Package com.amazon.ion.impl

Interface ReaderLookaheadBuffer

  • All Known Implementing Classes:
    IonReaderLookaheadBuffer
    public interface ReaderLookaheadBuffer
    Interface for lookahead buffers that enable incremental reading of streaming data.

    • Method Detail

      • fillInput

        void fillInput()
        throws java.lang.Exception
        If possible, fills the input pipe with enough bytes to enable one more successful call to IonReader.next() on the non-incremental reader attached to the pipe. If not enough bytes were available in the raw input stream to complete the next top-level user value, calling moreDataRequired() after this method returns will return `true`. In this case, this method must be called again before calling `IonReader.next()` to position the reader on this value. Otherwise, `moreDataRequired()` will return `false` and a call to `IonReader.next()` may be made to position the reader on this value. Implementations may throw `IonException` if invalid Ion data is detected. Implementations may define exceptional cases.
        Throws:
        java.lang.Exception - if an IOException is thrown by the underlying InputStream.

      • moreDataRequired

        boolean moreDataRequired()
        Indicates whether more data must become present in the raw input stream before a successful call to IonReader.next() may be made to position the reader on the most-recently-buffered value.
        Returns:
        true if more data is required to complete the next top-level user value; otherwise, false.

      • available

        int available()
        Indicates how many bytes are currently stored in the internal buffer. This can be used to detect whether calls to fillInput() are successfully retrieving data.
        Returns:
        The number of bytes waiting in the input buffer.

      • newIonReader

        IonReader newIonReader​(IonReaderBuilder builder)
        Builds a reader over the input pipe. NOTE: because IonReader construction consumes bytes from the stream (to determine whether the stream is binary or text Ion), fillInput() must have been called (such that moreDataRequired() returns `false`) before calling this method. For the same reason, this method must only be called once per instance of this class.
        Parameters:
        builder - the builder containing the reader's configuration.
        Returns:
        a new IonReader.