def get_encryption_materials()

in src/aws_encryption_sdk/materials_managers/caching.py [0:0]

• 31 lines of code
• 6 McCabe index (conditional complexity)

    def get_encryption_materials(self, request):
        """Provides encryption materials appropriate for the request.

        :param request: Encryption materials request
        :type request: aws_encryption_sdk.materials_managers.EncryptionMaterialsRequest
        :returns: encryption materials
        :rtype: aws_encryption_sdk.materials_managers.EncryptionMaterials
        """
        if not self._should_cache_encryption_request(request):
            return self.backing_materials_manager.get_encryption_materials(request)

        # Inner request strips any information about the plaintext from the actual request.
        # This is done because the resulting encryption materials may be used to encrypt
        #  multiple plaintexts.
        inner_request = EncryptionMaterialsRequest(
            encryption_context=request.encryption_context,
            frame_length=request.frame_length,
            algorithm=request.algorithm,
            commitment_policy=request.commitment_policy,
        )
        cache_key = build_encryption_materials_cache_key(partition=self.partition_name, request=inner_request)

        # Attempt to retrieve from cache
        try:
            cache_entry = self.cache.get_encryption_materials(
                cache_key=cache_key, plaintext_length=request.plaintext_length
            )
        except CacheKeyError:
            pass
        else:
            if self._cache_entry_has_exceeded_limits(cache_entry):
                self.cache.remove(cache_entry)
            else:
                return cache_entry.value

        # Nothing found in cache: try the material manager
        new_result = self.backing_materials_manager.get_encryption_materials(inner_request)

        if not new_result.algorithm.safe_to_cache() or request.plaintext_length >= self.max_bytes_encrypted:
            return new_result

        # Add results into cache
        self.cache.put_encryption_materials(
            cache_key=cache_key,
            encryption_materials=new_result,
            plaintext_length=request.plaintext_length,
            entry_hints=CryptoMaterialsCacheEntryHints(lifetime=self.max_age),
        )
        return new_result