Calculate fees with adjusted vsize

counterparty-core/counterpartycore/lib/composer.py

@@ -603,10 +603,62 @@ def generate_dummy_signed_tx(tx, selected_utxos):
     return dummy_signed_tx
 
 
-def get_needed_fee(tx, satoshis_per_vbyte, selected_utxos):
-    dummy_signed_tx = generate_dummy_signed_tx(tx, selected_utxos)
-    virtual_size = dummy_signed_tx.get_vsize()
-    return satoshis_per_vbyte * virtual_size
+def get_output_sigops_count(script_pub_key, is_redeem_script=False, is_segwit=False):
+    output_type = script.get_output_type(script_pub_key)
+    multiplicator = 1 if is_segwit else 4
+    count = 0
+    if output_type in ["P2PK", "P2PKH"]:
+        count = 1
+    elif output_type == "P2MS":
+        if is_redeem_script:
+            asm = script.script_to_asm(script_pub_key)
+            pubkeys_count = int(asm[-2])
+            if pubkeys_count > 16:
+                count = 20
+            else:
+                count = pubkeys_count
+        else:
+            count = 20
+    elif output_type in ["P2WPKH", "P2WSH", "P2TR"] and is_redeem_script:
+        return 1
+    return count * multiplicator
+
+
+def get_input_sigops_count(script_sig, script_pub_key):
+    prevout_type = script.get_output_type(script_pub_key)
+    if prevout_type == "P2SH":
+        asm = script.script_to_asm(script_sig)
+        redeem_script = binascii.hexlify(asm[-1]).decode("utf-8")
+        return get_output_sigops_count(redeem_script, is_redeem_script=True)
+    if prevout_type == "P2WPKH":
+        return 1
+    if prevout_type == "P2WSH":
+        return get_output_sigops_count(script_pub_key, is_segwit=True)
+    return 0
+
+
+# source: https://bitcoin.stackexchange.com/questions/67760/how-are-sigops-calculated
+def get_tx_sigops_count(tx, selected_utxos):
+    sigops_count = 0
+    for i, utxo in enumerate(selected_utxos):
+        script_pub_key = utxo["script_pub_key"]
+        script_sig = tx.inputs[i].script_sig.to_hex()
+        sigops_count += get_input_sigops_count(script_sig, script_pub_key)
+    for output in tx.outputs:
+        sigops_count += get_output_sigops_count(output.script_pubkey.to_hex())
+    return sigops_count
+
+
+# source: https://mempool.space/docs/faq#what-is-adjusted-vsize
+def get_size_info(tx, selected_utxos, signed=False):
+    if signed:
+        signed_tx = tx
+    else:
+        signed_tx = generate_dummy_signed_tx(tx, selected_utxos)
+    sigops_count = get_tx_sigops_count(signed_tx, selected_utxos)
+    virtual_size = signed_tx.get_vsize()
+    adjusted_vsize = max(sigops_count * 5, virtual_size)
+    return adjusted_vsize, virtual_size, sigops_count
 
 
 def prepare_fee_parameters(construct_params):
@@ -640,6 +692,7 @@ def prepare_inputs_and_change(db, source, outputs, unspent_list, construct_param
     change_outputs = []
     btc_in = 0
     needed_fee = 0
+    size_info = (0, 0, 0)
     # try with one input and increase until the change is enough for the fee
     use_all_inputs_set = construct_params.get("use_all_inputs_set", False)
     input_count = len(unspent_list) if use_all_inputs_set else 1
@@ -682,7 +735,10 @@ def prepare_inputs_and_change(db, source, outputs, unspent_list, construct_param
             + [create_tx_output(change_amount, change_address, unspent_list, construct_params)],
             has_segwit=has_segwit,
         )
-        needed_fee = get_needed_fee(tx, sat_per_vbyte, selected_utxos)
+
+        size_info = get_size_info(tx, selected_utxos)
+        adjusted_vsize = size_info[0]
+        needed_fee = sat_per_vbyte * adjusted_vsize
         if max_fee is not None:
             needed_fee = min(needed_fee, max_fee)
         # if change is enough for needed fee, add change output and break
@@ -696,7 +752,7 @@ def prepare_inputs_and_change(db, source, outputs, unspent_list, construct_param
         # else try with more inputs
         input_count += 1
 
-    return selected_utxos, btc_in, change_outputs
+    return selected_utxos, btc_in, change_outputs, size_info
 
 
 def get_default_args(func):
@@ -742,7 +798,7 @@ def construct(db, tx_info, construct_params):
     outputs = prepare_outputs(source, destinations, data, unspent_list, construct_params)
 
     # prepare inputs and change
-    selected_utxos, btc_in, change_outputs = prepare_inputs_and_change(
+    selected_utxos, btc_in, change_outputs, size_info = prepare_inputs_and_change(
         db, source, outputs, unspent_list, construct_params
     )
     inputs = utxos_to_txins(selected_utxos)
@@ -756,6 +812,7 @@ def construct(db, tx_info, construct_params):
     lock_scripts = [utxo["script_pub_key"] for utxo in selected_utxos]
     tx = Transaction(inputs, outputs + change_outputs)
     unsigned_tx_hex = tx.serialize()
+    adjusted_vsize, virtual_size, sigops_count = size_info
 
     return {
         "rawtransaction": unsigned_tx_hex,
@@ -765,6 +822,11 @@ def construct(db, tx_info, construct_params):
         "btc_fee": btc_in - btc_out - btc_change,
         "data": config.PREFIX + data if data else None,
         "lock_scripts": lock_scripts,
+        "signed_tx_estimated_size": {
+            "vsize": virtual_size,
+            "adjusted_vsize": adjusted_vsize,
+            "sigops_count": sigops_count,
+        },
     }
 
 

counterparty-core/counterpartycore/test/fixtures/contract_vectors/composer.py

@@ -2,7 +2,7 @@
 
 from bitcoinutils.keys import P2pkhAddress, P2wpkhAddress
 from bitcoinutils.script import Script, b_to_h
-from bitcoinutils.transactions import Transaction, TxInput, TxOutput
+from bitcoinutils.transactions import TxInput, TxOutput
 
 from counterpartycore.lib import config, exceptions
 
@@ -875,118 +875,6 @@
                 ],
             }
         ],
-        "get_needed_fee": [
-            {
-                "in": (
-                    Transaction(
-                        [
-                            TxInput(UTXO_1.split(":")[0], int(UTXO_1.split(":")[1])),
-                            TxInput(UTXO_2.split(":")[0], int(UTXO_2.split(":")[1])),
-                            TxInput(UTXO_3.split(":")[0], int(UTXO_3.split(":")[1])),
-                        ],
-                        [
-                            TxOutput(9999, P2pkhAddress(ADDR[0]).to_script_pub_key()),
-                            TxOutput(
-                                config.DEFAULT_MULTISIG_DUST_SIZE,
-                                Script(
-                                    [
-                                        1,
-                                        MULTISIG_PAIRS[0][0],
-                                        MULTISIG_PAIRS[0][1],
-                                        DEFAULT_PARAMS["pubkey"][ADDR[0]],
-                                        3,
-                                        "OP_CHECKMULTISIG",
-                                    ]
-                                ),
-                            ),
-                            TxOutput(
-                                config.DEFAULT_MULTISIG_DUST_SIZE,
-                                Script(
-                                    [
-                                        1,
-                                        MULTISIG_PAIRS[1][0],
-                                        MULTISIG_PAIRS[1][1],
-                                        DEFAULT_PARAMS["pubkey"][ADDR[0]],
-                                        3,
-                                        "OP_CHECKMULTISIG",
-                                    ]
-                                ),
-                            ),
-                            TxOutput(
-                                config.DEFAULT_MULTISIG_DUST_SIZE,
-                                Script(
-                                    [
-                                        1,
-                                        MULTISIG_PAIRS[2][0],
-                                        MULTISIG_PAIRS[2][1],
-                                        DEFAULT_PARAMS["pubkey"][ADDR[0]],
-                                        3,
-                                        "OP_CHECKMULTISIG",
-                                    ]
-                                ),
-                            ),
-                        ],
-                    ),
-                    3,
-                ),
-                "out": 1527,
-            },
-            {
-                "in": (
-                    Transaction(
-                        [
-                            TxInput(UTXO_1.split(":")[0], int(UTXO_1.split(":")[1])),
-                            TxInput(UTXO_2.split(":")[0], int(UTXO_2.split(":")[1])),
-                            TxInput(UTXO_3.split(":")[0], int(UTXO_3.split(":")[1])),
-                        ],
-                        [
-                            TxOutput(9999, P2pkhAddress(ADDR[0]).to_script_pub_key()),
-                            TxOutput(
-                                config.DEFAULT_MULTISIG_DUST_SIZE,
-                                Script(
-                                    [
-                                        1,
-                                        MULTISIG_PAIRS[0][0],
-                                        MULTISIG_PAIRS[0][1],
-                                        DEFAULT_PARAMS["pubkey"][ADDR[0]],
-                                        3,
-                                        "OP_CHECKMULTISIG",
-                                    ]
-                                ),
-                            ),
-                            TxOutput(
-                                config.DEFAULT_MULTISIG_DUST_SIZE,
-                                Script(
-                                    [
-                                        1,
-                                        MULTISIG_PAIRS[1][0],
-                                        MULTISIG_PAIRS[1][1],
-                                        DEFAULT_PARAMS["pubkey"][ADDR[0]],
-                                        3,
-                                        "OP_CHECKMULTISIG",
-                                    ]
-                                ),
-                            ),
-                            TxOutput(
-                                config.DEFAULT_MULTISIG_DUST_SIZE,
-                                Script(
-                                    [
-                                        1,
-                                        MULTISIG_PAIRS[2][0],
-                                        MULTISIG_PAIRS[2][1],
-                                        DEFAULT_PARAMS["pubkey"][ADDR[0]],
-                                        3,
-                                        "OP_CHECKMULTISIG",
-                                    ]
-                                ),
-                            ),
-                        ],
-                    ),
-                    6,
-                ),
-                "out": 3054,
-            },
-        ],
         "prepare_fee_parameters": [
             {"in": ({"exact_fee": 1000},), "out": (1000, None, None)},
             {"in": ({"exact_fee": 666, "max_fee": 1000},), "out": (666, None, None)},

counterparty-core/counterpartycore/test/fixtures/vectors.py

@@ -40,9 +40,9 @@
     DEFAULT_PARAMS as DP,
 )
 
-# UNITTEST_VECTOR = COMPOSER_VECTOR
+UNITTEST_VECTOR = COMPOSER_VECTOR
 
-UNITTEST_VECTOR = (
+UNITTEST_VECTOR_ = (
     FAIRMINTER_VECTOR
     | FAIRMINT_VECTOR
     | LEDGER_VECTOR

counterparty-core/counterpartycore/test/regtest/apidoc/group-compose.md

@@ -1,21 +1,9 @@
-**Notes about the Optional `encoding` Parameter.**
+**Notes about the Optional `sat_per_vbyte` Parameter.**
 
-By default the default value of the `encoding` parameter detailed above is `auto`, which means that `counterparty-server` automatically determines the best way to encode the Counterparty protocol data into a new transaction. If you know what you are doing and would like to explicitly specify an encoding:
+To calculate the fees required for a transaction, we do not know the final size of the transaction before signing it.
+So the  composer injects fake script_sig and witnesses into the transaction before calculating the vsize.
+Two remarks:
 
-- To return the transaction as an **OP_RETURN** transaction, specify `opreturn` for the `encoding` parameter.
-   - **OP_RETURN** transactions cannot have more than 80 bytes of data. If you force `OP_RETURN` encoding and your transaction would have more than this amount, an exception will be generated.
+1. this only works for standard scripts
 
-- To return the transaction as a **multisig** transaction, specify `multisig` for the `encoding` parameter.
-    - `pubkey` should be set to the hex-encoded public key of the source address.
-    - Note that with the newest versions of Bitcoin (0.12.1 onward), bare multisig encoding does not reliably propagate. More information on this is documented [here](https://github.com/rubensayshi/counterparty-core/pull/9).
-
-- To return the transaction as a **pubkeyhash** transaction, specify `pubkeyhash` for the `encoding` parameter.
-    - `pubkey` should be set to the hex-encoded public key of the source address.
-
-- To return the transaction as a 2 part **P2SH** transaction, specify `P2SH` for the encoding parameter.
-    - First call the `create_` method with the `encoding` set to `P2SH`.
-    - Sign the transaction as usual and broadcast it. It's recommended but not required to wait for the transaction to confirm as malleability is an issue here (P2SH isn't yet supported on segwit addresses).
-    - The resulting `txid` must be passed again on an identic call to the `create_` method, but now passing an additional parameter `p2sh_pretx_txid` with the value of the previous transaction's id.
-    - The resulting transaction is a `P2SH` encoded message, using the redeem script on the transaction inputs as data carrying mechanism.
-    - Sign the transaction following the `Bitcoinjs-lib on javascript, signing a P2SH redeeming transaction` section
-    - **NOTE**: Don't leave pretxs hanging without transmitting the second transaction as this pollutes the UTXO set and risks making bitcoin harder to run on low spec nodes.
+1. the size of DER signatures can vary by a few bytes and it is impossible to predict it. The composer uses a fixed size of 70 bytes so there may be a discrepancy of a few satoshis with the fees requested with `sat_per_vbyte` (for example if a DER signature is 72 bytes with `sat_per_vbyte=2` there will be an error of 4 sats in the calculated fees).