Summary of Changes

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This pull request introduces an experimental framework for implementing read resumption strategies for bidirectional (bidi) reads. It establishes an abstract base class for defining how to generate requests, update state from responses, and recover from failures during bidi operations. A concrete implementation for bidi reads is provided, which intelligently manages download state, generates requests for incomplete data segments, and includes robust integrity checks to prevent data corruption. This enhancement aims to improve the reliability and efficiency of large object downloads by enabling seamless resumption of interrupted transfers.

Highlights

• New Abstract Base Class: Introduced _BaseResumptionStrategy to define a common interface for bidi stream resumption, including abstract methods for generating requests, updating state from responses, and recovering from failures.
• Concrete Read Resumption Strategy: Added _ReadResumptionStrategy, a concrete implementation for bidi reads, which manages download state and handles request generation and response processing.
• Download State Management: Implemented _DownloadState to track the progress of individual download ranges, including initial offset, length, bytes written, and completion status.
• Intelligent Request Generation: The generate_requests method now intelligently creates ReadRange requests only for the incomplete portions of a download, enabling 'smarter resumption' of interrupted transfers.
• Response Processing and Integrity Checks: The update_state_from_response method processes incoming data, performs offset verification, writes data to a user buffer, and checks for byte count mismatches upon range completion, raising DataCorruption if issues are found.
• Error Recovery Framework: The recover_state_on_failure method is defined as an async abstract method, intended for future implementation of error handling logic, such as extracting routing tokens for redirects.
• Comprehensive Unit Tests: New unit tests ensure the correct behavior of _DownloadState and _ReadResumptionStrategy across various scenarios, including successful operations, partial downloads, and error conditions like data corruption.