Remove unnecessary extra Transaction Buffer parsing

6 years ago · 5b5daf84dd
3 changed files with 108 additions and 24 deletions
--- a/src/psbt.js
+++ b/src/psbt.js
@ -11,6 +11,39 @@ const bscript = require('./script');
 const transaction_1 = require('./transaction');
 const varuint = require('varuint-bitcoin');
 class Psbt extends bip174_1.Psbt {
+  static fromTransaction(txBuf) {
+    const tx = transaction_1.Transaction.fromBuffer(txBuf);
+    const psbt = new this();
+    psbt.__TX = tx;
+    let inputCount = tx.ins.length;
+    let outputCount = tx.outs.length;
+    while (inputCount > 0) {
+      psbt.inputs.push({
+        keyVals: [],
+      });
+      inputCount--;
+    }
+    while (outputCount > 0) {
+      psbt.outputs.push({
+        keyVals: [],
+      });
+      outputCount--;
+    }
+    return psbt;
+  }
+  static fromBuffer(buffer) {
+    let tx;
+    const txCountGetter = txBuf => {
+      tx = transaction_1.Transaction.fromBuffer(txBuf);
+      return {
+        inputCount: tx.ins.length,
+        outputCount: tx.outs.length,
+      };
+    };
+    const psbt = super.fromBuffer(buffer, txCountGetter);
+    psbt.__TX = tx;
+    return psbt;
+  }
  constructor(opts = {}) {
    super();
    // set defaults
@ -40,7 +73,7 @@ class Psbt extends bip174_1.Psbt {
        enumerable,
        writable,
      });
-    dpew(this, '__TX', false, false);
+    dpew(this, '__TX', false, true);
    dpew(this, '__TX_BUF_CACHE', false, true);
    dpew(this, 'opts', false, true);
  }
@ -112,7 +145,7 @@ class Psbt extends bip174_1.Psbt {
  }
  extractTransaction() {
    if (!this.inputs.every(isFinalized)) throw new Error('Not finalized');
-    const tx = transaction_1.Transaction.fromBuffer(this.globalMap.unsignedTx);
+    const tx = this.__TX.clone();
    this.inputs.forEach((input, idx) => {
      if (input.finalScriptSig) tx.ins[idx].script = input.finalScriptSig;
      if (input.finalScriptWitness) {
@ -138,7 +171,7 @@ class Psbt extends bip174_1.Psbt {
    const { script, isP2SH, isP2WSH, isSegwit } = getScriptFromInput(
      inputIndex,
      input,
-      this.globalMap.unsignedTx,
+      this.__TX,
    );
    if (!script) return false;
    const scriptType = classifyScript(script);
@ -166,7 +199,7 @@ class Psbt extends bip174_1.Psbt {
      this.inputs,
      inputIndex,
      keyPair.publicKey,
-      this.globalMap.unsignedTx,
+      this.__TX,
    );
    const partialSig = {
      pubkey: keyPair.publicKey,
@ -182,7 +215,7 @@ class Psbt extends bip174_1.Psbt {
        this.inputs,
        inputIndex,
        keyPair.publicKey,
-        this.globalMap.unsignedTx,
+        this.__TX,
      );
      Promise.resolve(keyPair.sign(hash)).then(signature => {
        const partialSig = {
@ -202,9 +235,13 @@ const DEFAULT_OPTS = {
 function isFinalized(input) {
  return !!input.finalScriptSig || !!input.finalScriptWitness;
 }
-function getHashAndSighashType(inputs, inputIndex, pubkey, txBuf) {
+function getHashAndSighashType(inputs, inputIndex, pubkey, unsignedTx) {
  const input = utils_1.checkForInput(inputs, inputIndex);
-  const { hash, sighashType, script } = getHashForSig(inputIndex, input, txBuf);
+  const { hash, sighashType, script } = getHashForSig(
+    inputIndex,
+    input,
+    unsignedTx,
+  );
  checkScriptForPubkey(pubkey, script);
  return {
    hash,
@ -322,8 +359,7 @@ function checkScriptForPubkey(pubkey, script) {
    );
  }
 }
-const getHashForSig = (inputIndex, input, txBuf) => {
-  const unsignedTx = transaction_1.Transaction.fromBuffer(txBuf);
+const getHashForSig = (inputIndex, input, unsignedTx) => {
  const sighashType =
    input.sighashType || transaction_1.Transaction.SIGHASH_ALL;
  let hash;
@ -442,7 +478,7 @@ const classifyScript = script => {
  if (isP2PK(script)) return 'pubkey';
  return 'nonstandard';
 };
-function getScriptFromInput(inputIndex, input, _unsignedTx) {
+function getScriptFromInput(inputIndex, input, unsignedTx) {
  const res = {
    script: null,
    isSegwit: false,
@ -454,7 +490,6 @@ function getScriptFromInput(inputIndex, input, _unsignedTx) {
      res.isP2SH = true;
      res.script = input.redeemScript;
    } else {
-      const unsignedTx = transaction_1.Transaction.fromBuffer(_unsignedTx);
      const nonWitnessUtxoTx = transaction_1.Transaction.fromBuffer(
        input.nonWitnessUtxo,
      );
--- a/ts_src/psbt.ts
+++ b/ts_src/psbt.ts
@ -17,6 +17,50 @@ import { Transaction } from './transaction';
 const varuint = require('varuint-bitcoin');

 export class Psbt extends PsbtBase {
+  static fromTransaction<T extends typeof PsbtBase>(
+    this: T,
+    txBuf: Buffer,
+  ): InstanceType<T> {
+    const tx = Transaction.fromBuffer(txBuf);
+    const psbt = new this() as Psbt;
+    psbt.__TX = tx;
+    let inputCount = tx.ins.length;
+    let outputCount = tx.outs.length;
+    while (inputCount > 0) {
+      psbt.inputs.push({
+        keyVals: [],
+      });
+      inputCount--;
+    }
+    while (outputCount > 0) {
+      psbt.outputs.push({
+        keyVals: [],
+      });
+      outputCount--;
+    }
+    return psbt as InstanceType<T>;
+  }
+  static fromBuffer<T extends typeof PsbtBase>(
+    this: T,
+    buffer: Buffer,
+  ): InstanceType<T> {
+    let tx: Transaction | undefined;
+    const txCountGetter = (
+      txBuf: Buffer,
+    ): {
+      inputCount: number;
+      outputCount: number;
+    } => {
+      tx = Transaction.fromBuffer(txBuf);
+      return {
+        inputCount: tx.ins.length,
+        outputCount: tx.outs.length,
+      };
+    };
+    const psbt = super.fromBuffer(buffer, txCountGetter) as Psbt;
+    psbt.__TX = tx!;
+    return psbt as InstanceType<T>;
+  }
  private __TX: Transaction;
  private __TX_BUF_CACHE?: Buffer;
  private opts: PsbtOpts;
@ -56,7 +100,7 @@ export class Psbt extends PsbtBase {
        enumerable,
        writable,
      });
-    dpew(this, '__TX', false, false);
+    dpew(this, '__TX', false, true);
    dpew(this, '__TX_BUF_CACHE', false, true);
    dpew(this, 'opts', false, true);
  }
@ -138,7 +182,7 @@ export class Psbt extends PsbtBase {

  extractTransaction(): Transaction {
    if (!this.inputs.every(isFinalized)) throw new Error('Not finalized');
-    const tx = Transaction.fromBuffer(this.globalMap.unsignedTx!);
+    const tx = this.__TX.clone();
    this.inputs.forEach((input, idx) => {
      if (input.finalScriptSig) tx.ins[idx].script = input.finalScriptSig;
      if (input.finalScriptWitness) {
@ -169,7 +213,7 @@ export class Psbt extends PsbtBase {
    const { script, isP2SH, isP2WSH, isSegwit } = getScriptFromInput(
      inputIndex,
      input,
-      this.globalMap.unsignedTx!,
+      this.__TX,
    );
    if (!script) return false;

@ -195,14 +239,14 @@ export class Psbt extends PsbtBase {
    return true;
  }

-  signInput(inputIndex: number, keyPair: Signer): Psbt {
+  signInput(inputIndex: number, keyPair: Signer): this {
    if (!keyPair || !keyPair.publicKey)
      throw new Error('Need Signer to sign input');
    const { hash, sighashType } = getHashAndSighashType(
      this.inputs,
      inputIndex,
      keyPair.publicKey,
-      this.globalMap.unsignedTx!,
+      this.__TX,
    );

    const partialSig = {
@ -222,7 +266,7 @@ export class Psbt extends PsbtBase {
          this.inputs,
          inputIndex,
          keyPair.publicKey,
-          this.globalMap.unsignedTx!,
+          this.__TX,
        );

        Promise.resolve(keyPair.sign(hash)).then(signature => {
@ -269,13 +313,17 @@ function getHashAndSighashType(
  inputs: PsbtInput[],
  inputIndex: number,
  pubkey: Buffer,
-  txBuf: Buffer,
+  unsignedTx: Transaction,
 ): {
  hash: Buffer;
  sighashType: number;
 } {
  const input = checkForInput(inputs, inputIndex);
-  const { hash, sighashType, script } = getHashForSig(inputIndex, input, txBuf);
+  const { hash, sighashType, script } = getHashForSig(
+    inputIndex,
+    input,
+    unsignedTx,
+  );
  checkScriptForPubkey(pubkey, script);
  return {
    hash,
@ -424,9 +472,8 @@ interface HashForSigData {
 const getHashForSig = (
  inputIndex: number,
  input: PsbtInput,
-  txBuf: Buffer,
+  unsignedTx: Transaction,
 ): HashForSigData => {
-  const unsignedTx = Transaction.fromBuffer(txBuf);
  const sighashType = input.sighashType || Transaction.SIGHASH_ALL;
  let hash: Buffer;
  let script: Buffer;
@ -571,7 +618,7 @@ interface GetScriptReturn {
 function getScriptFromInput(
  inputIndex: number,
  input: PsbtInput,
-  _unsignedTx: Buffer,
+  unsignedTx: Transaction,
 ): GetScriptReturn {
  const res: GetScriptReturn = {
    script: null,
@ -584,7 +631,6 @@ function getScriptFromInput(
      res.isP2SH = true;
      res.script = input.redeemScript;
    } else {
-      const unsignedTx = Transaction.fromBuffer(_unsignedTx);
      const nonWitnessUtxoTx = Transaction.fromBuffer(input.nonWitnessUtxo);
      const prevoutIndex = unsignedTx.ins[inputIndex].index;
      res.script = nonWitnessUtxoTx.outs[prevoutIndex].script;
--- a/types/psbt.d.ts
+++ b/types/psbt.d.ts
@ -1,9 +1,12 @@
+/// <reference types="node" />
 import { Psbt as PsbtBase } from 'bip174';
 import { TransactionInput, TransactionOutput } from 'bip174/src/lib/interfaces';
 import { Signer, SignerAsync } from './ecpair';
 import { Network } from './networks';
 import { Transaction } from './transaction';
 export declare class Psbt extends PsbtBase {
+    static fromTransaction<T extends typeof PsbtBase>(this: T, txBuf: Buffer): InstanceType<T>;
+    static fromBuffer<T extends typeof PsbtBase>(this: T, buffer: Buffer): InstanceType<T>;
    private __TX;
    private __TX_BUF_CACHE?;
    private opts;
@ -18,7 +21,7 @@ export declare class Psbt extends PsbtBase {
        inputResults: boolean[];
    };
    finalizeInput(inputIndex: number): boolean;
-    signInput(inputIndex: number, keyPair: Signer): Psbt;
+    signInput(inputIndex: number, keyPair: Signer): this;
    signInputAsync(inputIndex: number, keyPair: SignerAsync): Promise<void>;
 }
 interface PsbtOptsOptional {