Make LIFO/HIFO accounting methods O(n*log(m))

src/rp2/abstract_accounting_method.py

@@ -14,7 +14,8 @@
 
 
 from enum import Enum
-from typing import Dict, List, NamedTuple, Optional
+from heapq import heappop, heappush
+from typing import Dict, List, NamedTuple, Optional, Tuple, Union
 
 from rp2.abstract_transaction import AbstractTransaction
 from rp2.in_transaction import InTransaction
@@ -41,11 +42,17 @@ def __init__(
     ) -> None:
         self.__accounting_method: AbstractAccountingMethod = accounting_method
         self.__acquired_lot_list = acquired_lot_list
+        self.__acquired_lot_heap: List[Tuple[Union[float, RP2Decimal], InTransaction]] = []
         self.__acquired_lot_2_partial_amount = acquired_lot_2_partial_amount
         self.__up_to_index = 0
         self.__from_index = 0
 
     def set_up_to_index(self, up_to_index: int) -> None:
+        # Control how far to advance the iterator, caller is responsible for updating
+        if self.__accounting_method.use_heap():
+            for i in range(self.__up_to_index, up_to_index + 1):
+                lot = self.__acquired_lot_list[i]
+                self.add_selected_lot_to_heap(lot)
         self.__up_to_index = up_to_index
 
     def set_from_index(self, from_index: int) -> None:
@@ -69,8 +76,15 @@ def set_partial_amount(self, acquired_lot: InTransaction, amount: RP2Decimal) ->
     def clear_partial_amount(self, acquired_lot: InTransaction) -> None:
         self.set_partial_amount(acquired_lot, ZERO)
 
-    def __iter__(self) -> "AccountingMethodIterator":
-        return AccountingMethodIterator(self.__acquired_lot_list, self.__from_index, self.__up_to_index, self.__accounting_method.lot_candidates_order())
+    def add_selected_lot_to_heap(self, lot: InTransaction) -> None:
+        heap_item = (self.__accounting_method.heap_key(lot), lot)
+        heappush(self.__acquired_lot_heap, heap_item)
+
+    def __iter__(self) -> Union["AccountingMethodIterator", "HeapAccountingMethodIterator"]:
+        if self.__accounting_method.use_heap():  # pylint: disable=no-else-return
+            return HeapAccountingMethodIterator(self.__acquired_lot_heap)
+        else:
+            return AccountingMethodIterator(self.__acquired_lot_list, self.__from_index, self.__up_to_index, self.__accounting_method.lot_candidates_order())
 
 
 class AccountingMethodIterator:
@@ -96,6 +110,17 @@ def __next__(self) -> InTransaction:
         raise StopIteration(self)
 
 
+class HeapAccountingMethodIterator:
+    def __init__(self, acquired_lot_heap: List[Tuple[Union[float, RP2Decimal], InTransaction]]) -> None:
+        self.__acquired_lot_heap = acquired_lot_heap
+
+    def __next__(self) -> InTransaction:
+        while len(self.__acquired_lot_heap) > 0:
+            _, result = heappop(self.__acquired_lot_heap)
+            return result
+        raise StopIteration(self)
+
+
 class AbstractAccountingMethod:
     def seek_non_exhausted_acquired_lot(
         self,
@@ -114,3 +139,9 @@ def name(self) -> str:
 
     def __repr__(self) -> str:
         return self.name
+
+    def heap_key(self, lot: InTransaction) -> Union[RP2Decimal, float]:
+        raise NotImplementedError("Abstract function")
+
+    def use_heap(self) -> bool:
+        raise NotImplementedError("Abstract function")

src/rp2/in_transaction.py

@@ -206,3 +206,6 @@ def is_crypto_fee_defined(self) -> bool:
 
     def is_taxable(self) -> bool:
         return self.transaction_type.is_earn_type()
+
+    def __lt__(self, other: "InTransaction") -> bool:
+        return self.timestamp < other.timestamp

src/rp2/plugin/accounting_method/fifo.py

@@ -63,3 +63,9 @@ def seek_non_exhausted_acquired_lot(
 
     def lot_candidates_order(self) -> AcquiredLotCandidatesOrder:
         return AcquiredLotCandidatesOrder.OLDER_TO_NEWER
+
+    def heap_key(self, lot: InTransaction) -> RP2Decimal:
+        raise ValueError()
+
+    def use_heap(self) -> bool:
+        return False

src/rp2/plugin/accounting_method/hifo.py

@@ -51,14 +51,22 @@ def seek_non_exhausted_acquired_lot(
                 # The acquired lot has zero partial amount
                 continue
 
-            if selected_acquired_lot is None or selected_acquired_lot.spot_price < acquired_lot.spot_price:
+            if acquired_lot_amount > ZERO:
                 selected_acquired_lot_amount = acquired_lot_amount
                 selected_acquired_lot = acquired_lot
+                break
 
         if selected_acquired_lot_amount > ZERO and selected_acquired_lot:
             lot_candidates.clear_partial_amount(selected_acquired_lot)
+            lot_candidates.add_selected_lot_to_heap(selected_acquired_lot)
             return AcquiredLotAndAmount(acquired_lot=selected_acquired_lot, amount=selected_acquired_lot_amount)
         return None
 
     def lot_candidates_order(self) -> AcquiredLotCandidatesOrder:
         return AcquiredLotCandidatesOrder.OLDER_TO_NEWER
+
+    def heap_key(self, lot: InTransaction) -> RP2Decimal:
+        return -lot.spot_price
+
+    def use_heap(self) -> bool:
+        return True

src/rp2/plugin/accounting_method/lifo.py

@@ -25,7 +25,7 @@
 from rp2.rp2_decimal import ZERO, RP2Decimal
 
 
-# LIFO plugin. See https://www.investopedia.com/terms/l/lifo.asp. This plugin uses universal application, not per-wallet application:
+# Last In, First Out (LIFO) plugin. See https://www.investopedia.com/terms/l/lifo.asp. This plugin uses universal application, not per-wallet application:
 # this means there is one queue for each coin across every wallet and exchange and the accounting method is applied to each such queue.
 # More on this at https://www.forbes.com/sites/shehanchandrasekera/2020/09/17/what-crypto-taxpayers-need-to-know-about-fifo-lifo-hifo-specific-id/
 # Note that under LIFO the date acquired must still be before or on the date sold: for details see
@@ -59,8 +59,15 @@ def seek_non_exhausted_acquired_lot(
 
         if selected_acquired_lot_amount > ZERO and selected_acquired_lot:
             lot_candidates.clear_partial_amount(selected_acquired_lot)
+            lot_candidates.add_selected_lot_to_heap(selected_acquired_lot)
             return AcquiredLotAndAmount(acquired_lot=selected_acquired_lot, amount=selected_acquired_lot_amount)
         return None
 
     def lot_candidates_order(self) -> AcquiredLotCandidatesOrder:
         return AcquiredLotCandidatesOrder.NEWER_TO_OLDER
+
+    def heap_key(self, lot: InTransaction) -> float:
+        return -lot.timestamp.timestamp()
+
+    def use_heap(self) -> bool:
+        return True

src/rp2/rp2_decimal.py

@@ -125,5 +125,8 @@ def __rmod__(self, other: object) -> "RP2Decimal":
             raise RP2TypeError(f"Operand has non-Decimal value {repr(other)}")
         return RP2Decimal(Decimal.__rmod__(self, other))
 
+    def __neg__(self) -> "RP2Decimal":
+        return RP2Decimal(Decimal.__neg__(self))
+
 
 ZERO: RP2Decimal = RP2Decimal("0")