SizeEstimation::getLengthOfVector() - Code Metrics - Inspection of "Size estimation static fixtures" - blocktrail/blocktrail-sdk-php - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#93)

by thomas

created 2017-11-27 14:44 UTC

SizeEstimation::getLengthOfVector() A

↳ Parent: SizeEstimation

Complexity

Conditions	2
Paths	2

Size

Total Lines	7
Code Lines	5

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	5
CRAP Score	2

Importance

Changes

Metric	Value
cc	2
eloc	5
nc	2
nop	1
dl	0
loc	7
ccs	5
cts	5
cp	1
crap	2
rs	9.4285
c	0
b	0
f	0

<?php

namespace Blocktrail\SDK;

use BitWasp\Bitcoin\Script\ScriptFactory;
use BitWasp\Bitcoin\Script\ScriptType;
use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PublicKeyInterface;
use \BitWasp\Bitcoin\Script\ScriptInfo\Multisig;
use \BitWasp\Bitcoin\Script\ScriptInfo\PayToPubKey;
use \BitWasp\Bitcoin\Script\Classifier\OutputClassifier;
use BitWasp\Bitcoin\Script\ScriptInterface;
use BitWasp\Bitcoin\Transaction\TransactionOutputInterface;

class SizeEstimation
{
    const SIZE_DER_SIGNATURE = 72;
    const SIZE_V0_P2WSH = 36;

    /**
     * @param bool $compressed
     * @return int
     */
    public static function getPublicKeySize($compressed = true) {
        return $compressed ? PublicKeyInterface::LENGTH_COMPRESSED : PublicKeyInterface::LENGTH_UNCOMPRESSED;
    }

    /**
     * @param int $length
     * @return int
     */
    public static function getLengthOfScriptLengthElement($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 \RuntimeException('Size of pushdata too large');
        }
    }

    /**
     * @param int $length
     * @return int
     */
    public static function getLengthOfVarInt($length) {
        if ($length < 253) {
            return 1;
        } else if ($length < 65535) {
            $num_bytes = 2;
        } else if ($length < 4294967295) {
            $num_bytes = 4;
        } else if ($length < 18446744073709551615) {
            $num_bytes = 8;
        } else {
            throw new \InvalidArgumentException("Invalid decimal");
        }
        return 1 + $num_bytes;
    }

    /**
     * @param array $vectorSizes
     * @return int|mixed
     */
    public static function getLengthOfVector(array $vectorSizes) {
        $vectorSize = self::getLengthOfVarInt(count($vectorSizes));
        foreach ($vectorSizes as $size) {
            $vectorSize += self::getLengthOfVarInt($size) + $size;
        }
        return $vectorSize;
    }

    /**
     * @param Multisig $multisig
     * @return array - first is array of stack sizes, second is script len
     */
    public static function estimateMultisigStackSize(Multisig $multisig) {
        $stackSizes = [0];
        for ($i = 0; $i < $multisig->getRequiredSigCount(); $i++) {
            $stackSizes[] = self::SIZE_DER_SIGNATURE;
        }

        $scriptSize = 1; // OP_$m
        $keys = $multisig->getKeyBuffers();
        for ($i = 0, $n = $multisig->getKeyCount(); $i < $n; $i++) {
            $scriptSize += 1 + $keys[$i]->getSize();
        }

        $scriptSize += 1 + 1; // OP_$n OP_CHECKMULTISIG
        return [$stackSizes, $scriptSize];
    }

    /**
     * @param PayToPubKey $info
     * @return array - first is array of stack sizes, second is script len
     */
    public static function estimateP2PKStackSize(PayToPubKey $info) {
        $stackSizes = [self::SIZE_DER_SIGNATURE];

        $scriptSize = 1 + $info->getKeyBuffer()->getSize(); // PUSHDATA[<75] PUBLICKEY

        $scriptSize += 1; // OP_CHECKSIG
        return [$stackSizes, $scriptSize];
    }

    /**
     * @param bool $isCompressed
     * @return array - first is array of stack sizes, second is script len
     */
    public static function estimateP2PKHStackSize($isCompressed = true) {
        $pubKeySize = self::getPublicKeySize($isCompressed);
        $stackSizes = [self::SIZE_DER_SIGNATURE, $pubKeySize];

        $scriptSize = 1 + 1 + 1 + 20 + 1 + 1;
        return [$stackSizes, $scriptSize];
    }

    /**
     * @param array $stackSizes - array of integer size of a value (for scriptSig or witness)
     * @param bool $isWitness
     * @param ScriptInterface $redeemScript
     * @param ScriptInterface $witnessScript
     * @return array
     */
    public static function estimateSizeForStack(array $stackSizes, $isWitness, ScriptInterface $redeemScript = null, ScriptInterface $witnessScript = null) {
        assert(($witnessScript === null) || $isWitness);

        if ($isWitness) {
            $scriptSigSizes = [];
            $witnessSizes = $stackSizes;
            if ($witnessScript instanceof ScriptInterface) {
                $witnessSizes[] = $witnessScript->getBuffer()->getSize();
            }
        } else {
            $scriptSigSizes = $stackSizes;
            $witnessSizes = [];
        }

        if ($redeemScript instanceof ScriptInterface) {
            $scriptSigSizes[] = $redeemScript->getBuffer()->getSize();
        }

        $scriptSigSize = 0;
        foreach ($scriptSigSizes as $size) {
            $len = self::getLengthOfScriptLengthElement($size);
            $scriptSigSize += $len;
            $scriptSigSize += $size;
        }

        // Make sure to count the CScriptBase length prefix..
        $scriptSigSize += self::getLengthOfVarInt($scriptSigSize);

        // make sure this is set to 0 when not used.
        // Summing WitnessSize is used in addition to $withWitness
        // because a tx without witnesses _cannot_ use witness serialization
        // total witnessSize = 0 means don't use that format
        $witnessSize = 0;
        if (count($witnessSizes) > 0) {
            // witness has a prefix indicating `n` elements in vector
            $witnessSize = self::getLengthOfVector($witnessSizes);
        }
        return [$scriptSigSize, $witnessSize];
    }

    /**
     * @param ScriptInterface $script - not the scriptPubKey, might be SPK,RS,WS
     * @param ScriptInterface|null $redeemScript
     * @param ScriptInterface $witnessScript
     * @param bool $isWitness
     * @return array
     */
    public static function estimateInputFromScripts(ScriptInterface $script, ScriptInterface $redeemScript = null, ScriptInterface $witnessScript = null, $isWitness) {
        assert($witnessScript === null || $isWitness);
        $classifier = new OutputClassifier();
        if ($classifier->isMultisig($script)) {
            list ($stackSizes, ) = SizeEstimation::estimateMultisigStackSize(new Multisig($script));
        } else if ($classifier->isPayToPublicKey($script)) {
            list ($stackSizes, ) = SizeEstimation::estimateP2PKStackSize(new PayToPubKey($script));
        } else if ($classifier->isPayToPublicKeyHash($script)) {
            // defaults to compressed, tough luck
            list ($stackSizes, ) = SizeEstimation::estimateP2PKHStackSize();
        } else {
            throw new \InvalidArgumentException("Unsupported script type");
        }

        return self::estimateSizeForStack($stackSizes, $isWitness, $redeemScript, $witnessScript);
    }

    /**
     * @param UTXO $utxo
     * @return array
     */
    public static function estimateUtxo(UTXO $utxo) {
        $classifier = new OutputClassifier();
        $decodePK = $classifier->decode($utxo->scriptPubKey);
        $witness = false;
        if ($decodePK->getType() === ScriptType::P2SH) {
            if (null === $utxo->redeemScript) {
                throw new \RuntimeException("Can't estimate, missing redeem script");
            }
            $decodePK = $classifier->decode($utxo->redeemScript);
        }

        if ($decodePK->getType() === ScriptType::P2WKH) {
            $scriptSitu = ScriptFactory::scriptPubKey()->p2pkh($decodePK->getSolution());
            $decodePK = $classifier->decode($scriptSitu);
            $witness = true;
        } else if ($decodePK->getType() === ScriptType::P2WSH) {
            if (null === $utxo->witnessScript) {
                throw new \RuntimeException("Can't estimate, missing witness script");
            }
            $decodePK = $classifier->decode($utxo->witnessScript);
            $witness = true;
        }

        if (!in_array($decodePK->getType(), [ScriptType::MULTISIG, ScriptType::P2PKH, ScriptType::P2PK])) {
            throw new \RuntimeException("Unsupported script type");
        }

        $script = $decodePK->getScript();
        list ($scriptSig, $witness) = SizeEstimation::estimateInputFromScripts($script, $utxo->redeemScript, $utxo->witnessScript, $witness);

        return [
            "scriptSig" => $scriptSig,
            "witness" => $witness,
        ];
    }

    /**
     * @param UTXO[] $utxos
     * @param bool $withWitness
     * @return integer
     */
    public static function estimateInputsSize(array $utxos, $withWitness) {
        $inputSize = 0;
        $witnessSize = 0;
        foreach ($utxos as $utxo) {
            $estimate = SizeEstimation::estimateUtxo($utxo);
            $inputSize += 32 + 4 + 4;
            $inputSize += $estimate['scriptSig'];
            if ($withWitness) {
                $witnessSize += $estimate['witness'];
            }
        }

        if ($withWitness && $witnessSize != 0) {
            $inputSize += $witnessSize;
            $inputSize += 2; // flag bytes
        }

        return $inputSize;
    }

    /**
     * @param array $outputs
     * @return int
     */
    public static function estimateOutputsSize(array $outputs) {
        $outputSize = 0;
        foreach ($outputs as $output) {
            $outputSize += 8;

            $scriptSize = null;
            if ($output instanceof TransactionOutputInterface) {
                $scriptSize = $output->getScript()->getBuffer()->getSize();
            } else {
                if (isset($output['scriptPubKey'])) {
                    if ($output['scriptPubKey'] instanceof ScriptInterface) {
                        $scriptSize = $output['scriptPubKey']->getBuffer()->getSize();
                    } else {
                        $scriptSize = strlen($output['scriptPubKey']) / 2;
                    }
                } else {
                    $scriptSize += 25;
                }
            }

            $outputSize += SizeEstimation::getLengthOfVarInt($scriptSize) + $scriptSize;
        }

        return $outputSize;
    }

    /**
     * @param UTXO[] $utxos
     * @param array $outputs
     * @return int
     */
    public static function estimateVsize(array $utxos, array $outputs) {
        return (int)ceil(self::estimateWeight($utxos, $outputs) / 4);
    }

    /**
     * @param UTXO[] $utxos
     * @param array $outputs
     * @return int
     */
    public static function estimateWeight(array $utxos, array $outputs) {
        $outputsSize = SizeEstimation::estimateOutputsSize($outputs);
        $baseSize = 4
            + SizeEstimation::getLengthOfVarInt(count($utxos)) + SizeEstimation::estimateInputsSize($utxos, false)
            + SizeEstimation::getLengthOfVarInt(count($outputs)) + $outputsSize
            + 4;
        $witnessSize = 4
            + SizeEstimation::getLengthOfVarInt(count($utxos)) + SizeEstimation::estimateInputsSize($utxos, true)
            + SizeEstimation::getLengthOfVarInt(count($outputs)) + $outputsSize
            + 4;

        return ($baseSize * 3) + $witnessSize;
    }
}


1		<?php
2
3		namespace Blocktrail\SDK;
4
5		use BitWasp\Bitcoin\Script\ScriptFactory;
6		use BitWasp\Bitcoin\Script\ScriptType;
7		use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PublicKeyInterface;
8		use \BitWasp\Bitcoin\Script\ScriptInfo\Multisig;
9		use \BitWasp\Bitcoin\Script\ScriptInfo\PayToPubKey;
10		use \BitWasp\Bitcoin\Script\Classifier\OutputClassifier;
11		use BitWasp\Bitcoin\Script\ScriptInterface;
12		use BitWasp\Bitcoin\Transaction\TransactionOutputInterface;
13
14		class SizeEstimation
15		{
16		const SIZE_DER_SIGNATURE = 72;
17		const SIZE_V0_P2WSH = 36;
18
19		/**
20		* @param bool $compressed
21		* @return int
22		*/
23	2	public static function getPublicKeySize($compressed = true) {
24	2	return $compressed ? PublicKeyInterface::LENGTH_COMPRESSED : PublicKeyInterface::LENGTH_UNCOMPRESSED;
25		}
26
27		/**
28		* @param int $length
29		* @return int
30		*/
31	26	public static function getLengthOfScriptLengthElement($length) {
32	26	if ($length < 75) {
33	18	return 1;
34	17	} else if ($length <= 0xff) {
35	13	return 2;
36	4	} else if ($length <= 0xffff) {
37	3	return 3;
38	1	} else if ($length <= 0xffffffff) {
39	1	return 5;
40		} else {
41		throw new \RuntimeException('Size of pushdata too large');
42		}
43		}
44
45		/**
46		* @param int $length
47		* @return int
48		*/
49	31	public static function getLengthOfVarInt($length) {
50	31	if ($length < 253) {
51	18	return 1;
52	19	} else if ($length < 65535) {
53	12	$num_bytes = 2;
54	7	} else if ($length < 4294967295) {
55	4	$num_bytes = 4;
56	3	} else if ($length < 18446744073709551615) {
57	3	$num_bytes = 8;
58		} else {
59		throw new \InvalidArgumentException("Invalid decimal");
60		}
61	19	return 1 + $num_bytes;
62		}
63
64		/**
65		* @param array $vectorSizes
66		* @return int\|mixed
67		*/
68	8	public static function getLengthOfVector(array $vectorSizes) {
69	8	$vectorSize = self::getLengthOfVarInt(count($vectorSizes));
70	8	foreach ($vectorSizes as $size) {
71	8	$vectorSize += self::getLengthOfVarInt($size) + $size;
72		}
73	8	return $vectorSize;
74		}
75
76		/**
77		* @param Multisig $multisig
78		* @return array - first is array of stack sizes, second is script len
79		*/
80	19	public static function estimateMultisigStackSize(Multisig $multisig) {
81	19	$stackSizes = [0];
82	19	for ($i = 0; $i < $multisig->getRequiredSigCount(); $i++) {
83	19	$stackSizes[] = self::SIZE_DER_SIGNATURE;
84		}
85
86	19	$scriptSize = 1; // OP_$m
87	19	$keys = $multisig->getKeyBuffers();
88	19	for ($i = 0, $n = $multisig->getKeyCount(); $i < $n; $i++) {
89	19	$scriptSize += 1 + $keys[$i]->getSize();
90		}
91
92	19	$scriptSize += 1 + 1; // OP_$n OP_CHECKMULTISIG
93	19	return [$stackSizes, $scriptSize];
94		}
95
96		/**
97		* @param PayToPubKey $info
98		* @return array - first is array of stack sizes, second is script len
99		*/
100		public static function estimateP2PKStackSize(PayToPubKey $info) {
101		$stackSizes = [self::SIZE_DER_SIGNATURE];
102
103		$scriptSize = 1 + $info->getKeyBuffer()->getSize(); // PUSHDATA[<75] PUBLICKEY
		0 ignored issues – show Unused Code Comprehensibility introduced 2017-10-05 15:22 UTC by Report Bug Copy Issue Report `38%` of this comment could be valid code. Did you maybe forget this after debugging? Sometimes obsolete code just ends up commented out instead of removed. In this case it is better to remove the code once you have checked you do not need it. The code might also have been commented out for debugging purposes. In this case it is vital that someone uncomments it again or your project may behave in very unexpected ways in production. This check looks for comments that seem to be mostly valid code and reports them. Loading history...
104		$scriptSize += 1; // OP_CHECKSIG
105		return [$stackSizes, $scriptSize];
106		}
107
108		/**
109		* @param bool $isCompressed
110		* @return array - first is array of stack sizes, second is script len
111		*/
112	2	public static function estimateP2PKHStackSize($isCompressed = true) {
113	2	$pubKeySize = self::getPublicKeySize($isCompressed);
114	2	$stackSizes = [self::SIZE_DER_SIGNATURE, $pubKeySize];
115
116	2	$scriptSize = 1 + 1 + 1 + 20 + 1 + 1;
117	2	return [$stackSizes, $scriptSize];
118		}
119
120		/**
121		* @param array $stackSizes - array of integer size of a value (for scriptSig or witness)
122		* @param bool $isWitness
123		* @param ScriptInterface $redeemScript
124		* @param ScriptInterface $witnessScript
125		* @return array
126		*/
127	18	public static function estimateSizeForStack(array $stackSizes, $isWitness, ScriptInterface $redeemScript = null, ScriptInterface $witnessScript = null) {
128	18	assert(($witnessScript === null) \|\| $isWitness);
129
130	18	if ($isWitness) {
131	8	$scriptSigSizes = [];
132	8	$witnessSizes = $stackSizes;
133	8	if ($witnessScript instanceof ScriptInterface) {
134	8	$witnessSizes[] = $witnessScript->getBuffer()->getSize();
135		}
136		} else {
137	11	$scriptSigSizes = $stackSizes;
138	11	$witnessSizes = [];
139		}
140
141	18	if ($redeemScript instanceof ScriptInterface) {
142	13	$scriptSigSizes[] = $redeemScript->getBuffer()->getSize();
143		}
144
145	18	$scriptSigSize = 0;
146	18	foreach ($scriptSigSizes as $size) {
147	15	$len = self::getLengthOfScriptLengthElement($size);
148	15	$scriptSigSize += $len;
149	15	$scriptSigSize += $size;
150		}
151
152		// Make sure to count the CScriptBase length prefix..
153	18	$scriptSigSize += self::getLengthOfVarInt($scriptSigSize);
154
155		// make sure this is set to 0 when not used.
156		// Summing WitnessSize is used in addition to $withWitness
157		// because a tx without witnesses _cannot_ use witness serialization
158		// total witnessSize = 0 means don't use that format
159	18	$witnessSize = 0;
160	18	if (count($witnessSizes) > 0) {
161		// witness has a prefix indicating `n` elements in vector
162	8	$witnessSize = self::getLengthOfVector($witnessSizes);
163		}
164	18	return [$scriptSigSize, $witnessSize];
165		}
166
167		/**
168		* @param ScriptInterface $script - not the scriptPubKey, might be SPK,RS,WS
169		* @param ScriptInterface\|null $redeemScript
170		* @param ScriptInterface $witnessScript
171		* @param bool $isWitness
172		* @return array
173		*/
174	14	public static function estimateInputFromScripts(ScriptInterface $script, ScriptInterface $redeemScript = null, ScriptInterface $witnessScript = null, $isWitness) {
175	14	assert($witnessScript === null \|\| $isWitness);
176	14	$classifier = new OutputClassifier();
177	14	if ($classifier->isMultisig($script)) {
178	12	list ($stackSizes, ) = SizeEstimation::estimateMultisigStackSize(new Multisig($script));
179	2	} else if ($classifier->isPayToPublicKey($script)) {
180		list ($stackSizes, ) = SizeEstimation::estimateP2PKStackSize(new PayToPubKey($script));
181	2	} else if ($classifier->isPayToPublicKeyHash($script)) {
182		// defaults to compressed, tough luck
183	2	list ($stackSizes, ) = SizeEstimation::estimateP2PKHStackSize();
184		} else {
185		throw new \InvalidArgumentException("Unsupported script type");
186		}
187
188	14	return self::estimateSizeForStack($stackSizes, $isWitness, $redeemScript, $witnessScript);
189		}
190
191		/**
192		* @param UTXO $utxo
193		* @return array
194		*/
195	14	public static function estimateUtxo(UTXO $utxo) {
196	14	$classifier = new OutputClassifier();
197	14	$decodePK = $classifier->decode($utxo->scriptPubKey);
198	14	$witness = false;
199	14	if ($decodePK->getType() === ScriptType::P2SH) {
200	11	if (null === $utxo->redeemScript) {
201		throw new \RuntimeException("Can't estimate, missing redeem script");
202		}
203	11	$decodePK = $classifier->decode($utxo->redeemScript);
204		}
205
206	14	if ($decodePK->getType() === ScriptType::P2WKH) {
207	2	$scriptSitu = ScriptFactory::scriptPubKey()->p2pkh($decodePK->getSolution());
208	2	$decodePK = $classifier->decode($scriptSitu);
209	2	$witness = true;
210	12	} else if ($decodePK->getType() === ScriptType::P2WSH) {
211	4	if (null === $utxo->witnessScript) {
212		throw new \RuntimeException("Can't estimate, missing witness script");
213		}
214	4	$decodePK = $classifier->decode($utxo->witnessScript);
215	4	$witness = true;
216		}
217
218	14	if (!in_array($decodePK->getType(), [ScriptType::MULTISIG, ScriptType::P2PKH, ScriptType::P2PK])) {
219		throw new \RuntimeException("Unsupported script type");
220		}
221
222	14	$script = $decodePK->getScript();
223	14	list ($scriptSig, $witness) = SizeEstimation::estimateInputFromScripts($script, $utxo->redeemScript, $utxo->witnessScript, $witness);
224
225		return [
226	14	"scriptSig" => $scriptSig,
227	14	"witness" => $witness,
228		];
229		}
230
231		/**
232		* @param UTXO[] $utxos
233		* @param bool $withWitness
234		* @return integer
235		*/
236	9	public static function estimateInputsSize(array $utxos, $withWitness) {
237	9	$inputSize = 0;
238	9	$witnessSize = 0;
239	9	foreach ($utxos as $utxo) {
240	9	$estimate = SizeEstimation::estimateUtxo($utxo);
241	9	$inputSize += 32 + 4 + 4;
242	9	$inputSize += $estimate['scriptSig'];
243	9	if ($withWitness) {
244	9	$witnessSize += $estimate['witness'];
245		}
246		}
247
248	9	if ($withWitness && $witnessSize != 0) {
249	4	$inputSize += $witnessSize;
250	4	$inputSize += 2; // flag bytes
251		}
252
253	9	return $inputSize;
254		}
255
256		/**
257		* @param array $outputs
258		* @return int
259		*/
260	9	public static function estimateOutputsSize(array $outputs) {
261	9	$outputSize = 0;
262	9	foreach ($outputs as $output) {
263	9	$outputSize += 8;
264
265	9	$scriptSize = null;
266	9	if ($output instanceof TransactionOutputInterface) {
267	2	$scriptSize = $output->getScript()->getBuffer()->getSize();
268		} else {
269	9	if (isset($output['scriptPubKey'])) {
270	4	if ($output['scriptPubKey'] instanceof ScriptInterface) {
271	4	$scriptSize = $output['scriptPubKey']->getBuffer()->getSize();
272		} else {
273	4	$scriptSize = strlen($output['scriptPubKey']) / 2;
274		}
275		} else {
276	7	$scriptSize += 25;
277		}
278		}
279
280	9	$outputSize += SizeEstimation::getLengthOfVarInt($scriptSize) + $scriptSize;
281		}
282
283	9	return $outputSize;
284		}
285
286		/**
287		* @param UTXO[] $utxos
288		* @param array $outputs
289		* @return int
290		*/
291	9	public static function estimateVsize(array $utxos, array $outputs) {
292	9	return (int)ceil(self::estimateWeight($utxos, $outputs) / 4);
293		}
294
295		/**
296		* @param UTXO[] $utxos
297		* @param array $outputs
298		* @return int
299		*/
300	9	public static function estimateWeight(array $utxos, array $outputs) {
301	9	$outputsSize = SizeEstimation::estimateOutputsSize($outputs);
302		$baseSize = 4
303	9	+ SizeEstimation::getLengthOfVarInt(count($utxos)) + SizeEstimation::estimateInputsSize($utxos, false)
304	9	+ SizeEstimation::getLengthOfVarInt(count($outputs)) + $outputsSize
305	9	+ 4;
306		$witnessSize = 4
307	9	+ SizeEstimation::getLengthOfVarInt(count($utxos)) + SizeEstimation::estimateInputsSize($utxos, true)
308	9	+ SizeEstimation::getLengthOfVarInt(count($outputs)) + $outputsSize
309	9	+ 4;
310
311	9	return ($baseSize * 3) + $witnessSize;
312		}
313		}
314

blocktrail / blocktrail-sdk-php

Pull Request — master (#93)

SizeEstimation::getLengthOfVector() A

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