strip non-essential data from redis cache txs

backend/src/api/bitcoin/bitcoin-api.ts

@@ -5,6 +5,7 @@ import { IEsploraApi } from './esplora-api.interface';
 import blocks from '../blocks';
 import mempool from '../mempool';
 import { TransactionExtended } from '../../mempool.interfaces';
+import transactionUtils from '../transaction-utils';
 
 class BitcoinApi implements AbstractBitcoinApi {
   private rawMempoolCache: IBitcoinApi.RawMempool | null = null;
@@ -63,9 +64,16 @@ class BitcoinApi implements AbstractBitcoinApi {
     return Promise.resolve([]);
   }
 
-  $getTransactionHex(txId: string): Promise<string> {
+  async $getTransactionHex(txId: string): Promise<string> {
-    return this.$getRawTransaction(txId, true)
+    const txInMempool = mempool.getMempool()[txId];
-      .then((tx) => tx.hex || '');
+    if (txInMempool && txInMempool.hex) {
+      return txInMempool.hex;
+    }
+
+    return this.bitcoindClient.getRawTransaction(txId, true)
+      .then((transaction: IBitcoinApi.Transaction) => {
+        return transaction.hex;
+      });
   }
 
   $getBlockHeightTip(): Promise<number> {
@@ -209,7 +217,7 @@ class BitcoinApi implements AbstractBitcoinApi {
         scriptpubkey: vout.scriptPubKey.hex,
         scriptpubkey_address: vout.scriptPubKey && vout.scriptPubKey.address ? vout.scriptPubKey.address
           : vout.scriptPubKey.addresses ? vout.scriptPubKey.addresses[0] : '',
-        scriptpubkey_asm: vout.scriptPubKey.asm ? this.convertScriptSigAsm(vout.scriptPubKey.hex) : '',
+        scriptpubkey_asm: vout.scriptPubKey.asm ? transactionUtils.convertScriptSigAsm(vout.scriptPubKey.hex) : '',
         scriptpubkey_type: this.translateScriptPubKeyType(vout.scriptPubKey.type),
       };
     });
@@ -219,7 +227,7 @@ class BitcoinApi implements AbstractBitcoinApi {
         is_coinbase: !!vin.coinbase,
         prevout: null,
         scriptsig: vin.scriptSig && vin.scriptSig.hex || vin.coinbase || '',
-        scriptsig_asm: vin.scriptSig && this.convertScriptSigAsm(vin.scriptSig.hex) || '',
+        scriptsig_asm: vin.scriptSig && transactionUtils.convertScriptSigAsm(vin.scriptSig.hex) || '',
         sequence: vin.sequence,
         txid: vin.txid || '',
         vout: vin.vout || 0,
@@ -291,7 +299,7 @@ class BitcoinApi implements AbstractBitcoinApi {
       }
       const innerTx = await this.$getRawTransaction(vin.txid, false, false);
       vin.prevout = innerTx.vout[vin.vout];
-      this.addInnerScriptsToVin(vin);
+      transactionUtils.addInnerScriptsToVin(vin);
     }
     return transaction;
   }
@@ -330,7 +338,7 @@ class BitcoinApi implements AbstractBitcoinApi {
       }
       const innerTx = await this.$getRawTransaction(transaction.vin[i].txid, false, false);
       transaction.vin[i].prevout = innerTx.vout[transaction.vin[i].vout];
-      this.addInnerScriptsToVin(transaction.vin[i]);
+      transactionUtils.addInnerScriptsToVin(transaction.vin[i]);
       totalIn += innerTx.vout[transaction.vin[i].vout].value;
     }
     if (lazyPrevouts && transaction.vin.length > 12) {
@@ -342,122 +350,6 @@ class BitcoinApi implements AbstractBitcoinApi {
     return transaction;
   }
 
-  private convertScriptSigAsm(hex: string): string {
-    const buf = Buffer.from(hex, 'hex');
-
-    const b: string[] = [];
-
-    let i = 0;
-    while (i < buf.length) {
-      const op = buf[i];
-      if (op >= 0x01 && op <= 0x4e) {
-        i++;
-        let push: number;
-        if (op === 0x4c) {
-          push = buf.readUInt8(i);
-          b.push('OP_PUSHDATA1');
-          i += 1;
-        } else if (op === 0x4d) {
-          push = buf.readUInt16LE(i);
-          b.push('OP_PUSHDATA2');
-          i += 2;
-        } else if (op === 0x4e) {
-          push = buf.readUInt32LE(i);
-          b.push('OP_PUSHDATA4');
-          i += 4;
-        } else {
-          push = op;
-          b.push('OP_PUSHBYTES_' + push);
-        }
-
-        const data = buf.slice(i, i + push);
-        if (data.length !== push) {
-          break;
-        }
-
-        b.push(data.toString('hex'));
-        i += data.length;
-      } else {
-        if (op === 0x00) {
-          b.push('OP_0');
-        } else if (op === 0x4f) {
-          b.push('OP_PUSHNUM_NEG1');
-        } else if (op === 0xb1) {
-          b.push('OP_CLTV');
-        } else if (op === 0xb2) {
-          b.push('OP_CSV');
-        } else if (op === 0xba) {
-          b.push('OP_CHECKSIGADD');
-        } else {
-          const opcode = bitcoinjs.script.toASM([ op ]);
-          if (opcode && op < 0xfd) {
-            if (/^OP_(\d+)$/.test(opcode)) {
-              b.push(opcode.replace(/^OP_(\d+)$/, 'OP_PUSHNUM_$1'));
-            } else {
-              b.push(opcode);
-            }
-          } else {
-            b.push('OP_RETURN_' + op);
-          }
-        }
-        i += 1;
-      }
-    }
-
-    return b.join(' ');
-  }
-
-  private addInnerScriptsToVin(vin: IEsploraApi.Vin): void {
-    if (!vin.prevout) {
-      return;
-    }
-
-    if (vin.prevout.scriptpubkey_type === 'p2sh') {
-      const redeemScript = vin.scriptsig_asm.split(' ').reverse()[0];
-      vin.inner_redeemscript_asm = this.convertScriptSigAsm(redeemScript);
-      if (vin.witness && vin.witness.length > 2) {
-        const witnessScript = vin.witness[vin.witness.length - 1];
-        vin.inner_witnessscript_asm = this.convertScriptSigAsm(witnessScript);
-      }
-    }
-
-    if (vin.prevout.scriptpubkey_type === 'v0_p2wsh' && vin.witness) {
-      const witnessScript = vin.witness[vin.witness.length - 1];
-      vin.inner_witnessscript_asm = this.convertScriptSigAsm(witnessScript);
-    }
-
-    if (vin.prevout.scriptpubkey_type === 'v1_p2tr' && vin.witness) {
-      const witnessScript = this.witnessToP2TRScript(vin.witness);
-      if (witnessScript !== null) {
-        vin.inner_witnessscript_asm = this.convertScriptSigAsm(witnessScript);
-      }
-    }
-  }
-
-  /**
-   * This function must only be called when we know the witness we are parsing
-   * is a taproot witness.
-   * @param witness An array of hex strings that represents the witness stack of
-   *                the input.
-   * @returns null if the witness is not a script spend, and the hex string of
-   *          the script item if it is a script spend.
-   */
-  private witnessToP2TRScript(witness: string[]): string | null {
-    if (witness.length < 2) return null;
-    // Note: see BIP341 for parsing details of witness stack
-
-    // If there are at least two witness elements, and the first byte of the
-    // last element is 0x50, this last element is called annex a and
-    // is removed from the witness stack.
-    const hasAnnex = witness[witness.length - 1].substring(0, 2) === '50';
-    // If there are at least two witness elements left, script path spending is used.
-    // Call the second-to-last stack element s, the script.
-    // (Note: this phrasing from BIP341 assumes we've *removed* the annex from the stack)
-    if (hasAnnex && witness.length < 3) return null;
-    const positionOfScript = hasAnnex ? witness.length - 3 : witness.length - 2;
-    return witness[positionOfScript];
-  }
-
 }
 
 export default BitcoinApi;

backend/src/api/mempool.ts

@@ -149,8 +149,8 @@ class Mempool {
         logger.err('failed to fetch bulk mempool transactions from esplora');
       }
     }
-    return newTransactions;
     logger.info(`Done inserting loaded mempool transactions into local cache`);
+    return newTransactions;
   }
 
   public async $updateMemPoolInfo() {
@@ -219,7 +219,11 @@ class Mempool {
       logger.info(`Missing ${transactions.length - currentMempoolSize} mempool transactions, attempting to reload in bulk from esplora`);
       try {
         newTransactions = await this.$reloadMempool(transactions.length);
-        redisCache.$addTransactions(newTransactions);
+        if (config.REDIS.ENABLED) {
+          for (const tx of newTransactions) {
+            await redisCache.$addTransaction(tx);
+          }
+        }
         loaded = true;
       } catch (e) {
         logger.err('failed to load mempool in bulk from esplora, falling back to fetching individual transactions');

backend/src/api/redis-cache.ts

@@ -5,6 +5,7 @@ import logger from '../logger';
 import config from '../config';
 import { BlockExtended, BlockSummary, MempoolTransactionExtended } from '../mempool.interfaces';
 import rbfCache from './rbf-cache';
+import transactionUtils from './transaction-utils';
 
 enum NetworkDB {
   mainnet = 0,
@@ -20,7 +21,7 @@ class RedisCache {
   private schemaVersion = 1;
 
   private cacheQueue: MempoolTransactionExtended[] = [];
-  private txFlushLimit: number = 1000;
+  private txFlushLimit: number = 10000;
 
   constructor() {
     if (config.REDIS.ENABLED) {
@@ -81,7 +82,7 @@ class RedisCache {
 
   async $addTransaction(tx: MempoolTransactionExtended) {
     this.cacheQueue.push(tx);
-    if (this.cacheQueue.length > this.txFlushLimit) {
+    if (this.cacheQueue.length >= this.txFlushLimit) {
       await this.$flushTransactions();
     }
   }
@@ -89,15 +90,28 @@ class RedisCache {
   async $flushTransactions() {
     const success = await this.$addTransactions(this.cacheQueue);
     if (success) {
+      logger.info(`Flushed ${this.cacheQueue.length} transactions to Redis cache`);
       this.cacheQueue = [];
+    } else {
+      logger.err(`Failed to flush ${this.cacheQueue.length} transactions to Redis cache`);
     }
   }
 
-  async $addTransactions(newTransactions: MempoolTransactionExtended[]): Promise<boolean> {
+  private async $addTransactions(newTransactions: MempoolTransactionExtended[]): Promise<boolean> {
     try {
       await this.$ensureConnected();
       await Promise.all(newTransactions.map(tx => {
-        return this.client.json.set(`mempool:${tx.txid.slice(0,1)}`, tx.txid, tx);
+        const minified: any = { ...tx };
+        delete minified.hex;
+        for (const vin of minified.vin) {
+          delete vin.inner_redeemscript_asm;
+          delete vin.inner_witnessscript_asm;
+          delete vin.scriptsig_asm;
+        }
+        for (const vout of minified.vout) {
+          delete vout.scriptpubkey_asm;
+        }
+        return this.client.json.set(`mempool:${tx.txid.slice(0,1)}`, tx.txid, minified);
       }));
       return true;
     } catch (e) {
@@ -201,6 +215,7 @@ class RedisCache {
     const loadedBlockSummaries = await this.$getBlockSummaries();
     // Load mempool
     const loadedMempool = await this.$getMempool();
+    this.inflateLoadedTxs(loadedMempool);
     // Load rbf data
     const rbfTxs = await this.$getRbfEntries('tx');
     const rbfTrees = await this.$getRbfEntries('tree');
@@ -217,6 +232,22 @@ class RedisCache {
     });
   }
 
+  private inflateLoadedTxs(mempool: { [txid: string]: MempoolTransactionExtended }) {
+    for (const tx of Object.values(mempool)) {
+      for (const vin of tx.vin) {
+        if (vin.scriptsig) {
+          vin.scriptsig_asm = transactionUtils.convertScriptSigAsm(vin.scriptsig);
+          transactionUtils.addInnerScriptsToVin(vin);
+        }
+      }
+      for (const vout of tx.vout) {
+        if (vout.scriptpubkey) {
+          vout.scriptpubkey_asm = transactionUtils.convertScriptSigAsm(vout.scriptpubkey);
+        }
+      }
+    }
+  }
+
 }
 
 export default new RedisCache();

backend/src/api/transaction-utils.ts

@@ -188,6 +188,122 @@ class TransactionUtils {
       16
     );
   }
+
+  public addInnerScriptsToVin(vin: IEsploraApi.Vin): void {
+    if (!vin.prevout) {
+      return;
+    }
+
+    if (vin.prevout.scriptpubkey_type === 'p2sh') {
+      const redeemScript = vin.scriptsig_asm.split(' ').reverse()[0];
+      vin.inner_redeemscript_asm = this.convertScriptSigAsm(redeemScript);
+      if (vin.witness && vin.witness.length > 2) {
+        const witnessScript = vin.witness[vin.witness.length - 1];
+        vin.inner_witnessscript_asm = this.convertScriptSigAsm(witnessScript);
+      }
+    }
+
+    if (vin.prevout.scriptpubkey_type === 'v0_p2wsh' && vin.witness) {
+      const witnessScript = vin.witness[vin.witness.length - 1];
+      vin.inner_witnessscript_asm = this.convertScriptSigAsm(witnessScript);
+    }
+
+    if (vin.prevout.scriptpubkey_type === 'v1_p2tr' && vin.witness) {
+      const witnessScript = this.witnessToP2TRScript(vin.witness);
+      if (witnessScript !== null) {
+        vin.inner_witnessscript_asm = this.convertScriptSigAsm(witnessScript);
+      }
+    }
+  }
+
+  public convertScriptSigAsm(hex: string): string {
+    const buf = Buffer.from(hex, 'hex');
+
+    const b: string[] = [];
+
+    let i = 0;
+    while (i < buf.length) {
+      const op = buf[i];
+      if (op >= 0x01 && op <= 0x4e) {
+        i++;
+        let push: number;
+        if (op === 0x4c) {
+          push = buf.readUInt8(i);
+          b.push('OP_PUSHDATA1');
+          i += 1;
+        } else if (op === 0x4d) {
+          push = buf.readUInt16LE(i);
+          b.push('OP_PUSHDATA2');
+          i += 2;
+        } else if (op === 0x4e) {
+          push = buf.readUInt32LE(i);
+          b.push('OP_PUSHDATA4');
+          i += 4;
+        } else {
+          push = op;
+          b.push('OP_PUSHBYTES_' + push);
+        }
+
+        const data = buf.slice(i, i + push);
+        if (data.length !== push) {
+          break;
+        }
+
+        b.push(data.toString('hex'));
+        i += data.length;
+      } else {
+        if (op === 0x00) {
+          b.push('OP_0');
+        } else if (op === 0x4f) {
+          b.push('OP_PUSHNUM_NEG1');
+        } else if (op === 0xb1) {
+          b.push('OP_CLTV');
+        } else if (op === 0xb2) {
+          b.push('OP_CSV');
+        } else if (op === 0xba) {
+          b.push('OP_CHECKSIGADD');
+        } else {
+          const opcode = bitcoinjs.script.toASM([ op ]);
+          if (opcode && op < 0xfd) {
+            if (/^OP_(\d+)$/.test(opcode)) {
+              b.push(opcode.replace(/^OP_(\d+)$/, 'OP_PUSHNUM_$1'));
+            } else {
+              b.push(opcode);
+            }
+          } else {
+            b.push('OP_RETURN_' + op);
+          }
+        }
+        i += 1;
+      }
+    }
+
+    return b.join(' ');
+  }
+
+  /**
+   * This function must only be called when we know the witness we are parsing
+   * is a taproot witness.
+   * @param witness An array of hex strings that represents the witness stack of
+   *                the input.
+   * @returns null if the witness is not a script spend, and the hex string of
+   *          the script item if it is a script spend.
+   */
+  public witnessToP2TRScript(witness: string[]): string | null {
+    if (witness.length < 2) return null;
+    // Note: see BIP341 for parsing details of witness stack
+
+    // If there are at least two witness elements, and the first byte of the
+    // last element is 0x50, this last element is called annex a and
+    // is removed from the witness stack.
+    const hasAnnex = witness[witness.length - 1].substring(0, 2) === '50';
+    // If there are at least two witness elements left, script path spending is used.
+    // Call the second-to-last stack element s, the script.
+    // (Note: this phrasing from BIP341 assumes we've *removed* the annex from the stack)
+    if (hasAnnex && witness.length < 3) return null;
+    const positionOfScript = hasAnnex ? witness.length - 3 : witness.length - 2;
+    return witness[positionOfScript];
+  }
 }
 
 export default new TransactionUtils();