Package com.exonum.binding.core.blockchain

Class Block

  • public abstract class Block
extends Object
    Exonum block header data structure.

    A block is essentially a list of transactions, which is a result of the consensus algorithm (thus authenticated by the supermajority of validators) and is applied atomically to the blockchain state.

    This structure only contains the amount of transactions and the transactions root hash as well as other information, but not the transactions themselves.

    See Also:
    Blockchain

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  Block.Builder  

    • Constructor Summary

      Constructors 
      Constructor Description
      Block()  

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      static Block.Builder builder()
      Creates a new block builder.
      static Block fromMessage​(com.exonum.messages.core.Blockchain.Block blockMessage)
      Creates a block from the block message.
      abstract com.google.common.collect.ImmutableMap<String,​com.google.protobuf.ByteString> getAdditionalHeaders()
      Contains additional block headers of the block.
      abstract com.exonum.binding.common.hash.HashCode getBlockHash()
      Returns the SHA-256 hash of this block.
      abstract com.exonum.binding.common.hash.HashCode getErrorHash()
      Root hash of exceptions occurred in the block.
      abstract long getHeight()
      Returns the height of this block which is a distance between the last block and the "genesis" block.
      abstract int getNumTransactions()
      Number of transactions in this block.
      abstract com.exonum.binding.common.hash.HashCode getPreviousBlockHash()
      Hash link to the previous block in the blockchain.
      abstract int getProposerId()
      Identifier of the leader node which has proposed the block.
      abstract com.exonum.binding.common.hash.HashCode getStateHash()
      Hash of the blockchain state after applying transactions in the block.
      abstract com.exonum.binding.common.hash.HashCode getTxRootHash()
      Root hash of the Merkle tree of transactions in this block.
      int hashCode()  
      boolean isEmpty()
      Returns true if this block is empty: contains no transactions.
      static Block parseFrom​(byte[] serializedBlock)
      Creates a block from the serialized block message.
      static com.google.gson.TypeAdapter<Block> typeAdapter​(com.google.gson.Gson gson)
      Provides a Gson type adapter for this class.

    • Constructor Detail

      • Block

        public Block()

    • Method Detail

      • getBlockHash

        public abstract com.exonum.binding.common.hash.HashCode getBlockHash()
        Returns the SHA-256 hash of this block.

      • getProposerId

        public abstract int getProposerId()
        Identifier of the leader node which has proposed the block.

      • getHeight

        public abstract long getHeight()
        Returns the height of this block which is a distance between the last block and the "genesis" block. Genesis block has 0 height. Therefore, the blockchain height is equal to the number of blocks plus one.

        The height also identifies each block in the blockchain.

      • isEmpty

        public final boolean isEmpty()
        Returns true if this block is empty: contains no transactions.

      • getNumTransactions

        public abstract int getNumTransactions()
        Number of transactions in this block.

      • getPreviousBlockHash

        public abstract com.exonum.binding.common.hash.HashCode getPreviousBlockHash()
        Hash link to the previous block in the blockchain.

      • getTxRootHash

        public abstract com.exonum.binding.common.hash.HashCode getTxRootHash()
        Root hash of the Merkle tree of transactions in this block. These transactions can be accessed with Blockchain.getBlockTransactions(Block).

      • getStateHash

        public abstract com.exonum.binding.common.hash.HashCode getStateHash()
        Hash of the blockchain state after applying transactions in the block.
        See Also:
        Schema

      • getErrorHash

        public abstract com.exonum.binding.common.hash.HashCode getErrorHash()
        Root hash of exceptions occurred in the block.
        See Also:
        Blockchain.getCallRecords(long)

      • getAdditionalHeaders

        public abstract com.google.common.collect.ImmutableMap<String,​com.google.protobuf.ByteString> getAdditionalHeaders()
        Contains additional block headers of the block. The key is a block header; and the value is a header bytes value.

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object

      • typeAdapter

        public static com.google.gson.TypeAdapter<Block> typeAdapter​(com.google.gson.Gson gson)
        Provides a Gson type adapter for this class.
        See Also:
        CoreTypeAdapterFactory

      • fromMessage

        public static Block fromMessage​(com.exonum.messages.core.Blockchain.Block blockMessage)
        Creates a block from the block message.
        Parameters:
        blockMessage - a block

      • parseFrom

        public static Block parseFrom​(byte[] serializedBlock)
        Creates a block from the serialized block message.
        Parameters:
        serializedBlock - a serialized block message
        Throws:
        IllegalArgumentException - if the block bytes are not a serialized Blockchain.Block

      • builder

        public static Block.Builder builder()
        Creates a new block builder.