openthenread

OpenThenRead, written here as openthenread, is a term used in computing to describe a pattern and, in some contexts, a project name that centers on the sequential lifecycle of resource handling: open then read. The concept emphasizes separating the operation that opens a resource from the subsequent reading of its content, which can aid in clearer error handling and resource management, particularly in streaming and asynchronous I/O scenarios.

The idea is used across programming languages and libraries, though it is not always formalized as a standard. In practice, implementations provide an API that first opens a resource and returns a handle or stream, followed by one or more read operations. This approach can be contrasted with patterns where reading begins immediately after opening, or where lazy evaluation governs when data is fetched. OpenThenRead interfaces typically include explicit close semantics to ensure proper resource cleanup.

Design goals commonly associated with openthenread include safe resource lifecycle management (ensuring resources are released even in error conditions), support for non-blocking or asynchronous I/O, and backpressure-aware reading to match downstream consumption. Typical technical patterns involve promises, futures, or async/await for asynchronous flows, along with robust error propagation along the read path and a dedicated close or dispose operation.

Use cases for openthenread-like patterns include processing large files, consuming network streams, and building data-processing pipelines where controlling when a resource opens and when data is consumed is advantageous. Potential drawbacks include added boilerplate and the need for careful error handling to prevent resource leaks.

See also: streaming I/O, resource management, backpressure, asynchronous programming.