Shared Files

✨ Disk-Based Single-Writer, Multiple-Reader In-Process File Sharing ✨

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Functionality for asynchronous single-writer, multiple-reader file operations where multiple concurrent readers need to read from a file that is currently being written by the same process. The intended use case is the parallel processing of byte streams with minimum (process) memory requirements, e.g. in web services moving around large files.

Normally, reading a file while it is written results in the read stream ending prematurely as EOF; the purpose of this crate is to prevent exactly that.

Any file type can be used as a backing as long as it implements the crate's SharedFileType trait, which in turn requires tokio::io::AsyncWrite and tokio::io::AsyncRead.

Features

• async-tempfile: Enables the SharedTemporaryFile type via the async-tempfile crate. Since this is how this crate was initially meant to be used, this feature is enabled by default.

Example

See tests/parallel_write_read.rs for a usage example. The example requires the async-tempfile crate feature. To run it, use e.g.

cargo test --test parallel_write_read --features=async-tempfile