Adds time_cache for blockheight

The cache is invalidated after time-to-live

bitcash/network/APIs/BitcoinDotComAPI.py

@@ -2,10 +2,11 @@
 from decimal import Decimal
 from bitcash.exceptions import InvalidEndpointURLProvided
 from bitcash.network import currency_to_satoshi
-from bitcash.network.APIs import BaseAPI
+from bitcash.network.APIs import BaseAPI, DEFAULT_CACHE_TIME
 from bitcash.network.meta import Unspent
 from bitcash.network.transaction import Transaction, TxPart
 from bitcash.format import cashtokenaddress_to_address
+from bitcash.utils import time_cache
 
 # This class is the interface for Bitcash to interact with
 # Bitcoin.com based RESTful interfaces.
@@ -53,6 +54,7 @@ def get_default_endpoints(cls, network):
     def make_endpoint_url(self, path):
         return self.network_endpoint + self.PATHS[path]
 
+    @time_cache(DEFAULT_CACHE_TIME)
     def get_blockheight(self, *args, **kwargs):
         api_url = self.make_endpoint_url("block-height")
         r = session.get(api_url)

bitcash/network/APIs/ChaingraphAPI.py

@@ -1,9 +1,10 @@
 from bitcash.network.http import session
 from bitcash.exceptions import InvalidEndpointURLProvided
-from bitcash.network.APIs import BaseAPI
+from bitcash.network.APIs import BaseAPI, DEFAULT_CACHE_TIME
 from bitcash.network.meta import Unspent
 from bitcash.network.transaction import Transaction, TxPart
 from bitcash.cashaddress import Address
+from bitcash.utils import time_cache
 
 
 class ChaingraphAPI(BaseAPI):
@@ -56,6 +57,7 @@ def send_request(self, json_request, *args, **kwargs):
     def get_default_endpoints(cls, network):
         return cls.DEFAULT_ENDPOINTS[network]
 
+    @time_cache(DEFAULT_CACHE_TIME)
     def get_blockheight(self, *args, **kwargs):
         json_request = {
             "query": """

bitcash/network/APIs/__init__.py

@@ -1,6 +1,10 @@
 from abc import ABC, abstractmethod
 
 
+# default cache time for the blockheigt retrieval
+DEFAULT_CACHE_TIME = 120
+
+
 class BaseAPI(ABC):
     """
     Abstract class for API classes

bitcash/utils.py

@@ -1,4 +1,6 @@
 import decimal
+import functools
+import time
 from binascii import hexlify
 
 
@@ -68,3 +70,36 @@ def varint_to_int(val):
     if start_byte == b"\xfd":
         return int.from_bytes(val.read(2), "little")
     return int.from_bytes(start_byte, "little")
+
+
+def time_cache(max_age):
+    """
+    Timed cache decorator to store a value until time-to-live
+
+    :param max_age: Time, in seconds, untill when the value is invalidated.
+    """
+
+    class ReturnValue:
+        def __init__(self, value, expiry):
+            self.value = value
+            self.expiry = expiry
+
+    def _decorator(fn):
+        @functools.cache
+        def cache_fn(*args, **kwargs):
+            value = fn(*args, **kwargs)
+            expiry = time.monotonic() + max_age
+            return ReturnValue(value, expiry)
+
+        @functools.wraps(fn)
+        def _wrapped(*args, **kwargs):
+            return_value = cache_fn(*args, **kwargs)
+            if return_value.expiry < time.monotonic():
+                # update the reference to the cache
+                return_value.value = fn(*args, **kwargs)
+                return_value.expiry = time.monotonic() + max_age
+            return return_value.value
+
+        return _wrapped
+
+    return _decorator

tests/network/APIs/test_ChaingraphAPI.py

@@ -41,9 +41,7 @@ def test_get_blockheight(self):
         return_json = {
             "data": {
                 "block": [
-                    {
-                        "height": "123456"
-                    },
+                    {"height": "123456"},
                 ]
             }
         }