Files
hush3/src/replacementpool.cpp

97 lines
2.4 KiB
C++

#include <map>
#include <string>
#include <iterator>
#include "main.h"
#include "coins.h"
#include "replacementpool.h"
CTxReplacementPool replacementPool;
/*
* Add a transaction to the pool, with a priority.
* Return true if valid, false if not valid. */
bool ValidateReplacementPoolItem(CTxReplacementPoolItem item)
{
// Perform some validations.
if (item.tx.vin.size() > 1) {
// Replaceable transactions with multiple inputs are disabled for now. It's not yet clear
// what edge cases may arise. It is speculated that it will "just work", since if
// replaceable transactions spend multiple outputs using the replacement protocol,
// they will never conflict in the replaceMap data structure. But for now, to be prudent, disable.
return false;
}
// A transaction with 0 priority is not valid.
if (item.priority == 0) {
return false;
}
return true;
}
/*
* Validate the item
*
* Compare the item with any current replacement candidate
*
* Ensure that the item is not passed the replacement window
*
* Insert the item into the map
*/
CTxReplacementPoolResult CTxReplacementPool::replace(CTxReplacementPoolItem &item)
{
if (!ValidateReplacementPoolItem(item)) {
return RP_Invalid;
}
auto it = replaceMap.find(item.tx.vin[0].prevout);
if (it != replaceMap.end()) {
if (it->second.priority >= item.priority) {
// Already have a transaction with equal or greater priority; this is not valid
return RP_Invalid;
}
// copy the previous starting block over
item.startBlock = it->second.startBlock;
}
// This transaction has higher priority
replaceMap[item.tx.vin[0].prevout] = item;
return RP_Valid;
}
void CTxReplacementPool::removePending(int height, std::vector<CTransaction> &txs)
{
for (auto it = replaceMap.begin(); it != replaceMap.end(); /**/) {
CTxReplacementPoolItem &rep = it->second;
if (rep.GetTargetBlock() <= height) {
txs.push_back(rep.tx);
replaceMap.erase(it++);
} else {
++it;
}
}
}
/*
* O(n) lookup of tx by hash
*/
bool CTxReplacementPool::lookup(uint256 txHash, CTransaction &tx)
{
for (auto it = replaceMap.begin(); it != replaceMap.end(); it++) {
if (it->second.tx.GetHash() == txHash) {
tx = it->second.tx;
return true;
}
}
return false;
}