Author

Topic: [Dev] LoadExternalBlockFile: Deserialize or I/O error - Read attempted past buff (Read 196 times)

newbie
Activity: 26
Merit: 9
However, we are running into the following error:

Quote
LoadExternalBlockFile: Deserialize or I/O error - Read attempted past buffer limit: iostream error

I'm getting this running Bitcoin Core 0.13 currently... would also like to know how to fix it!
hero member
Activity: 595
Merit: 503
workingForBitcoins.com
Having issues with updating the code, would really appreciate some help.

So what we are trying to do is trying to add merged mining (AuxPow) to a code base used by bitcoin/litecoin.


However, we are running into the following error:

Quote
LoadExternalBlockFile: Deserialize or I/O error - Read attempted past buffer limit: iostream error

This error comes from:

Code:
streams.h, near line 626 in the "read" method of CBufferedFile.  

When trying to read a block with AuxPow, the relevant local variables in "read" are:

Code:
nsize 32, nReadPos 755, nReadLimit 776


The code base where most of the changes happen related to this happen in block.h:

Code:
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_PRIMITIVES_BLOCK_H
#define BITCOIN_PRIMITIVES_BLOCK_H

#include "primitives/transaction.h"
#include "serialize.h"
#include "uint256.h"

/** 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
 * to everyone and the block is added to the block chain.  The first transaction
 * in the block is a special one that creates a new coin owned by the creator
 * of the block.
 */


class CAuxMerkleBranch : public CMutableTransaction
{

public:
    uint256 hashBlock;
    std::vector vMerkleBranch;
    int nIndex;

    // memory only
    mutable bool fMerkleVerified;


    CAuxMerkleBranch()
    {
        Init();
    }

    CAuxMerkleBranch(const CMutableTransaction& txIn) : CMutableTransaction(txIn)
    {
        Init();
    }

    void Init()
    {
        hashBlock = uint256();
        nIndex = -1;
        fMerkleVerified = false;
    }

    ADD_SERIALIZE_METHODS;

    template
    inline void SerializationOp(Stream& s, Operation ser_action)
    {
        READWRITE(*(CMutableTransaction*)this);
        READWRITE(hashBlock);
        READWRITE(vMerkleBranch);
        READWRITE(nIndex);
    }
};

class CPureBlockHeader
{
public:
    // header
    int32_t nVersion;
    uint256 hashPrevBlock;
    uint256 hashMerkleRoot;
    uint32_t nTime;
    uint32_t nBits;
    uint32_t nNonce;

    CPureBlockHeader()
    {
        SetNull();
    }

    ADD_SERIALIZE_METHODS;

    template
    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;
    }
};


class CAuxPow: public CAuxMerkleBranch
{
public:
    CAuxMerkleBranch coinbase_branch;
    int nChainIndex;
    CPureBlockHeader parent_block;

public:
    inline explicit CAuxPow(const CMutableTransaction& txIn)
        : CAuxMerkleBranch(txIn)
    {
    }

    inline CAuxPow()
        : CAuxMerkleBranch()
    {
    }

    ADD_SERIALIZE_METHODS;

    template
    inline void SerializationOp(Stream& s, Operation ser_action) {
        READWRITE(*static_cast(this));

        READWRITE(coinbase_branch);
        READWRITE(nChainIndex);
        READWRITE(parent_block);
    }

};


class CBlockHeader
{
public:
    // header
    int32_t nVersion;
    uint256 hashPrevBlock;
    uint256 hashMerkleRoot;
    uint32_t nTime;
    uint32_t nBits;
    uint32_t nNonce;
    CAuxPow auxpow;

    CBlockHeader()
    {
        SetNull();
    }

    ADD_SERIALIZE_METHODS;

    template
    inline void SerializationOp(Stream& s, Operation ser_action) {
        READWRITE(this->nVersion);
        READWRITE(hashPrevBlock);
        READWRITE(hashMerkleRoot);
        READWRITE(nTime);
        READWRITE(nBits);
        READWRITE(nNonce);
        if (this->nVersion == 6422786) {
            READWRITE(auxpow);
        }
    }

    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;
    }
};


class CBlock : public CBlockHeader
{
public:
    // network and disk
    std::vector vtx;

    // memory only
    mutable bool fChecked;

    CBlock()
    {
        SetNull();
    }

    CBlock(const CBlockHeader &header)
    {
        SetNull();
        *((CBlockHeader*)this) = header;
    }

    ADD_SERIALIZE_METHODS;

    template
    inline void SerializationOp(Stream& s, Operation ser_action) {
        READWRITE(*(CBlockHeader*)this);
        READWRITE(vtx);
    }

    void SetNull()
    {
        CBlockHeader::SetNull();
        vtx.clear();
        fChecked = false;
    }

    CBlockHeader GetBlockHeader() const
    {
        CBlockHeader block;
        block.nVersion       = nVersion;
        block.hashPrevBlock  = hashPrevBlock;
        block.hashMerkleRoot = hashMerkleRoot;
        block.nTime          = nTime;
        block.nBits          = nBits;
        block.nNonce         = nNonce;
        return block;
    }

    std::string ToString() const;
};

/** Describes a place in the block chain to another node such that if the
 * other node doesn't have the same branch, it can find a recent common trunk.
 * The further back it is, the further before the fork it may be.
 */
struct CBlockLocator
{
    std::vector vHave;

    CBlockLocator() {}

    CBlockLocator(const std::vector& vHaveIn)
    {
        vHave = vHaveIn;
    }

    ADD_SERIALIZE_METHODS;

    template
    inline void SerializationOp(Stream& s, Operation ser_action) {
        int nVersion = s.GetVersion();
        if (!(s.GetType() & SER_GETHASH))
            READWRITE(nVersion);
        READWRITE(vHave);
    }

    void SetNull()
    {
        vHave.clear();
    }

    bool IsNull() const
    {
        return vHave.empty();
    }
};

/** Compute the consensus-critical block weight (see BIP 141). */
int64_t GetBlockWeight(const CBlock& tx);

#endif // BITCOIN_PRIMITIVES_BLOCK_H

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