return more complete cpfp data for mempool transactions

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

@@ -201,6 +201,8 @@ class BitcoinRoutes {
         res.json({
           ancestors: tx.ancestors,
           bestDescendant: tx.bestDescendant || null,
+          descendants: tx.descendants || null,
+          effectiveFeePerVsize: tx.effectiveFeePerVsize || null,
         });
         return;
       }

backend/src/api/mempool-blocks.ts

@@ -155,6 +155,7 @@ class MempoolBlocks {
       if (newMempool[txid] && mempool[txid]) {
         newMempool[txid].effectiveFeePerVsize = mempool[txid].effectiveFeePerVsize;
         newMempool[txid].ancestors = mempool[txid].ancestors;
+        newMempool[txid].descendants = mempool[txid].descendants;
         newMempool[txid].bestDescendant = mempool[txid].bestDescendant;
         newMempool[txid].cpfpChecked = mempool[txid].cpfpChecked;
       }

backend/src/api/tx-selection-worker.ts

@@ -108,36 +108,38 @@ function makeBlockTemplates({ mempool, blockLimit, weightLimit, condenseRest }:
       if (blockWeight + nextTx.ancestorWeight < config.MEMPOOL.BLOCK_WEIGHT_UNITS) {
         blockWeight += nextTx.ancestorWeight;
         const ancestors: AuditTransaction[] = Array.from(nextTx.ancestorMap.values());
+        const descendants: AuditTransaction[] = [];
         // sort ancestors by dependency graph (equivalent to sorting by ascending ancestor count)
         const sortedTxSet = [...ancestors.sort((a, b) => { return (a.ancestorMap.size || 0) - (b.ancestorMap.size || 0); }), nextTx];
         const effectiveFeeRate = nextTx.ancestorFee / (nextTx.ancestorWeight / 4);
-        sortedTxSet.forEach((ancestor, i, arr) => {
+
+        while (sortedTxSet.length) {
+          const ancestor = sortedTxSet.pop();
           const mempoolTx = mempool[ancestor.txid];
           if (ancestor && !ancestor?.used) {
             ancestor.used = true;
             // update original copy of this tx with effective fee rate & relatives data
             mempoolTx.effectiveFeePerVsize = effectiveFeeRate;
-            mempoolTx.ancestors = (Array.from(ancestor.ancestorMap?.values()) as AuditTransaction[]).map((a) => {
+            mempoolTx.ancestors = sortedTxSet.map((a) => {
+              return {
+                txid: a.txid,
+                fee: a.fee,
+                weight: a.weight,
+              };
+            }).reverse();
+            mempoolTx.descendants = descendants.map((a) => {
               return {
                 txid: a.txid,
                 fee: a.fee,
                 weight: a.weight,
               };
             });
+            descendants.push(ancestor);
             mempoolTx.cpfpChecked = true;
-            if (i < arr.length - 1) {
-              mempoolTx.bestDescendant = {
-                txid: arr[arr.length - 1].txid,
-                fee: arr[arr.length - 1].fee,
-                weight: arr[arr.length - 1].weight,
-              };
-            } else {
-              mempoolTx.bestDescendant = null;
-            }
             transactions.push(ancestor);
             blockSize += ancestor.size;
           }
-        });
+        }
 
         // remove these as valid package ancestors for any descendants remaining in the mempool
         if (sortedTxSet.length) {

backend/src/mempool.interfaces.ts

@@ -72,6 +72,7 @@ export interface TransactionExtended extends IEsploraApi.Transaction {
   firstSeen?: number;
   effectiveFeePerVsize: number;
   ancestors?: Ancestor[];
+  descendants?: Ancestor[];
   bestDescendant?: BestDescendant | null;
   cpfpChecked?: boolean;
   deleteAfter?: number;