1 files changed, 47 insertions, 0 deletions
diff --git a/src/policy/rbf.cpp b/src/policy/rbf.cpp
new file mode 100644
index 0000000000..133cff611d
--- /dev/null
+++ b/src/policy/rbf.cpp
@@ -0,0 +1,47 @@
+// Copyright (c) 2016 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "policy/rbf.h"
+
+bool SignalsOptInRBF(const CTransaction &tx)
+{
+    BOOST_FOREACH(const CTxIn &txin, tx.vin) {
+        if (txin.nSequence < std::numeric_limits<unsigned int>::max()-1) {
+            return true;
+        }
+    }
+    return false;
+}
+
+RBFTransactionState IsRBFOptIn(const CTransaction &tx, CTxMemPool &pool)
+{
+    AssertLockHeld(pool.cs);
+
+    CTxMemPool::setEntries setAncestors;
+
+    // First check the transaction itself.
+    if (SignalsOptInRBF(tx)) {
+        return RBF_TRANSACTIONSTATE_REPLACEABLE_BIP125;
+    }
+
+    // If this transaction is not in our mempool, then we can't be sure
+    // we will know about all its inputs.
+    if (!pool.exists(tx.GetHash())) {
+        return RBF_TRANSACTIONSTATE_UNKNOWN;
+    }
+
+    // If all the inputs have nSequence >= maxint-1, it still might be
+    // signaled for RBF if any unconfirmed parents have signaled.
+    uint64_t noLimit = std::numeric_limits<uint64_t>::max();
+    std::string dummy;
+    CTxMemPoolEntry entry = *pool.mapTx.find(tx.GetHash());
+    pool.CalculateMemPoolAncestors(entry, setAncestors, noLimit, noLimit, noLimit, noLimit, dummy, false);
+
+    BOOST_FOREACH(CTxMemPool::txiter it, setAncestors) {
+        if (SignalsOptInRBF(it->GetTx())) {
+            return RBF_TRANSACTIONSTATE_REPLACEABLE_BIP125;
+        }
+    }
+    return RBF_TRANSACTIONSTATE_FINAL;
+}