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wanderer🌟 / js-primea-hypervisor



Tree: 104b97b6875d1f6ba6bd5ebaa5b680ad29f492bb

Files: 104b97b6875d1f6ba6bd5ebaa5b680ad29f492bb / 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      throw new Error('Negative gas deduction requested')
70    }
71
72    this.takeGas(amount)
73  }
74
75  /**
76   * Returns the current amount of gas
77   * @return {integer}
78   */
79  getGasLeft () {
80    this.takeGas(2)
81
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    const callData = this.environment.callData.slice(dataOffset, dataOffset + length)
167    this.setMemory(offset, length, callData)
168  }
169
170  /**
171   * Copys the input data in current environment to memory. This pertains to
172   * the input data passed with the message call instruction or transaction.
173   * @param {integer} offset the offset in memory to load into
174   * @param {integer} dataOffset the offset in the input data
175   */
176  callDataCopy256 (offset, dataOffset) {
177    this.takeGas(3)
178    const callData = this.environment.callData.slice(dataOffset, dataOffset + 32)
179    this.setMemory(offset, U256_SIZE_BYTES, callData)
180  }
181
182  /**
183   * Gets the size of code running in current environment.
184   * @return {interger}
185   */
186  getCodeSize () {
187    this.takeGas(2)
188
189    return this.environment.code.length
190  }
191
192  /**
193   * Copys the code running in current environment to memory.
194   * @param {integer} offset the memory offset
195   * @param {integer} codeOffset the code offset
196   * @param {integer} length the length of code to copy
197   */
198  codeCopy (resultOffset, codeOffset, length) {
199    this.takeGas(3 + Math.ceil(length / 32) * 3)
200
201    const code = new Uint8Array(this.environment.code, codeOffset, length)
202    this.setMemory(resultOffset, length, code)
203  }
204
205  /**
206   * Get size of an account’s code.
207   * @param {integer} addressOffset the offset in memory to load the address from
208   * @return {integer}
209   */
210  getExternalCodeSize (addressOffset) {
211    this.takeGas(20)
212
213    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
214    const code = this.environment.getCode(address)
215    return code.length
216  }
217
218  /**
219   * Copys the code of an account to memory.
220   * @param {integer} addressOffset the memory offset of the address
221   * @param {integer} resultOffset the memory offset
222   * @param {integer} codeOffset the code offset
223   * @param {integer} length the length of code to copy
224   */
225  externalCodeCopy (addressOffset, resultOffset, codeOffset, length) {
226    this.takeGas(20 + Math.ceil(length / 32) * 3)
227
228    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
229    let code = this.environment.getCode(address)
230    code = new Uint8Array(code, codeOffset, length)
231    this.setMemory(resultOffset, length, code)
232  }
233
234  /**
235   * Gets price of gas in current environment.
236   * @return {integer}
237   */
238  getTxGasPrice () {
239    this.takeGas(2)
240
241    return this.environment.gasPrice
242  }
243
244  /**
245   * Gets the hash of one of the 256 most recent complete blocks.
246   * @param {integer} number which block to load
247   * @param {integer} offset the offset to load the hash into
248   */
249  getBlockHash (number, offset) {
250    this.takeGas(20)
251
252    const diff = this.environment.block.number - number
253    let hash
254
255    if (diff > 256 || diff <= 0) {
256      hash = new U256(0)
257    } else {
258      hash = new U256(this.environment.getBlockHash(number))
259    }
260    this.setMemory(offset, U256_SIZE_BYTES, hash.toMemory())
261  }
262
263  /**
264   * Gets the block’s beneficiary address and loads into memory.
265   * @param offset
266   */
267  getBlockCoinbase (offset) {
268    this.takeGas(2)
269
270    this.setMemory(offset, ADDRESS_SIZE_BYTES, this.environment.block.coinbase.toMemory())
271  }
272
273  /**
274   * Get the block’s timestamp.
275   * @return {integer}
276   */
277  getBlockTimestamp () {
278    this.takeGas(2)
279
280    return this.environment.block.timestamp
281  }
282
283  /**
284   * Get the block’s number.
285   * @return {integer}
286   */
287  getBlockNumber () {
288    this.takeGas(2)
289
290    return this.environment.block.number
291  }
292
293  /**
294   * Get the block’s difficulty.
295   * @return {integer}
296   */
297  getBlockDifficulty (offset) {
298    this.takeGas(2)
299
300    this.setMemory(offset, U256_SIZE_BYTES, this.environment.block.difficulty.toMemory())
301  }
302
303  /**
304   * Get the block’s gas limit.
305   * @return {integer}
306   */
307  getBlockGasLimit () {
308    this.takeGas(2)
309
310    return this.environment.block.gasLimit
311  }
312
313  /**
314   * Creates a new log in the current environment
315   * @param {integer} dataOffset the offset in memory to load the memory
316   * @param {integer} length the data length
317   * @param {integer} number of topics
318   */
319  log (dataOffset, length, numberOfTopics, topic1, topic2, topic3, topic4) {
320    if (numberOfTopics < 0 || numberOfTopics > 4) {
321      throw new Error('Invalid numberOfTopics')
322    }
323
324    this.takeGas(375 + length * 8 + numberOfTopics * 375)
325
326    const data = this.getMemory(dataOffset, length).slice(0)
327    let topics = []
328
329    if (numberOfTopics > 0) {
330      topics.push(U256.fromMemory(this.getMemory(topic1, U256_SIZE_BYTES)))
331    }
332
333    if (numberOfTopics > 1) {
334      topics.push(U256.fromMemory(this.getMemory(topic2, U256_SIZE_BYTES)))
335    }
336
337    if (numberOfTopics > 2) {
338      topics.push(U256.fromMemory(this.getMemory(topic3, U256_SIZE_BYTES)))
339    }
340
341    if (numberOfTopics > 3) {
342      topics.push(U256.fromMemory(this.getMemory(topic4, U256_SIZE_BYTES)))
343    }
344
345    this.environment.logs.push({
346      data: data,
347      topics: topics
348    })
349  }
350
351  /**
352   * Creates a new contract with a given value.
353   * @param {integer} valueOffset the offset in memory to the value from
354   * @param {integer} dataOffset the offset to load the code for the new contract from
355   * @param {integer} length the data length
356   */
357  create (valueOffset, dataOffset, length) {
358    this.takeGas(32000)
359
360    const value = U256.fromMemory(this.getMemory(valueOffset, U128_SIZE_BYTES))
361    const data = this.getMemory(dataOffset, length).slice(0)
362    const result = this.environment.create(value, data)
363    return result
364  }
365
366  /**
367   * Sends a message with arbiatary data to a given address path
368   * @param {integer} addressOffset the offset to load the address path from
369   * @param {integer} valueOffset the offset to load the value from
370   * @param {integer} dataOffset the offset to load data from
371   * @param {integer} dataLength the length of data
372   * @param {integer} resultOffset the offset to store the result data at
373   * @param {integer} resultLength
374   * @param {integer} gas
375   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
376   */
377  call (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
378    // FIXME: count properly
379    this.takeGas(40)
380
381    // Load the params from mem
382    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
383    const value = U256.fromMemory(this.getMemory(valueOffset, U128_SIZE_BYTES))
384    const data = this.getMemory(dataOffset, dataLength).slice(0)
385    // Run the call
386    const [result, errorCode] = this.environment.call(gas, address, value, data)
387    this.setMemory(resultOffset, resultLength, result)
388    return errorCode
389  }
390
391  /**
392   * Message-call into this account with an alternative account’s code.
393   * @param {integer} addressOffset the offset to load the address path from
394   * @param {integer} valueOffset the offset to load the value from
395   * @param {integer} dataOffset the offset to load data from
396   * @param {integer} dataLength the length of data
397   * @param {integer} resultOffset the offset to store the result data at
398   * @param {integer} resultLength
399   * @param {integer} gas
400   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
401   */
402  callCode (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
403    // FIXME: count properly
404    this.takeGas(40)
405
406    // Load the params from mem
407    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
408    const value = U256.fromMemory(this.getMemory(valueOffset, U128_SIZE_BYTES))
409    const data = this.getMemory(dataOffset, dataLength).slice(0)
410    // Run the call
411    const [result, errorCode] = this.environment.callCode(gas, address, value, data)
412    this.setMemory(resultOffset, resultLength, result)
413    return errorCode
414  }
415
416  /**
417   * Message-call into this account with an alternative account’s code, but
418   * persisting the current values for sender and value.
419   * @param {integer} gas
420   * @param {integer} addressOffset the offset to load the address path from
421   * @param {integer} valueOffset the offset to load the value from
422   * @param {integer} dataOffset the offset to load data from
423   * @param {integer} dataLength the length of data
424   * @param {integer} resultOffset the offset to store the result data at
425   * @param {integer} resultLength
426   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
427   */
428  callDelegate (gas, addressOffset, dataOffset, dataLength, resultOffset, resultLength) {
429    // FIXME: count properly
430    this.takeGas(40)
431
432    const data = this.getMemory(dataOffset, dataLength).slice(0)
433    const address = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
434    const [result, errorCode] = this.environment.callDelegate(gas, address, data)
435    this.setMemory(resultOffset, resultLength, result)
436    return errorCode
437  }
438
439  /**
440   * store a value at a given path in long term storage which are both loaded
441   * from Memory
442   * @param {interger} pathOffest the memory offset to load the the path from
443   * @param {interger} valueOffset the memory offset to load the value from
444   */
445  storageStore (pathOffset, valueOffset) {
446    const path = new Buffer(this.getMemory(pathOffset, U256_SIZE_BYTES)).toString('hex')
447    // copy the value
448    const value = this.getMemory(valueOffset, U256_SIZE_BYTES).slice(0)
449    const oldValue = this.environment.state.get(path)
450    const valIsZero = value.every((i) => i === 0)
451
452    this.takeGas(5000)
453
454    // write
455    if (!valIsZero && !oldValue) {
456      this.takeGas(15000)
457    }
458
459    // delete
460    if (valIsZero && oldValue) {
461      this.environment.gasRefund += 15000
462      this.environment.state.delete(path)
463    } else {
464      this.environment.state.set(path, value)
465    }
466  }
467
468  /**
469   * reterives a value at a given path in long term storage
470   * @param {interger} pathOffest the memory offset to load the the path from
471   * @param {interger} resultOffset the memory offset to load the value from
472   */
473  storageLoad (pathOffset, resultOffset) {
474    this.takeGas(50)
475
476    const path = new Buffer(this.getMemory(pathOffset, U256_SIZE_BYTES)).toString('hex')
477    const result = this.environment.state.get(path)
478    this.setMemory(resultOffset, U256_SIZE_BYTES, result)
479  }
480
481  /**
482   * Halt execution returning output data.
483   * @param {integer} offset the offset of the output data.
484   * @param {integer} length the length of the output data.
485   */
486  return (offset, length) {
487    this.environment.returnValue = this.getMemory(offset, length).slice(0)
488  }
489
490  /**
491   * Halt execution and register account for later deletion giving the remaining
492   * balance to an address path
493   * @param {integer} offset the offset to load the address from
494   */
495  selfDestruct (addressOffset) {
496    this.environment.suicideAddress = Address.fromMemory(this.getMemory(addressOffset, ADDRESS_SIZE_BYTES))
497    this.environment.gasRefund += 24000
498  }
499
500  getMemory (offset, length) {
501    return new Uint8Array(this.module.exports.memory, offset, length)
502  }
503
504  setMemory (offset, length, value) {
505    const memory = new Uint8Array(this.module.exports.memory, offset, length)
506    memory.set(value)
507  }
508
509  /*
510   * Takes gas from the tank. Only needs to check if there's gas left to be taken,
511   * because every caller of this method is trusted.
512   */
513  takeGas (amount) {
514    if (this.environment.gasLeft < amount) {
515      throw new Error('Ran out of gas')
516    }
517    this.environment.gasLeft -= amount
518  }
519}
520
521//
522// Polyfill required unless this is sorted: https://bugs.chromium.org/p/chromium/issues/detail?id=633895
523//
524// Polyfill from: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind
525//
526Function.prototype.bind = function (oThis) { // eslint-disable-line
527  if (typeof this !== 'function') {
528    // closest thing possible to the ECMAScript 5
529    // internal IsCallable function
530    throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable')
531  }
532
533  var aArgs = Array.prototype.slice.call(arguments, 1)
534  var fToBind = this
535  var fNOP = function () {}
536  var fBound = function () {
537    return fToBind.apply(this instanceof fNOP ? this : oThis,
538     aArgs.concat(Array.prototype.slice.call(arguments)))
539  }
540
541  if (this.prototype) {
542    // Function.prototype doesn't have a prototype property
543    fNOP.prototype = this.prototype
544  }
545
546  fBound.prototype = new fNOP() // eslint-disable-line new-cap
547
548  return fBound
549}
550

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