Fix: forking value and code deletion/destruction (#482)

* WIP * Fix: forked deletion now works (at least at head of tree) * Make sure we handle deleted contracts, too * Remove log and fix typo
trufflesuite · Sep 13, 2019 · 395cc10 · 395cc10
1 parent 9b5a54b
commit 395cc10
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Showing 6 changed files with 103 additions and 40 deletions.
diff --git a/lib/utils/forkedblockchain.js b/lib/utils/forkedblockchain.js
@@ -306,17 +306,25 @@ ForkedBlockchain.prototype.getCode = function(address, number, callback) {
       if (exists && number > to.number(self.forkBlockNumber)) {
         BlockchainDouble.prototype.getCode.call(self, address, number, callback);
       } else {
-        // Else, we need to fetch it from web3. If our number is greater than
-        // the fork, let's just use "latest".
-        if (number > to.number(self.forkBlockNumber)) {
-          number = "latest";
-        }
-
-        self.fetchCodeFromFallback(address, number, function(err, code) {
-          if (code) {
-            code = utils.toBuffer(code);
+        self.stateTrie.keyIsDeleted(address, (err, deleted) => {
+          if (err) {
+            return callback(err);
+          }
+          if (deleted) {
+            return callback(null, Buffer.allocUnsafe(0));
           }
-          callback(err, code);
+          // Else, we need to fetch it from web3. If our number is greater than
+          // the fork, let's just use "latest".
+          if (number > to.number(self.forkBlockNumber)) {
+            number = "latest";
+          }
+
+          self.fetchCodeFromFallback(address, number, function(err, code) {
+            if (code) {
+              code = utils.toBuffer(code);
+            }
+            callback(err, code);
+          });
         });
       }
     });

diff --git a/lib/utils/forkedstoragetrie.js b/lib/utils/forkedstoragetrie.js
@@ -1,3 +1,4 @@
+const Sublevel = require("level-sublevel");
 const MerklePatriciaTree = require("merkle-patricia-tree");
 const BaseTrie = require("merkle-patricia-tree/baseTrie");
 const checkpointInterface = require("merkle-patricia-tree/checkpoint-interface");
@@ -10,6 +11,7 @@ inherits(ForkedStorageBaseTrie, BaseTrie);
 
 function ForkedStorageBaseTrie(db, root, options) {
   BaseTrie.call(this, db, root);
+  this._deleted = Sublevel(this.db).sublevel("deleted");
 
   this.options = options;
   this.address = options.address;
@@ -45,45 +47,71 @@ ForkedStorageBaseTrie.prototype.get = function(key, blockNumber, callback) {
         callback(err, r);
       });
     } else {
-      // If this is the main trie, get the whole account.
-      if (self.address == null) {
-        self.blockchain.fetchAccountFromFallback(key, blockNumber, function(err, account) {
-          if (err) {
-            return callback(err);
-          }
-
-          callback(null, account.serialize());
-        });
-      } else {
-        if (to.number(blockNumber) > to.number(self.forkBlockNumber)) {
-          blockNumber = self.forkBlockNumber;
+      self.keyIsDeleted(key, (err, deleted) => {
+        if (err) {
+          return callback(err);
         }
-        self.web3.eth.getStorageAt(to.rpcDataHexString(self.address), to.rpcDataHexString(key), blockNumber, function(
-          err,
-          value
-        ) {
-          if (err) {
-            return callback(err);
-          }
 
-          value = utils.rlp.encode(value);
+        if (deleted) {
+          // it was deleted. return nothing.
+          callback(null, Buffer.allocUnsafe(0));
+          return;
+        }
 
-          callback(null, value);
-        });
-      }
+        // If this is the main trie, get the whole account.
+        if (self.address == null) {
+          self.blockchain.fetchAccountFromFallback(key, blockNumber, function(err, account) {
+            if (err) {
+              return callback(err);
+            }
+
+            callback(null, account.serialize());
+          });
+        } else {
+          if (to.number(blockNumber) > to.number(self.forkBlockNumber)) {
+            blockNumber = self.forkBlockNumber;
+          }
+          self.web3.eth.getStorageAt(to.rpcDataHexString(self.address), to.rpcDataHexString(key), blockNumber, function(
+            err,
+            value
+          ) {
+            if (err) {
+              return callback(err);
+            }
+
+            value = utils.rlp.encode(value);
+
+            callback(null, value);
+          });
+        }
+      });
     }
   });
 };
 
 ForkedStorageBaseTrie.prototype.keyExists = function(key, callback) {
   key = utils.toBuffer(key);
-
-  this.findPath(key, function(err, node, remainder, stack) {
+  this.findPath(key, (err, node, remainder, stack) => {
     const exists = node && remainder.length === 0;
     callback(err, exists);
   });
 };
 
+ForkedStorageBaseTrie.prototype.keyIsDeleted = function(key, callback) {
+  const rpcKey = to.rpcDataHexString(key);
+  this._deleted.get(rpcKey, (_, result) => {
+    callback(null, result === 1);
+  });
+};
+
+const originalDelete = ForkedStorageBaseTrie.prototype.del;
+ForkedStorageBaseTrie.prototype.del = function(key, callback) {
+  const rpcKey = to.rpcDataHexString(key);
+  this._deleted.put(rpcKey, 1, () => {
+    originalDelete.call(this, key, callback);
+  });
+};
+
 ForkedStorageBaseTrie.prototype.copy = function() {
   return new ForkedStorageBaseTrie(this.db, this.root, this.options);
 };

diff --git a/test/block-tags.js b/test/block-tags.js
@@ -93,12 +93,12 @@ describe("Block Tags", function() {
     assert.notStrictEqual(block.transactionsRoot, block.receiptsRoot, "Trie roots should not be equal.");
     assert.strictEqual(
       block.transactionsRoot,
-      "0x474793ee3373c6d26f28a1f2d2f3250bdabb45cecb1363878faaf741e452fc6e",
+      "0xac9fd78357964d268cecfafaab179473c0f02dda08edb172bf446fbe9c4aafc2",
       "Should produce correct transactionsRoot"
     );
     assert.strictEqual(
       block.receiptsRoot,
-      "0xc892acfe66c3eccdc78fba6505871bc47a64fceb076d8aff440fb3545ef4a285",
+      "0x281d7cb7302acfc7cc33b1f2d06cad99650882ff1b0abebbdd32f77c14c9b98e",
       "Should produce correct receiptsRoot"
     );
   });

diff --git a/test/contracts/examples/Example.sol b/test/contracts/examples/Example.sol
@@ -13,4 +13,8 @@ contract Example {
     value = val;
     emit ValueSet(val);
   }
+
+  function destruct() public {
+    selfdestruct(msg.sender);
+  }
 }
diff --git a/test/forking.js b/test/forking.js
@@ -478,6 +478,29 @@ describe("Forking", function() {
     assert.strictEqual(mainNetwork, forkedNetwork);
   });
 
+  it("should be able to delete data", async() => {
+    const from = mainAccounts[0];
+    const example = new mainWeb3.eth.Contract(contract.abi, contractAddress);
+
+    // delete the data from our fork
+    await example.methods.setValue(0).send({ from });
+    const result = await example.methods.value().call();
+    assert.strictEqual(result, "0");
+    await example.methods.setValue(7).send({ from });
+    const result2 = await example.methods.value().call();
+    assert.strictEqual(result2, "7");
+  });
+
+  it("should be able to selfdestruct a contract", async() => {
+    const from = mainAccounts[0];
+    const example = new mainWeb3.eth.Contract(contract.abi, contractAddress);
+
+    // delete the contract from our fork
+    await example.methods.destruct().send({ from });
+    const code = await mainWeb3.eth.getCode(contractAddress);
+    assert.strictEqual(code, "0x");
+  });
+
   describe("Can debug a transaction", function() {
     let send;
     before("generate send", function() {

diff --git a/test/requests.js b/test/requests.js
@@ -959,7 +959,7 @@ const tests = function(web3) {
       const startingBlockNumber = await web3.eth.getBlockNumber();
 
       const gasEstimate = await web3.eth.estimateGas(txData);
-      assert.strictEqual(gasEstimate, 27773);
+      assert.strictEqual(gasEstimate, 27795);
 
       const blockNumber = await web3.eth.getBlockNumber();
 
@@ -976,7 +976,7 @@ const tests = function(web3) {
       txData.from = "0x1234567890123456789012345678901234567890";
 
       const result = await web3.eth.estimateGas(txData);
-      assert.strictEqual(result, 27773);
+      assert.strictEqual(result, 27795);
     });
 
     it("should estimate gas when no account is listed (eth_estimateGas)", async function() {
@@ -985,7 +985,7 @@ const tests = function(web3) {
       delete txData.from;
 
       const result = await web3.eth.estimateGas(txData);
-      assert.strictEqual(result, 27773);
+      assert.strictEqual(result, 27795);
     });
 
     it("should send a state changing transaction (eth_sendTransaction)", async function() {