/**
* Restore the UTXO in a Coin at a given COutPoint
* @param undo The Coin to be restored.
* @param view The coins view to which to apply the changes.
* @param out The out point that corresponds to the tx input.
* @return A DisconnectResult as an int
*/
int CViewManager::ApplyTxInUndo(Coin &&undo, CCoinsViewCache &view, const COutPoint &out)
{
bool fClean = true;
if (view.HaveCoin(out))
fClean = false; // overwriting transaction output
if (undo.nHeight == 0)
{
// Missing undo metadata (height and coinbase). Older versions included this
// information only in undo records for the last spend of a transactions'
// outputs. This implies that it must be present for some other output of the same tx.
const Coin &alternate = AccessByTxid(view, out.hash);
if (!alternate.IsSpent())
{
undo.nHeight = alternate.nHeight;
undo.fCoinBase = alternate.fCoinBase;
} else
{
return DISCONNECT_FAILED; // adding output for transaction without known metadata
}
}
// The potential_overwrite parameter to AddCoin is only allowed to be false if we know for
// sure that the coin did not already exist in the cache. As we have queried for that above
// using HaveCoin, we don't need to guess. When fClean is false, a coin already existed and
// it is an overwrite.
view.AddCoin(out, std::move(undo), !fClean);
return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
}
UniValue gettxoutproof(const JSONRPCRequest& request)
{
if (request.fHelp || (request.params.size() != 1 && request.params.size() != 2))
throw std::runtime_error(
"gettxoutproof [\"txid\",...] ( blockhash )\n"
"\nReturns a hex-encoded proof that \"txid\" was included in a block.\n"
"\nNOTE: By default this function only works sometimes. This is when there is an\n"
"unspent output in the utxo for this transaction. To make it always work,\n"
"you need to maintain a transaction index, using the -txindex command line option or\n"
"specify the block in which the transaction is included manually (by blockhash).\n"
"\nArguments:\n"
"1. \"txids\" (string) A json array of txids to filter\n"
" [\n"
" \"txid\" (string) A transaction hash\n"
" ,...\n"
" ]\n"
"2. \"blockhash\" (string, optional) If specified, looks for txid in the block with this hash\n"
"\nResult:\n"
"\"data\" (string) A string that is a serialized, hex-encoded data for the proof.\n"
);
std::set<uint256> setTxids;
uint256 oneTxid;
UniValue txids = request.params[0].get_array();
for (unsigned int idx = 0; idx < txids.size(); idx++) {
const UniValue& txid = txids[idx];
if (txid.get_str().length() != 64 || !IsHex(txid.get_str()))
throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid txid ")+txid.get_str());
uint256 hash(uint256S(txid.get_str()));
if (setTxids.count(hash))
throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated txid: ")+txid.get_str());
setTxids.insert(hash);
oneTxid = hash;
}
LOCK(cs_main);
CBlockIndex* pblockindex = nullptr;
uint256 hashBlock;
if (!request.params[1].isNull())
{
hashBlock = uint256S(request.params[1].get_str());
if (!mapBlockIndex.count(hashBlock))
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
pblockindex = mapBlockIndex[hashBlock];
} else {
// Loop through txids and try to find which block they're in. Exit loop once a block is found.
for (const auto& tx : setTxids) {
const Coin& coin = AccessByTxid(*pcoinsTip, tx);
if (!coin.IsSpent()) {
pblockindex = chainActive[coin.nHeight];
break;
}
}
}
if (pblockindex == nullptr)
{
CTransactionRef tx;
if (!GetTransaction(oneTxid, tx, Params().GetConsensus(), hashBlock, false) || hashBlock.IsNull())
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Transaction not yet in block");
if (!mapBlockIndex.count(hashBlock))
throw JSONRPCError(RPC_INTERNAL_ERROR, "Transaction index corrupt");
pblockindex = mapBlockIndex[hashBlock];
}
CBlock block;
if(!ReadBlockFromDisk(block, pblockindex, Params().GetConsensus()))
throw JSONRPCError(RPC_INTERNAL_ERROR, "Can't read block from disk");
unsigned int ntxFound = 0;
for (const auto& tx : block.vtx)
if (setTxids.count(tx->GetHash()))
ntxFound++;
if (ntxFound != setTxids.size())
throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Not all transactions found in specified or retrieved block");
CDataStream ssMB(SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
CMerkleBlock mb(block, setTxids);
ssMB << mb;
std::string strHex = HexStr(ssMB.begin(), ssMB.end());
return strHex;
}
