[accelerator] on-demand polling support

backend/src/api/mempool.ts

@@ -396,10 +396,6 @@ class Mempool {
   }
 
   public $updateAccelerations(newAccelerations: Acceleration[]): string[] {
-    if (!config.MEMPOOL_SERVICES.ACCELERATIONS) {
-      return [];
-    }
-
     try {
       const changed: string[] = [];
 

backend/src/api/mining/mining-routes.ts

@@ -9,6 +9,7 @@ import bitcoinClient from '../bitcoin/bitcoin-client';
 import mining from "./mining";
 import PricesRepository from '../../repositories/PricesRepository';
 import AccelerationRepository from '../../repositories/AccelerationRepository';
+import accelerationApi from '../services/acceleration';
 
 class MiningRoutes {
   public initRoutes(app: Application) {
@@ -41,6 +42,8 @@ class MiningRoutes {
       .get(config.MEMPOOL.API_URL_PREFIX + 'accelerations/block/:height', this.$getAccelerationsByHeight)
       .get(config.MEMPOOL.API_URL_PREFIX + 'accelerations/recent/:interval', this.$getRecentAccelerations)
       .get(config.MEMPOOL.API_URL_PREFIX + 'accelerations/total', this.$getAccelerationTotals)
+      .get(config.MEMPOOL.API_URL_PREFIX + 'accelerations', this.$getActiveAccelerations)
+      .post(config.MEMPOOL.API_URL_PREFIX + 'acceleration/request/:txid', this.$requestAcceleration)
     ;
   }
 
@@ -445,6 +448,37 @@ class MiningRoutes {
       res.status(500).send(e instanceof Error ? e.message : e);
     }
   }
+
+  private async $getActiveAccelerations(req: Request, res: Response): Promise<void> {
+    try {
+      res.header('Pragma', 'public');
+      res.header('Cache-control', 'public');
+      res.setHeader('Expires', new Date(Date.now() + 1000 * 60).toUTCString());
+      if (!config.MEMPOOL_SERVICES.ACCELERATIONS || ['testnet', 'signet', 'liquidtestnet', 'liquid'].includes(config.MEMPOOL.NETWORK)) {
+        res.status(400).send('Acceleration data is not available.');
+        return;
+      }
+      res.status(200).send(accelerationApi.accelerations || []);
+    } catch (e) {
+      res.status(500).send(e instanceof Error ? e.message : e);
+    }
+  }
+
+  private async $requestAcceleration(req: Request, res: Response): Promise<void> {
+    if (config.MEMPOOL_SERVICES.ACCELERATIONS || config.MEMPOOL.OFFICIAL) {
+      res.status(405).send('not available.');
+      return;
+    }
+    res.setHeader('Pragma', 'no-cache');
+    res.setHeader('Cache-control', 'private, no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0');
+    res.setHeader('expires', -1);
+    try {
+      accelerationApi.accelerationRequested(req.params.txid);
+      res.status(200).send('ok');
+    } catch (e) {
+      res.status(500).send(e instanceof Error ? e.message : e);
+    }
+  }
 }
 
 export default new MiningRoutes();

backend/src/api/services/acceleration.ts

@@ -1,8 +1,10 @@
 import config from '../../config';
 import logger from '../../logger';
-import { BlockExtended, PoolTag } from '../../mempool.interfaces';
+import { BlockExtended } from '../../mempool.interfaces';
 import axios from 'axios';
 
+type MyAccelerationStatus = 'requested' | 'accelerating' | 'done';
+
 export interface Acceleration {
   txid: string,
   added: number,
@@ -35,18 +37,88 @@ export interface AccelerationHistory {
 };
 
 class AccelerationApi {
-  public async $fetchAccelerations(): Promise<Acceleration[] | null> {
+  private apiPath = config.MEMPOOL.OFFICIAL ? (config.MEMPOOL_SERVICES.API + '/accelerator/accelerations') : (config.EXTERNAL_DATA_SERVER.MEMPOOL_API + '/accelerations');
-    if (config.MEMPOOL_SERVICES.ACCELERATIONS) {
+  private _accelerations: Acceleration[] | null = null;
+  private lastPoll = 0;
+  private forcePoll = false;
+  private myAccelerations: Record<string, { status: MyAccelerationStatus, added: number, acceleration?: Acceleration }> = {};
+
+  public get accelerations(): Acceleration[] | null {
+    return this._accelerations;
+  }
+
+  public countMyAccelerationsWithStatus(filter: MyAccelerationStatus): number {
+    return Object.values(this.myAccelerations).reduce((count, {status}) => { return count + (status === filter ? 1 : 0); }, 0);
+  }
+
+  public accelerationRequested(txid: string): void {
+    this.myAccelerations[txid] = { status: 'requested', added: Date.now() };
+  }
+
+  public accelerationConfirmed(): void {
+    this.forcePoll = true;
+  }
+
+  private async $fetchAccelerations(): Promise<Acceleration[] | null> {
     try {
-        const response = await axios.get(`${config.MEMPOOL_SERVICES.API}/accelerator/accelerations`, { responseType: 'json', timeout: 10000 });
+      const response = await axios.get(this.apiPath, { responseType: 'json', timeout: 10000 });
-        return response.data as Acceleration[];
+      return response?.data || [];
     } catch (e) {
       logger.warn('Failed to fetch current accelerations from the mempool services backend: ' + (e instanceof Error ? e.message : e));
       return null;
     }
-    } else {
-      return [];
   }
+
+  public async $updateAccelerations(): Promise<Acceleration[] | null> {
+    if (config.MEMPOOL_SERVICES.ACCELERATIONS) {
+      const accelerations = await this.$fetchAccelerations();
+      if (accelerations) {
+        this._accelerations = accelerations;
+        return this._accelerations;
+      }
+    } else {
+      return this.$updateAccelerationsOnDemand();
+    }
+    return null;
+  }
+
+  private async $updateAccelerationsOnDemand(): Promise<Acceleration[] | null> {
+    const shouldUpdate = this.forcePoll
+      || this.countMyAccelerationsWithStatus('requested') > 0
+      || (this.countMyAccelerationsWithStatus('accelerating') > 0 && this.lastPoll < (Date.now() - (10 * 60 * 1000)));
+
+    // update accelerations if necessary
+    if (shouldUpdate) {
+      const accelerations = await this.$fetchAccelerations();
+      this.lastPoll = Date.now();
+      this.forcePoll = false;
+      if (accelerations) {
+        const latestAccelerations: Record<string, Acceleration> = {};
+        // set relevant accelerations to 'accelerating'
+        for (const acc of accelerations) {
+          if (this.myAccelerations[acc.txid]) {
+            latestAccelerations[acc.txid] = acc;
+            this.myAccelerations[acc.txid] = { status: 'accelerating', added: Date.now(), acceleration: acc };
+          }
+        }
+        // txs that are no longer accelerating are either confirmed or canceled, so mark for expiry
+        for (const [txid, { status, acceleration }] of Object.entries(this.myAccelerations)) {
+          if (status === 'accelerating' && !latestAccelerations[txid]) {
+            this.myAccelerations[txid] = { status: 'done', added: Date.now(), acceleration };
+          }
+        }
+      }
+    }
+
+    // clear expired accelerations (confirmed / failed / not accepted) after 10 minutes
+    for (const [txid, { status, added }] of Object.entries(this.myAccelerations)) {
+      if (['requested', 'done'].includes(status) && added < (Date.now() - (1000 * 60 * 10))) {
+        delete this.myAccelerations[txid];
+      }
+    }
+
+    this._accelerations = Object.values(this.myAccelerations).map(({ acceleration }) => acceleration).filter(acc => acc) as Acceleration[];
+    return this._accelerations;
   }
 
   public async $fetchAccelerationHistory(page?: number, status?: string): Promise<AccelerationHistory[] | null> {

backend/src/api/websocket-handler.ts

@@ -538,9 +538,9 @@ class WebsocketHandler {
     }
 
     if (config.MEMPOOL.RUST_GBT) {
-      await mempoolBlocks.$rustUpdateBlockTemplates(transactionIds, newMempool, added, removed, candidates, config.MEMPOOL_SERVICES.ACCELERATIONS);
+      await mempoolBlocks.$rustUpdateBlockTemplates(transactionIds, newMempool, added, removed, candidates, true);
     } else {
-      await mempoolBlocks.$updateBlockTemplates(transactionIds, newMempool, added, removed, candidates, accelerationDelta, true, config.MEMPOOL_SERVICES.ACCELERATIONS);
+      await mempoolBlocks.$updateBlockTemplates(transactionIds, newMempool, added, removed, candidates, accelerationDelta, true, true);
     }
 
     const mBlocks = mempoolBlocks.getMempoolBlocks();
@@ -949,9 +949,8 @@ class WebsocketHandler {
     if (config.MEMPOOL.AUDIT && memPool.isInSync()) {
       let projectedBlocks;
       const auditMempool = _memPool;
-      const isAccelerated = config.MEMPOOL_SERVICES.ACCELERATIONS && accelerationApi.isAcceleratedBlock(block, Object.values(mempool.getAccelerations()));
+      const isAccelerated = accelerationApi.isAcceleratedBlock(block, Object.values(mempool.getAccelerations()));
 
-      if ((config.MEMPOOL_SERVICES.ACCELERATIONS)) {
       if (config.MEMPOOL.RUST_GBT) {
         const added = memPool.limitGBT ? (candidates?.added || []) : [];
         const removed = memPool.limitGBT ? (candidates?.removed || []) : [];
@@ -959,9 +958,6 @@ class WebsocketHandler {
       } else {
         projectedBlocks = await mempoolBlocks.$makeBlockTemplates(transactionIds, auditMempool, candidates, false, isAccelerated, block.extras.pool.id);
       }
-      } else {
-        projectedBlocks = mempoolBlocks.getMempoolBlocksWithTransactions();
-      }
 
       if (Common.indexingEnabled()) {
         const { censored, added, prioritized, fresh, sigop, fullrbf, accelerated, score, similarity } = Audit.auditBlock(transactions, projectedBlocks, auditMempool);
@@ -1040,7 +1036,7 @@ class WebsocketHandler {
       const removed = memPool.limitGBT ? (candidates?.removed || []) : transactions;
       await mempoolBlocks.$rustUpdateBlockTemplates(transactionIds, _memPool, added, removed, candidates, true);
     } else {
-      await mempoolBlocks.$makeBlockTemplates(transactionIds, _memPool, candidates, true, config.MEMPOOL_SERVICES.ACCELERATIONS);
+      await mempoolBlocks.$makeBlockTemplates(transactionIds, _memPool, candidates, true, true);
     }
     const mBlocks = mempoolBlocks.getMempoolBlocks();
     const mBlockDeltas = mempoolBlocks.getMempoolBlockDeltas();

backend/src/index.ts

@@ -229,7 +229,7 @@ class Server {
       const newMempool = await bitcoinApi.$getRawMempool();
       const minFeeMempool = memPool.limitGBT ? await bitcoinSecondClient.getRawMemPool() : null;
       const minFeeTip = memPool.limitGBT ? await bitcoinSecondClient.getBlockCount() : -1;
-      const newAccelerations = await accelerationApi.$fetchAccelerations();
+      const newAccelerations = await accelerationApi.$updateAccelerations();
       const numHandledBlocks = await blocks.$updateBlocks();
       const pollRate = config.MEMPOOL.POLL_RATE_MS * (indexer.indexerIsRunning() ? 10 : 1);
       if (numHandledBlocks === 0) {

backend/src/repositories/AccelerationRepository.ts

@@ -213,6 +213,15 @@ class AccelerationRepository {
         this.$saveAcceleration(accelerationInfo, block, block.extras.pool.id, successfulAccelerations);
       }
     }
+    let anyConfirmed = false;
+    for (const acc of accelerations) {
+      if (blockTxs[acc.txid]) {
+        anyConfirmed = true;
+      }
+    }
+    if (anyConfirmed) {
+      accelerationApi.accelerationConfirmed();
+    }
     const lastSyncedHeight = await this.$getLastSyncedHeight();
     // if we've missed any blocks, let the indexer catch up from the last synced height on the next run
     if (block.height === lastSyncedHeight + 1) {