Get cost model from context

Author: cffls

examples/plutus/forty_two/forty_two.py

@@ -26,7 +26,9 @@ def get_env_val(key):
 payment_vkey = PaymentVerificationKey.from_signing_key(payment_skey)
 
 chain_context = BlockFrostChainContext(
-    project_id=get_env_val("BLOCKFROST_ID"), network=NETWORK
+    project_id=get_env_val("BLOCKFROST_ID"),
+    network=NETWORK,
+    base_url="https://cardano-preview.blockfrost.io/api",
 )
 
 
@@ -67,7 +69,7 @@ def create_collateral(target_address, skey):
     script_hex = f.read()
     forty_two_script = cbor2.loads(bytes.fromhex(script_hex))
 
-script_hash = plutus_script_hash(forty_two_script)
+script_hash = plutus_script_hash(PlutusV1Script(forty_two_script))
 
 script_address = Address(script_hash, network=NETWORK)
 
@@ -94,11 +96,20 @@ def create_collateral(target_address, skey):
 # Put integer 42 (the secret that unlocks the fund) in the redeemer.
 redeemer = Redeemer(RedeemerTag.SPEND, 42)
 
-utxo_to_spend = chain_context.utxos(str(script_address))[0]
+utxo_to_spend = None
+for utxo in chain_context.utxos(str(script_address)):
+    if utxo.output.datum_hash == datum_hash(datum):
+        utxo_to_spend = utxo
+        break
+
+if utxo_to_spend is None:
+    raise Exception("Can't find utxo to spend! Please try again later.")
 
 builder = TransactionBuilder(chain_context)
 
-builder.add_script_input(utxo_to_spend, forty_two_script, datum, redeemer)
+builder.add_script_input(
+    utxo_to_spend, PlutusV1Script(forty_two_script), datum, redeemer
+)
 
 # Send 5 ADA to taker address. The remaining ADA (~4.7) will be sent as change.
 take_output = TransactionOutput(taker_address, 5000000)

pycardano/backend/base.py

@@ -97,6 +97,10 @@ class ProtocolParameters:
 
     coins_per_utxo_byte: int = None
 
+    cost_models: Dict[str, Dict[str, int]] = None
+    """A dict contains cost models for Plutus. The key will be "PlutusV1", "PlutusV2", etc.
+    The value will be a dict of cost model parameters."""
+
 
 @typechecked
 class ChainContext:

pycardano/backend/blockfrost.py

@@ -1,4 +1,3 @@
-import argparse
 import os
 import tempfile
 import time
@@ -28,13 +27,6 @@
 __all__ = ["BlockFrostChainContext"]
 
 
-def _namespace_to_dict(namespace: argparse.Namespace) -> dict:
-    return {
-        k: _namespace_to_dict(v) if isinstance(v, argparse.Namespace) else v
-        for k, v in vars(namespace).items()
-    }
-
-
 class BlockFrostChainContext(ChainContext):
     """A `BlockFrost <https://blockfrost.io/>`_ API wrapper for the client code to interact with.
 
@@ -119,8 +111,12 @@ def protocol_param(self) -> ProtocolParameters:
                 max_val_size=int(params.max_val_size),
                 collateral_percent=int(params.collateral_percent),
                 max_collateral_inputs=int(params.max_collateral_inputs),
-                coins_per_utxo_word=int(params.coins_per_utxo_word) or int(params.coins_per_utxo_size),
+                coins_per_utxo_word=int(params.coins_per_utxo_word)
+                or int(params.coins_per_utxo_size),
                 coins_per_utxo_byte=int(params.coins_per_utxo_size),
+                cost_models={
+                    k: v.to_dict() for k, v in params.cost_models.to_dict().items()
+                },
             )
         return self._protocol_param
 

pycardano/backend/ogmios.py

@@ -121,8 +121,14 @@ def protocol_param(self) -> ProtocolParameters:
                     "coinsPerUtxoWord", ALONZO_COINS_PER_UTXO_WORD
                 ),
                 coins_per_utxo_byte=result.get("coinsPerUtxoByte", 0),
+                cost_models=result.get("costModels", {}),
             )
 
+            if "plutus:v1" in param.cost_models:
+                param.cost_models["PlutusV1"] = param.cost_models.pop("plutus:v1")
+            if "plutus:v2" in param.cost_models:
+                param.cost_models["PlutusV2"] = param.cost_models.pop("plutus:v2")
+
             args = {"query": "genesisConfig"}
             result = self._request(method, args)
             param.min_utxo = result["protocolParameters"]["minUtxoValue"]

pycardano/txbuilder.py

@@ -384,10 +384,16 @@ def script_data_hash(self) -> Optional[ScriptDataHash]:
         if self.datums or self.redeemers:
             cost_models = {}
             for s in self.all_scripts:
-                if isinstance(s, PlutusV1Script):
-                    cost_models[0] = PLUTUS_V1_COST_MODEL
+                if isinstance(s, PlutusV1Script) or type(s) == bytes:
+                    cost_models[0] = (
+                        self.context.protocol_param.cost_models.get("PlutusV1")
+                        or PLUTUS_V1_COST_MODEL
+                    )
                 if isinstance(s, PlutusV2Script):
-                    cost_models[1] = PLUTUS_V2_COST_MODEL
+                    cost_models[1] = (
+                        self.context.protocol_param.cost_models.get("PlutusV2")
+                        or PLUTUS_V2_COST_MODEL
+                    )
             return script_data_hash(
                 self.redeemers, list(self.datums.values()), CostModels(cost_models)
             )

test/pycardano/backend/test_ogmios.py

@@ -125,6 +125,7 @@ def test_protocol_param(self):
                 max_collateral_inputs=5,
                 coins_per_utxo_word=1,
                 coins_per_utxo_byte=1,
+                cost_models={},
             )
             == self.chain_context.protocol_param
         )

test/pycardano/util.py

@@ -45,6 +45,7 @@ class FixedChainContext(ChainContext):
         max_collateral_inputs=3,
         coins_per_utxo_word=34482,
         coins_per_utxo_byte=4310,
+        cost_models={},
     )
 
     _genesis_param = GenesisParameters(