@ethereumjs/blockchain/src/db/helpers.ts

A module to store and interact with blocks

import { Block } from '@ethereumjs/block'
import { RLP } from '@ethereumjs/rlp'
import { BIGINT_0 } from '@ethereumjs/util'

import { bytesBE8 } from './constants.ts'
import { DBOp, DBTarget } from './operation.ts'

import type { BlockHeader } from '@ethereumjs/block'

/*
 * This extra helper file serves as an interface between the blockchain API functionality
 * and the DB operations from `db/operation.ts` and also handles the right encoding of the keys
 */

function DBSetTD(TD: bigint, blockNumber: bigint, blockHash: Uint8Array): DBOp {
  return DBOp.set(DBTarget.TotalDifficulty, RLP.encode(TD), {
    blockNumber,
    blockHash,
  })
}

/*
 * This method accepts either a BlockHeader or a Block and returns a list of DatabaseOperation instances
 *
 * - A "Set Header Operation" is always added
 * - A "Set Body Operation" is only added if the body is not empty (it has transactions/uncles) or if the block is the genesis block
 * (if there is a header but no block saved the DB will implicitly assume the block to be empty)
 */
function DBSetBlockOrHeader(blockBody: Block | BlockHeader): DBOp[] {
  const header: BlockHeader = blockBody instanceof Block ? blockBody.header : blockBody
  const dbOps = []

  const blockNumber = header.number
  const blockHash = header.hash()

  const headerValue = header.serialize()
  dbOps.push(
    DBOp.set(DBTarget.Header, headerValue, {
      blockNumber,
      blockHash,
    }),
  )

  const isGenesis = header.number === BIGINT_0

  if (isGenesis || blockBody instanceof Block) {
    const bodyValue = RLP.encode(blockBody.raw().slice(1))
    dbOps.push(
      DBOp.set(DBTarget.Body, bodyValue, {
        blockNumber,
        blockHash,
      }),
    )
  }

  return dbOps
}

function DBSetHashToNumber(blockHash: Uint8Array, blockNumber: bigint): DBOp {
  const blockNumber8Byte = bytesBE8(blockNumber)
  return DBOp.set(DBTarget.HashToNumber, blockNumber8Byte, {
    blockHash,
  })
}

function DBSaveLookups(blockHash: Uint8Array, blockNumber: bigint, skipNumIndex?: boolean): DBOp[] {
  const ops = []
  if (skipNumIndex !== true) {
    ops.push(DBOp.set(DBTarget.NumberToHash, blockHash, { blockNumber }))
  }

  const blockNumber8Bytes = bytesBE8(blockNumber)
  ops.push(
    DBOp.set(DBTarget.HashToNumber, blockNumber8Bytes, {
      blockHash,
    }),
  )
  return ops
}

export { DBOp, DBSaveLookups, DBSetBlockOrHeader, DBSetHashToNumber, DBSetTD }