Package org.rocksdb

Class WriteBatch

  • All Implemented Interfaces:
    java.lang.AutoCloseable, WriteBatchInterface
    public class WriteBatch
extends AbstractWriteBatch
    WriteBatch holds a collection of updates to apply atomically to a DB. The updates are applied in the order in which they are added to the WriteBatch. For example, the value of "key" will be "v3" after the following batch is written: batch.put("key", "v1"); batch.remove("key"); batch.put("key", "v2"); batch.put("key", "v3"); Multiple threads can invoke const methods on a WriteBatch without external synchronization, but if any of the threads may call a non-const method, all threads accessing the same WriteBatch must use external synchronization.

    • Constructor Detail

      • WriteBatch

        public WriteBatch()
        Constructs a WriteBatch instance.

      • WriteBatch

        public WriteBatch​(int reserved_bytes)
        Constructs a WriteBatch instance with a given size.
        Parameters:
        reserved_bytes - reserved size for WriteBatch

      • WriteBatch

        public WriteBatch​(byte[] serialized)
        Constructs a WriteBatch instance from a serialized representation as returned by data().
        Parameters:
        serialized - the serialized representation.

    • Method Detail

      • iterate

        public void iterate​(WriteBatch.Handler handler)
             throws RocksDBException
        Support for iterating over the contents of a batch.
        Parameters:
        handler - A handler that is called back for each update present in the batch
        Throws:
        RocksDBException - If we cannot iterate over the batch

      • data

        public byte[] data()
            throws RocksDBException
        Retrieve the serialized version of this batch.
        Returns:
        the serialized representation of this write batch.
        Throws:
        RocksDBException - if an error occurs whilst retrieving the serialized batch data.

      • getDataSize

        public long getDataSize()
        Retrieve data size of the batch.
        Returns:
        the serialized data size of the batch.

      • hasPut

        public boolean hasPut()
        Returns true if Put will be called during Iterate.
        Returns:
        true if Put will be called during Iterate.

      • hasDelete

        public boolean hasDelete()
        Returns true if Delete will be called during Iterate.
        Returns:
        true if Delete will be called during Iterate.

      • hasSingleDelete

        public boolean hasSingleDelete()
        Returns true if SingleDelete will be called during Iterate.
        Returns:
        true if SingleDelete will be called during Iterate.

      • hasDeleteRange

        public boolean hasDeleteRange()
        Returns true if DeleteRange will be called during Iterate.
        Returns:
        true if DeleteRange will be called during Iterate.

      • hasMerge

        public boolean hasMerge()
        Returns true if Merge will be called during Iterate.
        Returns:
        true if Merge will be called during Iterate.

      • hasBeginPrepare

        public boolean hasBeginPrepare()
        Returns true if MarkBeginPrepare will be called during Iterate.
        Returns:
        true if MarkBeginPrepare will be called during Iterate.

      • hasEndPrepare

        public boolean hasEndPrepare()
        Returns true if MarkEndPrepare will be called during Iterate.
        Returns:
        true if MarkEndPrepare will be called during Iterate.

      • hasCommit

        public boolean hasCommit()
        Returns true if MarkCommit will be called during Iterate.
        Returns:
        true if MarkCommit will be called during Iterate.

      • hasRollback

        public boolean hasRollback()
        Returns true if MarkRollback will be called during Iterate.
        Returns:
        true if MarkRollback will be called during Iterate.

      • markWalTerminationPoint

        public void markWalTerminationPoint()
        Marks this point in the WriteBatch as the last record to be inserted into the WAL, provided the WAL is enabled.