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wanderer🌟 / js-primea-hypervisor



Tree: 0031bf1b8a9976595e38cc4e2b49124a79ff927d

Files: 0031bf1b8a9976595e38cc4e2b49124a79ff927d / interface.js

16433 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)
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 = new Address(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.toBuffer(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)
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)
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.toBuffer(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   * @param {integer} length the length of data to copy
173   */
174  callDataCopy256 (offset, dataOffset) {
175    this.takeGas(3)
176    const callData = this.environment.callData.slice(dataOffset, dataOffset + 32)
177    this.setMemory(offset, 32, callData)
178  }
179
180  /**
181   * Gets the size of code running in current environment.
182   * @return {interger}
183   */
184  getCodeSize () {
185    this.takeGas(2)
186
187    return this.environment.code.length
188  }
189
190  /**
191   * Copys the code running in current environment to memory.
192   * @param {integer} offset the memory offset
193   * @param {integer} codeOffset the code offset
194   * @param {integer} length the length of code to copy
195   */
196  codeCopy (resultOffset, codeOffset, length) {
197    this.takeGas(3 + ((length / 32) * 3))
198
199    const code = new Uint8Array(this.environment.code, codeOffset, length)
200    this.setMemory(resultOffset, length, code)
201  }
202
203  /**
204   * Get size of an account’s code.
205   * @param {integer} addressOffset the offset in memory to load the address from
206   * @return {integer}
207   */
208  getExternalCodeSize (addressOffset) {
209    this.takeGas(20)
210
211    const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
212    const code = this.environment.getCode(address)
213    return code.length
214  }
215
216  /**
217   * Copys the code of an account to memory.
218   * @param {integer} addressOffset the memory offset of the address
219   * @param {integer} resultOffset the memory offset
220   * @param {integer} codeOffset the code offset
221   * @param {integer} length the length of code to copy
222   */
223  externalCodeCopy (addressOffset, resultOffset, codeOffset, length) {
224    this.takeGas(20 + ((length / 32) * 3))
225
226    const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
227    let code = this.environment.getCode(address)
228    code = new Uint8Array(code, codeOffset, length)
229    this.setMemory(resultOffset, length, code)
230  }
231
232  /**
233   * Gets price of gas in current environment.
234   * @return {integer}
235   */
236  getTxGasPrice () {
237    this.takeGas(2)
238
239    return this.environment.gasPrice
240  }
241
242  /**
243   * Gets the hash of one of the 256 most recent complete blocks.
244   * @param {integer} number which block to load
245   * @param {integer} offset the offset to load the hash into
246   */
247  getBlockHash (number, offset) {
248    this.takeGas(20)
249
250    const diff = this.environment.block.number - number
251    let hash
252
253    if (diff > 256 || diff <= 0) {
254      hash = new U256(0)
255    } else {
256      hash = new U256(this.environment.getBlockHash(number))
257    }
258    this.setMemory(offset, 32, hash.toBuffer())
259  }
260
261  /**
262   * Gets the block’s beneficiary address and loads into memory.
263   * @param offset
264   */
265  getBlockCoinbase (offset) {
266    this.takeGas(2)
267
268    this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.block.coinbase)
269  }
270
271  /**
272   * Get the block’s timestamp.
273   * @return {integer}
274   */
275  getBlockTimestamp () {
276    this.takeGas(2)
277
278    return this.environment.block.timestamp
279  }
280
281  /**
282   * Get the block’s number.
283   * @return {integer}
284   */
285  getBlockNumber () {
286    this.takeGas(2)
287
288    return this.environment.block.number
289  }
290
291  /**
292   * Get the block’s difficulty.
293   * @return {integer}
294   */
295  getBlockDifficulty (offset) {
296    this.takeGas(2)
297
298    this.setMemory(offset, 32, this.environment.block.difficulty.toBuffer())
299  }
300
301  /**
302   * Get the block’s gas limit.
303   * @return {integer}
304   */
305  getBlockGasLimit () {
306    this.takeGas(2)
307
308    return this.environment.block.gasLimit
309  }
310
311  /**
312   * Creates a new log in the current environment
313   * @param {integer} dataOffset the offset in memory to load the memory
314   * @param {integer} length the data length
315   * TODO: replace with variadic
316   */
317  log (dataOffset, length, topic1, topic2, topic3, topic4, topic5) {
318    // FIXME: calculate gas for topics set
319    this.takeGas(375 + length * 8)
320
321    const data = this.getMemory(dataOffset, length)
322    this.environment.logs.push({
323      data: data,
324      topics: [topic1, topic2, topic3, topic4, topic5]
325    })
326  }
327
328  /**
329   * Creates a new contract with a given value.
330   * @param {integer} valueOffset the offset in memory to the value from
331   * @param {integer} dataOffset the offset to load the code for the new contract from
332   * @param {integer} length the data length
333   */
334  create (valueOffset, dataOffset, length) {
335    this.takeGas(32000)
336
337    const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES))
338    const data = this.getMemory(dataOffset, length)
339    const result = this.environment.create(value, data)
340    return result
341  }
342
343  /**
344   * Sends a message with arbiatary data to a given address path
345   * @param {integer} addressOffset the offset to load the address path from
346   * @param {integer} valueOffset the offset to load the value from
347   * @param {integer} dataOffset the offset to load data from
348   * @param {integer} dataLength the length of data
349   * @param {integer} resultOffset the offset to store the result data at
350   * @param {integer} resultLength
351   * @param {integer} gas
352   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
353   */
354  call (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
355    // FIXME: count properly
356    this.takeGas(40)
357
358    // Load the params from mem
359    const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
360    const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES))
361    const data = this.getMemory(dataOffset, dataLength)
362    // Run the call
363    const [result, errorCode] = this.environment.call(gas, address, value, data)
364    this.setMemory(resultOffset, resultLength, result)
365    return errorCode
366  }
367
368  /**
369   * Message-call into this account with an alternative account’s code.
370   * @param {integer} addressOffset the offset to load the address path from
371   * @param {integer} valueOffset the offset to load the value from
372   * @param {integer} dataOffset the offset to load data from
373   * @param {integer} dataLength the length of data
374   * @param {integer} resultOffset the offset to store the result data at
375   * @param {integer} resultLength
376   * @param {integer} gas
377   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
378   */
379  callCode (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) {
380    // FIXME: count properly
381    this.takeGas(40)
382
383    // Load the params from mem
384    const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
385    const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES))
386    const data = this.getMemory(dataOffset, dataLength)
387    // Run the call
388    const [result, errorCode] = this.environment.callCode(gas, address, value, data)
389    this.setMemory(resultOffset, resultLength, result)
390    return errorCode
391  }
392
393  /**
394   * Message-call into this account with an alternative account’s code, but
395   * persisting the current values for sender and value.
396   * @param {integer} gas
397   * @param {integer} addressOffset the offset to load the address path from
398   * @param {integer} valueOffset the offset to load the value from
399   * @param {integer} dataOffset the offset to load data from
400   * @param {integer} dataLength the length of data
401   * @param {integer} resultOffset the offset to store the result data at
402   * @param {integer} resultLength
403   * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not
404   */
405  callDelegate (gas, addressOffset, dataOffset, dataLength, resultOffset, resultLength) {
406    // FIXME: count properly
407    this.takeGas(40)
408
409    const data = this.getMemory(dataOffset, dataLength)
410    const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
411    const [result, errorCode] = this.environment.callDelegate(gas, address, data)
412    this.setMemory(resultOffset, resultLength, result)
413    return errorCode
414  }
415
416  /**
417   * store a value at a given path in long term storage which are both loaded
418   * from Memory
419   * @param {interger} pathOffest the memory offset to load the the path from
420   * @param {interger} valueOffset the memory offset to load the value from
421   */
422  storageStore (pathOffset, valueOffset) {
423    const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex')
424    // copy the value
425    const value = this.getMemory(valueOffset, 32).slice(0)
426    const oldValue = this.environment.state.get(path)
427    const valIsZero = value.every((i) => i === 0)
428
429    this.takeGas(5000)
430
431    // write
432    if (!valIsZero && !oldValue) {
433      this.takeGas(15000)
434    }
435
436    // delete
437    if (valIsZero && oldValue) {
438      this.environment.gasRefund += 15000
439      this.environment.state.delete(path)
440    } else {
441      this.environment.state.set(path, value)
442    }
443  }
444
445  /**
446   * reterives a value at a given path in long term storage
447   * @param {interger} pathOffest the memory offset to load the the path from
448   * @param {interger} resultOffset the memory offset to load the value from
449   */
450  storageLoad (pathOffset, resultOffset) {
451    this.takeGas(50)
452
453    const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex')
454    const result = this.environment.state.get(path)
455    this.setMemory(resultOffset, 32, result)
456  }
457
458  /**
459   * Halt execution returning output data.
460   * @param {integer} offset the offset of the output data.
461   * @param {integer} length the length of the output data.
462   */
463  return (offset, length) {
464    this.environment.returnValue = this.getMemory(offset, length)
465  }
466
467  /**
468   * Halt execution and register account for later deletion giving the remaining
469   * balance to an address path
470   * @param {integer} offset the offset to load the address from
471   */
472  selfDestruct (addressOffset) {
473    this.environment.suicideAddress = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES))
474    this.environment.gasRefund += 24000
475  }
476
477  getMemory (offset, length) {
478    return new Uint8Array(this.module.exports.memory, offset, length)
479  }
480
481  setMemory (offset, length, value) {
482    const memory = new Uint8Array(this.module.exports.memory, offset, length)
483    memory.set(value)
484  }
485
486  /*
487   * Takes gas from the tank. Only needs to check if there's gas left to be taken,
488   * because every caller of this method is trusted.
489   */
490  takeGas (amount) {
491    if (this.environment.gasLeft < amount) {
492      throw new Error('Ran out of gas')
493    }
494    this.environment.gasLeft -= amount
495  }
496}
497
498//
499// Polyfill required unless this is sorted: https://bugs.chromium.org/p/chromium/issues/detail?id=633895
500//
501// Polyfill from: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind
502//
503Function.prototype.bind = function (oThis) { // eslint-disable-line
504  if (typeof this !== 'function') {
505    // closest thing possible to the ECMAScript 5
506    // internal IsCallable function
507    throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable')
508  }
509
510  var aArgs = Array.prototype.slice.call(arguments, 1)
511  var fToBind = this
512  var fNOP = function () {}
513  var fBound = function () {
514    return fToBind.apply(this instanceof fNOP ? this : oThis,
515     aArgs.concat(Array.prototype.slice.call(arguments)))
516  }
517
518  if (this.prototype) {
519    // Function.prototype doesn't have a prototype property
520    fNOP.prototype = this.prototype
521  }
522
523  fBound.prototype = new fNOP() // eslint-disable-line new-cap
524
525  return fBound
526}
527

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