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wanderer🌟 / js-primea-hypervisor



Tree: a2d4372bc21bc705e7d5c559b431d90588315e10

Files: a2d4372bc21bc705e7d5c559b431d90588315e10 / interface.js

16491 bytesRaw
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 constants = require('./constants.js')
6const Address = require('./address.js')
7const U256 = require('./u256.js')
8
9// The interface exposed to the WebAessembly Core
10module.exports = class Interface {
11  constructor (environment) {
12    this.environment = environment
13  }
14
15  get exportTable () {
16    let exportMethods = [
17      // include all the public methods according to the Ethereum Environment Interface (EEI) r1
18      'useGas',
19      'getGasLeft',
20      'getAddress',
21      'getBalance',
22      'getTxOrigin',
23      'getCaller',
24      'getCallValue',
25      'getCallDataSize',
26      'callDataCopy',
27      'callDataCopy256',
28      'getCodeSize',
29      'codeCopy',
30      'getExternalCodeSize',
31      'externalCodeCopy',
32      'getTxGasPrice',
33      'getBlockHash',
34      'getBlockCoinbase',
35      'getBlockTimestamp',
36      'getBlockNumber',
37      'getBlockDifficulty',
38      'getBlockGasLimit',
39      'log',
40      'create',
41      'call',
42      'callCode',
43      'callDelegate',
44      'storageStore',
45      'storageLoad',
46      'return',
47      'selfDestruct'
48    ]
49    let ret = {}
50    exportMethods.forEach((method) => {
51      ret[method] = this[method].bind(this)
52    })
53    return ret
54  }
55
56  setModule (mod) {
57    this.module = mod
58  }
59
60  /**
61   * Subtracts an amount to the gas counter
62   * @param {integer} amount the amount to subtract to the gas counter
63   */
64  useGas (amount) {
65    if (amount < 0) {
66      throw new Error('Negative gas deduction requested')
67    }
68
69    this.takeGas(amount)
70  }
71
72  /**
73   * Returns the current amount of gas
74   * @return {integer}
75   */
76  getGasLeft () {
77    this.takeGas(2)
78
79    return this.environment.gasLeft
80  }
81
82  /**
83   * Gets address of currently executing account and loads it into memory at
84   * the given offset.
85   * @param {integer} offset
86   */
87  getAddress (offset) {
88    this.takeGas(2)
89
90    this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.address.toMemory())
91  }
92
93  /**
94   * Gets balance of the given account and loads it into memory at the given
95   * offset.
96   * @param {integer} addressOffset the memory offset to laod the address
97   * @param {integer} resultOffset
98   */
99  getBalance (addressOffset, offset) {
100    this.takeGas(20)
101
102    const address = Address.fromMemory(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
103    // call the parent contract and ask for the balance of one of its child contracts
104    const balance = this.environment.getBalance(address)
105    this.setMemory(offset, constants.BALANCE_SIZE_BYTES, balance.toMemory(constants.BALANCE_SIZE_BYTES))
106  }
107
108  /**
109   * Gets the execution's origination address and loads it into memory at the
110   * given offset. This is the sender of original transaction; it is never an
111   * account with non-empty associated code.
112   * @param {integer} offset
113   */
114  getTxOrigin (offset) {
115    this.takeGas(2)
116
117    this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.origin.toMemory())
118  }
119
120  /**
121   * Gets caller address and loads it into memory at the given offset. This is
122   * the address of the account that is directly responsible for this execution.
123   * @param {integer} offset
124   */
125  getCaller (offset) {
126    this.takeGas(2)
127
128    this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.caller.toMemory())
129  }
130
131  /**
132   * Gets the deposited value by the instruction/transaction responsible for
133   * this execution and loads it into memory at the given location.
134   * @param {integer} offset
135   */
136  getCallValue (offset) {
137    this.takeGas(2)
138
139    this.setMemory(offset, constants.BALANCE_SIZE_BYTES, this.environment.callValue.toMemory(constants.BALANCE_SIZE_BYTES))
140  }
141
142  /**
143   * Get size of input data in current environment. This pertains to the input
144   * data passed with the message call instruction or transaction.
145   * @return {integer}
146   */
147  getCallDataSize () {
148    this.takeGas(2)
149
150    return this.environment.callData.length
151  }
152
153  /**
154   * Copys the input data in current environment to memory. This pertains to
155   * the input data passed with the message call instruction or transaction.
156   * @param {integer} offset the offset in memory to load into
157   * @param {integer} dataOffset the offset in the input data
158   * @param {integer} length the length of data to copy
159   */
160  callDataCopy (offset, dataOffset, length) {
161    this.takeGas(3 + ((length / 32) * 3))
162
163    const callData = this.environment.callData.slice(dataOffset, dataOffset + length)
164    this.setMemory(offset, length, callData)
165  }
166
167  /**
168   * Copys the input data in current environment to memory. This pertains to
169   * the input data passed with the message call instruction or transaction.
170   * @param {integer} offset the offset in memory to load into
171   * @param {integer} dataOffset the offset in the input data
172   */
173  callDataCopy256 (offset, dataOffset) {
174    this.takeGas(3)
175    const callData = this.environment.callData.slice(dataOffset, dataOffset + 32)
176    this.setMemory(offset, 32, callData)
177  }
178
179  /**
180   * Gets the size of code running in current environment.
181   * @return {interger}
182   */
183  getCodeSize () {
184    this.takeGas(2)
185
186    return this.environment.code.length
187  }
188
189  /**
190   * Copys the code running in current environment to memory.
191   * @param {integer} offset the memory offset
192   * @param {integer} codeOffset the code offset
193   * @param {integer} length the length of code to copy
194   */
195  codeCopy (resultOffset, codeOffset, length) {
196    this.takeGas(3 + ((length / 32) * 3))
197
198    const code = new Uint8Array(this.environment.code, codeOffset, length)
199    this.setMemory(resultOffset, length, code)
200  }
201
202  /**
203   * Get size of an account’s code.
204   * @param {integer} addressOffset the offset in memory to load the address from
205   * @return {integer}
206   */
207  getExternalCodeSize (addressOffset) {
208    this.takeGas(20)
209
210    const address = Address.fromMemory(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
211    const code = this.environment.getCode(address)
212    return code.length
213  }
214
215  /**
216   * Copys the code of an account to memory.
217   * @param {integer} addressOffset the memory offset of the address
218   * @param {integer} resultOffset the memory offset
219   * @param {integer} codeOffset the code offset
220   * @param {integer} length the length of code to copy
221   */
222  externalCodeCopy (addressOffset, resultOffset, codeOffset, length) {
223    this.takeGas(20 + ((length / 32) * 3))
224
225    const address = Address.fromMemory(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
226    let code = this.environment.getCode(address)
227    code = new Uint8Array(code, codeOffset, length)
228    this.setMemory(resultOffset, length, code)
229  }
230
231  /**
232   * Gets price of gas in current environment.
233   * @return {integer}
234   */
235  getTxGasPrice () {
236    this.takeGas(2)
237
238    return this.environment.gasPrice
239  }
240
241  /**
242   * Gets the hash of one of the 256 most recent complete blocks.
243   * @param {integer} number which block to load
244   * @param {integer} offset the offset to load the hash into
245   */
246  getBlockHash (number, offset) {
247    this.takeGas(20)
248
249    const diff = this.environment.block.number - number
250    let hash
251
252    if (diff > 256 || diff <= 0) {
253      hash = new U256(0)
254    } else {
255      hash = new U256(this.environment.getBlockHash(number))
256    }
257    this.setMemory(offset, 32, hash.toMemory())
258  }
259
260  /**
261   * Gets the block’s beneficiary address and loads into memory.
262   * @param offset
263   */
264  getBlockCoinbase (offset) {
265    this.takeGas(2)
266
267    this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.block.coinbase.toMemory())
268  }
269
270  /**
271   * Get the block’s timestamp.
272   * @return {integer}
273   */
274  getBlockTimestamp () {
275    this.takeGas(2)
276
277    return this.environment.block.timestamp
278  }
279
280  /**
281   * Get the block’s number.
282   * @return {integer}
283   */
284  getBlockNumber () {
285    this.takeGas(2)
286
287    return this.environment.block.number
288  }
289
290  /**
291   * Get the block’s difficulty.
292   * @return {integer}
293   */
294  getBlockDifficulty (offset) {
295    this.takeGas(2)
296
297    this.setMemory(offset, 32, this.environment.block.difficulty.toMemory())
298  }
299
300  /**
301   * Get the block’s gas limit.
302   * @return {integer}
303   */
304  getBlockGasLimit () {
305    this.takeGas(2)
306
307    return this.environment.block.gasLimit
308  }
309
310  /**
311   * Creates a new log in the current environment
312   * @param {integer} dataOffset the offset in memory to load the memory
313   * @param {integer} length the data length
314   * TODO: replace with variadic
315   */
316  log (dataOffset, length, topic1, topic2, topic3, topic4, topic5) {
317    // FIXME: calculate gas for topics set
318    this.takeGas(375 + length * 8)
319
320    const data = this.getMemory(dataOffset, length)
321    this.environment.logs.push({
322      data: data,
323      topics: [topic1, topic2, topic3, topic4, topic5]
324    })
325  }
326
327  /**
328   * Creates a new contract with a given value.
329   * @param {integer} valueOffset the offset in memory to the value from
330   * @param {integer} dataOffset the offset to load the code for the new contract from
331   * @param {integer} length the data length
332   */
333  create (valueOffset, dataOffset, length) {
334    this.takeGas(32000)
335
336    const value = U256.fromMemory(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES))
337    const data = this.getMemory(dataOffset, length)
338    const result = this.environment.create(value, data)
339    return result
340  }
341
342  /**
343   * Sends a message with arbiatary data to a given address path
344   * @param {integer} addressOffset the offset to load the address path from
345   * @param {integer} valueOffset the offset to load the value from
346   * @param {integer} dataOffset the offset to load data from
347   * @param {integer} dataLength the length of data
348   * @param {integer} resultOffset the offset to store the result data at
349   * @param {integer} resultLength
350   * @param {integer} gas
351   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
352   */
353  call (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
354    // FIXME: count properly
355    this.takeGas(40)
356
357    // Load the params from mem
358    const address = Address.fromMemory(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
359    const value = U256.fromMemory(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES))
360    const data = this.getMemory(dataOffset, dataLength)
361    // Run the call
362    const [result, errorCode] = this.environment.call(gas, address, value, data)
363    this.setMemory(resultOffset, resultLength, result)
364    return errorCode
365  }
366
367  /**
368   * Message-call into this account with an alternative account’s code.
369   * @param {integer} addressOffset the offset to load the address path from
370   * @param {integer} valueOffset the offset to load the value from
371   * @param {integer} dataOffset the offset to load data from
372   * @param {integer} dataLength the length of data
373   * @param {integer} resultOffset the offset to store the result data at
374   * @param {integer} resultLength
375   * @param {integer} gas
376   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
377   */
378  callCode (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
379    // FIXME: count properly
380    this.takeGas(40)
381
382    // Load the params from mem
383    const address = Address.fromMemory(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
384    const value = U256.fromMemory(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES))
385    const data = this.getMemory(dataOffset, dataLength)
386    // Run the call
387    const [result, errorCode] = this.environment.callCode(gas, address, value, data)
388    this.setMemory(resultOffset, resultLength, result)
389    return errorCode
390  }
391
392  /**
393   * Message-call into this account with an alternative account’s code, but
394   * persisting the current values for sender and value.
395   * @param {integer} gas
396   * @param {integer} addressOffset the offset to load the address path from
397   * @param {integer} valueOffset the offset to load the value from
398   * @param {integer} dataOffset the offset to load data from
399   * @param {integer} dataLength the length of data
400   * @param {integer} resultOffset the offset to store the result data at
401   * @param {integer} resultLength
402   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
403   */
404  callDelegate (gas, addressOffset, dataOffset, dataLength, resultOffset, resultLength) {
405    // FIXME: count properly
406    this.takeGas(40)
407
408    const data = this.getMemory(dataOffset, dataLength)
409    const address = Address.fromMemory(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
410    const [result, errorCode] = this.environment.callDelegate(gas, address, data)
411    this.setMemory(resultOffset, resultLength, result)
412    return errorCode
413  }
414
415  /**
416   * store a value at a given path in long term storage which are both loaded
417   * from Memory
418   * @param {interger} pathOffest the memory offset to load the the path from
419   * @param {interger} valueOffset the memory offset to load the value from
420   */
421  storageStore (pathOffset, valueOffset) {
422    const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex')
423    // copy the value
424    const value = this.getMemory(valueOffset, 32).slice(0)
425    const oldValue = this.environment.state.get(path)
426    const valIsZero = value.every((i) => i === 0)
427
428    this.takeGas(5000)
429
430    // write
431    if (!valIsZero && !oldValue) {
432      this.takeGas(15000)
433    }
434
435    // delete
436    if (valIsZero && oldValue) {
437      this.environment.gasRefund += 15000
438      this.environment.state.delete(path)
439    } else {
440      this.environment.state.set(path, value)
441    }
442  }
443
444  /**
445   * reterives a value at a given path in long term storage
446   * @param {interger} pathOffest the memory offset to load the the path from
447   * @param {interger} resultOffset the memory offset to load the value from
448   */
449  storageLoad (pathOffset, resultOffset) {
450    this.takeGas(50)
451
452    const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex')
453    const result = this.environment.state.get(path)
454    this.setMemory(resultOffset, 32, result)
455  }
456
457  /**
458   * Halt execution returning output data.
459   * @param {integer} offset the offset of the output data.
460   * @param {integer} length the length of the output data.
461   */
462  return (offset, length) {
463    this.environment.returnValue = this.getMemory(offset, length)
464  }
465
466  /**
467   * Halt execution and register account for later deletion giving the remaining
468   * balance to an address path
469   * @param {integer} offset the offset to load the address from
470   */
471  selfDestruct (addressOffset) {
472    this.environment.suicideAddress = Address.fromMemory(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
473    this.environment.gasRefund += 24000
474  }
475
476  getMemory (offset, length) {
477    return new Uint8Array(this.module.exports.memory, offset, length)
478  }
479
480  setMemory (offset, length, value) {
481    const memory = new Uint8Array(this.module.exports.memory, offset, length)
482    memory.set(value)
483  }
484
485  /*
486   * Takes gas from the tank. Only needs to check if there's gas left to be taken,
487   * because every caller of this method is trusted.
488   */
489  takeGas (amount) {
490    if (this.environment.gasLeft < amount) {
491      throw new Error('Ran out of gas')
492    }
493    this.environment.gasLeft -= amount
494  }
495}
496
497//
498// Polyfill required unless this is sorted: https://bugs.chromium.org/p/chromium/issues/detail?id=633895
499//
500// Polyfill from: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind
501//
502Function.prototype.bind = function (oThis) { // eslint-disable-line
503  if (typeof this !== 'function') {
504    // closest thing possible to the ECMAScript 5
505    // internal IsCallable function
506    throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable')
507  }
508
509  var aArgs = Array.prototype.slice.call(arguments, 1)
510  var fToBind = this
511  var fNOP = function () {}
512  var fBound = function () {
513    return fToBind.apply(this instanceof fNOP ? this : oThis,
514     aArgs.concat(Array.prototype.slice.call(arguments)))
515  }
516
517  if (this.prototype) {
518    // Function.prototype doesn't have a prototype property
519    fNOP.prototype = this.prototype
520  }
521
522  fBound.prototype = new fNOP() // eslint-disable-line new-cap
523
524  return fBound
525}
526

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