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wanderer🌟 / js-primea-hypervisor



Tree: 8acbfdf6688be5aabb51397bfe951bb0997b1c8b

Files: 8acbfdf6688be5aabb51397bfe951bb0997b1c8b / interface.js

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1/**
2 * This is the Ethereum interface that is exposed to the WASM instance which
3 * enables to interact with the Ethereum Environment
4 */
5const Address = require('./address.js')
6const U256 = require('./u256.js')
7
8const U128_SIZE_BYTES = 16
9const ADDRESS_SIZE_BYTES = 20
10const U256_SIZE_BYTES = 32
11
12// The interface exposed to the WebAessembly Core
13module.exports = class Interface {
14  constructor (environment) {
15    this.environment = environment
16  }
17
18  get exportTable () {
19    let exportMethods = [
20      // include all the public methods according to the Ethereum Environment Interface (EEI) r1
21      'useGas',
22      'getGasLeft',
23      'getAddress',
24      'getBalance',
25      'getTxOrigin',
26      'getCaller',
27      'getCallValue',
28      'getCallDataSize',
29      'callDataCopy',
30      'callDataCopy256',
31      'getCodeSize',
32      'codeCopy',
33      'getExternalCodeSize',
34      'externalCodeCopy',
35      'getTxGasPrice',
36      'getBlockHash',
37      'getBlockCoinbase',
38      'getBlockTimestamp',
39      'getBlockNumber',
40      'getBlockDifficulty',
41      'getBlockGasLimit',
42      'log',
43      'create',
44      'call',
45      'callCode',
46      'callDelegate',
47      'storageStore',
48      'storageLoad',
49      'return',
50      'selfDestruct'
51    ]
52    let ret = {}
53    exportMethods.forEach((method) => {
54      ret[method] = this[method].bind(this)
55    })
56    return ret
57  }
58
59  setModule (mod) {
60    this.module = mod
61  }
62
63  /**
64   * Subtracts an amount to the gas counter
65   * @param {integer} amount the amount to subtract to the gas counter
66   */
67  useGas (amount) {
68    if (amount < 0) {
69      // convert from a 32-bit two's compliment
70      amount = 0x100000000 - amount
71    }
72
73    this.takeGas(amount)
74  }
75
76  /**
77   * Returns the current amount of gas
78   * @return {integer}
79   */
80  getGasLeft () {
81    this.takeGas(2)
82    return this.environment.gasLeft
83  }
84
85  /**
86   * Gets address of currently executing account and loads it into memory at
87   * the given offset.
88   * @param {integer} offset
89   */
90  getAddress (offset) {
91    this.takeGas(2)
92
93    this.setMemory(offset, ADDRESS_SIZE_BYTES, this.environment.address.toMemory())
94  }
95
96  /**
97   * Gets balance of the given account and loads it into memory at the given
98   * offset.
99   * @param {integer} addressOffset the memory offset to laod the address
100   * @param {integer} resultOffset
101   */
102  getBalance (addressOffset, offset) {
103    this.takeGas(20)
104
105    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
106    // call the parent contract and ask for the balance of one of its child contracts
107    const balance = this.environment.getBalance(address)
108    this.setMemory(offset, U128_SIZE_BYTES, balance.toMemory(U128_SIZE_BYTES))
109  }
110
111  /**
112   * Gets the execution's origination address and loads it into memory at the
113   * given offset. This is the sender of original transaction; it is never an
114   * account with non-empty associated code.
115   * @param {integer} offset
116   */
117  getTxOrigin (offset) {
118    this.takeGas(2)
119
120    this.setMemory(offset, ADDRESS_SIZE_BYTES, this.environment.origin.toMemory())
121  }
122
123  /**
124   * Gets caller address and loads it into memory at the given offset. This is
125   * the address of the account that is directly responsible for this execution.
126   * @param {integer} offset
127   */
128  getCaller (offset) {
129    this.takeGas(2)
130
131    this.setMemory(offset, ADDRESS_SIZE_BYTES, this.environment.caller.toMemory())
132  }
133
134  /**
135   * Gets the deposited value by the instruction/transaction responsible for
136   * this execution and loads it into memory at the given location.
137   * @param {integer} offset
138   */
139  getCallValue (offset) {
140    this.takeGas(2)
141
142    this.setMemory(offset, U128_SIZE_BYTES, this.environment.callValue.toMemory(U128_SIZE_BYTES))
143  }
144
145  /**
146   * Get size of input data in current environment. This pertains to the input
147   * data passed with the message call instruction or transaction.
148   * @return {integer}
149   */
150  getCallDataSize () {
151    this.takeGas(2)
152
153    return this.environment.callData.length
154  }
155
156  /**
157   * Copys the input data in current environment to memory. This pertains to
158   * the input data passed with the message call instruction or transaction.
159   * @param {integer} offset the offset in memory to load into
160   * @param {integer} dataOffset the offset in the input data
161   * @param {integer} length the length of data to copy
162   */
163  callDataCopy (offset, dataOffset, length) {
164    this.takeGas(3 + Math.ceil(length / 32) * 3)
165
166    if (length) {
167      const callData = this.environment.callData.slice(dataOffset, dataOffset + length)
168      this.setMemory(offset, length, callData)
169    }
170  }
171
172  /**
173   * Copys the input data in current environment to memory. This pertains to
174   * the input data passed with the message call instruction or transaction.
175   * @param {integer} offset the offset in memory to load into
176   * @param {integer} dataOffset the offset in the input data
177   */
178  callDataCopy256 (offset, dataOffset) {
179    this.takeGas(3)
180    const callData = this.environment.callData.slice(dataOffset, dataOffset + 32)
181    this.setMemory(offset, U256_SIZE_BYTES, callData)
182  }
183
184  /**
185   * Gets the size of code running in current environment.
186   * @return {interger}
187   */
188  getCodeSize () {
189    this.takeGas(2)
190
191    return this.environment.code.length
192  }
193
194  /**
195   * Copys the code running in current environment to memory.
196   * @param {integer} offset the memory offset
197   * @param {integer} codeOffset the code offset
198   * @param {integer} length the length of code to copy
199   */
200  codeCopy (resultOffset, codeOffset, length) {
201    this.takeGas(3 + Math.ceil(length / 32) * 3)
202
203    if (length) {
204      const code = this.environment.code.slice(codeOffset, codeOffset + length)
205      this.setMemory(resultOffset, length, code)
206    }
207  }
208
209  /**
210   * Get size of an account’s code.
211   * @param {integer} addressOffset the offset in memory to load the address from
212   * @return {integer}
213   */
214  getExternalCodeSize (addressOffset) {
215    this.takeGas(20)
216
217    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
218    const code = this.environment.getCode(address)
219    return code.length
220  }
221
222  /**
223   * Copys the code of an account to memory.
224   * @param {integer} addressOffset the memory offset of the address
225   * @param {integer} resultOffset the memory offset
226   * @param {integer} codeOffset the code offset
227   * @param {integer} length the length of code to copy
228   */
229  externalCodeCopy (addressOffset, resultOffset, codeOffset, length) {
230    this.takeGas(20 + Math.ceil(length / 32) * 3)
231
232    if (length) {
233      const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
234      let code = this.environment.getCode(address)
235      code = code.slice(codeOffset, codeOffset + length)
236      this.setMemory(resultOffset, length, code)
237    }
238  }
239
240  /**
241   * Gets price of gas in current environment.
242   * @return {integer}
243   */
244  getTxGasPrice () {
245    this.takeGas(2)
246
247    return this.environment.gasPrice
248  }
249
250  /**
251   * Gets the hash of one of the 256 most recent complete blocks.
252   * @param {integer} number which block to load
253   * @param {integer} offset the offset to load the hash into
254   */
255  getBlockHash (number, offset) {
256    this.takeGas(20)
257
258    const diff = this.environment.block.number - number
259    let hash
260
261    if (diff > 256 || diff <= 0) {
262      hash = new U256(0)
263    } else {
264      hash = new U256(this.environment.getBlockHash(number))
265    }
266    this.setMemory(offset, U256_SIZE_BYTES, hash.toMemory())
267  }
268
269  /**
270   * Gets the block’s beneficiary address and loads into memory.
271   * @param offset
272   */
273  getBlockCoinbase (offset) {
274    this.takeGas(2)
275
276    this.setMemory(offset, ADDRESS_SIZE_BYTES, this.environment.block.coinbase.toMemory())
277  }
278
279  /**
280   * Get the block’s timestamp.
281   * @return {integer}
282   */
283  getBlockTimestamp () {
284    this.takeGas(2)
285
286    return this.environment.block.timestamp
287  }
288
289  /**
290   * Get the block’s number.
291   * @return {integer}
292   */
293  getBlockNumber () {
294    this.takeGas(2)
295
296    return this.environment.block.number
297  }
298
299  /**
300   * Get the block’s difficulty.
301   * @return {integer}
302   */
303  getBlockDifficulty (offset) {
304    this.takeGas(2)
305
306    this.setMemory(offset, U256_SIZE_BYTES, this.environment.block.difficulty.toMemory())
307  }
308
309  /**
310   * Get the block’s gas limit.
311   * @return {integer}
312   */
313  getBlockGasLimit () {
314    this.takeGas(2)
315
316    return this.environment.block.gasLimit
317  }
318
319  /**
320   * Creates a new log in the current environment
321   * @param {integer} dataOffset the offset in memory to load the memory
322   * @param {integer} length the data length
323   * @param {integer} number of topics
324   */
325  log (dataOffset, length, numberOfTopics, topic1, topic2, topic3, topic4) {
326    if (numberOfTopics < 0 || numberOfTopics > 4) {
327      throw new Error('Invalid numberOfTopics')
328    }
329
330    this.takeGas(375 + length * 8 + numberOfTopics * 375)
331
332    const data = length ? this.getMemory(dataOffset, length).slice(0) : new Uint8Array([])
333    const topics = []
334
335    if (numberOfTopics > 0) {
336      topics.push(U256.fromMemory(this.getMemory(topic1, U256_SIZE_BYTES)))
337    }
338
339    if (numberOfTopics > 1) {
340      topics.push(U256.fromMemory(this.getMemory(topic2, U256_SIZE_BYTES)))
341    }
342
343    if (numberOfTopics > 2) {
344      topics.push(U256.fromMemory(this.getMemory(topic3, U256_SIZE_BYTES)))
345    }
346
347    if (numberOfTopics > 3) {
348      topics.push(U256.fromMemory(this.getMemory(topic4, U256_SIZE_BYTES)))
349    }
350
351    this.environment.logs.push({
352      data: data,
353      topics: topics
354    })
355  }
356
357  /**
358   * Creates a new contract with a given value.
359   * @param {integer} valueOffset the offset in memory to the value from
360   * @param {integer} dataOffset the offset to load the code for the new contract from
361   * @param {integer} length the data length
362   * @param (integer} resultOffset the offset to write the new contract address to
363   * @return {integer} Return 1 or 0 depending on if the VM trapped on the message or not
364   */
365  create (valueOffset, dataOffset, length, resultOffset) {
366    this.takeGas(32000)
367
368    const value = U256.fromMemory(this.getMemory(valueOffset, U128_SIZE_BYTES))
369    if (length) {
370      const data = this.getMemory(dataOffset, length).slice(0)
371      // const [errorCode, address] = this.environment.create(value, data)
372    }
373    let address
374    if (value.gt(this.environment.value)) {
375      address = new Address()
376    } else {
377      address = new Address('0x945304eb96065b2a98b57a48a06ae28d285a71b5')
378    }
379    this.setMemory(resultOffset, ADDRESS_SIZE_BYTES, address.toMemory())
380    // return errorCode
381  }
382
383  /**
384   * Sends a message with arbiatary data to a given address path
385   * @param {integer} addressOffset the offset to load the address path from
386   * @param {integer} valueOffset the offset to load the value from
387   * @param {integer} dataOffset the offset to load data from
388   * @param {integer} dataLength the length of data
389   * @param {integer} resultOffset the offset to store the result data at
390   * @param {integer} resultLength
391   * @param {integer} gas
392   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
393   */
394  call (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
395    // Load the params from mem
396    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
397    const value = U256.fromMemory(this.getMemory(valueOffset, U128_SIZE_BYTES))
398
399    this.takeGas(40)
400
401    // const data = this.getMemory(dataOffset, dataLength).slice(0)
402
403    // // Special case for calling into empty account
404    // if (!this.environment.isAccountPresent(address)) {
405    //   this.takeGas(25000)
406    // }
407    if (address.lt(new U256(4))) {
408      this.takeGas(25000)
409    }
410    // // Special case for non-zero value
411    if (!value.isZero()) {
412      this.takeGas(9000 -  2300 + gas)
413      this.takeGas(-gas)
414    }
415
416    // const [errorCode, result] = this.environment.call(gas, address, value, data)
417    // this.setMemory(resultOffset, resultLength, result)
418    // return errorCode
419    //
420    return 1
421  }
422
423  /**
424   * Message-call into this account with an alternative account’s code.
425   * @param {integer} addressOffset the offset to load the address path from
426   * @param {integer} valueOffset the offset to load the value from
427   * @param {integer} dataOffset the offset to load data from
428   * @param {integer} dataLength the length of data
429   * @param {integer} resultOffset the offset to store the result data at
430   * @param {integer} resultLength
431   * @param {integer} gas
432   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
433   */
434  callCode (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
435    // Load the params from mem
436    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
437    const value = U256.fromMemory(this.getMemory(valueOffset, U128_SIZE_BYTES))
438
439    this.takeGas(40)
440
441    // const data = this.getMemory(dataOffset, dataLength).slice(0)
442
443    // // Special case for calling into empty account
444    // if (!this.environment.isAccountPresent(address)) {
445    //   this.takeGas(25000)
446    // }
447    // // Special case for non-zero value
448    if (!value.isZero()) {
449      this.takeGas(9000 - 2300 + gas)
450      this.takeGas(-gas)
451    }
452
453    // const [errorCode, result] = this.environment.call(gas, address, value, data)
454    // this.setMemory(resultOffset, resultLength, result)
455    // return errorCode
456    //
457    return 1
458  }
459
460  /**
461   * Message-call into this account with an alternative account’s code, but
462   * persisting the current values for sender and value.
463   * @param {integer} gas
464   * @param {integer} addressOffset the offset to load the address path from
465   * @param {integer} valueOffset the offset to load the value from
466   * @param {integer} dataOffset the offset to load data from
467   * @param {integer} dataLength the length of data
468   * @param {integer} resultOffset the offset to store the result data at
469   * @param {integer} resultLength
470   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
471   */
472  callDelegate (gas, addressOffset, dataOffset, dataLength, resultOffset, resultLength) {
473    // FIXME: count properly
474    this.takeGas(40)
475
476    const data = this.getMemory(dataOffset, dataLength).slice(0)
477    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
478    const [errorCode, result] = this.environment.callDelegate(gas, address, data)
479    this.setMemory(resultOffset, resultLength, result)
480    return errorCode
481  }
482
483  /**
484   * store a value at a given path in long term storage which are both loaded
485   * from Memory
486   * @param {interger} pathOffest the memory offset to load the the path from
487   * @param {interger} valueOffset the memory offset to load the value from
488   */
489  storageStore (pathOffset, valueOffset) {
490    const path = new Buffer(this.getMemory(pathOffset, U256_SIZE_BYTES)).toString('hex')
491    // copy the value
492    const value = this.getMemory(valueOffset, U256_SIZE_BYTES).slice(0)
493    const oldValue = this.environment.state.get(path)
494    const valIsZero = value.every((i) => i === 0)
495
496    this.takeGas(5000)
497
498    // write
499    if (!valIsZero && !oldValue) {
500      this.takeGas(15000)
501    }
502
503    // delete
504    if (valIsZero && oldValue) {
505      this.environment.gasRefund += 15000
506      this.environment.state.delete(path)
507    } else {
508      this.environment.state.set(path, value)
509    }
510  }
511
512  /**
513   * reterives a value at a given path in long term storage
514   * @param {interger} pathOffest the memory offset to load the the path from
515   * @param {interger} resultOffset the memory offset to load the value from
516   */
517  storageLoad (pathOffset, resultOffset) {
518    this.takeGas(50)
519
520    const path = new Buffer(this.getMemory(pathOffset, U256_SIZE_BYTES)).toString('hex')
521    const result = this.environment.state.get(path) || new Uint8Array(32)
522    this.setMemory(resultOffset, U256_SIZE_BYTES, result)
523  }
524
525  /**
526   * Halt execution returning output data.
527   * @param {integer} offset the offset of the output data.
528   * @param {integer} length the length of the output data.
529   */
530  return (offset, length) {
531    if (length) {
532      this.environment.returnValue = this.getMemory(offset, length).slice(0)
533    }
534  }
535
536  /**
537   * Halt execution and register account for later deletion giving the remaining
538   * balance to an address path
539   * @param {integer} offset the offset to load the address from
540   */
541  selfDestruct (addressOffset) {
542    this.environment.selfDestruct = true
543    this.environment.selfDestructAddress = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
544    this.environment.gasRefund += 24000
545  }
546
547  getMemory (offset, length) {
548    return new Uint8Array(this.module.exports.memory, offset, length)
549  }
550
551  setMemory (offset, length, value) {
552    const memory = new Uint8Array(this.module.exports.memory, offset, length)
553    memory.set(value)
554  }
555
556  /*
557   * Takes gas from the tank. Only needs to check if there's gas left to be taken,
558   * because every caller of this method is trusted.
559   */
560  takeGas (amount) {
561    if (this.environment.gasLeft < amount) {
562      throw new Error('Ran out of gas')
563    }
564    this.environment.gasLeft -= amount
565  }
566}
567
568//
569// Polyfill required unless this is sorted: https://bugs.chromium.org/p/chromium/issues/detail?id=633895
570//
571// Polyfill from: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind
572//
573Function.prototype.bind = function (oThis) { // eslint-disable-line
574  if (typeof this !== 'function') {
575    // closest thing possible to the ECMAScript 5
576    // internal IsCallable function
577    throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable')
578  }
579
580  var aArgs = Array.prototype.slice.call(arguments, 1)
581  var fToBind = this
582  var fNOP = function () {}
583  var fBound = function () {
584    return fToBind.apply(this instanceof fNOP ? this : oThis,
585     aArgs.concat(Array.prototype.slice.call(arguments)))
586  }
587
588  if (this.prototype) {
589    // Function.prototype doesn't have a prototype property
590    fNOP.prototype = this.prototype
591  }
592
593  fBound.prototype = new fNOP() // eslint-disable-line new-cap
594
595  return fBound
596}
597

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