feat: use timestamp expiry

ExchangeUnion · Dec 1, 2020 · 67da614 · 67da614
1 parent 2644404
commit 67da614
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Showing 2 changed files with 56 additions and 30 deletions.
diff --git a/lib/connextclient/ConnextClient.ts b/lib/connextclient/ConnextClient.ts
@@ -36,6 +36,7 @@ import {
   OnchainTransferResponse,
   ConnextBlockNumberResponse,
   ConnextChannelDetails,
+  GetBlockByNumberResponse,
 } from './types';
 import { parseResponseBody } from '../utils/utils';
 import { Observable, fromEvent, from, defer, Subscription, throwError, interval, timer } from 'rxjs';
@@ -96,6 +97,9 @@ const CHAIN_IDENTIFIERS: { [key: string]: number } = {
   mainnet: 1,
 };
 
+const AVERAGE_ETH_BLOCK_TIME_SECONDS = 15;
+const ONE_SECOND_IN_MS = 1000;
+
 /**
  * A class representing a client to interact with connext.
  */
@@ -214,15 +218,19 @@ class ConnextClient extends SwapClient {
     } = expectedIncomingTransfer;
     const currency = this.getCurrencyByTokenaddress(tokenAddress);
     const blockHeight = await this.getHeight();
-    const timelock = expiry - blockHeight;
+    const block = await this.getBlockByNumber(blockHeight);
+    const currentTime = parseInt(block.result.timestamp, 16);
     // The timelock can be up to 10 blocks less than the agreed upon value
     const TIMELOCK_BUFFER = 10;
+    // We calculate the timelock from current timestamp to the expiry
+    const TIME_DIFF_IN_MS = expiry - currentTime;
+    const timelock = TIME_DIFF_IN_MS / ONE_SECOND_IN_MS / AVERAGE_ETH_BLOCK_TIME_SECONDS;
     if (
       tokenAddress === expectedTokenAddress &&
       units === expectedUnits &&
       timelock >= expectedTimelock - TIMELOCK_BUFFER
     ) {
-      this.logger.debug(`accepting incoming transfer with rHash: ${rHash}, units: ${units}, timelock ${timelock}, currency ${currency}, and routingId ${routingId}`);
+      this.logger.debug(`accepting incoming transfer with rHash: ${rHash}, units: ${units}, timelock ${timelock.toFixed(0)}, currency ${currency}, and routingId ${routingId}`);
       this.expectedIncomingTransfers.delete(rHash);
       this.emit('htlcAccepted', rHash, units, currency);
     } else {
@@ -437,36 +445,17 @@ class ConnextClient extends SwapClient {
   }
 
   public sendSmallestAmount = async (
-    rHash: string,
-    destination: string,
-    currency: string,
   ) => {
-    const tokenAddress = this.getTokenAddress(currency);
-
-    assert(this.channelAddress, 'cannot send transfer without channel address');
-    assert(this.publicIdentifier, 'cannot send transfer with channel address');
-    const expiry = await this.getExpiry(this.finalLock);
-    await this.executeHashLockTransfer({
-      type: 'HashlockTransfer',
-      amount: '1',
-      assetId: tokenAddress,
-      details: {
-        expiry,
-        lockHash: `0x${rHash}`,
-      },
-      recipient: destination,
-      meta: {
-        routingId: this.deriveRoutingId(rHash, tokenAddress),
-      },
-      channelAddress: this.channelAddress,
-      publicIdentifier: this.publicIdentifier,
-    });
-    return 'sendSmallestAmount is broken';
+    throw new Error('Connext.sendSmallestAmount is not implemented');
   }
 
   private getExpiry = async (locktime: number): Promise<string> => {
     const blockHeight = await this.getHeight();
-    return (blockHeight + locktime).toString();
+    const currentBlock = await this.getBlockByNumber(blockHeight);
+    const currentTimeStamp = parseInt(currentBlock.result.timestamp, 16);
+    const locktimeMilliseconds = AVERAGE_ETH_BLOCK_TIME_SECONDS * locktime * ONE_SECOND_IN_MS;
+    const expiry = currentTimeStamp + locktimeMilliseconds;
+    return expiry.toString();
   }
 
   private deriveRoutingId = (lockHash: string, assetId: string): string => {
@@ -719,6 +708,18 @@ class ConnextClient extends SwapClient {
     return true;
   }
 
+  private getBlockByNumber = async (blockNumber: number) => {
+    const res = await this.sendRequest(`/ethprovider/${CHAIN_IDENTIFIERS[this.network]}`, 'POST', {
+      method: 'eth_getBlockByNumber',
+      params: [
+        `0x${blockNumber.toString(16)}`,
+        false
+      ],
+    });
+    const block = await parseResponseBody<GetBlockByNumberResponse>(res);
+    return block;
+  }
+
   public getHeight = async () => {
     const res = await this.sendRequest(`/ethprovider/${CHAIN_IDENTIFIERS[this.network]}`, 'POST', {
       method: 'eth_blockNumber',

diff --git a/lib/connextclient/types.ts b/lib/connextclient/types.ts
@@ -72,7 +72,7 @@ export type ConnextChannelDetails = {
  * The payload for tokenPayment call.
  */
 export type ConnextTransferRequest = {
-  type: 'HashlockTransfer';
+  type: "HashlockTransfer";
   channelAddress: string;
   amount: string;
   assetId: string;
@@ -126,6 +126,31 @@ export type ConnextBalanceResponse = {
   result: string;
 };
 
+export type GetBlockByNumberResponse = {
+  result: {
+    difficulty: string;
+    extraData: string;
+    gasLimit: string;
+    gasUsed: string;
+    hash: string;
+    logsBloom: string;
+    miner: string;
+    mixHash: string;
+    nonce: string;
+    number: string;
+    parentHash: string;
+    receiptsRoot: string;
+    sha3Uncles: string;
+    size: string;
+    stateRoot: string;
+    timestamp: string;
+    totalDifficulty: string;
+    transactions: string[];
+    transactionsRoot: string;
+    uncles: string[];
+  };
+};
+
 /**
  * The response for hashLockTransfer call.
  */
@@ -139,8 +164,8 @@ export type ConnextTransferResponse = {
  * The response for withdraw call.
  */
 export type ConnextWithdrawResponse = {
-  channelAddress: '0xa929dB0530daB525596f5d48Fb5C322fDa8A337B';
-  transferId: '0xc2e4592d3fb6c02ee1d3b07bed83b5914f8ca084b0f91d6b80bf8107e58c9c38';
+  channelAddress: "0xa929dB0530daB525596f5d48Fb5C322fDa8A337B";
+  transferId: "0xc2e4592d3fb6c02ee1d3b07bed83b5914f8ca084b0f91d6b80bf8107e58c9c38";
 };
 
 type ConnextRoutingPath = {