basic implementation of transaction replacement. requires cleanup and testing

src/komodo_cryptoconditions.cpp

@@ -1,24 +1,93 @@
 
+#include "replacementpool.h"
+#include "komodo_cryptoconditions.h"
 #include "cryptoconditions/include/cryptoconditions.h"
 #include "script/interpreter.h"
+#include "coins.h"
 
 
-int TransactionSignatureChecker::CheckAuxCondition(const CC *cond) const
+#define REPLACEMENT_WINDOW_BLOCKS 2
+
+
+bool GetOpReturnData(const CScript &sig, std::vector<unsigned char> &data)
 {
-    // Check that condition is equal to fulfillment
-    if (0 == strcmp((const char*)cond->method, "equals")) {
-        return (cond->conditionAuxLength == cond->fulfillmentAuxLength) &&
-               (0 == memcmp(cond->conditionAux, cond->fulfillmentAux, cond->conditionAuxLength));
-    }
+    auto pc = sig.begin();
+    opcodetype opcode;
+    if (sig.GetOp(pc, opcode))
+        if (opcode == OP_RETURN)
+            if (sig.GetOp(pc, opcode, data))
+                return opcode > OP_0 && opcode <= OP_PUSHDATA4;
+    return false;
+}
 
-    // Check that pubKeyScript specified in fulfillment is OP_RETURN
-    if (0 == strcmp((const char*)cond->method, "inputIsReturn")) {
-        if (cond->fulfillmentAuxLength != 1) return 0;
-        int n = (int) cond->fulfillmentAux[0];
-        if (n >= txTo->vout.size()) return 0;
-        uint8_t *ptr = (uint8_t *)txTo->vout[n].scriptPubKey.data();
-        return ptr[0] == OP_RETURN;
+
+bool EvalConditionBool(const CC *cond, const CTransaction *txTo)
+{
+    if (strcmp(cond->method, "testEval") == 0) {
+        return cond->paramsBinLength == 8 &&
+            memcmp(cond->paramsBin, "testEval", 8) == 0;
     }
-    printf("no defined behaviour for method:%s\n", cond->method);
+    if (strcmp(cond->method, "testReplace") == 0) {
+        return true;
+    }
+    fprintf(stderr, "no defined behaviour for method: %s\n", cond->method);
     return 0;
 }
+
+
+bool GetConditionPriority(const CC *cond, CTxReplacementPoolItem *rep)
+{
+    if (strcmp((const char*)cond->method, "testReplace") == 0) {
+        std::vector<unsigned char> data;
+        if (GetOpReturnData(rep->tx.vout[0].scriptPubKey, data)) {
+            rep->priority = (uint64_t) data[0];
+            rep->replacementWindow = REPLACEMENT_WINDOW_BLOCKS;
+            return true;
+        }
+    }
+    return false;
+}
+
+
+bool TransactionSignatureChecker::CheckEvalCondition(const CC *cond) const
+{
+    return EvalConditionBool(cond, txTo);
+}
+
+
+extern "C"
+{
+    int visitConditionPriority(CC *cond, struct CCVisitor visitor);
+}
+
+
+int visitConditionPriority(CC *cond, struct CCVisitor visitor)
+{
+    if (cc_typeId(cond) == CC_Eval) {
+        if (GetConditionPriority(cond, (CTxReplacementPoolItem*)visitor.context)) {
+            return 0; // stop
+        }
+    }
+    return 1; // continue
+}
+
+
+bool SetReplacementParams(CTxReplacementPoolItem &rep)
+{
+    // first, see if we have a cryptocondition
+    const CScript &sig = rep.tx.vin[0].scriptSig;
+    if (!sig.IsPushOnly()) return false;
+    CScript::const_iterator pc = sig.begin();
+    std::vector<unsigned char> data;
+    opcodetype opcode;
+    if (!sig.GetOp(pc, opcode, data)) return false;
+    CC *cond = cc_readFulfillmentBinary((unsigned char*)data.data(), data.size());
+    if (!cond) return false;
+
+    // now, see if it has a replacement node
+    CC *replacementNode = 0;
+    CCVisitor visitor = {&visitConditionPriority, (const unsigned char*)"", 0, &rep};
+    bool out = cc_visit(cond, visitor);
+    cc_free(cond);
+    return !out;
+}