feat: include base processors

Author: gmcrocetti

aws_lambda_powertools/utilities/batch/base.py

@@ -0,0 +1,79 @@
+# -*- coding: utf-8 -*-
+
+"""
+Batch processing utilities
+"""
+
+from abc import ABC, abstractmethod
+from typing import Any, Callable, Iterable, List, MutableSequence, Tuple
+
+
+class BaseProcessor(ABC):
+
+    # init with lambda's context ?
+
+    @abstractmethod
+    def _prepare(self):
+        """
+        Prepare context manager.
+        """
+        raise NotImplementedError()
+
+    @abstractmethod
+    def _clean(self):
+        """
+        Clear context manager.
+        """
+        raise NotImplementedError()
+
+    @abstractmethod
+    def _process_record(self):
+        raise NotImplementedError()
+
+    def process(self) -> List[Tuple]:
+        return [self._process_record(record) for record in self.records]
+
+    def __enter__(self):
+        self._prepare()
+        return self
+
+    def __exit__(self, exception_type, exception_value, traceback):
+        self._clean()
+
+    def __call__(self, records: Iterable[Any], handler: Callable):
+        """
+        Set instance attributes before execution
+
+        Parameters
+        ----------
+
+        records: Iterable[Any]
+            Iterable with objects to be processed.
+        handler: Callable
+            Callable to process "records" entries.
+        """
+        self.records = records
+        self.handler = handler
+        return self
+
+
+class BasePartialProcessor(BaseProcessor):
+
+    success_messages: MutableSequence = None
+    fail_messages: MutableSequence = None
+
+    def success_handler(self, record, result):
+        """
+        Success callback
+        """
+        entry = (result, record)
+        self.success_messages.append(record)
+        return entry
+
+    def failure_handler(self, record, error):
+        """
+        Failure callback
+        """
+        entry = (error, record)
+        self.fail_messages.append(entry)
+        return entry