Package org.dellroad.stuff.io

Interface StreamRepository

All Known Implementing Classes:
FileStreamRepository
public interface StreamRepository
Interface for atomic storage and retrieval of an opaque byte array, with access being done via the InputStream and OutputStream interfaces.

Conceptually, there is a single underlying byte array. Instances behave as if an atomic readable snapshot is made at the moment getInputStream() is invoked, and the results of that snapshot are then available in the returned InputStream.

Similarly, instances behave as if the underlying byte array is atomically updated at the moment the output stream returned by getOutputStream() is successfully closed. If the close operation fails, or never takes place, the underlying byte array is not updated.

Instances are thread safe, and support multiple concurrent open input and output streams. In particular, two output streams may be closed at the same time by two different threads, and one will always win the race.

  • Method Summary

    Modifier and Type
    Method
    Description
    InputStream
    getInputStream()
    Get an input stream reading the current value of the underlying store.
    OutputStream
    getOutputStream()
    Get an output stream writing to the underlying store.

  • Method Details

    • getInputStream

      InputStream getInputStream() throws IOException
      Get an input stream reading the current value of the underlying store.
      Returns:
      input containing current repository contents
      Throws:
      IOException - if an error occurs

    • getOutputStream

      OutputStream getOutputStream() throws IOException
      Get an output stream writing to the underlying store. The underlying store is not modified until if/when the returned output stream is successfully closed, at which time it is atomically updated with the newly written content.

      If the returned stream throws an IOException at any time, including during close(), or if close() is never invoked, then no update to the underlying storage occurs.

      Returns:
      output for overwriting the current repository contents
      Throws:
      IOException - if an error occurs