SizeEstimation.estimateUtxo - Code Metrics - blocktrail/blocktrail-sdk-nodejs - Measure and Improve Code Quality continuously with Scrutinizer

SizeEstimation.estimateUtxo D
last analyzed 2018-06-20 17:31 UTC

↳ Parent: lib/size_estimation.js

Complexity

Conditions	9
Paths	6

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	9
c	1
b	0
f	0
nc	6
dl	0
loc	40
rs	4.909
nop	2

var assert = require('assert');
var bitcoin = require('bitcoinjs-lib');

var SizeEstimation = {
    SIZE_DER_SIGNATURE: 72,
    SIZE_V0_P2WSH: 36
};

SizeEstimation.getPublicKeySize = function(isCompressed) {
    return isCompressed ? 33 : 65;
};

SizeEstimation.getLengthForScriptPush = function(length) {
    if (length < 75) {
        return 1;
    } else if (length <= 0xff) {
        return 2;
    } else if (length <= 0xffff) {
        return 3;
    } else if (length <= 0xffffffff) {
        return 5;
    } else {
        throw new Error("Size of pushdata too large");
    }
};

SizeEstimation.getLengthForVarInt = function(length) {
    if (length < 253) {
        return 1;
    }

    // Rest have a prefix byte
    var numBytes;
    if (length < 65535) {
        numBytes = 2;
    } else if (length < 4294967295) {
        numBytes = 4;
    } else if (length < 18446744073709551615) {
        numBytes = 8;
    } else {
        throw new Error("Size of varint too large");
    }

    return 1 + numBytes;
};

SizeEstimation.estimateMultisigStackSize = function(m, keys) {
    // Initialize with OP_0
    var stackSizes = [0];
    var i;
    for (i = 0; i < m; i++) {
        stackSizes.push(SizeEstimation.SIZE_DER_SIGNATURE);
    }

    var scriptSize = 1; // OP_$m
    for (i = 0; i < keys.length; i++) {
        scriptSize += this.getLengthForScriptPush(keys[i].length) + keys[i].length;
    }
    scriptSize += 2; // OP_$n OP_CHECKMULTISIG
    return [stackSizes, scriptSize];
};

SizeEstimation.estimateP2PKStackSize = function(key) {
    var stackSizes = [SizeEstimation.SIZE_DER_SIGNATURE];
    var scriptSize = this.getLengthForScriptPush(key.length) + key.length + 1; // KEY OP_CHECKSIG

    return [stackSizes, scriptSize];
};

SizeEstimation.estimateP2PKHStackSize = function(isCompressed) {
    if (typeof isCompressed === 'undefined') {
        isCompressed = true;
    }

    var stackSizes = [this.SIZE_DER_SIGNATURE, this.getPublicKeySize(isCompressed)];
    var scriptSize = 2 + this.getLengthForScriptPush(20) + 20 + 2;

    return [stackSizes, scriptSize];
};

/**
 * As pure a function as it gets, but without the overhead
 * of checking everything. Make sure your calls are correct.
 *
 * @param {Buffer} stackSizes
 * @param {Buffer} isWitness
 * @param {Buffer} rs
 * @param {Buffer} ws
 */
SizeEstimation.estimateStackSignatureSize = function(stackSizes, isWitness, rs, ws) {
    assert(ws === null || isWitness);

    var scriptSigSizes = [];
    var witnessSizes = [];
    if (isWitness) {
        witnessSizes = stackSizes;
        if (ws instanceof Buffer) {

            witnessSizes.push(ws.length);
        }
    } else {
        scriptSigSizes = stackSizes;
    }

    if (rs instanceof Buffer) {
        scriptSigSizes.push(rs.length);
    }

    var self = this;
    var scriptSigSize = 0;
    scriptSigSizes.map(function(elementLen) {
        scriptSigSize += self.getLengthForScriptPush(elementLen) + elementLen;
    });

    scriptSigSize += self.getLengthForVarInt(scriptSigSize);

    var witnessSize = 0;
    if (witnessSizes.length > 0) {
        witnessSizes.map(function(elementLen) {
            witnessSize += self.getLengthForVarInt(elementLen) + elementLen;
        });
        witnessSize += self.getLengthForVarInt(witnessSizes.length);
    }

    return [scriptSigSize, witnessSize];
};

/**
 *
 * @param {Buffer} script - main script, can equal RS/WS too
 * @param {Buffer} redeemScript
 * @param {Buffer} witnessScript
 * @param {boolean} isWitness - required, covers P2WPKH and so on
 * @param {boolean} compressed - only strictly required for p2pkh
 */
SizeEstimation.estimateInputFromScripts = function(script, redeemScript, witnessScript, isWitness, compressed) {
    assert(witnessScript === null || isWitness);

    var stackSizes;
    if (bitcoin.script.multisig.output.check(script)) {
        var multisig = bitcoin.script.multisig.output.decode(script);
        stackSizes = this.estimateMultisigStackSize(multisig.m, multisig.pubKeys)[0];
    } else if (bitcoin.script.pubKey.output.check(script)) {
        var p2pk = bitcoin.script.pubKey.output.decode(script);
        stackSizes = this.estimateP2PKStackSize(p2pk)[0];
    } else if (bitcoin.script.pubKeyHash.output.check(script)) {
        stackSizes = this.estimateP2PKHStackSize(compressed)[0];
    } else {
        throw new Error("Unsupported script type");
    }

    return this.estimateStackSignatureSize(stackSizes, isWitness, redeemScript, witnessScript);
};

SizeEstimation.estimateUtxo = function(utxo, compressed) {
    var spk = Buffer.from(utxo.scriptpubkey_hex, 'hex');

    var rs = typeof utxo.redeem_script === 'string' ? Buffer.from(utxo.redeem_script, 'hex') : null;
    var ws = typeof utxo.witness_script === 'string' ? Buffer.from(utxo.witness_script, 'hex') : null;
    var witness = false;

    var signScript = spk;
    if (bitcoin.script.scriptHash.output.check(signScript)) {
        if (null === rs) {
            throw new Error("Cant estimate, missing redeem script");
        }
        signScript = rs;
    }

    if (bitcoin.script.witnessPubKeyHash.output.check(signScript)) {
        var p2wpkh = bitcoin.script.witnessPubKeyHash.output.decode(signScript);
        signScript = bitcoin.script.pubKeyHash.output.encode(p2wpkh);
        witness = true;
    } else if (bitcoin.script.witnessScriptHash.output.check(signScript)) {
        if (null === ws) {
            throw new Error("Can't estimate, missing witness script");
        }
        signScript = ws;
        witness = true;
    }

    var types = bitcoin.script.types;
    var allowedTypes = [types.MULTISIG, types.P2PKH, types.P2PK];
    var type = bitcoin.script.classifyOutput(signScript);
    if (allowedTypes.indexOf(type) === -1) {
        throw new Error("Unsupported script type");
    }

    var estimation = this.estimateInputFromScripts(signScript, rs, ws, witness, compressed);

    return {
        scriptSig: estimation[0],
        witness: estimation[1]
    };
};

/**
 * Returns the size of input related data, given a set
 * of utxos we can estimate for. witness data is included
 * if withWitness=true, and is required for vsize/weight
 * calculations
 * @param {object} utxos
 * @param {boolean} withWitness
 * @returns {number}
 */
SizeEstimation.estimateInputsSize = function(utxos, withWitness) {
    var inputSize = 0;
    var witnessSize = 0;
    utxos.map(function(utxo) {
        var estimate = SizeEstimation.estimateUtxo(utxo);
        // txid + vout + sequence + scriptSig
        inputSize += 32 + 4 + 4 + estimate.scriptSig;
        if (withWitness) {
            witnessSize += estimate.witness;
        }
    });

    if (withWitness && witnessSize > 0) {
        inputSize += 2 + witnessSize;
    }

    return inputSize;
};

/**
 * Calculates number of bytes to serialize tx outputs
 * @param {Array} outs
 * @returns {number}
 */
SizeEstimation.calculateOutputsSize = function(outs) {
    var outputsSize = 0;
    outs.map(function(out) {
        var scriptSize = SizeEstimation.getLengthForVarInt(out.script.length);
        outputsSize += 8 + scriptSize + (out.script.length);
    });
    return outputsSize;
};

/**
 * Returns the transactions weight.
 *
 * @param {bitcoin.Transaction} tx
 * @param {array} utxos
 * @returns {*}
 */
SizeEstimation.estimateTxWeight = function(tx, utxos) {
    var outSize = SizeEstimation.calculateOutputsSize(tx.outs);
    // version + vinLen + vin + voutLen + vout + nlocktime
    var baseSize = 4 + SizeEstimation.getLengthForVarInt(utxos.length) + this.estimateInputsSize(utxos, false) +
        SizeEstimation.getLengthForVarInt(tx.outs.length) + outSize + 4;
    // version + vinLen + vin (includes witness) + voutLen + vout + nlocktime
    var witSize = 4 + SizeEstimation.getLengthForVarInt(utxos.length) + this.estimateInputsSize(utxos, true) +
        SizeEstimation.getLengthForVarInt(tx.outs.length) + outSize + 4;

    return (3 * baseSize) + witSize;
};

/**
 * Returns the vsize for a transaction. Same as size
 * for transaction with no witness data.
 *
 * @param {bitcoin.Transaction} tx
 * @param {array} utxos
 * @returns {Number}
 */
SizeEstimation.estimateTxVsize = function(tx, utxos) {
    return parseInt(Math.ceil(SizeEstimation.estimateTxWeight(tx, utxos) / 4), 10);
};

module.exports = SizeEstimation;


1			var assert = require('assert');
2			var bitcoin = require('bitcoinjs-lib');
3
4			var SizeEstimation = {
5			SIZE_DER_SIGNATURE: 72,
6			SIZE_V0_P2WSH: 36
7			};
8
9			SizeEstimation.getPublicKeySize = function(isCompressed) {
10			return isCompressed ? 33 : 65;
11			};
12
13			SizeEstimation.getLengthForScriptPush = function(length) {
14			if (length < 75) {
15			return 1;
16			} else if (length <= 0xff) {
17			return 2;
18			} else if (length <= 0xffff) {
19			return 3;
20			} else if (length <= 0xffffffff) {
21			return 5;
22			} else {
23			throw new Error("Size of pushdata too large");
24			}
25			};
26
27			SizeEstimation.getLengthForVarInt = function(length) {
28			if (length < 253) {
29			return 1;
30			}
31
32			// Rest have a prefix byte
33			var numBytes;
34			if (length < 65535) {
35			numBytes = 2;
36			} else if (length < 4294967295) {
37			numBytes = 4;
38			} else if (length < 18446744073709551615) {
39			numBytes = 8;
40			} else {
41			throw new Error("Size of varint too large");
42			}
43
44			return 1 + numBytes;
45			};
46
47			SizeEstimation.estimateMultisigStackSize = function(m, keys) {
48			// Initialize with OP_0
49			var stackSizes = [0];
50			var i;
51			for (i = 0; i < m; i++) {
52			stackSizes.push(SizeEstimation.SIZE_DER_SIGNATURE);
53			}
54
55			var scriptSize = 1; // OP_$m
56			for (i = 0; i < keys.length; i++) {
57			scriptSize += this.getLengthForScriptPush(keys[i].length) + keys[i].length;
58			}
59			scriptSize += 2; // OP_$n OP_CHECKMULTISIG
60			return [stackSizes, scriptSize];
61			};
62
63			SizeEstimation.estimateP2PKStackSize = function(key) {
64			var stackSizes = [SizeEstimation.SIZE_DER_SIGNATURE];
65			var scriptSize = this.getLengthForScriptPush(key.length) + key.length + 1; // KEY OP_CHECKSIG
66
67			return [stackSizes, scriptSize];
68			};
69
70			SizeEstimation.estimateP2PKHStackSize = function(isCompressed) {
71			if (typeof isCompressed === 'undefined') {
72			isCompressed = true;
73			}
74
75			var stackSizes = [this.SIZE_DER_SIGNATURE, this.getPublicKeySize(isCompressed)];
76			var scriptSize = 2 + this.getLengthForScriptPush(20) + 20 + 2;
77
78			return [stackSizes, scriptSize];
79			};
80
81			/**
82			* As pure a function as it gets, but without the overhead
83			* of checking everything. Make sure your calls are correct.
84			*
85			* @param {Buffer} stackSizes
86			* @param {Buffer} isWitness
87			* @param {Buffer} rs
88			* @param {Buffer} ws
89			*/
90			SizeEstimation.estimateStackSignatureSize = function(stackSizes, isWitness, rs, ws) {
91			assert(ws === null \|\| isWitness);
92
93			var scriptSigSizes = [];
94			var witnessSizes = [];
95			if (isWitness) {
96			witnessSizes = stackSizes;
97			if (ws instanceof Buffer) {
			0 ignored issues – show Bug introduced 2017-11-14 22:25 UTC by Report Bug Copy Issue Report The variable `Buffer` seems to be never declared. If this is a global, consider adding a `/** global: Buffer */` comment. This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed. To learn more about declaring variables in Javascript, see the MDN. Loading history...
98			witnessSizes.push(ws.length);
99			}
100			} else {
101			scriptSigSizes = stackSizes;
102			}
103
104			if (rs instanceof Buffer) {
105			scriptSigSizes.push(rs.length);
106			}
107
108			var self = this;
109			var scriptSigSize = 0;
110			scriptSigSizes.map(function(elementLen) {
111			scriptSigSize += self.getLengthForScriptPush(elementLen) + elementLen;
112			});
113
114			scriptSigSize += self.getLengthForVarInt(scriptSigSize);
115
116			var witnessSize = 0;
117			if (witnessSizes.length > 0) {
118			witnessSizes.map(function(elementLen) {
119			witnessSize += self.getLengthForVarInt(elementLen) + elementLen;
120			});
121			witnessSize += self.getLengthForVarInt(witnessSizes.length);
122			}
123
124			return [scriptSigSize, witnessSize];
125			};
126
127			/**
128			*
129			* @param {Buffer} script - main script, can equal RS/WS too
130			* @param {Buffer} redeemScript
131			* @param {Buffer} witnessScript
132			* @param {boolean} isWitness - required, covers P2WPKH and so on
133			* @param {boolean} compressed - only strictly required for p2pkh
134			*/
135			SizeEstimation.estimateInputFromScripts = function(script, redeemScript, witnessScript, isWitness, compressed) {
136			assert(witnessScript === null \|\| isWitness);
137
138			var stackSizes;
139			if (bitcoin.script.multisig.output.check(script)) {
140			var multisig = bitcoin.script.multisig.output.decode(script);
141			stackSizes = this.estimateMultisigStackSize(multisig.m, multisig.pubKeys)[0];
142			} else if (bitcoin.script.pubKey.output.check(script)) {
143			var p2pk = bitcoin.script.pubKey.output.decode(script);
144			stackSizes = this.estimateP2PKStackSize(p2pk)[0];
145			} else if (bitcoin.script.pubKeyHash.output.check(script)) {
146			stackSizes = this.estimateP2PKHStackSize(compressed)[0];
147			} else {
148			throw new Error("Unsupported script type");
149			}
150
151			return this.estimateStackSignatureSize(stackSizes, isWitness, redeemScript, witnessScript);
152			};
153
154			SizeEstimation.estimateUtxo = function(utxo, compressed) {
155			var spk = Buffer.from(utxo.scriptpubkey_hex, 'hex');
			0 ignored issues – show Bug introduced 2017-10-05 14:18 UTC by Report Bug Copy Issue Report The variable `Buffer` seems to be never declared. If this is a global, consider adding a `/** global: Buffer */` comment. This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed. To learn more about declaring variables in Javascript, see the MDN. Loading history...
156			var rs = typeof utxo.redeem_script === 'string' ? Buffer.from(utxo.redeem_script, 'hex') : null;
157			var ws = typeof utxo.witness_script === 'string' ? Buffer.from(utxo.witness_script, 'hex') : null;
158			var witness = false;
159
160			var signScript = spk;
161			if (bitcoin.script.scriptHash.output.check(signScript)) {
162			if (null === rs) {
163			throw new Error("Cant estimate, missing redeem script");
164			}
165			signScript = rs;
166			}
167
168			if (bitcoin.script.witnessPubKeyHash.output.check(signScript)) {
169			var p2wpkh = bitcoin.script.witnessPubKeyHash.output.decode(signScript);
170			signScript = bitcoin.script.pubKeyHash.output.encode(p2wpkh);
171			witness = true;
172			} else if (bitcoin.script.witnessScriptHash.output.check(signScript)) {
173			if (null === ws) {
174			throw new Error("Can't estimate, missing witness script");
175			}
176			signScript = ws;
177			witness = true;
178			}
179
180			var types = bitcoin.script.types;
181			var allowedTypes = [types.MULTISIG, types.P2PKH, types.P2PK];
182			var type = bitcoin.script.classifyOutput(signScript);
183			if (allowedTypes.indexOf(type) === -1) {
184			throw new Error("Unsupported script type");
185			}
186
187			var estimation = this.estimateInputFromScripts(signScript, rs, ws, witness, compressed);
188
189			return {
190			scriptSig: estimation[0],
191			witness: estimation[1]
192			};
193			};
194
195			/**
196			* Returns the size of input related data, given a set
197			* of utxos we can estimate for. witness data is included
198			* if withWitness=true, and is required for vsize/weight
199			* calculations
200			* @param {object} utxos
201			* @param {boolean} withWitness
202			* @returns {number}
203			*/
204			SizeEstimation.estimateInputsSize = function(utxos, withWitness) {
205			var inputSize = 0;
206			var witnessSize = 0;
207			utxos.map(function(utxo) {
208			var estimate = SizeEstimation.estimateUtxo(utxo);
209			// txid + vout + sequence + scriptSig
210			inputSize += 32 + 4 + 4 + estimate.scriptSig;
211			if (withWitness) {
212			witnessSize += estimate.witness;
213			}
214			});
215
216			if (withWitness && witnessSize > 0) {
217			inputSize += 2 + witnessSize;
218			}
219
220			return inputSize;
221			};
222
223			/**
224			* Calculates number of bytes to serialize tx outputs
225			* @param {Array} outs
226			* @returns {number}
227			*/
228			SizeEstimation.calculateOutputsSize = function(outs) {
229			var outputsSize = 0;
230			outs.map(function(out) {
231			var scriptSize = SizeEstimation.getLengthForVarInt(out.script.length);
232			outputsSize += 8 + scriptSize + (out.script.length);
233			});
234			return outputsSize;
235			};
236
237			/**
238			* Returns the transactions weight.
239			*
240			* @param {bitcoin.Transaction} tx
241			* @param {array} utxos
242			* @returns {*}
243			*/
244			SizeEstimation.estimateTxWeight = function(tx, utxos) {
245			var outSize = SizeEstimation.calculateOutputsSize(tx.outs);
246			// version + vinLen + vin + voutLen + vout + nlocktime
247			var baseSize = 4 + SizeEstimation.getLengthForVarInt(utxos.length) + this.estimateInputsSize(utxos, false) +
248			SizeEstimation.getLengthForVarInt(tx.outs.length) + outSize + 4;
249			// version + vinLen + vin (includes witness) + voutLen + vout + nlocktime
250			var witSize = 4 + SizeEstimation.getLengthForVarInt(utxos.length) + this.estimateInputsSize(utxos, true) +
251			SizeEstimation.getLengthForVarInt(tx.outs.length) + outSize + 4;
252
253			return (3 * baseSize) + witSize;
254			};
255
256			/**
257			* Returns the vsize for a transaction. Same as size
258			* for transaction with no witness data.
259			*
260			* @param {bitcoin.Transaction} tx
261			* @param {array} utxos
262			* @returns {Number}
263			*/
264			SizeEstimation.estimateTxVsize = function(tx, utxos) {
265			return parseInt(Math.ceil(SizeEstimation.estimateTxWeight(tx, utxos) / 4), 10);
266			};
267
268			module.exports = SizeEstimation;
269

blocktrail / blocktrail-sdk-nodejs

SizeEstimation.estimateUtxo D last analyzed 2018-06-20 17:31 UTC

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SizeEstimation.estimateUtxo D
last analyzed 2018-06-20 17:31 UTC