refactor: encode methods accept and return buffer for clean chaining

b00f · b00f · commit dcadef6b0f59 · 2026-07-01T03:01:31.000+08:00
All encode() signatures changed from  to .
This allows callers to pass a buffer through, appending in one fluid chain:

    buf = self.sender.encode(buf)
    buf = self.receiver.encode(buf)
    return self.amount.encode(buf)

Updated: Amount, Height, Round, Hash, Address, all crypto Signatures/PublicKeys,
all payloads, and Transaction._get_unsigned_bytes/sign/sign_bytes.
diff --git a/pactus/crypto/address.py b/pactus/crypto/address.py
@@ -86,8 +86,7 @@ def is_account_address(self) -> bool:
     def is_validator_address(self) -> bool:
         return self.address_type() == AddressType.VALIDATOR
 
-    def encode(self) -> bytes:
-        buf = b""
+    def encode(self, buf: bytes) -> bytes:
         if self.is_treasury_address():
             return encoding.append_uint8(buf, AddressType.TREASURY.value)
         return encoding.append_fixed_bytes(buf, self.raw_bytes())
diff --git a/pactus/crypto/bls/public_key.py b/pactus/crypto/bls/public_key.py
@@ -61,8 +61,8 @@ def string(self) -> str:
             self.raw_bytes(),
         )
 
-    def encode(self) -> bytes:
-        return encoding.append_fixed_bytes(b"", self.raw_bytes())
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_fixed_bytes(buf, self.raw_bytes())
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:
diff --git a/pactus/crypto/bls/signature.py b/pactus/crypto/bls/signature.py
@@ -39,8 +39,8 @@ def raw_bytes(self) -> bytes:
     def string(self) -> str:
         return self.raw_bytes().hex()
 
-    def encode(self) -> bytes:
-        return encoding.append_fixed_bytes(b"", self.raw_bytes())
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_fixed_bytes(buf, self.raw_bytes())
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:
diff --git a/pactus/crypto/ed25519/public_key.py b/pactus/crypto/ed25519/public_key.py
@@ -50,8 +50,8 @@ def string(self) -> str:
             self.raw_bytes(),
         )
 
-    def encode(self) -> bytes:
-        return encoding.append_fixed_bytes(b"", self.raw_bytes())
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_fixed_bytes(buf, self.raw_bytes())
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:
diff --git a/pactus/crypto/ed25519/signature.py b/pactus/crypto/ed25519/signature.py
@@ -26,8 +26,8 @@ def raw_bytes(self) -> bytes:
     def string(self) -> str:
         return self.sig.hex()
 
-    def encode(self) -> bytes:
-        return encoding.append_fixed_bytes(b"", self.sig)
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_fixed_bytes(buf, self.sig)
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:
diff --git a/pactus/crypto/hash.py b/pactus/crypto/hash.py
@@ -28,8 +28,8 @@ def __str__(self) -> str:
     def is_undef(self) -> bool:
         return self.data == bytes(HASH_SIZE)
 
-    def encode(self) -> bytes:
-        return encoding.append_fixed_bytes(b"", self.data)
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_fixed_bytes(buf, self.data)
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple[Hash, bytes]:
diff --git a/pactus/crypto/public_key.py b/pactus/crypto/public_key.py
@@ -22,7 +22,7 @@ def string(self) -> str:
         pass
 
     @abstractmethod
-    def encode(self) -> bytes:
+    def encode(self, buf: bytes) -> bytes:
         pass
 
     @classmethod
diff --git a/pactus/crypto/secp256k1/public_key.py b/pactus/crypto/secp256k1/public_key.py
@@ -50,8 +50,8 @@ def string(self) -> str:
             self.raw_bytes(),
         )
 
-    def encode(self) -> bytes:
-        return encoding.append_fixed_bytes(b"", self.raw_bytes())
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_fixed_bytes(buf, self.raw_bytes())
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:
diff --git a/pactus/crypto/secp256k1/signature.py b/pactus/crypto/secp256k1/signature.py
@@ -26,8 +26,8 @@ def raw_bytes(self) -> bytes:
     def string(self) -> str:
         return self.sig.hex()
 
-    def encode(self) -> bytes:
-        return encoding.append_fixed_bytes(b"", self.sig)
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_fixed_bytes(buf, self.sig)
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:
diff --git a/pactus/crypto/signature.py b/pactus/crypto/signature.py
@@ -18,7 +18,7 @@ def string(self) -> str:
         pass
 
     @abstractmethod
-    def encode(self) -> bytes:
+    def encode(self, buf: bytes) -> bytes:
         pass
 
     @classmethod
diff --git a/pactus/transaction/payload/_payload.py b/pactus/transaction/payload/_payload.py
@@ -14,7 +14,7 @@ class PayloadType(Enum):
 
 class Payload(ABC):
     @abstractmethod
-    def encode(self, buf: list) -> None:
+    def encode(self, buf: bytes) -> bytes:
         """Append the payload data to the buffer."""
 
     @abstractmethod
diff --git a/pactus/transaction/payload/bond.py b/pactus/transaction/payload/bond.py
@@ -18,11 +18,11 @@ def __init__(
         self.public_key = public_key
         self.stake = stake
 
-    def encode(self, buf: list) -> None:
-        encoding.append_fixed_bytes(buf, self.sender.encode())
-        encoding.append_fixed_bytes(buf, self.receiver.encode())
-        encoding.append_fixed_bytes(buf, self.public_key)
-        encoding.append_fixed_bytes(buf, self.stake.encode())
+    def encode(self, buf: bytes) -> bytes:
+        buf = self.sender.encode(buf)
+        buf = self.receiver.encode(buf)
+        buf = encoding.append_fixed_bytes(buf, self.public_key)
+        return self.stake.encode(buf)
 
     def get_type(self) -> PayloadType:
         return PayloadType.BOND
diff --git a/pactus/transaction/payload/sortition.py b/pactus/transaction/payload/sortition.py
@@ -9,9 +9,9 @@ def __init__(self, address: Address, proof: bytes) -> None:
         self.address = address
         self.proof = proof
 
-    def encode(self, buf: list) -> None:
-        encoding.append_fixed_bytes(buf, self.address.encode())
-        encoding.append_fixed_bytes(buf, self.proof)
+    def encode(self, buf: bytes) -> bytes:
+        buf = self.address.encode(buf)
+        return encoding.append_fixed_bytes(buf, self.proof)
 
     def get_type(self) -> PayloadType:
         return PayloadType.SORTITION
diff --git a/pactus/transaction/payload/transfer.py b/pactus/transaction/payload/transfer.py
@@ -1,5 +1,4 @@
 from pactus.crypto.address import Address
-from pactus.encoding import encoding
 from pactus.types.amount import Amount
 
 from ._payload import PayloadType
@@ -11,10 +10,10 @@ def __init__(self, sender: Address, receiver: Address, amount: Amount) -> None:
         self.receiver = receiver
         self.amount = amount
 
-    def encode(self, buf: list) -> None:
-        encoding.append_fixed_bytes(buf, self.sender.encode())
-        encoding.append_fixed_bytes(buf, self.receiver.encode())
-        encoding.append_fixed_bytes(buf, self.amount.encode())
+    def encode(self, buf: bytes) -> bytes:
+        buf = self.sender.encode(buf)
+        buf = self.receiver.encode(buf)
+        return self.amount.encode(buf)
 
     def get_type(self) -> PayloadType:
         return PayloadType.TRANSFER
diff --git a/pactus/transaction/payload/unbond.py b/pactus/transaction/payload/unbond.py
@@ -1,5 +1,4 @@
 from pactus.crypto.address import Address
-from pactus.encoding import encoding
 
 from ._payload import PayloadType
 
@@ -8,8 +7,8 @@ class UnbondPayload:
     def __init__(self, validator: Address) -> None:
         self.validator = validator
 
-    def encode(self, buf: list) -> None:
-        encoding.append_fixed_bytes(buf, self.validator.encode())
+    def encode(self, buf: bytes) -> bytes:
+        return self.validator.encode(buf)
 
     def get_type(self) -> PayloadType:
         return PayloadType.UNBOND
diff --git a/pactus/transaction/payload/withdraw.py b/pactus/transaction/payload/withdraw.py
@@ -1,5 +1,4 @@
 from pactus.crypto.address import Address
-from pactus.encoding import encoding
 from pactus.types.amount import Amount
 
 from ._payload import PayloadType
@@ -11,10 +10,10 @@ def __init__(self, from_addr: Address, to_addr: Address, amount: Amount) -> None
         self.to_addr = to_addr
         self.amount = amount
 
-    def encode(self, buf: list) -> None:
-        encoding.append_fixed_bytes(buf, self.from_addr.encode())
-        encoding.append_fixed_bytes(buf, self.to_addr.encode())
-        encoding.append_fixed_bytes(buf, self.amount.encode())
+    def encode(self, buf: bytes) -> bytes:
+        buf = self.from_addr.encode(buf)
+        buf = self.to_addr.encode(buf)
+        return self.amount.encode(buf)
 
     def get_type(self) -> PayloadType:
         return PayloadType.WITHDRAW
diff --git a/pactus/transaction/transaction.py b/pactus/transaction/transaction.py
@@ -166,55 +166,28 @@ def create_withdraw_tx(
         return cls(lock_time, fee, memo, payload)
 
     def _get_unsigned_bytes(self, buf: bytes) -> bytes:
-        """
-        Generate the unsigned representation of the transaction,
-        including flags and payload.
-
-        This method appends various transaction components to the buffer
-        in a specific order, ensuring correct serialization.
-        """
-        encoding.append_uint8(buf, self.flags)
-        encoding.append_uint8(buf, self.version)
-        encoding.append_uint32(buf, self.lock_time.value)
-        encoding.append_var_int(buf, self.fee.value)
-        encoding.append_str(buf, self.memo)
-        encoding.append_uint8(buf, self.payload.get_type().value)
-        self.payload.encode(buf)
-
-        return buf
+        """Generate the unsigned bytes of the transaction for signing."""
+        buf = encoding.append_uint8(buf, self.flags)
+        buf = encoding.append_uint8(buf, self.version)
+        buf = self.lock_time.encode(buf)
+        buf = self.fee.encode(buf)
+        buf = encoding.append_str(buf, self.memo)
+        buf = encoding.append_uint8(buf, self.payload.get_type().value)
+        return self.payload.encode(buf)
 
     def sign_bytes(self) -> bytes:
-        """
-        Generate the transaction data that needs to be signed.
-
-        The signature should be computed over this data, excluding the
-        transaction flags, which are removed before returning.
-        """
-        buf = bytearray()
-        sign_bytes = self._get_unsigned_bytes(buf)
-
-        return sign_bytes[1:]  # flags is not part of the sign bytes.
+        """Return the bytes to be signed (everything except flags)."""
+        buf = self._get_unsigned_bytes(b"")
+        return buf[1:]
 
     def sign(self, private_key: PrivateKey) -> bytes:
-        """
-        Generate the signed representation of the transaction,
-        including the flags, payload, and cryptographic signature.
-
-        This method first generates the data needs to be signed,
-        signs it using the provided private key, and then appends
-        both the signature and the corresponding public key to ensure
-        verifiability.
-        """
-        buf = bytearray()
-
-        sign_bytes = self._get_unsigned_bytes(buf)
-        sig = private_key.sign(
-            bytes(sign_bytes[1:]),
-        )
+        """Sign the transaction and return signed bytes."""
+        buf = self._get_unsigned_bytes(b"")
+        sig = private_key.sign(buf[1:])
         pub = private_key.public_key()
 
-        encoding.append_fixed_bytes(buf, sig.raw_bytes())
-        encoding.append_fixed_bytes(buf, pub.raw_bytes())
+        buf = sig.encode(buf)
+        buf = pub.encode(buf)
 
         self.public_key = pub
         self.signature = sig
diff --git a/pactus/types/amount.py b/pactus/types/amount.py
@@ -79,8 +79,7 @@ def from_string(cls, s: str) -> "Amount":
 
         return cls.from_pac(f)
 
-    def encode(self) -> bytes:
-        buf = b""
+    def encode(self, buf: bytes) -> bytes:
         return encoding.append_var_int(buf, self.value)
 
     @classmethod
diff --git a/pactus/types/height.py b/pactus/types/height.py
@@ -24,8 +24,8 @@ def __hash__(self) -> int:
     def __str__(self) -> str:
         return str(self.value)
 
-    def encode(self) -> bytes:
-        return encoding.append_uint32(b"", self.value)
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_uint32(buf, self.value)
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:
diff --git a/pactus/types/round.py b/pactus/types/round.py
@@ -23,8 +23,8 @@ def __hash__(self) -> int:
     def __str__(self) -> str:
         return str(self.value)
 
-    def encode(self) -> bytes:
-        return encoding.append_uint16(b"", self.value)
+    def encode(self, buf: bytes) -> bytes:
+        return encoding.append_uint16(buf, self.value)
 
     @classmethod
     def decode(cls, buf: bytes) -> tuple:

Original file line number	Diff line number	Diff line change
`@@ -61,8 +61,8 @@ def string(self) -> str:`
`61`	`61`	`self.raw_bytes(),`
`62`	`62`	`)`
`63`	`63`
`64`		`- def encode(self) -> bytes:`
`65`		`- return encoding.append_fixed_bytes(b"", self.raw_bytes())`
	`64`	`+ def encode(self, buf: bytes) -> bytes:`
	`65`	`+ return encoding.append_fixed_bytes(buf, self.raw_bytes())`
`66`	`66`
`67`	`67`	`@classmethod`
`68`	`68`	`def decode(cls, buf: bytes) -> tuple:`
Original file line number	Diff line number	Diff line change
`@@ -50,8 +50,8 @@ def string(self) -> str:`
`50`	`50`	`self.raw_bytes(),`
`51`	`51`	`)`
`52`	`52`
`53`		`- def encode(self) -> bytes:`
`54`		`- return encoding.append_fixed_bytes(b"", self.raw_bytes())`
	`53`	`+ def encode(self, buf: bytes) -> bytes:`
	`54`	`+ return encoding.append_fixed_bytes(buf, self.raw_bytes())`
`55`	`55`
`56`	`56`	`@classmethod`
`57`	`57`	`def decode(cls, buf: bytes) -> tuple:`