Patent attributes
Systems and methods are described for providing input data to and reading output data from one or more owner-specified functions. A function can implement a data manipulation, such as filtering out sensitive data before reading or writing the data. Input data can be provided to the function as an entire object, a stream of objects, or on-demand based on data or portions thereof that the function attempts to access. The function can provide output data as a single instance of output data or a stream of output data regardless of the manner in which input data is provided to the function. The input data can be stored in a staging area that is accessible to the function via a local file system. Similarly, the function can store the output data in a staging area that is accessible to the function via a local file system.