Package org.bitcoinj.core

Class StoredBlock

java.lang.Object
org.bitcoinj.core.StoredBlock
public class StoredBlock extends Object
Wraps a Block object with extra data that can be derived from the block chain but is slow or inconvenient to calculate. By storing it alongside the block header we reduce the amount of work required significantly. Recalculation is slow because the fields are cumulative - to find the chainWork you have to iterate over every block in the chain back to the genesis block, which involves lots of seeking/loading etc. So we just keep a running total: it's a disk space vs cpu/io tradeoff.

StoredBlocks are put inside a BlockStore which saves them to memory or disk.

  • Field Details

  • Constructor Details

    • StoredBlock

      public StoredBlock(Block header, BigInteger chainWork, int height)
      Create a StoredBlock from a (header-only) Block, chain work value, and block height
      Parameters:
      header - A Block object with only a header (no transactions should be included)
      chainWork - Calculated chainWork for this block
      height - block height for this block

  • Method Details

    • getHeader

      public Block getHeader()
      The block header this object wraps. The referenced block object must not have any transactions in it.

    • getChainWork

      public BigInteger getChainWork()
      The total sum of work done in this block, and all the blocks below it in the chain. Work is a measure of how many tries are needed to solve a block. If the target is set to cover 10% of the total hash value space, then the work represented by a block is 10.

    • getHeight

      public int getHeight()
      Position in the chain for this block. The genesis block has a height of zero.

    • moreWorkThan

      public boolean moreWorkThan(StoredBlock other)
      Returns true if this objects chainWork is higher than the others.

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • build

      public StoredBlock build(Block block) throws VerificationException
      Creates a new StoredBlock, calculating the additional fields by adding to the values in this block.
      Throws:
      VerificationException

    • getPrev

      public StoredBlock getPrev(BlockStore store) throws BlockStoreException
      Given a block store, looks up the previous block in this chain. Convenience method for doing store.get(this.getHeader().getPrevBlockHash()).
      Returns:
      the previous block in the chain or null if it was not found in the store.
      Throws:
      BlockStoreException

    • serializeCompact

      public void serializeCompact(ByteBuffer buffer)
      Serializes the stored block to a custom packed format. Used internally. As of June 22, 2024, it takes 12 unsigned bytes to store the chain work value, so developers should use serializeCompactV2(ByteBuffer).
      Parameters:
      buffer - buffer to write to

    • serializeCompactV2

      public void serializeCompactV2(ByteBuffer buffer)
      Serializes the stored block to a custom packed format. Used internally.
      Parameters:
      buffer - buffer to write to

    • deserializeCompact

      public static StoredBlock deserializeCompact(ByteBuffer buffer) throws ProtocolException
      Deserializes the stored block from a custom packed format. Used internally. As of June 22, 2024, it takes 12 unsigned bytes to store the chain work value, so developers should use deserializeCompactV2(ByteBuffer).
      Parameters:
      buffer - data to deserialize
      Returns:
      deserialized stored block
      Throws:
      ProtocolException

    • deserializeCompactV2

      public static StoredBlock deserializeCompactV2(ByteBuffer buffer) throws ProtocolException
      Deserializes the stored block from a custom packed format. Used internally.
      Parameters:
      buffer - data to deserialize
      Returns:
      deserialized stored block
      Throws:
      ProtocolException

    • deserializeCompact

      @Deprecated public static StoredBlock deserializeCompact(MessageSerializer serializer, ByteBuffer buffer) throws ProtocolException
      Deprecated.
      use deserializeCompact(ByteBuffer)
      Throws:
      ProtocolException

    • toString

      public String toString()
      Overrides:
      toString in class Object