Package org.agrona.concurrent.broadcast

Class RecordDescriptor

java.lang.Object
org.agrona.concurrent.broadcast.RecordDescriptor
public final class RecordDescriptor extends Object
Description of the structure for a record in the broadcast buffer. All messages are stored in records with the following format. 
   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |R|                        Length                               |
  +-+-------------------------------------------------------------+
  |                           Type                                |
  +---------------------------------------------------------------+
  |                      Encoded Message                         ...
 ...                                                              |
  +---------------------------------------------------------------+

(R) bits are reserved.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    HEADER_LENGTH
    Length of the record header in bytes.
    static final int
    LENGTH_OFFSET
    Offset within the record at which the record length field begins.
    static final int
    PADDING_MSG_TYPE_ID
    Message type is padding to prevent fragmentation in the buffer.
    static final int
    RECORD_ALIGNMENT
    Alignment as a multiple of bytes for each record.
    static final int
    TYPE_OFFSET
    Offset within the record at which the message type field begins.

  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    calculateMaxMessageLength(int capacity)
    Calculate the maximum supported message length for a buffer of given capacity.
    static void
    checkTypeId(int msgTypeId)
    Check that and message id is in the valid range.
    static int
    lengthOffset(int recordOffset)
    The buffer offset at which the message length field begins.
    static int
    msgOffset(int recordOffset)
    The buffer offset at which the encoded message begins.
    static int
    typeOffset(int recordOffset)
    The buffer offset at which the message type field begins.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • PADDING_MSG_TYPE_ID

      public static final int PADDING_MSG_TYPE_ID
      Message type is padding to prevent fragmentation in the buffer.
      See Also:

    • LENGTH_OFFSET

      public static final int LENGTH_OFFSET
      Offset within the record at which the record length field begins.
      See Also:

    • TYPE_OFFSET

      public static final int TYPE_OFFSET
      Offset within the record at which the message type field begins.
      See Also:

    • HEADER_LENGTH

      public static final int HEADER_LENGTH
      Length of the record header in bytes.
      See Also:

    • RECORD_ALIGNMENT

      public static final int RECORD_ALIGNMENT
      Alignment as a multiple of bytes for each record.
      See Also:

  • Method Details

    • calculateMaxMessageLength

      public static int calculateMaxMessageLength(int capacity)
      Calculate the maximum supported message length for a buffer of given capacity.
      Parameters:
      capacity - of the log buffer.
      Returns:
      the maximum supported size for a message.

    • lengthOffset

      public static int lengthOffset(int recordOffset)
      The buffer offset at which the message length field begins.
      Parameters:
      recordOffset - at which the frame begins.
      Returns:
      the offset at which the message length field begins.

    • typeOffset

      public static int typeOffset(int recordOffset)
      The buffer offset at which the message type field begins.
      Parameters:
      recordOffset - at which the frame begins.
      Returns:
      the offset at which the message type field begins.

    • msgOffset

      public static int msgOffset(int recordOffset)
      The buffer offset at which the encoded message begins.
      Parameters:
      recordOffset - at which the frame begins.
      Returns:
      the offset at which the encoded message begins.

    • checkTypeId

      public static void checkTypeId(int msgTypeId)
      Check that and message id is in the valid range.
      Parameters:
      msgTypeId - to be checked.
      Throws:
      IllegalArgumentException - if the id is not in the valid range.