# -*- coding: utf-8 -*-
import base64
from decimal import Context, Decimal, Inexact
from .asset import Asset
from .stellarxdr import Xdr
from .utils import (account_xdr_object, best_rational_approximation as best_r,
division, encode_check, signer_key_xdr_object,
is_valid_address, convert_hex_to_bytes)
from .exceptions import XdrLengthError
ONE = Decimal(10**7)
[docs]class Operation(object):
"""The :class:`Operation` object, which represents an operation on
Stellar's network.
An operation is an individual command that mutates Stellar's ledger. It is
typically rolled up into a transaction (a transaction is a list of
operations with additional metadata).
Operations are executed on behalf of the source account specified in the
transaction, unless there is an override defined for the operation.
For more on operations, see `Stellar's documentation on operations
<https://www.stellar.org/developers/guides/concepts/operations.html>`_ as
well as `Stellar's List of Operations
<https://www.stellar.org/developers/guides/concepts/list-of-operations.html>`_,
which includes information such as the security necessary for a given
operation, as well as information about when validity checks occur on the
network.
The :class:`Operation` class is typically not used, but rather one of its
subclasses is typically included in transactions.
:param str source: The source account for the payment. Defaults to the
transaction's source account.
"""
def __init__(self, source=None):
self.source = source
self.body = Xdr.nullclass()
def __eq__(self, other):
return self.xdr() == other.xdr()
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`Operation`.
"""
try:
source_account = [account_xdr_object(self.source)]
except TypeError:
source_account = []
return Xdr.types.Operation(source_account, self.body)
[docs] def xdr(self):
"""Packs and base64 encodes this :class:`Operation` as an XDR string.
"""
op = Xdr.StellarXDRPacker()
op.pack_Operation(self.to_xdr_object())
return base64.b64encode(op.get_buffer())
[docs] @staticmethod
def to_xdr_amount(value):
"""Converts an amount to the appropriate value to send over the network
as a part of an XDR object.
Each asset amount is encoded as a signed 64-bit integer in the XDR
structures. An asset amount unit (that which is seen by end users) is
scaled down by a factor of ten million (10,000,000) to arrive at the
native 64-bit integer representation. For example, the integer amount
value 25,123,456 equals 2.5123456 units of the asset. This scaling
allows for seven decimal places of precision in human-friendly amount
units.
This static method correctly multiplies the value by the scaling factor
in order to come to the integer value used in XDR structures.
See `Stellar's documentation on Asset Precision
<https://www.stellar.org/developers/guides/concepts/assets.html#amount-precision-and-representation>`_
for more information.
:param str value: The amount to convert to an integer for XDR
serialization.
"""
if not isinstance(value, str):
raise TypeError("value of type '{}' is not a string"
".".format(value))
# throw exception if value * ONE has decimal places (it can't be
# represented as int64)
return int((Decimal(value) *
ONE).to_integral_exact(context=Context(traps=[Inexact])))
@staticmethod
def to_xdr_price(price):
if isinstance(price, dict):
if not ('n' in price and 'd' in price):
raise ValueError(
"You need pass `price` params as `digit` or `{'n': numerator, 'd': denominator}`"
)
else:
price = best_r(price)
return price
[docs] @staticmethod
def from_xdr_amount(value):
"""Converts an amount from an XDR object into its appropriate integer
representation.
Each asset amount is encoded as a signed 64-bit integer in the XDR
structures. An asset amount unit (that which is seen by end users) is
scaled down by a factor of ten million (10,000,000) to arrive at the
native 64-bit integer representation. For example, the integer amount
value 25,123,456 equals 2.5123456 units of the asset. This scaling
allows for seven decimal places of precision in human-friendly amount
units.
This static method correctly divides the value by the scaling factor in
order to get the proper units of the asset.
See `Stellar's documentation on Asset Precision
<https://www.stellar.org/developers/guides/concepts/assets.html#amount-precision-and-representation>`_
for more information.
:param int value: The amount to convert to a string from an XDR int64
amount.
"""
return str(Decimal(value) / ONE)
@classmethod
def type_code(cls):
pass
@classmethod
def from_xdr_object(cls, operation):
for sub_cls in cls.__subclasses__():
if sub_cls.type_code() == operation.type:
return sub_cls.from_xdr_object(operation)
raise NotImplementedError("Operation of type={} is not implemented"
".".format(operation.type))
[docs] @classmethod
def from_xdr(cls, xdr):
"""Create the appropriate :class:`Operation` subclass from the XDR
structure.
Decode an XDR base64 encoded string and create the appropriate
:class:`Operation` object.
:param str xdr: The XDR object to create an :class:`Operation` (or
subclass) instance from.
"""
xdr_decode = base64.b64decode(xdr)
op = Xdr.StellarXDRUnpacker(xdr_decode)
op = op.unpack_Operation()
return cls.from_xdr_object(op)
[docs]class CreateAccount(Operation):
"""The :class:`CreateAccount` object, which represents a Create Account
operation on Stellar's network.
This operation creates and funds a new account with the specified starting
balance.
Threshold: Medium
:param str destination: Destination account ID to create an account for.
:param str starting_balance: Amount in XLM the account should be
funded for. Must be greater than the [reserve balance amount]
(https://www.stellar.org/developers/learn/concepts/fees.html).
:param str source: The source account for the payment. Defaults to the
transaction's source account.
"""
@classmethod
def type_code(cls):
return Xdr.const.CREATE_ACCOUNT
def __init__(self, destination, starting_balance, source=None):
super(CreateAccount, self).__init__(source)
self.destination = destination
self.starting_balance = starting_balance
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`CreateAccount`.
"""
destination = account_xdr_object(self.destination)
create_account_op = Xdr.types.CreateAccountOp(
destination, Operation.to_xdr_amount(self.starting_balance))
self.body.type = Xdr.const.CREATE_ACCOUNT
self.body.createAccountOp = create_account_op
return super(CreateAccount, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`CreateAccount` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
destination = encode_check(
'account',
op_xdr_object.body.createAccountOp.destination.ed25519).decode()
starting_balance = Operation.from_xdr_amount(
op_xdr_object.body.createAccountOp.startingBalance)
return cls(
source=source,
destination=destination,
starting_balance=starting_balance,
)
[docs]class Payment(Operation):
"""The :class:`Payment` object, which represents a Payment operation on
Stellar's network.
Sends an amount in a specific asset to a destination account.
Threshold: Medium
:param str destination: The destination account ID.
:param Asset asset: The asset to send.
:param str amount: The amount to send.
:param str source: The source account for the payment. Defaults to the
transaction's source account.
"""
@classmethod
def type_code(cls):
return Xdr.const.PAYMENT
def __init__(self, destination, asset, amount, source=None):
super(Payment, self).__init__(source)
self.destination = destination
self.asset = asset
self.amount = amount
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`Payment`.
"""
asset = self.asset.to_xdr_object()
destination = account_xdr_object(self.destination)
amount = Operation.to_xdr_amount(self.amount)
payment_op = Xdr.types.PaymentOp(destination, asset, amount)
self.body.type = Xdr.const.PAYMENT
self.body.paymentOp = payment_op
return super(Payment, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`Payment` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
destination = encode_check(
'account',
op_xdr_object.body.paymentOp.destination.ed25519).decode()
asset = Asset.from_xdr_object(op_xdr_object.body.paymentOp.asset)
amount = Operation.from_xdr_amount(op_xdr_object.body.paymentOp.amount)
return cls(
source=source,
destination=destination,
asset=asset,
amount=amount,
)
[docs]class PathPayment(Operation):
"""The :class:`PathPayment` object, which represents a PathPayment
operation on Stellar's network.
Sends an amount in a specific asset to a destination account through a path
of offers. This allows the asset sent (e.g., 450 XLM) to be different from
the asset received (e.g, 6 BTC).
Threshold: Medium
:param str destination: The destination account to send to.
:param Asset send_asset: The asset to pay with.
:param str send_max: The maximum amount of send_asset to send.
:param Asset dest_asset: The asset the destination will receive.
:param str dest_amount: The amount the destination receives.
:param list path: A list of Asset objects to use as the path.
:param str source: The source account for the payment. Defaults to the
transaction's source account.
"""
@classmethod
def type_code(cls):
return Xdr.const.PATH_PAYMENT
def __init__(self,
destination,
send_asset,
send_max,
dest_asset,
dest_amount,
path,
source=None):
super(PathPayment, self).__init__(source)
self.destination = destination
self.send_asset = send_asset
self.send_max = send_max
self.dest_asset = dest_asset
self.dest_amount = dest_amount
self.path = path # a list of paths/assets
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`PathPayment`.
"""
destination = account_xdr_object(self.destination)
send_asset = self.send_asset.to_xdr_object()
dest_asset = self.dest_asset.to_xdr_object()
path = [asset.to_xdr_object() for asset in self.path]
path_payment = Xdr.types.PathPaymentOp(
send_asset, Operation.to_xdr_amount(self.send_max), destination,
dest_asset, Operation.to_xdr_amount(self.dest_amount), path)
self.body.type = Xdr.const.PATH_PAYMENT
self.body.pathPaymentOp = path_payment
return super(PathPayment, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`PathPayment` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
destination = encode_check(
'account',
op_xdr_object.body.pathPaymentOp.destination.ed25519).decode()
send_asset = Asset.from_xdr_object(
op_xdr_object.body.pathPaymentOp.sendAsset)
dest_asset = Asset.from_xdr_object(
op_xdr_object.body.pathPaymentOp.destAsset)
send_max = Operation.from_xdr_amount(
op_xdr_object.body.pathPaymentOp.sendMax)
dest_amount = Operation.from_xdr_amount(
op_xdr_object.body.pathPaymentOp.destAmount)
path = []
if op_xdr_object.body.pathPaymentOp.path:
for x in op_xdr_object.body.pathPaymentOp.path:
path.append(Asset.from_xdr_object(x))
return cls(
source=source,
destination=destination,
send_asset=send_asset,
send_max=send_max,
dest_asset=dest_asset,
dest_amount=dest_amount,
path=path)
[docs]class ChangeTrust(Operation):
"""The :class:`ChangeTrust` object, which represents a ChangeTrust
operation on Stellar's network.
Creates, updates, or deletes a trustline. For more on trustlines, please
refer to the `assets documentation
<https://www.stellar.org/developers/guides/concepts/assets.html>_`.
Threshold: Medium
:param Asset asset: The asset for the trust line.
:param str limit: The limit for the asset, defaults to max int64.
If the limit is set to "0" it deletes the trustline.
:param str source: The source account (defaults to transaction source).
"""
default_limit = "922337203685.4775807"
@classmethod
def type_code(cls):
return Xdr.const.CHANGE_TRUST
def __init__(self, asset, limit=None, source=None):
super(ChangeTrust, self).__init__(source)
self.line = asset
self.limit = limit or self.default_limit
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`ChangeTrust`.
"""
line = self.line.to_xdr_object()
limit = Operation.to_xdr_amount(self.limit)
change_trust_op = Xdr.types.ChangeTrustOp(line, limit)
self.body.type = Xdr.const.CHANGE_TRUST
self.body.changeTrustOp = change_trust_op
return super(ChangeTrust, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`ChangeTrust` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
line = Asset.from_xdr_object(op_xdr_object.body.changeTrustOp.line)
limit = Operation.from_xdr_amount(
op_xdr_object.body.changeTrustOp.limit)
return cls(source=source, asset=line, limit=limit)
[docs]class AllowTrust(Operation):
"""The :class:`AllowTrust` object, which represents a AllowTrust operation
on Stellar's network.
Updates the authorized flag of an existing trustline. This can only be
called by the issuer of a trustline's `asset
<https://www.stellar.org/developers/guides/concepts/assets.html>`_.
The issuer can only clear the authorized flag if the issuer has the
AUTH_REVOCABLE_FLAG set. Otherwise, the issuer can only set the authorized
flag.
Threshold: Low
:param str trustor: The trusting account (the one being authorized)
:param str asset_code: The asset code being authorized.
:param str source: The source account (defaults to transaction source).
"""
@classmethod
def type_code(cls):
return Xdr.const.ALLOW_TRUST
def __init__(self, trustor, asset_code, authorize, source=None):
super(AllowTrust, self).__init__(source)
self.trustor = trustor
self.asset_code = asset_code
self.authorize = authorize
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`AllowTrust`.
"""
trustor = account_xdr_object(self.trustor)
length = len(self.asset_code)
assert length <= 12
pad_length = 4 - length if length <= 4 else 12 - length
# asset_code = self.asset_code + '\x00' * pad_length
# asset_code = bytearray(asset_code, encoding='utf-8')
asset_code = bytearray(self.asset_code, 'ascii') + b'\x00' * pad_length
asset = Xdr.nullclass()
if len(asset_code) == 4:
asset.type = Xdr.const.ASSET_TYPE_CREDIT_ALPHANUM4
asset.assetCode4 = asset_code
else:
asset.type = Xdr.const.ASSET_TYPE_CREDIT_ALPHANUM12
asset.assetCode12 = asset_code
allow_trust_op = Xdr.types.AllowTrustOp(trustor, asset, self.authorize)
self.body.type = Xdr.const.ALLOW_TRUST
self.body.allowTrustOp = allow_trust_op
return super(AllowTrust, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`AllowTrust` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
trustor = encode_check(
'account',
op_xdr_object.body.allowTrustOp.trustor.ed25519).decode()
authorize = op_xdr_object.body.allowTrustOp.authorize
asset_type = op_xdr_object.body.allowTrustOp.asset.type
if asset_type == Xdr.const.ASSET_TYPE_CREDIT_ALPHANUM4:
asset_code = (
op_xdr_object.body.allowTrustOp.asset.assetCode4.decode())
elif asset_type == Xdr.const.ASSET_TYPE_CREDIT_ALPHANUM12:
asset_code = (
op_xdr_object.body.allowTrustOp.asset.assetCode12.decode())
else:
raise NotImplementedError(
"Operation of asset_type={} is not implemented"
".".format(asset_type.type))
return cls(
source=source,
trustor=trustor,
authorize=authorize,
asset_code=asset_code)
[docs]class SetOptions(Operation):
"""The :class:`SetOptions` object, which represents a SetOptions operation
on Stellar's network.
This operation sets the options for an account.
For more information on the signing options, please refer to the `multi-sig
doc <https://www.stellar.org/developers/guides/concepts/multi-sig.html>`_.
When updating signers or other thresholds, the threshold of this operation
is high.
Threshold: Medium or High
:param str inflation_dest: Set this account ID as the account's inflation destination.
:param int clear_flags: Bitmap integer for which account flags to clear.
:param int set_flags: Bitmap integer for which account flags to set.
:param int master_weight: The master key weight.
:param int low_threshold: The sum weight for the low threshold.
:param int med_threshold: The sum weight for the medium threshold.
:param int high_threshold: The sum weight for the high threshold.
:param str home_domain: sets the home domain used for reverse federation lookup.
:param signer_address: signer
:type signer_address: str, bytes
:param str signer_type: The type of signer, it should be 'ed25519PublicKey',
'hashX' or 'preAuthTx'
:param int signer_weight: The weight of the new signer (0 to delete or 1-255)
:param str source: The source account (defaults to transaction source).
"""
@classmethod
def type_code(cls):
return Xdr.const.SET_OPTIONS
def __init__(self,
inflation_dest=None,
clear_flags=None,
set_flags=None,
master_weight=None,
low_threshold=None,
med_threshold=None,
high_threshold=None,
home_domain=None,
signer_address=None,
signer_type=None,
signer_weight=None,
source=None):
super(SetOptions, self).__init__(source)
self.inflation_dest = inflation_dest
self.clear_flags = clear_flags
self.set_flags = set_flags
self.master_weight = master_weight
self.low_threshold = low_threshold
self.med_threshold = med_threshold
self.high_threshold = high_threshold
if isinstance(home_domain, str):
self.home_domain = bytearray(home_domain, encoding='utf-8')
else:
self.home_domain = home_domain
self.signer_address = signer_address
self.signer_type = signer_type
self.signer_weight = signer_weight
if self.signer_address is not None and self.signer_type is None:
if not is_valid_address(self.signer_address):
raise ValueError(
'Must be a valid strkey if not give signer_type')
self.signer_type = 'ed25519PublicKey'
signer_is_invalid_type = (
self.signer_type is not None and
self.signer_type not in ('ed25519PublicKey', 'hashX', 'preAuthTx'))
if signer_is_invalid_type:
raise ValueError('Invalid signer type, sign_type should '
'be ed25519PublicKey, hashX or preAuthTx')
if self.signer_type in ('hashX', 'preAuthTx'):
self.signer_address = convert_hex_to_bytes(self.signer_address)
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`SetOptions`.
"""
def assert_option_array(x):
if x is None:
return []
if not isinstance(x, list):
return [x]
return x
if self.inflation_dest is not None:
inflation_dest = [account_xdr_object(self.inflation_dest)]
else:
inflation_dest = []
self.clear_flags = assert_option_array(self.clear_flags)
self.set_flags = assert_option_array(self.set_flags)
self.master_weight = assert_option_array(self.master_weight)
self.low_threshold = assert_option_array(self.low_threshold)
self.med_threshold = assert_option_array(self.med_threshold)
self.high_threshold = assert_option_array(self.high_threshold)
self.home_domain = assert_option_array(self.home_domain)
req_signer_fields = (self.signer_address, self.signer_type,
self.signer_weight)
if all(signer_field is not None for signer_field in req_signer_fields):
signer = [
Xdr.types.Signer(
signer_key_xdr_object(self.signer_type,
self.signer_address),
self.signer_weight)
]
else:
signer = []
set_options_op = Xdr.types.SetOptionsOp(
inflation_dest, self.clear_flags, self.set_flags,
self.master_weight, self.low_threshold, self.med_threshold,
self.high_threshold, self.home_domain, signer)
self.body.type = Xdr.const.SET_OPTIONS
self.body.setOptionsOp = set_options_op
return super(SetOptions, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`SetOptions` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
if not op_xdr_object.body.setOptionsOp.inflationDest:
inflation_dest = None
else:
inflation_dest = encode_check(
'account', op_xdr_object.body.setOptionsOp.inflationDest[0]
.ed25519).decode()
clear_flags = op_xdr_object.body.setOptionsOp.clearFlags # list
set_flags = op_xdr_object.body.setOptionsOp.setFlags
master_weight = op_xdr_object.body.setOptionsOp.masterWeight
low_threshold = op_xdr_object.body.setOptionsOp.lowThreshold
med_threshold = op_xdr_object.body.setOptionsOp.medThreshold
high_threshold = op_xdr_object.body.setOptionsOp.highThreshold
home_domain = op_xdr_object.body.setOptionsOp.homeDomain
if op_xdr_object.body.setOptionsOp.signer:
key = op_xdr_object.body.setOptionsOp.signer[0].key
if key.type == Xdr.const.SIGNER_KEY_TYPE_ED25519:
signer_address = encode_check('account', key.ed25519).decode()
signer_type = 'ed25519PublicKey'
if key.type == Xdr.const.SIGNER_KEY_TYPE_PRE_AUTH_TX:
signer_address = key.preAuthTx
signer_type = 'preAuthTx'
if key.type == Xdr.const.SIGNER_KEY_TYPE_HASH_X:
signer_address = key.hashX
signer_type = 'hashX'
signer_weight = op_xdr_object.body.setOptionsOp.signer[0].weight
else:
signer_address = None
signer_type = None
signer_weight = None
return cls(
source=source,
inflation_dest=inflation_dest,
clear_flags=clear_flags,
set_flags=set_flags,
master_weight=master_weight,
low_threshold=low_threshold,
med_threshold=med_threshold,
high_threshold=high_threshold,
home_domain=home_domain,
signer_address=signer_address,
signer_type=signer_type,
signer_weight=signer_weight)
[docs]class ManageOffer(Operation):
"""The :class:`ManageOffer` object, which represents a ManageOffer
operation on Stellar's network.
Creates, updates, or deletes an offer.
If you want to create a new offer set Offer ID to 0.
If you want to update an existing offer set Offer ID to existing offer ID.
If you want to delete an existing offer set Offer ID to existing offer ID
and set Amount to 0.
Threshold: Medium
:param Asset selling: What you're selling.
:param Asset buying: What you're buying.
:param str amount: The total amount you're selling. If 0,
deletes the offer.
:param price: Price of 1 unit of `selling` in
terms of `buying`.
:type price: str, dict
:param int offer_id: If `0`, will create a new offer (default). Otherwise,
edits an existing offer.
:param str source: The source account (defaults to transaction source).
"""
@classmethod
def type_code(cls):
return Xdr.const.MANAGE_OFFER
def __init__(self, selling, buying, amount, price, offer_id=0,
source=None):
super(ManageOffer, self).__init__(source)
self.selling = selling # Asset
self.buying = buying # Asset
self.amount = amount
self.price = price
self.offer_id = offer_id
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`ManageOffer`.
"""
selling = self.selling.to_xdr_object()
buying = self.buying.to_xdr_object()
price = Operation.to_xdr_price(self.price)
price = Xdr.types.Price(price['n'], price['d'])
amount = Operation.to_xdr_amount(self.amount)
manage_offer_op = Xdr.types.ManageOfferOp(selling, buying, amount,
price, self.offer_id)
self.body.type = Xdr.const.MANAGE_OFFER
self.body.manageOfferOp = manage_offer_op
return super(ManageOffer, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`ManageOffer` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
selling = Asset.from_xdr_object(
op_xdr_object.body.manageOfferOp.selling)
buying = Asset.from_xdr_object(op_xdr_object.body.manageOfferOp.buying)
amount = Operation.from_xdr_amount(
op_xdr_object.body.manageOfferOp.amount)
n = op_xdr_object.body.manageOfferOp.price.n
d = op_xdr_object.body.manageOfferOp.price.d
price = division(n, d)
offer_id = op_xdr_object.body.manageOfferOp.offerID
return cls(
source=source,
selling=selling,
buying=buying,
amount=amount,
price=price,
offer_id=offer_id)
[docs]class CreatePassiveOffer(Operation):
"""The :class:`CreatePassiveOffer` object, which represents a
CreatePassiveOffer operation on Stellar's network.
A passive offer is an offer that does not act on and take a reverse offer
of equal price. Instead, they only take offers of lesser price. For
example, if an offer exists to buy 5 BTC for 30 XLM, and you make a passive
offer to buy 30 XLM for 5 BTC, your passive offer does not take the first
offer.
Note that regular offers made later than your passive offer can act on and
take your passive offer, even if the regular offer is of the same price as
your passive offer.
Passive offers allow market makers to have zero spread. If you want to
trade EUR for USD at 1:1 price and USD for EUR also at 1:1, you can create
two passive offers so the two offers don't immediately act on each other.
Once the passive offer is created, you can manage it like any other offer
using the manage offer operation - see :class:`ManageOffer` for more
details.
:param Asset selling: What you're selling.
:param Asset buying: What you're buying.
:param str amount: The total amount you're selling. If 0,
deletes the offer.
:param price: Price of 1 unit of `selling` in
terms of `buying`.
:type price: str, dict
:param str source: The source account (defaults to transaction source).
"""
@classmethod
def type_code(cls):
return Xdr.const.CREATE_PASSIVE_OFFER
def __init__(self, selling, buying, amount, price, source=None):
super(CreatePassiveOffer, self).__init__(source)
self.selling = selling
self.buying = buying
self.amount = amount
self.price = price
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`CreatePassiveOffer`.
"""
selling = self.selling.to_xdr_object()
buying = self.buying.to_xdr_object()
price = Operation.to_xdr_price(self.price)
price = Xdr.types.Price(price['n'], price['d'])
amount = Operation.to_xdr_amount(self.amount)
create_passive_offer_op = Xdr.types.CreatePassiveOfferOp(
selling, buying, amount, price)
self.body.type = Xdr.const.CREATE_PASSIVE_OFFER
self.body.createPassiveOfferOp = create_passive_offer_op
return super(CreatePassiveOffer, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`CreatePassiveOffer` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
selling = Asset.from_xdr_object(
op_xdr_object.body.createPassiveOfferOp.selling)
buying = Asset.from_xdr_object(
op_xdr_object.body.createPassiveOfferOp.buying)
amount = Operation.from_xdr_amount(
op_xdr_object.body.createPassiveOfferOp.amount)
n = op_xdr_object.body.createPassiveOfferOp.price.n
d = op_xdr_object.body.createPassiveOfferOp.price.d
price = division(n, d)
return cls(
source=source,
selling=selling,
buying=buying,
amount=amount,
price=price)
[docs]class AccountMerge(Operation):
"""The :class:`AccountMerge` object, which represents a
AccountMerge operation on Stellar's network.
Transfers the native balance (the amount of XLM an account holds) to
another account and removes the source account from the ledger.
Threshold: High
:param str destination: Destination to merge the source account into.
:param str source: The source account (defaults to transaction source).
"""
@classmethod
def type_code(cls):
return Xdr.const.ACCOUNT_MERGE
def __init__(self, destination, source=None):
super(AccountMerge, self).__init__(source)
self.destination = destination
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`AccountMerge`.
"""
destination = account_xdr_object(self.destination)
self.body.type = Xdr.const.ACCOUNT_MERGE
self.body.destination = destination
return super(AccountMerge, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`AccountMerge` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
destination = encode_check(
'account', op_xdr_object.body.destination.ed25519).decode()
return cls(source=source, destination=destination)
[docs]class Inflation(Operation):
"""The :class:`Inflation` object, which represents a
Inflation operation on Stellar's network.
This operation runs inflation.
Threshold: Low
:param str source: The source account (defaults to transaction source).
"""
@classmethod
def type_code(cls):
return Xdr.const.INFLATION
def __init__(self, source=None):
super(Inflation, self).__init__(source)
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`Inflation`.
"""
self.body.type = Xdr.const.INFLATION
return super(Inflation, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`Inflation` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
return cls(source=source)
[docs]class ManageData(Operation):
"""The :class:`ManageData` object, which represents a
ManageData operation on Stellar's network.
Allows you to set, modify or delete a Data Entry (name/value pair) that is
attached to a particular account. An account can have an arbitrary amount
of DataEntries attached to it. Each DataEntry increases the minimum balance
needed to be held by the account.
DataEntries can be used for application specific things. They are not used
by the core Stellar protocol.
Threshold: Medium
:param str data_name: The name of the data entry.
:param data_value: The value of the data entry.
:type data_value: str, bytes, None
:param str source: The optional source account.
"""
@classmethod
def type_code(cls):
return Xdr.const.MANAGE_DATA
def __init__(self, data_name, data_value, source=None):
super(ManageData, self).__init__(source)
self.data_name = data_name
self.data_value = data_value
valid_data_name_len = len(self.data_name) <= 64
valid_data_val_len = (self.data_value is None
or len(self.data_value) <= 64)
if not valid_data_name_len or not valid_data_val_len:
raise XdrLengthError(
"Data or value should be <= 64 bytes (ascii encoded).")
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`ManageData`.
"""
data_name = bytearray(self.data_name, encoding='utf-8')
if self.data_value is not None:
if isinstance(self.data_value, bytes):
data_value = [bytearray(self.data_value)]
else:
data_value = [bytearray(self.data_value, 'utf-8')]
else:
data_value = []
manage_data_op = Xdr.types.ManageDataOp(data_name, data_value)
self.body.type = Xdr.const.MANAGE_DATA
self.body.manageDataOp = manage_data_op
return super(ManageData, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`ManageData` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
data_name = op_xdr_object.body.manageDataOp.dataName.decode()
if op_xdr_object.body.manageDataOp.dataValue:
data_value = op_xdr_object.body.manageDataOp.dataValue[0]
else:
data_value = None
return cls(source=source, data_name=data_name, data_value=data_value)
[docs]class BumpSequence(Operation):
"""The :class:`BumpSequence` object, which represents a
BumpSequence operation on Stellar's network.
Only available in protocol version 10 and above
Bump sequence allows to bump forward the sequence number of the source account of the
operation, allowing to invalidate any transactions with a smaller sequence number.
If the specified bumpTo sequence number is greater than the source account’s sequence number,
the account’s sequence number is updated with that value, otherwise it’s not modified.
Threshold: Low
:param int bump_to: Sequence number to bump to.
:param str source: The optional source account.
"""
@classmethod
def type_code(cls):
return Xdr.const.BUMP_SEQUENCE
def __init__(self, bump_to, source=None):
super(BumpSequence, self).__init__(source)
self.bump_to = bump_to
[docs] def to_xdr_object(self):
"""Creates an XDR Operation object that represents this
:class:`BumpSequence`.
"""
bump_sequence_op = Xdr.types.BumpSequenceOp(self.bump_to)
self.body.type = Xdr.const.BUMP_SEQUENCE
self.body.bumpSequenceOp = bump_sequence_op
return super(BumpSequence, self).to_xdr_object()
[docs] @classmethod
def from_xdr_object(cls, op_xdr_object):
"""Creates a :class:`BumpSequence` object from an XDR Operation
object.
"""
if not op_xdr_object.sourceAccount:
source = None
else:
source = encode_check(
'account', op_xdr_object.sourceAccount[0].ed25519).decode()
bump_to = op_xdr_object.body.bumpSequenceOp.bumpTo
return cls(source=source, bump_to=bump_to)