block-model.md

description
An introduction and overview of the VeChainThor blockchain block model.

Block Model

VeChainThor defines a block in Golang as:

// block.go

type Block struct {
	header *Header
	txs    tx.Transactions
}

type Header struct {
	body headerBody
}

type headerBody struct {
	ParentID    thor.Bytes32
	Timestamp   uint64
	GasLimit    uint64
	Beneficiary thor.Address

	GasUsed    uint64
	TotalScore uint64

	TxsRoot      thor.Bytes32
	StateRoot    thor.Bytes32
	ReceiptsRoot thor.Bytes32

	Signature []byte
}

type Transactions []*Transaction

Fields within the headerBody, $$\Gamma$$, are defined as:

• ParentID - the ID of the parent block.
• Timestamp - the block time
• GasLimit - the maximum amount of gas that all transactions inside the block are allowed to consume
• Beneficiary - the address assigned by the block generator to receive reward (in VTHO)
• GasUsed - the actual amount of gas used within the block
• TotalScore - the accumulated witness number of the chain branch headed by the block. See #meta-transaction-features-3for more detail.
• TxsRoot - root hash of the transaction in the payload
• StateRoot - root hash for the global state after applying changes in this block
• ReceiptsRoot - hash of the transaction receipts trie
• Signature - signature of block builder

The block ID (thor.Bytes32) can be computed as:

$$BlkID = h \circ (hash(\Gamma - sig )[4:]$$

where $$h$$ is the block number stored as a uint32 and $$[4:]$$ the operation that discards the first four bytes.