Compute decoded tx CPFP data in the backend

backend/src/api/bitcoin/bitcoin.routes.ts

@@ -12,14 +12,14 @@ import backendInfo from '../backend-info';
 import transactionUtils from '../transaction-utils';
 import { IEsploraApi } from './esplora-api.interface';
 import loadingIndicators from '../loading-indicators';
-import { MempoolTransactionExtended, TransactionExtended } from '../../mempool.interfaces';
+import { TransactionExtended } from '../../mempool.interfaces';
 import logger from '../../logger';
 import blocks from '../blocks';
 import bitcoinClient from './bitcoin-client';
 import difficultyAdjustment from '../difficulty-adjustment';
 import transactionRepository from '../../repositories/TransactionRepository';
 import rbfCache from '../rbf-cache';
-import { calculateMempoolTxCpfp } from '../cpfp';
+import { calculateMempoolTxCpfp, calculateLocalTxCpfp } from '../cpfp';
 import { handleError } from '../../utils/api';
 
 class BitcoinRoutes {
@@ -50,6 +50,7 @@ class BitcoinRoutes {
       .get(config.MEMPOOL.API_URL_PREFIX + 'blocks-bulk/:from', this.getBlocksByBulk.bind(this))
       .get(config.MEMPOOL.API_URL_PREFIX + 'blocks-bulk/:from/:to', this.getBlocksByBulk.bind(this))
       .post(config.MEMPOOL.API_URL_PREFIX + 'prevouts', this.$getPrevouts)
+      .post(config.MEMPOOL.API_URL_PREFIX + 'cpfp', this.getCpfpLocalTx)
       // Temporarily add txs/package endpoint for all backends until esplora supports it
       .post(config.MEMPOOL.API_URL_PREFIX + 'txs/package', this.$submitPackage)
       ;
@@ -829,11 +830,11 @@ class BitcoinRoutes {
     try {
       const outpoints = req.body;
       if (!Array.isArray(outpoints) || outpoints.some((item) => !/^[a-fA-F0-9]{64}$/.test(item.txid) || typeof item.vout !== 'number')) {
-        return res.status(400).json({ error: 'Invalid input format' });
+        return res.status(400).json({ message: 'Invalid input format' });
       }
 
       if (outpoints.length > 100) {
-        return res.status(400).json({ error: 'Too many prevouts requested' });
+        return res.status(400).json({ message: 'Too many prevouts requested' });
       }
 
       const result = Array(outpoints.length).fill(null);
@@ -842,12 +843,14 @@ class BitcoinRoutes {
       for (let i = 0; i < outpoints.length; i++) {
         const outpoint = outpoints[i];
         let prevout: IEsploraApi.Vout | null = null;
-        let tx: MempoolTransactionExtended | null = null;
+        let unconfirmed: boolean | null = null;
 
         const mempoolTx = memPool[outpoint.txid];
         if (mempoolTx) {
+          if (outpoint.vout < mempoolTx.vout.length) {
             prevout = mempoolTx.vout[outpoint.vout];
-          tx = mempoolTx;
+            unconfirmed = true;  
+          }
         } else {
           const rawPrevout = await bitcoinClient.getTxOut(outpoint.txid, outpoint.vout, false);
           if (rawPrevout) {
@@ -858,11 +861,12 @@ class BitcoinRoutes {
               scriptpubkey_type: transactionUtils.translateScriptPubKeyType(rawPrevout.scriptPubKey.type),
               scriptpubkey_address: rawPrevout.scriptPubKey && rawPrevout.scriptPubKey.address ? rawPrevout.scriptPubKey.address : '',
             };
+            unconfirmed = false;
           }
         }
 
         if (prevout) {
-          result[i] = { prevout, tx };
+          result[i] = { prevout, unconfirmed };
         }
       }
 
@@ -872,6 +876,30 @@ class BitcoinRoutes {
       handleError(req, res, 500, e instanceof Error ? e.message : e);
     }
   }
+
+  private getCpfpLocalTx(req: Request, res: Response) {
+    try {
+      const tx = req.body;
+
+      if (
+        !tx || typeof tx !== "object" ||
+        !tx.txid || typeof tx.txid !== "string" ||
+        typeof tx.weight !== "number" ||
+        typeof tx.sigops !== "number" ||
+        typeof tx.fee !== "number" ||
+        !Array.isArray(tx.vin) ||
+        !Array.isArray(tx.vout)
+      ) {
+        return res.status(400).json({ message: 'Invalid transaction format: missing or incorrect fields' });
+      }
+
+      const cpfpInfo = calculateLocalTxCpfp(tx, mempool.getMempool());
+      res.json(cpfpInfo);
+
+    } catch (e) {
+      handleError(req, res, 500, e instanceof Error ? e.message : e);
+    }
+  }
 }
 
 export default new BitcoinRoutes();

backend/src/api/cpfp.ts

@@ -222,6 +222,34 @@ export function calculateMempoolTxCpfp(tx: MempoolTransactionExtended, mempool:
   };
 }
 
+
+/**
+ * Takes an unbroadcasted transaction and a copy of the current mempool, and calculates an estimate
+ * of the CPFP data if the transaction were to enter the mempool. This only returns potential ancerstors 
+ * and effective fee rate, and does not update the CPFP data of other transactions in the cluster.
+ */
+export function calculateLocalTxCpfp(tx: MempoolTransactionExtended, mempool: { [txid: string]: MempoolTransactionExtended }): CpfpInfo {
+  const ancestorMap = new Map<string, GraphTx>();
+  const graphTx = convertToGraphTx(tx, memPool.getSpendMap());
+  ancestorMap.set(tx.txid, graphTx);
+
+  const allRelatives = expandRelativesGraph(mempool, ancestorMap, memPool.getSpendMap());
+  const relativesMap = initializeRelatives(allRelatives);
+  const cluster = calculateCpfpCluster(tx.txid, relativesMap);
+
+  let totalVsize = 0;
+  let totalFee = 0;
+  for (const tx of cluster.values()) {
+    totalVsize += tx.vsize;
+    totalFee += tx.fees.base;
+  }
+
+  return {
+    ancestors: Array.from(cluster.get(tx.txid)?.ancestors.values() || []).map(ancestor => ({ txid: ancestor.txid, weight: ancestor.weight, fee: ancestor.fees.base })),
+    effectiveFeePerVsize: totalFee / totalVsize
+  }
+}
+
 /**
    * Given a root transaction and a list of in-mempool ancestors,
    * Calculate the CPFP cluster

frontend/src/app/components/transaction/transaction-raw.component.html

@@ -51,6 +51,12 @@
       </div>
     }
 
+    @if (errorCpfpInfo) {
+      <div class="alert alert-mempool">
+        <span><strong>Error loading CPFP data</strong>. Reason: {{ errorCpfpInfo }}</span>
+      </div>
+    }
+
     <app-transaction-details
       [network]="stateService.network"
       [tx]="transaction"
@@ -61,11 +67,14 @@
       [filters]="filters"
       [hasEffectiveFeeRate]="false"
       [cpfpInfo]="null"
-      [hasCpfp]="false"
       [ETA$]="ETA$"
+      [hasEffectiveFeeRate]="hasEffectiveFeeRate"
+      [cpfpInfo]="cpfpInfo"
+      [hasCpfp]="hasCpfp"
       (toggleCpfp$)="this.showCpfpDetails = !this.showCpfpDetails"
     ></app-transaction-details>
   
+    <app-cpfp-info *ngIf="showCpfpDetails" [cpfpInfo]="cpfpInfo" [tx]="transaction"></app-cpfp-info>
     <br>
 
     <ng-container *ngIf="flowEnabled; else flowPlaceholder">
@@ -188,7 +197,9 @@
   @if (isLoading) {
     <div class="text-center">
       <div class="spinner-border text-light mt-2 mb-2"></div>
-      <h3 i18n="transaction.error.loading-prevouts">Loading transaction prevouts</h3>
+      <h3 i18n="transaction.error.loading-prevouts">
+        Loading {{ isLoadingPrevouts ? 'transaction prevouts' : isLoadingCpfpInfo ? 'CPFP' : '' }}
+      </h3>
     </div>
   }
 </div>

frontend/src/app/components/transaction/transaction-raw.component.ts

@@ -13,6 +13,7 @@ import { SeoService } from '../../services/seo.service';
 import { seoDescriptionNetwork } from '@app/shared/common.utils';
 import { ApiService } from '../../services/api.service';
 import { RelativeUrlPipe } from '@app/shared/pipes/relative-url/relative-url.pipe';
+import { CpfpInfo } from '../../interfaces/node-api.interface';
 
 @Component({
   selector: 'app-transaction-raw',
@@ -23,10 +24,13 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
 
   pushTxForm: UntypedFormGroup;
   isLoading: boolean;
+  isLoadingPrevouts: boolean;
+  isLoadingCpfpInfo: boolean;
   offlineMode: boolean = false;
   transaction: Transaction;
   error: string;
   errorPrevouts: string;
+  errorCpfpInfo: string;
   hasPrevouts: boolean;
   missingPrevouts: string[];
   isLoadingBroadcast: boolean;
@@ -46,6 +50,10 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
   flowEnabled: boolean;
   adjustedVsize: number;
   filters: Filter[] = [];
+  hasEffectiveFeeRate: boolean;
+  fetchCpfp: boolean;
+  cpfpInfo: CpfpInfo | null;
+  hasCpfp: boolean = false;
   showCpfpDetails = false;
   ETA$: Observable<ETA | null>;
   mempoolBlocksSubscription: Subscription;
@@ -78,6 +86,7 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
     try {
       const tx = decodeRawTransaction(this.pushTxForm.get('txRaw').value, this.stateService.network);
       await this.fetchPrevouts(tx);
+      await this.fetchCpfpInfo(tx);
       this.processTransaction(tx);
     } catch (error) {
       this.error = error.message;
@@ -100,8 +109,9 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
 
     try {
       this.missingPrevouts = [];
+      this.isLoadingPrevouts = true;
 
-      const prevouts: { prevout: Vout, tx?: any }[] = await firstValueFrom(this.apiService.getPrevouts$(prevoutsToFetch));
+      const prevouts: { prevout: Vout, unconfirmed: boolean }[] = await firstValueFrom(this.apiService.getPrevouts$(prevoutsToFetch));
 
       if (prevouts?.length !== prevoutsToFetch.length) {
         throw new Error();
@@ -121,27 +131,57 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
         throw new Error(`Some prevouts do not exist or are already spent (${this.missingPrevouts.length})`);
       }
 
+      transaction.fee = transaction.vin.some(input => input.is_coinbase)
+        ? 0
+        : transaction.vin.reduce((fee, input) => {
+          return fee + (input.prevout?.value || 0);
+        }, 0) - transaction.vout.reduce((sum, output) => sum + output.value, 0);
+      transaction.feePerVsize = transaction.fee / (transaction.weight / 4);
+      transaction.sigops = countSigops(transaction);
+
       this.hasPrevouts = true;
+      this.isLoadingPrevouts = false;
+      this.fetchCpfp = prevouts.some(prevout => prevout?.unconfirmed);
     } catch (error) {
-      this.errorPrevouts = error.message;
+      this.errorPrevouts = error?.error?.message || error?.message;
+      this.isLoadingPrevouts = false;
+    }
+  }
+
+  async fetchCpfpInfo(transaction: Transaction): Promise<void> {
+    // Fetch potential cpfp data if all prevouts were parsed successfully and at least one of them is unconfirmed
+    if (this.hasPrevouts && this.fetchCpfp) {
+      try {
+        this.isLoadingCpfpInfo = true;
+        const cpfpInfo: CpfpInfo = await firstValueFrom(this.apiService.getCpfpLocalTx$({
+          txid: transaction.txid,
+          weight: transaction.weight,
+          sigops: transaction.sigops,
+          fee: transaction.fee,
+          vin: transaction.vin,
+          vout: transaction.vout
+        }));
+
+        if (cpfpInfo && cpfpInfo.ancestors.length > 0) {
+          const { ancestors, effectiveFeePerVsize } = cpfpInfo;
+          transaction.effectiveFeePerVsize = effectiveFeePerVsize;
+          this.cpfpInfo = { ancestors, effectiveFeePerVsize };
+          this.hasCpfp = true;
+          this.hasEffectiveFeeRate = true;
+        }
+        this.isLoadingCpfpInfo = false;
+      } catch (error) {
+        this.errorCpfpInfo = error?.error?.message || error?.message;
+        this.isLoadingCpfpInfo = false;
+      }
     }
   }
 
   processTransaction(tx: Transaction): void {
     this.transaction = tx;
 
-    if (this.hasPrevouts) {
-      this.transaction.fee = this.transaction.vin.some(input => input.is_coinbase)
-        ? 0
-        : this.transaction.vin.reduce((fee, input) => {
-          return fee + (input.prevout?.value || 0);
-        }, 0) - this.transaction.vout.reduce((sum, output) => sum + output.value, 0);
-      this.transaction.feePerVsize = this.transaction.fee / (this.transaction.weight / 4);
-    }
-
     this.transaction.flags = getTransactionFlags(this.transaction, null, null, null, this.stateService.network);
     this.filters = this.transaction.flags ? toFilters(this.transaction.flags).filter(f => f.txPage) : [];
-    this.transaction.sigops = countSigops(this.transaction);
     if (this.transaction.sigops >= 0) {
       this.adjustedVsize = Math.max(this.transaction.weight / 4, this.transaction.sigops * 5);
     }
@@ -155,16 +195,15 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
     this.setGraphSize();
 
     this.ETA$ = combineLatest([
-      this.stateService.mempoolTxPosition$.pipe(startWith(null)),
       this.stateService.mempoolBlocks$.pipe(startWith(null)),
       this.stateService.difficultyAdjustment$.pipe(startWith(null)),
     ]).pipe(
-      map(([position, mempoolBlocks, da]) => {
+      map(([mempoolBlocks, da]) => {
         return this.etaService.calculateETA(
           this.stateService.network,
           this.transaction,
           mempoolBlocks,
-          position,
+          null,
           da,
           null,
           null,
@@ -177,7 +216,7 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
       if (this.transaction) {
         this.stateService.markBlock$.next({
           txid: this.transaction.txid,
-          txFeePerVSize: this.transaction.feePerVsize,
+          txFeePerVSize: this.transaction.effectiveFeePerVsize || this.transaction.feePerVsize,
         });
       }
     });
@@ -214,7 +253,15 @@ export class TransactionRawComponent implements OnInit, OnDestroy {
     this.errorBroadcast = null;
     this.successBroadcast = false;
     this.isLoading = false;
+    this.isLoadingPrevouts = false;
+    this.isLoadingCpfpInfo = false;
+    this.isLoadingBroadcast = false;
     this.adjustedVsize = null;
+    this.showCpfpDetails = false;
+    this.hasCpfp = false;
+    this.fetchCpfp = false;
+    this.cpfpInfo = null;
+    this.hasEffectiveFeeRate = false;
     this.filters = [];
     this.hasPrevouts = false;
     this.missingPrevouts = [];

frontend/src/app/services/api.service.ts

@@ -569,6 +569,10 @@ export class ApiService {
     return this.httpClient.post(this.apiBaseUrl + this.apiBasePath + '/api/v1/prevouts', outpoints);
   }
 
+  getCpfpLocalTx$(tx: any): Observable<CpfpInfo> {
+    return this.httpClient.post<CpfpInfo>(this.apiBaseUrl + this.apiBasePath + '/api/v1/cpfp', tx);
+  }
+
   // Cache methods
   async setBlockAuditLoaded(hash: string) {
     this.blockAuditLoaded[hash] = true;