Recreate adapter only per block

CHANGELOG

@@ -1,3 +1,5 @@
+- 0.2.9
+	* Minimize instantiations of adapters in filter execution
 - 0.2.8
 	* Upgrade chainsyncer
 - 0.2.7

chaind/filter.py

@@ -26,43 +26,69 @@ class StateFilter(SyncFilter):
         self.adapter_path = adapter_path
         self.tx_adapter = tx_adapter
         self.throttler = throttler
+        self.last_block_height = 0
+        self.adapter = None
+        self.store_lock = None
 
 
-    def filter(self, conn, block, tx, session=None):
-        cache_tx = None
-        store_lock = StoreLock()
-        queue_adapter = None
+    def __get_adapter(self, block, force_reload=False):
+        if self.store_lock == None:
+            self.store_lock = StoreLock()
+
+        reload = False
+        if block.number != self.last_block_height:
+            reload = True
+        elif self.adapter == None:
+            reload = True
+        elif force_reload:
+            reload = True
+        
+        self.last_block_height = block.number
+
+        if reload:
             while True:
+                logg.info('reloading adapter')
                 try:
-                queue_adapter = ChaindFsAdapter(
+                    self.adapter = ChaindFsAdapter(
                         self.chain_spec,
                         self.adapter_path,
                         self.tx_adapter,
                         None,
                         )
+                    break
                 except BackendError as e:
                     logg.error('adapter instantiation failed: {}, one more try'.format(e))
-                store_lock.again()
+                    self.store_lock.again()
                     continue
 
-            store_lock.reset()
+        return self.adapter
 
+
+    def filter(self, conn, block, tx, session=None):
+        cache_tx = None
+        queue_adapter = self.__get_adapter(block)
+        
+        self.store_lock.reset()
+    
+        while True:
             try:
                 cache_tx = queue_adapter.get(tx.hash)
                 break
             except NotLocalTxError:
                 logg.debug('skipping not local transaction {}'.format(tx.hash))
+                self.__stop_adapter()
                 return False
             except BackendError as e:
                 logg.error('adapter get failed: {}, one more try'.format(e))
-                queue_adapter = None
-                store_lock.again()
+                self.store_lock.again()
+                queue_adapter = self.__get_adapter(block, force_reload=True)
                 continue
 
         if cache_tx == None:
             raise NotLocalTxError(tx.hash)
 
-        store_lock = StoreLock()
+        self.store_lock.reset()
+
         queue_lock = StoreLock(error=QueueLockError)
         while True:
             try:
@@ -76,15 +102,18 @@ class StateFilter(SyncFilter):
                 queue_lock.again()
             except FileNotFoundError as e:
                 logg.debug('queue item {} not found, possible race condition, will retry: {}'.format(tx.hash, e))
-                store_lock.again()
+                self.store_lock.again()
+                queue_adapter = self.__get_adapter(block, force_reload=True)
                 continue
             except NotLocalTxError as e:
                 logg.debug('queue item {} not found, possible race condition, will retry: {}'.format(tx.hash, e))
-                store_lock.again()
+                self.store_lock.again()
+                queue_adapter = self.__get_adapter(block, force_reload=True)
                 continue
             except StateLockedKey as e:
                 logg.debug('queue item {} not found, possible race condition, will retry: {}'.format(tx.hash, e))
-                store_lock.again()
+                self.store_lock.again()
+                queue_adapter = self.__get_adapter(block, force_reload=True)
                 continue
 
         logg.info('filter registered {} for {} in {}'.format(tx.status.name, tx.hash, block))

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = chaind
-version = 0.2.8
+version = 0.2.9
 description = Base package for chain queue service
 author = Louis Holbrook
 author_email = dev@holbrook.no