trie -> new CP mechanism: removed all scratchDB related logic from CheckpointTrie, basic follow-up VM test fixes

Author: holgerd77

packages/trie/package.json

@@ -21,7 +21,7 @@
     "tsc": "ethereumjs-config-tsc",
     "test": "npm run test:node && npm run test:browser",
     "test:browser": "npm run build && karma start karma.conf.js",
-    "test:node": "npm run build && tape -r ts-node/register test/*.ts"
+    "test:node": "tape -r ts-node/register test/*.ts"
   },
   "author": {
     "name": "mjbecze",

packages/trie/src/checkpointTrie.ts

@@ -1,23 +1,13 @@
 import { Trie as BaseTrie } from './baseTrie'
-import { ScratchReadStream } from './scratchReadStream'
-import { ScratchDB } from './scratch'
-import { DB } from './db'
-const WriteStream = require('level-ws')
 
 /**
  * Adds checkpointing to the {@link BaseTrie}
  */
 export class CheckpointTrie extends BaseTrie {
-  _mainDB: DB
-  _scratch: ScratchDB | null
   _checkpoints: Buffer[]
 
   constructor(...args: any) {
     super(...args)
-    // Reference to main DB instance
-    this._mainDB = this.db
-    // DB instance used for checkpoints
-    this._scratch = null
     // Roots of trie at the moment of checkpoint
     this._checkpoints = []
   }
@@ -31,8 +21,7 @@ export class CheckpointTrie extends BaseTrie {
 
   /**
    * Creates a checkpoint that can later be reverted to or committed.
-   * After this is called, no changes to the trie will be permanently saved until `commit` is called.
-   * To override the checkpointing mechanism use `_maindb.put` to write directly write to db.
+   * After this is called, all changes can be reverted until `commit` is called.
    */
   checkpoint() {
     const wasCheckpoint = this.isCheckpoint
@@ -88,12 +77,10 @@ export class CheckpointTrie extends BaseTrie {
    * @param includeCheckpoints - If true and during a checkpoint, the copy will contain the checkpointing metadata and will use the same scratch as underlying db.
    */
   copy(includeCheckpoints = true): CheckpointTrie {
-    const db = this._mainDB.copy()
+    const db = this.db.copy()
     const trie = new CheckpointTrie(db._leveldb, this.root)
     if (includeCheckpoints && this.isCheckpoint) {
       trie._checkpoints = this._checkpoints.slice()
-      trie._scratch = this._scratch!.copy()
-      trie.db = trie._scratch
     }
     return trie
   }
@@ -102,43 +89,19 @@ export class CheckpointTrie extends BaseTrie {
    * Enter into checkpoint mode.
    * @private
    */
-  _enterCpMode() {
-    this._scratch = new ScratchDB(this._mainDB)
-    this.db = this._scratch
-  }
+  _enterCpMode() {}
 
   /**
    * Exit from checkpoint mode.
    * @private
    */
   async _exitCpMode(commitState: boolean): Promise<void> {
     return new Promise((resolve) => {
-      const scratch = this._scratch as ScratchDB
-      this._scratch = null
-      this.db = this._mainDB
-
-      if (commitState) {
-        this._createScratchReadStream(scratch)
-          .pipe(WriteStream(this.db._leveldb))
-          .on('close', resolve)
+      /*if (commitState) {
       } else {
-        process.nextTick(resolve)
-      }
+      }*/
+      commitState = !!commitState // Temporary dummy line for linting
+      resolve()
     })
   }
-
-  /**
-   * Returns a `ScratchReadStream` based on the state updates
-   * since checkpoint.
-   * @private
-   */
-  _createScratchReadStream(scratchDb?: ScratchDB) {
-    const scratch = scratchDb || this._scratch
-    if (!scratch) {
-      throw new Error('No scratch found to use')
-    }
-    const trie = new BaseTrie(scratch._leveldb, this.root)
-    trie.db = scratch
-    return new ScratchReadStream(trie)
-  }
 }

packages/trie/test/checkpoint.spec.ts

@@ -17,7 +17,7 @@ tape('testing checkpoints', function (tester) {
     t.end()
   })
 
-  it('should copy trie and get value before checkpoint', async function (t) {
+  it('should copy trie and get value added to original trie', async function (t) {
     trieCopy = trie.copy()
     t.equal(trieCopy.root.toString('hex'), preRoot)
     const res = await trieCopy.get(Buffer.from('do'))

packages/trie/test/stream.spec.ts

@@ -156,21 +156,21 @@ tape('db stream test', function (tester) {
     },
   ] as BatchDBOp[]
 
-  const expectedNodes = {
+  /*const expectedNodes = {
     '3c38d9aa6ad288c8e27da701e17fe99a5b67c8b12fd0469651c80494d36bc4c1': true,
     d5f61e1ff2b918d1c2a2c4b1732a3c68bd7e3fd64f35019f2f084896d4546298: true,
     e64329dadee2fb8a113b4c88cfe973aeaa9b523d4dc8510b84ca23f9d5bfbd90: true,
     c916d458bfb5f27603c5bd93b00f022266712514a59cde749f19220daffc743f: true,
     '2386bfb0de9cf93902a110f5ab07b917ffc0b9ea599cb7f4f8bb6fd1123c866c': true,
-  } as any
+  } as any*/
 
   it('should populate trie', async function (t) {
     trie.checkpoint()
     await trie.batch(ops)
     t.end()
   })
 
-  it('should only fetch nodes in the current trie', function (t) {
+  /*it('should only fetch nodes in the current trie', function (t) {
     const stream = trie._createScratchReadStream()
     stream.on('data', (d: any) => {
       const key = d.key.toString('hex')
@@ -182,5 +182,5 @@ tape('db stream test', function (tester) {
       t.equal(keys.length, 0)
       t.end()
     })
-  })
+  })*/
 })

packages/vm/lib/state/stateManager.ts

@@ -129,7 +129,7 @@ export default class DefaultStateManager implements StateManager {
       return
     }
 
-    await this._trie._mainDB.put(codeHash, value)
+    await this._trie.db.put(codeHash, value)
 
     const account = await this.getAccount(address)
     account.codeHash = codeHash
@@ -147,7 +147,7 @@ export default class DefaultStateManager implements StateManager {
     if (!account.isContract()) {
       return Buffer.alloc(0)
     }
-    const code = await this._trie._mainDB.get(account.codeHash)
+    const code = await this._trie.db.get(account.codeHash)
     return code || Buffer.alloc(0)
   }
 

packages/vm/tests/util.ts

@@ -326,7 +326,7 @@ export async function setupPreConditions(state: any, testData: any) {
     }
 
     // Put contract code
-    await state._mainDB.put(codeHash, codeBuf)
+    await state.db.put(codeHash, codeBuf)
 
     // Put account data
     const account = Account.fromAccountData({ nonce, balance, codeHash, stateRoot })