Okay as some of you might have noticed i'm developing a new pool backend:
http://forum.bitcoin.org/index.php?topic=19149.0 however as it's widly known around pool operators json-RCP is highly inefficient, especially the currently single threaded implementation in the official client.
For that reason i figured it might be a good idea to implement the chain handling and getwork method directly into the pool software which already is mostly done:
http://code.google.com/p/bitcoinsharp/ however it does not seem to have getwork implemented and as such i'm looking into what processing is involved in getting the different parts of the work data.
So far i've found very little about it, what i've found so far is from the client source code:
if (params.size() == 0)
{
// Update block
static unsigned int nTransactionsUpdatedLast;
static CBlockIndex* pindexPrev;
static int64 nStart;
static CBlock* pblock;
if (pindexPrev != pindexBest ||
(nTransactionsUpdated != nTransactionsUpdatedLast && GetTime() - nStart > 60))
{
if (pindexPrev != pindexBest)
{
// Deallocate old blocks since they're obsolete now
mapNewBlock.clear();
BOOST_FOREACH(CBlock* pblock, vNewBlock)
delete pblock;
vNewBlock.clear();
}
nTransactionsUpdatedLast = nTransactionsUpdated;
pindexPrev = pindexBest;
nStart = GetTime();
// Create new block
pblock = CreateNewBlock(reservekey);
if (!pblock)
throw JSONRPCError(-7, "Out of memory");
vNewBlock.push_back(pblock);
}
// Update nTime
pblock->nTime = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
pblock->nNonce = 0;
// Update nExtraNonce
static unsigned int nExtraNonce = 0;
static int64 nPrevTime = 0;
IncrementExtraNonce(pblock, pindexPrev, nExtraNonce, nPrevTime);
// Save
mapNewBlock[pblock->hashMerkleRoot] = make_pair(pblock, nExtraNonce);
// Prebuild hash buffers
char pmidstate[32];
char pdata[128];
char phash1[64];
FormatHashBuffers(pblock, pmidstate, pdata, phash1);
uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
Object result;
result.push_back(Pair("midstate", HexStr(BEGIN(pmidstate), END(pmidstate))));
result.push_back(Pair("data", HexStr(BEGIN(pdata), END(pdata))));
result.push_back(Pair("hash1", HexStr(BEGIN(phash1), END(phash1))));
result.push_back(Pair("target", HexStr(BEGIN(hashTarget), END(hashTarget))));
return result;
}
else
{
// Parse parameters
vector<unsigned char> vchData = ParseHex(params[0].get_str());
if (vchData.size() != 128)
throw JSONRPCError(-8, "Invalid parameter");
CBlock* pdata = (CBlock*)&vchData[0];
// Byte reverse
for (int i = 0; i < 128/4; i++)
((unsigned int*)pdata)[i] = CryptoPP::ByteReverse(((unsigned int*)pdata)[i]);
// Get saved block
if (!mapNewBlock.count(pdata->hashMerkleRoot))
return false;
CBlock* pblock = mapNewBlock[pdata->hashMerkleRoot].first;
unsigned int nExtraNonce = mapNewBlock[pdata->hashMerkleRoot].second;
pblock->nTime = pdata->nTime;
pblock->nNonce = pdata->nNonce;
pblock->vtx[0].vin[0].scriptSig = CScript() << pblock->nBits << CBigNum(nExtraNonce);
pblock->hashMerkleRoot = pblock->BuildMerkleTree();
return CheckWork(pblock, *pwalletMain, reservekey);
}
I get why it's checking for the number of parameters however i have a very hard time following the rest of the code as it seems rather cluttered with other only indirectly related stuff, for example what does the deallocation of old blocks have to do with getting new work?
So all in all the process of getting work is still in the dark for me, would anyone mind sharing links or their own knowledge about this process?
