.Stamp GetStampFunction()
-        {
-            // Poor man' way to optimize stamp...
-            // FIXME: We need to rather reorganize the serialization layout.
-            byte[] emptyNonce = Codec.Encode(MakeCandidateData(default));
-            byte[] oneByteNonce = Codec.Encode(MakeCandidateData(new Nonce(new byte[1])));
-            int offset = 0;
-            while (offset < emptyNonce.Length && emptyNonce[offset].Equals(oneByteNonce[offset]))
-            {
-                offset++;
-            }
-
-            // Prepares fixed parts (stampPrefix, stampSuffix, colon) ahead of time
-            // so that they can be reused:
-            const int nonceLength = 2;  // In Bencodex, empty bytes are represented as "0:".
-            byte[] stampPrefix = new byte[offset];
-            Array.Copy(emptyNonce, stampPrefix, stampPrefix.Length);
-            byte[] stampSuffix = new byte[emptyNonce.Length - offset - nonceLength];
-            Array.Copy(emptyNonce, offset + nonceLength, stampSuffix, 0, stampSuffix.Length);
-            byte[] colon = { 0x3a }; // ':'
-
-            byte[] Stamp(Nonce nonce)
-            {
-                int nLen = nonce.ByteArray.Length;
-                return stampPrefix
-                    .Concat(Encoding.ASCII.GetBytes(nLen.ToString(CultureInfo.InvariantCulture)))
-                    .Concat(colon)
-                    .Concat(nonce.ToByteArray())
-                    .Concat(stampSuffix)
-                    .ToArray();
-            }
-
-            return Stamp;
-        }
     }
 }