Merge pull request #1546 from rnicoll/1.17-auxpow1.17-dev

1.17 AuxPoW support

4 files changed, 222 insertions, 43 deletions

diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index c61dc5fb5..f272347a3 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -6,21 +6,21 @@
 #include <primitives/block.h>
 
 #include <hash.h>
-#include <crypto/scrypt.h>
 #include <tinyformat.h>
 #include <utilstrencodings.h>
 #include <crypto/common.h>
 
-uint256 CBlockHeader::GetHash() const
+void CBlockHeader::SetAuxpow (std::unique_ptr<CAuxPow> apow)
 {
-    return SerializeHash(*this);
-}
-
-uint256 CBlockHeader::GetPoWHash() const
-{
-    uint256 thash;
-    scrypt_1024_1_1_256(BEGIN(nVersion), BEGIN(thash));
-    return thash;
+    if (apow != nullptr)
+    {
+        auxpow.reset(apow.release());
+        SetAuxpowFlag(true);
+    } else
+    {
+        auxpow.reset();
+        SetAuxpowFlag(false);
+    }
 }
 
 std::string CBlock::ToString() const
diff --git a/src/primitives/block.h b/src/primitives/block.h
index 9bc06ad6b..1c3243bb3 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -6,10 +6,14 @@
 #ifndef BITCOIN_PRIMITIVES_BLOCK_H
 #define BITCOIN_PRIMITIVES_BLOCK_H
 
+#include <auxpow.h>
 #include <primitives/transaction.h>
+#include <primitives/pureheader.h>
 #include <serialize.h>
 #include <uint256.h>
 
+#include <memory>
+
 /** Nodes collect new transactions into a block, hash them into a hash tree,
  * and scan through nonce values to make the block's hash satisfy proof-of-work
  * requirements.  When they solve the proof-of-work, they broadcast the block
@@ -17,16 +21,12 @@
  * in the block is a special one that creates a new coin owned by the creator
  * of the block.
  */
-class CBlockHeader
+class CBlockHeader : public CPureBlockHeader
 {
 public:
-    // header
-    int32_t nVersion;
-    uint256 hashPrevBlock;
-    uint256 hashMerkleRoot;
-    uint32_t nTime;
-    uint32_t nBits;
-    uint32_t nNonce;
+
+    // auxpow (if this is a merge-minded block)
+    std::shared_ptr<CAuxPow> auxpow;
 
     CBlockHeader()
     {
@@ -37,37 +37,29 @@ public:
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream& s, Operation ser_action) {
-        READWRITE(this->nVersion);
-        READWRITE(hashPrevBlock);
-        READWRITE(hashMerkleRoot);
-        READWRITE(nTime);
-        READWRITE(nBits);
-        READWRITE(nNonce);
+        READWRITE(*(CPureBlockHeader*)this);
+
+        if (this->IsAuxpow())
+        {
+            if (ser_action.ForRead())
+                auxpow = std::make_shared<CAuxPow>();
+            assert(auxpow != nullptr);
+            READWRITE(*auxpow);
+        } else if (ser_action.ForRead())
+            auxpow.reset();
     }
 
     void SetNull()
     {
-        nVersion = 0;
-        hashPrevBlock.SetNull();
-        hashMerkleRoot.SetNull();
-        nTime = 0;
-        nBits = 0;
-        nNonce = 0;
-    }
-
-    bool IsNull() const
-    {
-        return (nBits == 0);
+        CPureBlockHeader::SetNull();
+        auxpow.reset();
     }
 
-    uint256 GetHash() const;
-
-    uint256 GetPoWHash() const;
-
-    int64_t GetBlockTime() const
-    {
-        return (int64_t)nTime;
-    }
+    /**
+     * Set the block's auxpow (or unset it).  This takes care of updating
+     * the version accordingly.
+     */
+    void SetAuxpow (std::unique_ptr<CAuxPow> apow);
 };
 
 
@@ -115,6 +107,7 @@ public:
         block.nTime          = nTime;
         block.nBits          = nBits;
         block.nNonce         = nNonce;
+        block.auxpow         = auxpow;
         return block;
     }
 
diff --git a/src/primitives/pureheader.cpp b/src/primitives/pureheader.cpp
new file mode 100644
index 000000000..2dc33d738
--- /dev/null
+++ b/src/primitives/pureheader.cpp
@@ -0,0 +1,29 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "primitives/pureheader.h"
+
+#include "crypto/scrypt.h"
+#include "hash.h"
+#include "utilstrencodings.h"
+
+void CPureBlockHeader::SetBaseVersion(int32_t nBaseVersion, int32_t nChainId)
+{
+    assert(nBaseVersion >= 1 && nBaseVersion < VERSION_AUXPOW);
+    assert(!IsAuxpow());
+    nVersion = nBaseVersion | (nChainId * VERSION_CHAIN_START);
+}
+
+uint256 CPureBlockHeader::GetHash() const
+{
+    return SerializeHash(*this);
+}
+
+uint256 CPureBlockHeader::GetPoWHash() const
+{
+    uint256 thash;
+    scrypt_1024_1_1_256(BEGIN(nVersion), BEGIN(thash));
+    return thash;
+}
diff --git a/src/primitives/pureheader.h b/src/primitives/pureheader.h
new file mode 100644
index 000000000..34373bbb7
--- /dev/null
+++ b/src/primitives/pureheader.h
@@ -0,0 +1,157 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2013 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_PRIMITIVES_PUREHEADER_H
+#define BITCOIN_PRIMITIVES_PUREHEADER_H
+
+#include "serialize.h"
+#include "uint256.h"
+
+/**
+ * A block header without auxpow information.  This "intermediate step"
+ * in constructing the full header is useful, because it breaks the cyclic
+ * dependency between auxpow (referencing a parent block header) and
+ * the block header (referencing an auxpow).  The parent block header
+ * does not have auxpow itself, so it is a pure header.
+ */
+class CPureBlockHeader
+{
+public:
+
+    /* Modifiers to the version.  */
+    static const int32_t VERSION_AUXPOW = (1 << 8);
+
+    /** Bits above are reserved for the auxpow chain ID.  */
+    static const int32_t VERSION_CHAIN_START = (1 << 16);
+
+    // header
+    int32_t nVersion;
+    uint256 hashPrevBlock;
+    uint256 hashMerkleRoot;
+    uint32_t nTime;
+    uint32_t nBits;
+    uint32_t nNonce;
+
+    CPureBlockHeader()
+    {
+        SetNull();
+    }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(this->nVersion);
+        READWRITE(hashPrevBlock);
+        READWRITE(hashMerkleRoot);
+        READWRITE(nTime);
+        READWRITE(nBits);
+        READWRITE(nNonce);
+    }
+
+    void SetNull()
+    {
+        nVersion = 0;
+        hashPrevBlock.SetNull();
+        hashMerkleRoot.SetNull();
+        nTime = 0;
+        nBits = 0;
+        nNonce = 0;
+    }
+
+    bool IsNull() const
+    {
+        return (nBits == 0);
+    }
+
+    uint256 GetHash() const;
+    uint256 GetPoWHash() const;
+
+    int64_t GetBlockTime() const
+    {
+        return (int64_t)nTime;
+    }
+
+    /* Below are methods to interpret the version with respect to
+       auxpow data and chain ID.  This used to be in the CBlockVersion
+       class, but was moved here when we switched back to nVersion being
+       a pure int member as preparation to undoing the "abuse" and
+       allowing BIP9 to work.  */
+
+    /**
+     * Extract the base version (without modifiers and chain ID).
+     * @return The base version./
+     */
+    inline int32_t GetBaseVersion() const
+    {
+        return GetBaseVersion(nVersion);
+    }
+    static inline int32_t GetBaseVersion(int32_t ver)
+    {
+        return ver % VERSION_AUXPOW;
+    }
+
+    /**
+     * Set the base version (apart from chain ID and auxpow flag) to
+     * the one given.  This should only be called when auxpow is not yet
+     * set, to initialise a block!
+     * @param nBaseVersion The base version.
+     * @param nChainId The auxpow chain ID.
+     */
+    void SetBaseVersion(int32_t nBaseVersion, int32_t nChainId);
+
+    /**
+     * Extract the chain ID.
+     * @return The chain ID encoded in the version.
+     */
+    inline int32_t GetChainId() const
+    {
+        return nVersion >> 16;
+    }
+
+    /**
+     * Set the chain ID.  This is used for the test suite.
+     * @param ch The chain ID to set.
+     */
+    inline void SetChainId(int32_t chainId)
+    {
+        nVersion %= VERSION_CHAIN_START;
+        nVersion |= chainId * VERSION_CHAIN_START;
+    }
+
+    /**
+     * Check if the auxpow flag is set in the version.
+     * @return True iff this block version is marked as auxpow.
+     */
+    inline bool IsAuxpow() const
+    {
+        return nVersion & VERSION_AUXPOW;
+    }
+
+    /**
+     * Set the auxpow flag.  This is used for testing.
+     * @param auxpow Whether to mark auxpow as true.
+     */
+    inline void SetAuxpowFlag(bool auxpow)
+    {
+        if (auxpow)
+            nVersion |= VERSION_AUXPOW;
+        else
+            nVersion &= ~VERSION_AUXPOW;
+    }
+
+    /**
+     * Check whether this is a "legacy" block without chain ID.
+     * @return True iff it is.
+     */
+    inline bool IsLegacy() const
+    {
+        return nVersion == 1
+            // Dogecoin: We have a random v2 block with no AuxPoW, treat as legacy
+            || (nVersion == 2 && GetChainId() == 0);
+    }
+};
+
+#endif // BITCOIN_PRIMITIVES_PUREHEADER_H