add and use optimistic number to hash key/dbop to avoid conflict with number to ahash and rebuild canonical while backfilling

Author: g11tech

packages/blockchain/src/blockchain.ts

@@ -362,13 +362,13 @@ export class Blockchain implements BlockchainInterface {
         if (isGenesis) {
           if (equalsBytes(this.genesisBlock.hash(), block.hash())) {
             // Try to re-put the existing genesis block, accept this
+            optimistic = false
             return
           }
           throw new Error(
             'Cannot put a different genesis block than current blockchain genesis: create a new Blockchain',
           )
           // genesis block is not optimistic
-          optimistic = false
         }
 
         if (block.common.chainId() !== this.common.chainId()) {
@@ -410,10 +410,10 @@ export class Blockchain implements BlockchainInterface {
         if (optimistic) {
           dbOps = dbOps.concat(DBSetBlockOrHeader(item))
           dbOps.push(DBSetHashToNumber(blockHash, blockNumber))
+          dbOps.push(DBOp.set(DBTarget.OptimisticNumberToHash, blockHash, { blockNumber }))
           await this.dbManager.batch(dbOps)
         } else {
           const currentTd = { header: BIGINT_0, block: BIGINT_0 }
-
           // set total difficulty in the current context scope
           if (this._headHeaderHash) {
             currentTd.header = await this.getTotalDifficulty(this._headHeaderHash)

packages/blockchain/src/db/constants.ts

@@ -28,6 +28,7 @@ const TD_SUFFIX = utf8ToBytes('t')
  * headerPrefix + number + numSuffix -> hash
  */
 const NUM_SUFFIX = utf8ToBytes('n')
+const OPTIMISTIC_NUM_SUFFIX = utf8ToBytes('o')
 
 /**
  * blockHashPrefix + hash -> number
@@ -55,6 +56,9 @@ const bodyKey = (n: bigint, hash: Uint8Array) => concatBytes(BODY_PREFIX, bytesB
 
 const numberToHashKey = (n: bigint) => concatBytes(HEADER_PREFIX, bytesBE8(n), NUM_SUFFIX)
 
+const optimisticNumberToHashKey = (n: bigint) =>
+  concatBytes(HEADER_PREFIX, bytesBE8(n), OPTIMISTIC_NUM_SUFFIX)
+
 const hashToNumberKey = (hash: Uint8Array) => concatBytes(BLOCK_HASH_PREFIX, hash)
 
 /**
@@ -69,5 +73,6 @@ export {
   headerKey,
   HEADS_KEY,
   numberToHashKey,
+  optimisticNumberToHashKey,
   tdKey,
 }

packages/blockchain/src/db/manager.ts

@@ -84,7 +84,10 @@ export class DBManager {
    * Fetches a block (header and body) given a block id,
    * which can be either its hash or its number.
    */
-  async getBlock(blockId: Uint8Array | bigint | number): Promise<Block | undefined> {
+  async getBlock(
+    blockId: Uint8Array | bigint | number,
+    optimistic: boolean = false,
+  ): Promise<Block | undefined> {
     if (typeof blockId === 'number' && Number.isInteger(blockId)) {
       blockId = BigInt(blockId)
     }
@@ -97,7 +100,13 @@ export class DBManager {
       number = await this.hashToNumber(blockId)
     } else if (typeof blockId === 'bigint') {
       number = blockId
-      hash = await this.numberToHash(blockId)
+      if (optimistic) {
+        hash = await this.optimisticNumberToHash(blockId)
+      }
+      // hash will be undefined if it no optimistic lookup was done or if that was not successful
+      if (hash === undefined) {
+        hash = await this.numberToHash(blockId)
+      }
     } else {
       throw new Error('Unknown blockId type')
     }
@@ -190,6 +199,11 @@ export class DBManager {
     return value
   }
 
+  async optimisticNumberToHash(blockNumber: bigint): Promise<Uint8Array | undefined> {
+    const value = await this.get(DBTarget.OptimisticNumberToHash, { blockNumber })
+    return value
+  }
+
   /**
    * Fetches a key from the db. If `opts.cache` is specified
    * it first tries to load from cache, and on cache miss will

packages/blockchain/src/db/operation.ts

@@ -8,6 +8,7 @@ import {
   hashToNumberKey,
   headerKey,
   numberToHashKey,
+  optimisticNumberToHashKey,
   tdKey,
 } from './constants.js'
 
@@ -25,6 +26,7 @@ export enum DBTarget {
   CliqueSignerStates,
   CliqueVotes,
   CliqueBlockSigners,
+  OptimisticNumberToHash,
 }
 
 /**
@@ -88,6 +90,11 @@ export class DBOp {
         this.cacheString = 'numberToHash'
         break
       }
+      case DBTarget.OptimisticNumberToHash: {
+        this.baseDBOp.key = optimisticNumberToHashKey(key!.blockNumber!)
+        this.cacheString = 'optimisticNumberToHash'
+        break
+      }
       case DBTarget.TotalDifficulty: {
         this.baseDBOp.key = tdKey(key!.blockNumber!, key!.blockHash!)
         this.cacheString = 'td'