Package io.camunda.zeebe.journal

Interface Journal

All Superinterfaces:
AutoCloseable
All Known Implementing Classes:
SegmentedJournal
public interface Journal extends AutoCloseable

  • Method Details

    • append

      JournalRecord append(BufferWriter recordDataWriter)
      Appends a new JournalRecord that contains the data to be written by the recordDataWriter. Use this for records that do not have a specific applicationSqNum. Examples for such record is raft record that indicates a leader change.
      Parameters:
      recordDataWriter - a writer that outputs the data of the record
      Returns:
      the journal record that was appended

    • append

      JournalRecord append(long asqn, BufferWriter recordDataWriter)
      Appends a new JournalRecord that contains the data to be written by the recordDataWriter. asqn refers to Application Sequence Number. It is a sequence number provided by the application. The given asqn must be positive and, it must be greater than the asqn of the previous record.
      Parameters:
      asqn - A sequence number provided by the application.
      recordDataWriter - a writer that outputs the data of the record
      Returns:
      the journal record that was appended

    • append

      void append(JournalRecord record)
      Appends a JournalRecord. If the index of the record is not the next expected index, the append will fail.
      Parameters:
      record - the record to be appended
      Throws:
      JournalException.InvalidIndex - if the index of record is not the next expected index
      JournalException.InvalidChecksum - if the checksum in record does not match the checksum of the data

    • deleteAfter

      void deleteAfter(long indexExclusive)
      Delete all records after indexExclusive. After a call to this method, getLastIndex() should return indexExclusive.
      Parameters:
      indexExclusive - the index after which the records will be deleted.

    • deleteUntil

      boolean deleteUntil(long indexExclusive)
      Attempts to delete all records until indexExclusive. The records may be immediately deleted or marked to be deleted later depending on the implementation.
      Parameters:
      indexExclusive - the index until which will be deleted. The record at this index is not deleted.
      Returns:
      true if anything was deleted, false otherwise

    • reset

      void reset(long nextIndex)
      Delete all records in the journal and reset the next index to nextIndex. The following calls to append(long, BufferWriter) will append at index nextIndex.

      After this operation, all readers must be reset explicitly. The readers that are not reset will return false for Iterator.hasNext(), cannot read any record.

      Parameters:
      nextIndex - the next index of the journal.

    • getLastIndex

      long getLastIndex()
      Returns the index of last record in the journal
      Returns:
      the last index

    • getFirstIndex

      long getFirstIndex()
      Returns the index of the first record.
      Returns:
      the first index

    • isEmpty

      boolean isEmpty()
      Check if the journal is empty.
      Returns:
      true if empty, false otherwise.

    • flush

      void flush()
      Depending on the implementation, appends to the journal may not be immediately flushed to the persistent storage. A call to this method guarantees that all records written are safely flushed to the persistent storage.

    • openReader

      JournalReader openReader()
      Opens a new JournalReader
      Returns:
      a journal reader

    • isOpen

      boolean isOpen()
      Check if the journal is open
      Returns:
      true if open, false otherwise