Stop using memoize for average block time; atxm instance will now kee…

…p a cached value of the first call result instead.

atxm/machine.py

@@ -130,6 +130,9 @@ def __init__(
         self._task.clock = self.__CLOCK
         self._task.interval = self._IDLE_INTERVAL
 
+        # block time
+        self._average_block_time = None
+
         super().__init__()
 
         self.add_listener(_Machine.LogObserver())
@@ -173,11 +176,14 @@ def _enter_idle_mode(self):
     @_transition_to_busy.before
     def _enter_busy_mode(self):
         """About to enter busy work mode (speed up interval)"""
-        average_block_time = _get_average_blocktime(
-            w3=self.w3, sample_size=self._BLOCK_SAMPLE_SIZE
-        )
+        if self._average_block_time is None:
+            average_block_time = _get_average_blocktime(
+                w3=self.w3, sample_size=self._BLOCK_SAMPLE_SIZE
+            )
+            self._average_block_time = average_block_time
+
         self._task.interval = max(
-            round(average_block_time * self._BLOCK_INTERVAL), self._MIN_INTERVAL
+            round(self._average_block_time * self._BLOCK_INTERVAL), self._MIN_INTERVAL
         )
         self.log.info(f"[working] cycle interval is now {self._task.interval} seconds")
 

atxm/utils.py

@@ -1,7 +1,6 @@
 import contextlib
 from typing import Callable, Optional
 
-from cytoolz import memoize
 from eth_utils import ValidationError
 from twisted.internet import reactor
 from web3 import Web3
@@ -18,7 +17,6 @@
 from atxm.tx import AsyncTx, PendingTx, TxHash
 
 
-@memoize
 def _get_average_blocktime(w3: Web3, sample_size: int) -> float:
     """Returns the average block time in seconds."""
     latest_block = w3.eth.get_block("latest")