Merge pull request #568 from godwokenrises/url-feature

refactor: instant-finality feature via special RPC url
godwokenrises · Nov 15, 2022 · 8c1c75d · 8c1c75d
2 parents f511003 + 9d97119
commit 8c1c75d
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Showing 7 changed files with 176 additions and 83 deletions.
diff --git a/README.md b/README.md
@@ -2,6 +2,8 @@
 
 A Web3 RPC compatible layer build upon Godwoken/Polyjuice.
 
+Checkout [additional feature](docs/addtional-feature.md).
+
 ## Development
 
 ### Config database
@@ -121,9 +123,26 @@ docker exec -it <CONTAINER NAME> /bin/bash
 $ root@ec562fe2172b:/godwoken-web3# pm2 monit
 ```
 
-Http url: http://your-url/
+#### URLs
+
+```sh
+# Http 
+http://example_web3_rpc_url
+
+# WebSocket
+ws://example_web3_rpc_url/ws
+```
 
-WebSocket url: ws://your-url/ws
+With instant-finality feature turn on:
+
+```sh
+# Http 
+http://example_web3_rpc_url?instant-finality-hack=true
+http://example_web3_rpc_url/instant-finality-hack
+
+# WebSocket
+ws://example_web3_rpc_url/ws?instant-finality-hack=true
+```
 
 ### Docker Prebuilds
 

diff --git a/docs/addtional-feature.md b/docs/addtional-feature.md
@@ -0,0 +1,22 @@
+# Additional Feature
+
+## Instant Finality
+
+Ethereum require a transaction to be on-chain(meaning the transaction is included in the latest block) before returning a final status(aka. transaction receipt) to users so they can know whether the transaction is success or not. 
+
+Godwoken provide a quicker way to confirm transaction. Once the transaction is validated in mempool, users can get instant transaction receipt. This feature is called Instant Finality.
+
+If your want to build a low latency user experience for on-chain interaction in your dapp, you can turn on such feature by using the RPC with additional path or query parameter:
+
+```sh
+# http
+https://example_web3_rpc_url?instant-finality-hack=true
+https://example_web3_rpc_url/instant-finality-hack
+
+# websocket
+ws://example_web3_rpc_url/ws?instant-finality-hack=true
+```
+
+Environment like [Hardhat](https://github.com/NomicFoundation/hardhat) will swallow the http url's query parameter, so you might want to use the `/instant-finality-hack` path to overcome that.
+
+Also notice that under such mode, there might have some [compatibility issue](https://github.com/godwokenrises/godwoken-web3/issues/283) with Ethereum toolchain like `ether.js`. If you care more about the compatibility, please use the bare RPC url `https://example_web3_rpc_url`, which is consider to be most compatible with Ethereum.
diff --git a/packages/api-server/src/methods/index.ts b/packages/api-server/src/methods/index.ts
@@ -75,4 +75,9 @@ function getMethods(argsList: ModConstructorArgs = {}) {
   return methods;
 }
 
+const instantFinalityHackMode = true;
+
 export const methods = getMethods();
+export const instantFinalityHackMethods = getMethods({
+  eth: [instantFinalityHackMode],
+});
diff --git a/packages/api-server/src/methods/modules/eth.ts b/packages/api-server/src/methods/modules/eth.ts
@@ -94,16 +94,18 @@ type GodwokenBlockParameter = U64 | undefined;
 export class Eth {
   private query: Query;
   private rpc: GodwokenClient;
+  private instantFinalityHackMode: boolean;
   private filterManager: FilterManager;
   private cacheStore: Store;
   private ethNormalizer: EthNormalizer;
 
-  constructor() {
+  constructor(instantFinalityHackMode: boolean = false) {
     this.query = new Query();
     this.rpc = new GodwokenClient(
       envConfig.godwokenJsonRpc,
       envConfig.godwokenReadonlyJsonRpc
     );
+    this.instantFinalityHackMode = instantFinalityHackMode;
     this.filterManager = new FilterManager(true);
     this.cacheStore = new Store(true, CACHE_EXPIRED_TIME_MILSECS);
     this.ethNormalizer = new EthNormalizer(this.rpc);
@@ -718,19 +720,19 @@ export class Eth {
 
   async getTransactionByHash(args: [string]): Promise<EthTransaction | null> {
     const ethTxHash: Hash = args[0];
-    const cacheKey = autoCreateAccountCacheKey(ethTxHash);
+    const acaCacheKey = autoCreateAccountCacheKey(ethTxHash);
 
     // 1. Find in db
     const tx = await this.query.getTransactionByEthTxHash(ethTxHash);
     if (tx != null) {
       // no need await
       // delete auto create account tx if already in db
-      this.cacheStore.delete(cacheKey);
+      this.cacheStore.delete(acaCacheKey);
       const apiTx = toApiTransaction(tx);
       return apiTx;
     }
 
-    // 2. If null, find pending transactions
+    // 2. Find pending tx from gw mempool block
     const ethTxHashKey = ethTxHashCacheKey(ethTxHash);
     const gwTxHash: Hash | null = await this.cacheStore.get(ethTxHashKey);
     if (gwTxHash != null) {
@@ -768,7 +770,7 @@ export class Eth {
     // 3. Find by auto create account tx
     // TODO: delete cache store if dropped by godwoken
     // convert to tx hash mapping store if account id generated ?
-    const polyjuiceRawTx = await this.cacheStore.get(cacheKey);
+    const polyjuiceRawTx = await this.cacheStore.get(acaCacheKey);
     if (polyjuiceRawTx != null) {
       const tipBlock = await this.query.getTipBlock();
       if (tipBlock == null) {
@@ -797,7 +799,7 @@ export class Eth {
         return apiTransaction;
       } else {
         // If not found, means dropped by godwoken, should delete cache
-        this.cacheStore.delete(cacheKey);
+        this.cacheStore.delete(acaCacheKey);
       }
     }
 
@@ -861,6 +863,7 @@ export class Eth {
       return null;
     }
 
+    // 1. Find in db
     const data = await this.query.getTransactionAndLogsByHash(gwTxHash);
     if (data != null) {
       const [tx, logs] = data;
@@ -869,37 +872,43 @@ export class Eth {
       return transactionReceipt;
     }
 
-    const godwokenTxWithStatus = await this.rpc.getTransaction(gwTxHash);
-    if (godwokenTxWithStatus == null) {
-      return null;
-    }
-    const godwokenTxReceipt = await this.rpc.getTransactionReceipt(gwTxHash);
-    if (godwokenTxReceipt == null) {
-      return null;
-    }
-    const tipBlock = await this.query.getTipBlock();
-    if (tipBlock == null) {
-      throw new Error(`tip block not found`);
-    }
-    let ethTxInfo = undefined;
-    try {
-      ethTxInfo = await filterWeb3Transaction(
-        ethTxHash,
-        this.rpc,
-        tipBlock.number,
-        tipBlock.hash,
-        godwokenTxWithStatus.transaction,
-        godwokenTxReceipt
+    // 2. If under instant-finality hack mode, build receipt from gw mempool block
+    if (this.instantFinalityHackMode) {
+      logger.debug(
+        `[eth_getTransactionReceipt] find with instant-finality hack`
       );
-    } catch (err) {
-      logger.error("filterWeb3Transaction:", err);
-      logger.info("godwoken tx:", godwokenTxWithStatus);
-      logger.info("godwoken receipt:", godwokenTxReceipt);
-      throw err;
-    }
-    if (ethTxInfo != null) {
-      const ethTxReceipt = ethTxInfo[1]!;
-      return ethTxReceipt;
+      const godwokenTxWithStatus = await this.rpc.getTransaction(gwTxHash);
+      if (godwokenTxWithStatus == null) {
+        return null;
+      }
+      const godwokenTxReceipt = await this.rpc.getTransactionReceipt(gwTxHash);
+      if (godwokenTxReceipt == null) {
+        return null;
+      }
+      const tipBlock = await this.query.getTipBlock();
+      if (tipBlock == null) {
+        throw new Error(`tip block not found`);
+      }
+      let ethTxInfo = undefined;
+      try {
+        ethTxInfo = await filterWeb3Transaction(
+          ethTxHash,
+          this.rpc,
+          tipBlock.number,
+          tipBlock.hash,
+          godwokenTxWithStatus.transaction,
+          godwokenTxReceipt
+        );
+      } catch (err) {
+        logger.error("filterWeb3Transaction:", err);
+        logger.info("godwoken tx:", godwokenTxWithStatus);
+        logger.info("godwoken receipt:", godwokenTxReceipt);
+        throw err;
+      }
+      if (ethTxInfo != null) {
+        const ethTxReceipt = ethTxInfo[1]!;
+        return ethTxReceipt;
+      }
     }
 
     return null;
@@ -1099,7 +1108,11 @@ export class Eth {
   ): Promise<GodwokenBlockParameter> {
     switch (blockParameter) {
       case "latest":
-        return undefined;
+        if (this.instantFinalityHackMode) {
+          // under instant-finality hack, we treat latest as pending
+          return undefined;
+        }
+        return await this.getTipNumber();
       case "earliest":
         return 0n;
       // It's supposed to be filtered in the validator, so throw an error if matched
@@ -1143,6 +1156,9 @@ export class Eth {
     return blockNumber;
   }
 
+  // Some RPCs does not support pending parameter
+  // eth_getBlockByNumber/eth_getBlockTransactionCountByNumber/eth_getTransactionByBlockNumberAndIndex
+  // TODO: maybe we should support for those as well?
   private async blockParameterToBlockNumber(
     blockParameter: BlockParameter
   ): Promise<U64> {
@@ -1468,7 +1484,7 @@ function serializeEthCallParameters(
     gasPrice: ethCallObj.gasPrice || "0x",
     data: ethCallObj.data || "0x",
     value: ethCallObj.value || "0x",
-    blockNumber: blockNumber ? "0x" + blockNumber?.toString(16) : "0x", // undefined means latest block, the key contains tipBlockHash, so there is no need to diff latest height
+    blockNumber: blockNumber ? "0x" + blockNumber?.toString(16) : "0x", // undefined means pending block, the key contains tipBlockHash, so there is no need to diff pending height
   };
   return JSON.stringify(toSerializeObj);
 }
@@ -1498,7 +1514,7 @@ function serializeEstimateGasParameters(
     gasPrice: estimateGasObj.gasPrice || "0x",
     data: estimateGasObj.data || "0x",
     value: estimateGasObj.value || "0x",
-    blockNumber: blockNumber ? "0x" + blockNumber?.toString(16) : "0x", // undefined means latest block, the key contains tipBlockHash, so there is no need to diff latest height
+    blockNumber: blockNumber ? "0x" + blockNumber?.toString(16) : "0x", // undefined means pending block, the key contains tipBlockHash, so there is no need to diff pending height
   };
   return JSON.stringify(toSerializeObj);
 }

diff --git a/packages/api-server/src/middlewares/jayson.ts b/packages/api-server/src/middlewares/jayson.ts
@@ -1,9 +1,11 @@
 import jayson from "jayson";
-import { methods } from "../methods/index";
+import { instantFinalityHackMethods, methods } from "../methods/index";
 import { Request, Response, NextFunction } from "express";
 import createServer from "connect";
+import { isInstantFinalityHackMode } from "../util";
 
 const server = new jayson.Server(methods);
+const instantFinalityHackServer = new jayson.Server(instantFinalityHackMethods);
 
 export const jaysonMiddleware = (
   req: Request,
@@ -16,6 +18,13 @@ export const jaysonMiddleware = (
     req.body.params = [] as any[];
   }
 
+  // enable additional feature for special URL
+  if (isInstantFinalityHackMode(req)) {
+    const middleware =
+      instantFinalityHackServer.middleware() as createServer.NextHandleFunction;
+    return middleware(req, res, next);
+  }
+
   const middleware = server.middleware() as createServer.NextHandleFunction;
   return middleware(req, res, next);
 };
diff --git a/packages/api-server/src/util.ts b/packages/api-server/src/util.ts
@@ -1,4 +1,5 @@
 import { HexString } from "@ckb-lumos/base";
+import { Request } from "express";
 import {
   TX_DATA_NONE_ZERO_GAS,
   TX_DATA_ZERO_GAS,
@@ -121,6 +122,14 @@ export function calcFee(serializedL2Tx: HexString, feeRate: bigint) {
   return byteLen * feeRate;
 }
 
+// WEB3_RPC_URL/instant-finality-hack or WEB3_RPC_URL?instant-finality-hack=true
+export function isInstantFinalityHackMode(req: Request): boolean {
+  return (
+    req.url == "/instant-finality-hack" ||
+    (req.query && req.query["instant-finality-hack"] == "true")
+  );
+}
+
 export async function asyncSleep(ms = 0) {
   return new Promise((r) => setTimeout(() => r("ok"), ms));
 }