SMT

README

SMT

Stateful Merkle Trees provide the support for building and maintaining information in multiple ordered and distributed blockchains.

The SMT implementation is a layered one:

• SMT
  • Construction: collect hashes and add to Merkle Tree
  • Build: Time Stamping, block building
  • Persistence: Record entries, Merkle States to the database
  • Validation: Validate entries to be added to the Merkle Tree

SMT

• func NewSMT() SMT

  create a new SMT object to manage a Merkle tree

Construction

• func (m \*SMT) AddHash([]byte) add a hash to the merkle tree
• func (m \*SMT) GetState() (index int64, state [][]byte) Returns State of Merkle tree. The index of the last hash added, the Merkle Tree state, and the ordered list of entry hashes as they were added to the Merkle Tree
• func (m \*SMT) SetState(index int64, state [][]byte) Sets the state of SMT to allow building on an existing Merkle Tree
• func (m \*SMT) GetDagRoot() []byte Returns the Dag Root for the current state of the Merkle Tree

Build

• func (m \*SMT) EndBlock() (dagRoot []byte, index int64, state [][]byte)

  ends the current block by adding the timestamp and header to the Merkle tree to SMT.
  The dagRoot sans the transaction

Validation

type Hash [32]byte

type Fee struct {
    TimeStamp      int64        // 8
    DDII           Hash         // 32
    ChainID        [33]byte     // 33
    Credits        int8         // 1
    SignatureIdx   int8         // 1
    Signature      []byte       // 64 minimum 
                                // 1 end byte ( 140 bytes for FEE)
    Transaction    []byte       // Transaction
}

type Validation interface {
    Type() string
    SetState(state *StateEntry)
    GetState() state *StateEntry
	ValidTx(entry *Entry) bool
	ValidTxList(entries []*Hash) bool
}

• func (m \*SMT) SetValidator(validator *Validation) Set the validator function on the SMT