consensus: AuxPoW header

Add the AuxPoW header to block storage, without yet adding code to mine or validate mined AuxPoW blocks.

src/Makefile.test.include

@@ -214,6 +214,7 @@ BITCOIN_TESTS =\
   test/addrman_tests.cpp \
   test/amount_tests.cpp \
   test/allocator_tests.cpp \
+  test/auxpow_tests.cpp \
   test/base32_tests.cpp \
   test/base58_tests.cpp \
   test/base64_tests.cpp \

src/rpc/auxpow_miner.cpp

@@ -0,0 +1,154 @@
+// Copyright(c) 2018-2020 Daniel Kraft
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <rpc/auxpow_miner.h>
+
+#include <arith_uint256.h>
+#include <auxpow.h>
+#include <chainparams.h>
+#include <net.h>
+#include <node/context.h>
+#include <rpc/blockchain.h>
+#include <rpc/protocol.h>
+#include <rpc/request.h>
+#include <util/check.h>
+#include <util/strencodings.h>
+#include <util/time.h>
+#include <validation.h>
+
+const CBlock*
+AuxpowMiner::getCurrentBlock(const CTxMemPool& mempool,
+                              const CScript& scriptPubKey, uint256& target) EXCLUSIVE_LOCKS_REQUIRED(cs)
+{
+  AssertLockHeld(cs);
+  const CBlock* pblockCur = nullptr;
+
+  {
+    LOCK(cs_main);
+    CScriptID scriptID(scriptPubKey);
+    auto iter = curBlocks.find(scriptID);
+    if (iter != curBlocks.end())
+      pblockCur = iter->second;
+
+    if (pblockCur == nullptr
+        || pindexPrev != ::ChainActive().Tip()
+        ||(mempool.GetTransactionsUpdated() != txUpdatedLast
+            && GetTime() - startTime > MAX_BLOCK_TEMPLATE_AGE_SECONDS))
+      {
+        if (pindexPrev != ::ChainActive().Tip())
+          {
+            /* Clear old blocks since they're obsolete now.  */
+            blocks.clear();
+            templates.clear();
+            curBlocks.clear();
+          }
+
+        /* Create new block with nonce = 0 and extraNonce = 1.  */
+        std::unique_ptr<CBlockTemplate> newBlock
+            = BlockAssembler(mempool, Params()).CreateNewBlock(scriptPubKey);
+        if (newBlock == nullptr)
+          throw JSONRPCError(RPC_OUT_OF_MEMORY, "out of memory");
+
+        /* Update state only when CreateNewBlock succeeded.  */
+        txUpdatedLast = mempool.GetTransactionsUpdated();
+        pindexPrev = ::ChainActive().Tip();
+        startTime = GetTime();
+
+        /* Finalise it by setting the version and building the merkle root.  */
+        IncrementExtraNonce(&newBlock->block, pindexPrev, extraNonce);
+        newBlock->block.SetAuxpowFlag(true);
+
+        /* Save in our map of constructed blocks.  */
+        pblockCur = &newBlock->block;
+        curBlocks.emplace(scriptID, pblockCur);
+        blocks[pblockCur->GetHash()] = pblockCur;
+        templates.push_back(std::move(newBlock));
+      }
+  }
+
+  /* At this point, pblockCur is always initialised:  If we make it here
+     without creating a new block above, it means that, in particular,
+     pindexPrev == ::ChainActive().Tip().  But for that to happen, we must
+     already have created a pblockCur in a previous call, as pindexPrev is
+     initialised only when pblockCur is.  */
+  CHECK_NONFATAL(pblockCur);
+
+  arith_uint256 arithTarget;
+  bool fNegative, fOverflow;
+  arithTarget.SetCompact(pblockCur->nBits, &fNegative, &fOverflow);
+  if (fNegative || fOverflow || arithTarget == 0)
+    throw std::runtime_error("invalid difficulty bits in block");
+  target = ArithToUint256(arithTarget);
+
+  return pblockCur;
+}
+
+const CBlock*
+AuxpowMiner::lookupSavedBlock(const uint256 hash) const EXCLUSIVE_LOCKS_REQUIRED(cs)
+{
+  AssertLockHeld(cs);
+
+  const auto iter = blocks.find(hash);
+  if (iter == blocks.end())
+    throw JSONRPCError(RPC_INVALID_PARAMETER, "block hash unknown");
+
+  return iter->second;
+}
+
+UniValue
+AuxpowMiner::createAuxBlock(const CTxMemPool& mempool,
+                            const CScript& scriptPubKey)
+{
+  LOCK(cs);
+
+  uint256 target;
+  const CBlock* pblock = getCurrentBlock(mempool, scriptPubKey, target);
+
+  UniValue result(UniValue::VOBJ);
+  result.pushKV("hash", pblock->GetHash().GetHex());
+  result.pushKV("chainid", pblock->GetChainId());
+  result.pushKV("previousblockhash", pblock->hashPrevBlock.GetHex());
+  result.pushKV("coinbasevalue",
+                 static_cast<int64_t>(pblock->vtx[0]->vout[0].nValue));
+  result.pushKV("bits", strprintf("%08x", pblock->nBits));
+  result.pushKV("height", static_cast<int64_t>(pindexPrev->nHeight + 1));
+  result.pushKV("_target", HexStr(target));
+
+  return result;
+}
+
+bool
+AuxpowMiner::submitAuxBlock(ChainstateManager& chainman,
+                            const uint256 hash,
+                            const std::string& auxpowHex) const
+{
+  std::shared_ptr<CBlock> shared_block;
+  {
+    LOCK(cs);
+    const CBlock* pblock = lookupSavedBlock(hash);
+    shared_block = std::make_shared<CBlock>(*pblock);
+  }
+
+  const std::vector<unsigned char> vchAuxPow = ParseHex(auxpowHex);
+  CDataStream ss(vchAuxPow, SER_GETHASH, PROTOCOL_VERSION);
+  std::unique_ptr<CAuxPow> pow(new CAuxPow());
+  ss >> *pow;
+  shared_block->SetAuxpow(std::move(pow));
+  CHECK_NONFATAL(shared_block->GetHash() == hash);
+
+  return chainman.ProcessNewBlock(Params(), shared_block, true, nullptr);
+}
+
+AuxpowMiner&
+AuxpowMiner::get()
+{
+  static AuxpowMiner* instance = nullptr;
+  static RecursiveMutex lock;
+
+  LOCK(lock);
+  if (instance == nullptr)
+    instance = new AuxpowMiner();
+
+  return *instance;
+}

src/rpc/auxpow_miner.h

@@ -0,0 +1,107 @@
+// Copyright (c) 2018-2020 Daniel Kraft
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_RPC_AUXPOW_MINER_H
+#define BITCOIN_RPC_AUXPOW_MINER_H
+
+#include <miner.h>
+#include <rpc/request.h>
+#include <script/script.h>
+#include <script/standard.h>
+#include <sync.h>
+#include <txmempool.h>
+#include <uint256.h>
+#include <univalue.h>
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+/** The maximum time to retain a built block template for, before forcing replacement. */
+// Dogecoin: This is a guesstimate, and may need refinement. Namecoin used 60 seconds (1/10th block interval).
+static const unsigned int MAX_BLOCK_TEMPLATE_AGE_SECONDS = 10;
+
+namespace auxpow_tests
+{
+class AuxpowMinerForTest;
+}
+
+/**
+ * This class holds "global" state used to construct blocks for the auxpow
+ * mining RPCs and the map of already constructed blocks to look them up
+ * in the submitauxblock RPC.
+ *
+ * It is used as a singleton that is initialised during startup, taking the
+ * place of the previously real global and static variables.
+ */
+class AuxpowMiner
+{
+
+private:
+
+  /** The lock used for state in this object.  */
+  mutable RecursiveMutex cs;
+  /** All currently "active" block templates.  */
+  std::vector<std::unique_ptr<CBlockTemplate>> templates;
+  /** Maps block hashes to pointers in vTemplates.  Does not own the memory.  */
+  std::map<uint256, const CBlock*> blocks;
+  /** Maps coinbase script hashes to pointers in vTemplates.  Does not own the memory.  */
+  std::map<CScriptID, const CBlock*> curBlocks;
+
+  /** The current extra nonce for block creation.  */
+  unsigned extraNonce = 0;
+
+  /* Some data about when the current block (pblock) was constructed.  */
+  unsigned txUpdatedLast;
+  const CBlockIndex* pindexPrev = nullptr;
+  uint64_t startTime;
+
+  /**
+   * Constructs a new current block if necessary (checking the current state to
+   * see if "enough changed" for this), and returns a pointer to the block
+   * that should be returned to a miner for working on at the moment.  Also
+   * fills in the difficulty target value.
+   */
+  const CBlock* getCurrentBlock(const CTxMemPool& mempool,
+                                const CScript& scriptPubKey, uint256& target);
+
+  /**
+   * Looks up a previously constructed block by its (hex-encoded) hash.  If the
+   * block is found, it is returned.  Otherwise, a JSONRPCError is thrown.
+   */
+  const CBlock* lookupSavedBlock(const uint256 hash) const;
+
+  friend class auxpow_tests::AuxpowMinerForTest;
+
+public:
+
+  AuxpowMiner () = default;
+
+  /**
+   * Performs the main work for the "createauxblock" RPC:  Construct a new block
+   * to work on with the given address for the block reward and return the
+   * necessary information for the miner to construct an auxpow for it.
+   */
+  UniValue createAuxBlock(const CTxMemPool& mempool,
+                          const CScript& scriptPubKey);
+
+  /**
+   * Performs the main work for the "submitauxblock" RPC:  Look up the block
+   * previously created for the given hash, attach the given auxpow to it
+   * and try to submit it.  Returns true if all was successful and the block
+   * was accepted.
+   */
+  bool submitAuxBlock(ChainstateManager& chainman,
+                      const uint256 hash,
+                      const std::string& auxpowHex) const;
+
+  /**
+   * Returns the singleton instance of AuxpowMiner that is used for RPCs.
+   */
+  static AuxpowMiner& get ();
+
+};
+
+#endif // BITCOIN_RPC_AUXPOW_MINER_H