Interface RecordParser

All Superinterfaces:
Handler<Buffer>, ReadStream<Buffer>, StreamBase
public interface RecordParser extends Handler<Buffer>, ReadStream<Buffer>
A helper class which allows you to easily parse protocols which are delimited by a sequence of bytes, or fixed size records.

Instances of this class take as input Buffer instances containing raw bytes, and output records.

For example, if I had a simple ASCII text protocol delimited by '\n' and the input was the following: 

buffer1:HELLO\nHOW ARE Y
buffer2:OU?\nI AM
buffer3: DOING OK
buffer4:\n
Then the output would be:

buffer1:HELLO
buffer2:HOW ARE YOU?
buffer3:I AM DOING OK
Instances of this class can be changed between delimited mode and fixed size record mode on the fly as individual records are read, this allows you to parse protocols where, for example, the first 5 records might all be fixed size (of potentially different sizes), followed by some delimited records, followed by more fixed size records.

Instances of this class can't currently be used for protocols where the text is encoded with something other than a 1-1 byte-char mapping.

Please see the documentation for more information.

Author:
Tim Fox, Lars Timm

  • Method Details

    • setOutput

      void setOutput(Handler<Buffer> output)

    • newDelimited

      static RecordParser newDelimited(String delim, Handler<Buffer> output)
      Like newDelimited(String) but set the output that will receive whole records which have been parsed.
      Parameters:
      delim - the initial delimiter string
      output - handler that will receive the output

    • newDelimited

      static RecordParser newDelimited(String delim, ReadStream<Buffer> stream)
      Like newDelimited(String) but wraps the stream. The stream handlers will be set/unset when the handler(Handler) is set.

      The pause()/resume() operations are propagated to the stream.

      Parameters:
      delim - the initial delimiter string
      stream - the wrapped stream

    • newDelimited

      static RecordParser newDelimited(String delim)
      Create a new RecordParser instance, initially in delimited mode, and where the delimiter can be represented by the String delim endcoded in latin-1 . Don't use this if your String contains other than latin-1 characters.

      output Will receive whole records which have been parsed.

      Parameters:
      delim - the initial delimiter string

    • newDelimited

      static RecordParser newDelimited(Buffer delim)
      Create a new RecordParser instance, initially in delimited mode, and where the delimiter can be represented by the Buffer delim.

      Parameters:
      delim - the initial delimiter buffer

    • newDelimited

      static RecordParser newDelimited(Buffer delim, Handler<Buffer> output)
      Like newDelimited(Buffer) but set the output that will receive whole records which have been parsed.
      Parameters:
      delim - the initial delimiter buffer
      output - handler that will receive the output

    • newDelimited

      static RecordParser newDelimited(Buffer delim, ReadStream<Buffer> stream)
      Like newDelimited(Buffer) but wraps the stream. The stream handlers will be set/unset when the handler(Handler) is set.

      The pause()/resume() operations are propagated to the stream.

      Parameters:
      delim - the initial delimiter buffer
      stream - the wrapped stream

    • newFixed

      static RecordParser newFixed(int size)
      Create a new RecordParser instance, initially in fixed size mode, and where the record size is specified by the size parameter.

      output Will receive whole records which have been parsed.

      Parameters:
      size - the initial record size

    • newFixed

      static RecordParser newFixed(int size, Handler<Buffer> output)
      Like newFixed(int) but set the output that will receive whole records which have been parsed.
      Parameters:
      size - the initial record size
      output - handler that will receive the output

    • newFixed

      static RecordParser newFixed(int size, ReadStream<Buffer> stream)
      Like newFixed(int) but wraps the stream. The stream handlers will be set/unset when the handler(Handler) is set.

      The pause()/resume() operations are propagated to the stream.

      Parameters:
      size - the initial record size
      stream - the wrapped stream

    • delimitedMode

      void delimitedMode(String delim)
      Flip the parser into delimited mode, and where the delimiter can be represented by the String delim encoded in latin-1 . Don't use this if your String contains other than latin-1 characters.

      This method can be called multiple times with different values of delim while data is being parsed.

      Parameters:
      delim - the new delimeter

    • delimitedMode

      void delimitedMode(Buffer delim)
      Flip the parser into delimited mode, and where the delimiter can be represented by the delimiter delim.

      This method can be called multiple times with different values of delim while data is being parsed.

      Parameters:
      delim - the new delimiter

    • fixedSizeMode

      void fixedSizeMode(int size)
      Flip the parser into fixed size mode, where the record size is specified by size in bytes.

      This method can be called multiple times with different values of size while data is being parsed.

      Parameters:
      size - the new record size

    • maxRecordSize

      RecordParser maxRecordSize(int size)
      Set the maximum allowed size for a record when using the delimited mode. The delimiter itself does not count for the record size.

      If a record is longer than specified, an IllegalStateException will be thrown.

      Parameters:
      size - the maximum record size
      Returns:
      a reference to this, so the API can be used fluently

    • handle

      void handle(Buffer buffer)
      This method is called to provide the parser with data.
      Specified by:
      handle in interface Handler<Buffer>
      Parameters:
      buffer - a chunk of data

    • exceptionHandler

      RecordParser exceptionHandler(Handler<Throwable> handler)
      Description copied from interface: ReadStream
      Set an exception handler on the read stream.
      Specified by:
      exceptionHandler in interface ReadStream<Buffer>
      Specified by:
      exceptionHandler in interface StreamBase
      Parameters:
      handler - the exception handler
      Returns:
      a reference to this, so the API can be used fluently

    • handler

      RecordParser handler(Handler<Buffer> handler)
      Description copied from interface: ReadStream
      Set a data handler. As data is read, the handler will be called with the data.
      Specified by:
      handler in interface ReadStream<Buffer>
      Returns:
      a reference to this, so the API can be used fluently

    • pause

      RecordParser pause()
      Description copied from interface: ReadStream
      Pause the ReadStream, it sets the buffer in fetch mode and clears the actual demand.

      While it's paused, no data will be sent to the data handler.

      Specified by:
      pause in interface ReadStream<Buffer>
      Returns:
      a reference to this, so the API can be used fluently

    • fetch

      RecordParser fetch(long amount)
      Description copied from interface: ReadStream
      Fetch the specified amount of elements. If the ReadStream has been paused, reading will recommence with the specified amount of items, otherwise the specified amount will be added to the current stream demand.
      Specified by:
      fetch in interface ReadStream<Buffer>
      Returns:
      a reference to this, so the API can be used fluently

    • resume

      RecordParser resume()
      Description copied from interface: ReadStream
      Resume reading, and sets the buffer in flowing mode.

      If the ReadStream has been paused, reading will recommence on it.

      Specified by:
      resume in interface ReadStream<Buffer>
      Returns:
      a reference to this, so the API can be used fluently

    • endHandler

      RecordParser endHandler(Handler<Void> endHandler)
      Description copied from interface: ReadStream
      Set an end handler. Once the stream has ended, and there is no more data to be read, this handler will be called.
      Specified by:
      endHandler in interface ReadStream<Buffer>
      Returns:
      a reference to this, so the API can be used fluently