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Remove default sizes #22

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119c259
Removing default lengths from main code
karelbilek Aug 13, 2017
268c20d
Adding lengths to tests
karelbilek Aug 13, 2017
38fbe25
Merge branch 'master' into remove_default_sizes
dcousens Jan 17, 2018
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4 changes: 2 additions & 2 deletions accumulative.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@ var utils = require('./utils')

// add inputs until we reach or surpass the target value (or deplete)
// worst-case: O(n)
module.exports = function accumulative (utxos, outputs, feeRate) {
module.exports = function accumulative (utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength) {
if (!isFinite(utils.uintOrNaN(feeRate))) return {}
var bytesAccum = utils.transactionBytes([], outputs)

Expand Down Expand Up @@ -31,7 +31,7 @@ module.exports = function accumulative (utxos, outputs, feeRate) {
// go again?
if (inAccum < outAccum + fee) continue

return utils.finalize(inputs, outputs, feeRate)
return utils.finalize(inputs, outputs, feeRate, changeInputLengthEstimate, changeOutputLength)
}

return { fee: feeRate * bytesAccum }
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6 changes: 3 additions & 3 deletions blackjack.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2,15 +2,15 @@ var utils = require('./utils')

// only add inputs if they don't bust the target value (aka, exact match)
// worst-case: O(n)
module.exports = function blackjack (utxos, outputs, feeRate) {
module.exports = function blackjack (utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength) {
if (!isFinite(utils.uintOrNaN(feeRate))) return {}

var bytesAccum = utils.transactionBytes([], outputs)

var inAccum = 0
var inputs = []
var outAccum = utils.sumOrNaN(outputs)
var threshold = utils.dustThreshold({}, feeRate)
var threshold = utils.dustThreshold(feeRate, changeInputLengthEstimate)

for (var i = 0; i < utxos.length; ++i) {
var input = utxos[i]
Expand All @@ -28,7 +28,7 @@ module.exports = function blackjack (utxos, outputs, feeRate) {
// go again?
if (inAccum < outAccum + fee) continue

return utils.finalize(inputs, outputs, feeRate)
return utils.finalize(inputs, outputs, feeRate, changeInputLengthEstimate, changeOutputLength)
}

return { fee: feeRate * bytesAccum }
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5 changes: 2 additions & 3 deletions break.js
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
var utils = require('./utils')

// break utxos into the maximum number of output possible
module.exports = function broken (utxos, output, feeRate) {
module.exports = function broken (utxos, output, feeRate, changeInputLengthEstimate, changeOutputLength) {
if (!isFinite(utils.uintOrNaN(feeRate))) return {}

var bytesAccum = utils.transactionBytes(utxos, [])
Expand Down Expand Up @@ -29,6 +29,5 @@ module.exports = function broken (utxos, output, feeRate) {
outAccum += value
outputs.push(output)
}

return utils.finalize(utxos, outputs, feeRate)
return utils.finalize(utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength)
}
6 changes: 3 additions & 3 deletions index.js
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Expand Up @@ -7,15 +7,15 @@ function utxoScore (x, feeRate) {
return x.value - (feeRate * utils.inputBytes(x))
}

module.exports = function coinSelect (utxos, outputs, feeRate) {
module.exports = function coinSelect (utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength) {
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@dcousens dcousens Aug 15, 2017 •
edited
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If we did this, it would have to be an options object with defaults.

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👍

utxos = utxos.concat().sort(function (a, b) {
return utxoScore(b, feeRate) - utxoScore(a, feeRate)
})

// attempt to use the blackjack strategy first (no change output)
var base = blackjack(utxos, outputs, feeRate)
var base = blackjack(utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength)
if (base.inputs) return base

// else, try the accumulative strategy
return accumulative(utxos, outputs, feeRate)
return accumulative(utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength)
}
8 changes: 4 additions & 4 deletions split.js
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
var utils = require('./utils')

// split utxos between each output, ignores outputs with .value defined
module.exports = function split (utxos, outputs, feeRate) {
module.exports = function split (utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength) {
if (!isFinite(utils.uintOrNaN(feeRate))) return {}

var bytesAccum = utils.transactionBytes(utxos, outputs)
Expand All @@ -17,7 +17,7 @@ module.exports = function split (utxos, outputs, feeRate) {
return a + !isFinite(x.value)
}, 0)

if (remaining === 0 && unspecified === 0) return utils.finalize(utxos, outputs, feeRate)
if (remaining === 0 && unspecified === 0) return utils.finalize(utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength)

var splitOutputsCount = outputs.reduce(function (a, x) {
return a + !x.value
Expand All @@ -26,7 +26,7 @@ module.exports = function split (utxos, outputs, feeRate) {

// ensure every output is either user defined, or over the threshold
if (!outputs.every(function (x) {
return x.value !== undefined || (splitValue > utils.dustThreshold(x, feeRate))
return x.value !== undefined || (splitValue > utils.dustThreshold(feeRate, changeInputLengthEstimate))
})) return { fee: fee }

// assign splitValue to outputs not user defined
Expand All @@ -40,5 +40,5 @@ module.exports = function split (utxos, outputs, feeRate) {
return y
})

return utils.finalize(utxos, outputs, feeRate)
return utils.finalize(utxos, outputs, feeRate, changeInputLengthEstimate, changeOutputLength)
}
22 changes: 9 additions & 13 deletions utils.js
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Original file line number Diff line number Diff line change
@@ -1,21 +1,18 @@
// baseline estimates, used to improve performance
var TX_EMPTY_SIZE = 4 + 1 + 1 + 4
var TX_INPUT_BASE = 32 + 4 + 1 + 4
var TX_INPUT_PUBKEYHASH = 107
var TX_OUTPUT_BASE = 8 + 1
var TX_OUTPUT_PUBKEYHASH = 25

function inputBytes (input) {
return TX_INPUT_BASE + (input.script ? input.script.length : TX_INPUT_PUBKEYHASH)
return TX_INPUT_BASE + input.script.length
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not clear what happens if the input provided has no script 🤔

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@itsMikeLowrey itsMikeLowrey Mar 5, 2020 •
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I think @dcousens has proposed that an option object with some defaults in case the user doesn't feed in input script and length.

}

function outputBytes (output) {
return TX_OUTPUT_BASE + (output.script ? output.script.length : TX_OUTPUT_PUBKEYHASH)
return TX_OUTPUT_BASE + output.script.length
}

function dustThreshold (output, feeRate) {
/* ... classify the output for input estimate */
return inputBytes({}) * feeRate
function dustThreshold (feeRate, inputLenghtEstimate) {
return inputBytes({script: {length: inputLenghtEstimate}}) * feeRate
}

function transactionBytes (inputs, outputs) {
Expand All @@ -40,16 +37,15 @@ function sumOrNaN (range) {
return range.reduce(function (a, x) { return a + uintOrNaN(x.value) }, 0)
}

var BLANK_OUTPUT = outputBytes({})

function finalize (inputs, outputs, feeRate) {
function finalize (inputs, outputs, feeRate, changeInputLengthEstimate, changeOutputLength) {
var bytesAccum = transactionBytes(inputs, outputs)
var feeAfterExtraOutput = feeRate * (bytesAccum + BLANK_OUTPUT)
var blankOutputBytes = outputBytes({script: {length: changeOutputLength}})
var feeAfterExtraOutput = feeRate * (bytesAccum + blankOutputBytes)
var remainderAfterExtraOutput = sumOrNaN(inputs) - (sumOrNaN(outputs) + feeAfterExtraOutput)

// is it worth a change output?
if (remainderAfterExtraOutput > dustThreshold({}, feeRate)) {
outputs = outputs.concat({ value: remainderAfterExtraOutput })
if (remainderAfterExtraOutput > dustThreshold(feeRate, changeInputLengthEstimate)) {
outputs = outputs.concat({ value: remainderAfterExtraOutput, script: {length: changeOutputLength} })
}

var fee = sumOrNaN(inputs) - sumOrNaN(outputs)
Expand Down