Package org.apache.kafka.streams.state

Interface HeadersBytesStore

public interface HeadersBytesStore
Marker interface to indicate that a bytes store understands the value-with-headers format and can convert legacy timestamped value entries (ValueAndTimestamp format) to the new format.

This is analogous to TimestampedBytesStore but for header-aware stores.

Per KIP-1271, the value format is: [headersSize(varint)][headersBytes][payloadBytes] where payloadBytes is the existing serialized value (e.g., [timestamp(8)][value] for timestamped stores).

  • Method Summary

    Static Methods
    Modifier and Type
    Method
    Description
    static byte[]
    convertFromPlainToHeaderFormat(byte[] value)
     
    static byte[]
    convertToHeaderFormat(byte[] value)
    Converts a legacy value (without headers) to the header-embedded format by adding empty headers prefix.

  • Method Details

    • convertToHeaderFormat

      static byte[] convertToHeaderFormat(byte[] value)
      Converts a legacy value (without headers) to the header-embedded format by adding empty headers prefix.

      This is a general-purpose method that prepends an empty headers prefix to any byte array. The header-embedded format is: [headersSize(varint)][headersBytes][payload] where empty headers are represented as headersSize=0 (encoded as [0x00]).

      Usage examples:

      • Timestamped stores: [timestamp(8)][value] → [0x00][timestamp(8)][value]
      • Window stores: [value] → [0x00][value]
      Parameters:
      value - the legacy value bytes (may include timestamp for timestamped stores, or plain value for window stores)
      Returns:
      the value in header-embedded format with empty headers prefix [0x00][value]

    • convertFromPlainToHeaderFormat

      static byte[] convertFromPlainToHeaderFormat(byte[] value)