Change function of -2 caching (previously called...

Change function of -2 caching (previously called DEFAULT_EXPIRE_IF_IRREVRESIBLE, now called EXPIRE IF REVERSIBLE). This caching is mainly used for caching blocks and block headers. Now irreversible blocks don't have an expiration time, so they only get evicted when the cache fills up. And the default expiration time for reversible blocks is 9s (EXTENDED_TTL)

jussi/cache/cache_group.py

@@ -33,7 +33,7 @@ from .utils import merge_cached_responses
 
 logger = structlog.getLogger(__name__)
 
-BATCH_IRREVERSIBLE_TTL_SET = frozenset([TTL.DEFAULT_EXPIRE_IF_IRREVERSIBLE])
+BATCH_IRREVERSIBLE_TTL_SET = frozenset([TTL.EXPIRE_IF_REVERSIBLE])
 
 # types
 CacheTTLValue = TypeVar('CacheTTL', int, float, type(None))
@@ -188,13 +188,14 @@ class CacheGroup:
                                             ) -> None:
         key = jsonrpc_cache_key(request)
         ttl = ttl or request.upstream.ttl
-        if ttl == TTL.DEFAULT_EXPIRE_IF_IRREVERSIBLE:
+        if ttl == TTL.EXPIRE_IF_REVERSIBLE:
             last_irreversible_block_num = last_irreversible_block_num or \
                 self._memory_cache.gets('last_irreversible_block_num') or \
                 await self.get('last_irreversible_block_num')
 
             ttl = irreversible_ttl(jsonrpc_response=response,
-                                   last_irreversible_block_num=last_irreversible_block_num)
+                                   last_irreversible_block_num=last_irreversible_block_num,
+                                   request=request)
         elif ttl == TTL.NO_CACHE:
             return
         value = self.prepare_response_for_cache(request, response)
@@ -218,7 +219,7 @@ class CacheGroup:
         else:
             new_ttls = []
             for i, ttl in enumerate(ttls):
-                if ttl == TTL.DEFAULT_EXPIRE_IF_IRREVERSIBLE:
+                if ttl == TTL.EXPIRE_IF_REVERSIBLE:
                     ttl = irreversible_ttl(responses[i], last_irreversible_block_num)
                 new_ttls.append(ttl)
             triplets = filter(lambda p: p[0] != TTL.NO_CACHE, zip(ttls, requests, responses))

jussi/cache/ttl.py

@@ -12,7 +12,7 @@ Method Settings
 - For readabilty/writabilty, there are shorthand variables for these 'special' TTL values:
    - `NO_EXPIRE` == 0
    - `NO_CACHE` == -1
-   - `DEFAULT_EXPIRE_IF_IRREVERSIBLE` == -2
+   - `EXPIRE_IF_REVERSIBLE` == -2
 
 """
 
@@ -21,9 +21,10 @@ from enum import Enum
 
 class TTL(Enum):
     DEFAULT_TTL = 3
+    EXTENDED_TTL = 9
     NO_EXPIRE = None
     NO_CACHE = -1
-    DEFAULT_EXPIRE_IF_IRREVERSIBLE = -2
+    EXPIRE_IF_REVERSIBLE = -2
 
     # pylint: disable=no-else-return
     def __eq__(self, other: int) -> bool:

jussi/cache/utils.py

@@ -21,7 +21,8 @@ def jsonrpc_cache_key(single_jsonrpc_request: SingleJrpcRequest) -> str:
 
 
 def irreversible_ttl(jsonrpc_response: dict=None,
-                     last_irreversible_block_num: int=None) -> TTL:
+                     last_irreversible_block_num: int=None,
+                     request: SingleJrpcRequest=None) -> TTL:
     if not jsonrpc_response:
         return TTL.NO_CACHE
     if not isinstance(last_irreversible_block_num, int):
@@ -30,12 +31,21 @@ def irreversible_ttl(jsonrpc_response: dict=None,
         return TTL.NO_CACHE
     try:
         jrpc_block_num = block_num_from_jsonrpc_response(jsonrpc_response)
-        return TTL.DEFAULT_TTL
+        if jrpc_block_num > last_irreversible_block_num:
+            return TTL.EXTENDED_TTL
+        else:
+            return TTL.NO_EXPIRE
     except Exception as e:
+        if request is not None:
+            request_string = request.json()
+        else:
+            request_string = 'None'
         logger.warning(
             'Unable to cache using last irreversible block',
             e=e,
-            lirb=last_irreversible_block_num)
+            lirb=last_irreversible_block_num,
+            request_string=request_string,
+            jsonrpc_response=jsonrpc_response)
     return TTL.NO_CACHE