Files: f148072e804e4e10c0a513d11513ed7e67030f0b / interface.js
13215 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 | */ |
5 | const constants = require('./constants.js') |
6 | |
7 | // The interface exposed to the WebAessembly Core |
8 | module.exports = class Interface { |
9 | constructor (environment) { |
10 | this.environment = environment |
11 | } |
12 | |
13 | get exportTable () { |
14 | let exportMethods = [ |
15 | // include all the public methods according to the Ethereum Environment Interface (EEI) |
16 | // FIXME: this currently doesn't match EEI r0 |
17 | 'useGas', |
18 | 'gas', |
19 | 'address', |
20 | 'balance', |
21 | 'origin', |
22 | 'caller', |
23 | 'callValue', |
24 | 'callDataSize', |
25 | 'callDataCopy', |
26 | 'codeSize', |
27 | 'codeCopy', |
28 | 'extCodeSize', |
29 | 'extCodeCopy', |
30 | 'gasPrice', |
31 | 'blockHash', |
32 | 'coinbase', |
33 | 'timestamp', |
34 | 'number', |
35 | 'difficulty', |
36 | 'gasLimit', |
37 | 'log', |
38 | 'create', |
39 | 'call', |
40 | 'callDelegate', |
41 | 'sstore', |
42 | 'sload', |
43 | 'return', |
44 | 'suicide' |
45 | ] |
46 | let ret = {} |
47 | exportMethods.forEach((method) => { |
48 | ret[method] = this[method].bind(this) |
49 | }) |
50 | return ret |
51 | } |
52 | |
53 | // FIXME: this shouldn't be needed |
54 | get env () { |
55 | return this.environment |
56 | } |
57 | |
58 | setModule (mod) { |
59 | this.module = mod |
60 | } |
61 | |
62 | /** |
63 | * Subtracts an amount to the gas counter |
64 | * @param {integer} amount the amount to subtract to the gas counter |
65 | */ |
66 | useGas (amount) { |
67 | if (amount > 0) { |
68 | if (this.environment.gasLimit < amount) { |
69 | throw new Error('Ran out of gas') |
70 | } |
71 | this.environment.gasLimit -= amount |
72 | } |
73 | } |
74 | |
75 | /** |
76 | * Returns the current amount of gas |
77 | * @return {integer} |
78 | */ |
79 | gas () { |
80 | return this.environment.gasLimit |
81 | } |
82 | |
83 | /** |
84 | * Gets address of currently executing account and loads it into memory at |
85 | * the given offset. |
86 | * @param {integer} offset |
87 | */ |
88 | address (offset) { |
89 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.address) |
90 | } |
91 | |
92 | /** |
93 | * Gets balance of the given account and loads it into memory at the given |
94 | * offset. |
95 | * @param {integer} addressOffset the memory offset to laod the address |
96 | * @param {integer} resultOffset |
97 | */ |
98 | balance (addressOffset, offset) { |
99 | const address = this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES) |
100 | // call the parent contract and ask for the balance of one of its child contracts |
101 | const balance = this.environment.parent.environment.getBalance(address) |
102 | this.setMemory(offset, constants.BALANCE_SIZE_BYTES, balance) |
103 | } |
104 | |
105 | /** |
106 | * Gets the execution's origination address and loads it into memory at the |
107 | * given offset. This is the sender of original transaction; it is never an |
108 | * account with non-empty associated code. |
109 | * @param {integer} offset |
110 | */ |
111 | origin (offset) { |
112 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.origin) |
113 | } |
114 | |
115 | /** |
116 | * Gets caller address and loads it into memory at the given offset. This is |
117 | * the address of the account that is directly responsible for this execution. |
118 | * @param {integer} offset |
119 | */ |
120 | caller (offset) { |
121 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.caller) |
122 | } |
123 | |
124 | /** |
125 | * Gets the deposited value by the instruction/transaction responsible for |
126 | * this execution and loads it into memory at the given location. |
127 | * @param {integer} offset |
128 | */ |
129 | callValue (offset) { |
130 | this.setMemory(offset, constants.BALANCE_SIZE_BYTES, this.environment.callValue) |
131 | } |
132 | |
133 | /** |
134 | * Get size of input data in current environment. This pertains to the input |
135 | * data passed with the message call instruction or transaction. |
136 | * @return {integer} |
137 | */ |
138 | callDataSize () { |
139 | return this.environment.callData.byteLength |
140 | } |
141 | |
142 | /** |
143 | * Copys the input data in current environment to memory. This pertains to |
144 | * the input data passed with the message call instruction or transaction. |
145 | * @param {integer} offset the offset in memory to load into |
146 | * @param {integer} dataOffset the offset in the input data |
147 | * @param {integer} length the length of data to copy |
148 | */ |
149 | callDataCopy (offset, dataOffset, length) { |
150 | const callData = new Uint8Array(this.environment.callData, offset, length) |
151 | this.setMemory(offset, length, callData) |
152 | } |
153 | |
154 | /** |
155 | * Gets the size of code running in current environment. |
156 | * @return {interger} |
157 | */ |
158 | codeSize () { |
159 | return this.environment.code.byteLength |
160 | } |
161 | |
162 | /** |
163 | * Copys the code running in current environment to memory. |
164 | * @param {integer} offset the memory offset |
165 | * @param {integer} codeOffset the code offset |
166 | * @param {integer} length the length of code to copy |
167 | */ |
168 | codeCopy (offset, codeOffset, length) { |
169 | const code = new Uint8Array(this.environment.code, codeOffset, length) |
170 | this.setMemory(offset, length, code) |
171 | } |
172 | |
173 | /** |
174 | * Get size of an account’s code. |
175 | * @param {integer} addressOffset the offset in memory to load the address from |
176 | * @return {integer} |
177 | */ |
178 | extCodeSize (addressOffset) { |
179 | const address = this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES) |
180 | const code = this.environment.getCode(address) |
181 | return code.byteLength |
182 | } |
183 | |
184 | /** |
185 | * Copys the code of an account to memory. |
186 | * @param {integer} addressOffset the memory offset of the address |
187 | * @param {integer} offset the memory offset |
188 | * @param {integer} codeOffset the code offset |
189 | * @param {integer} length the length of code to copy |
190 | */ |
191 | extCodeCopy (addressOffset, offset, codeOffset, length) { |
192 | const address = this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES) |
193 | let code = this.environment.getCode(address) |
194 | code = new Uint8Array(code, codeOffset, length) |
195 | this.setMemory(offset, length, code) |
196 | } |
197 | |
198 | /** |
199 | * Gets price of gas in current environment. |
200 | * @return {integer} |
201 | */ |
202 | gasPrice () { |
203 | return this.environment.gasPrice |
204 | } |
205 | |
206 | /** |
207 | * Gets the hash of one of the 256 most recent complete blocks. |
208 | * @param {integer} number which block to load |
209 | * @param {integer} offset the offset to load the hash into |
210 | */ |
211 | blockHash (number, offset) { |
212 | const hash = this.environment.getBlockHash(number) |
213 | this.setMemory(offset, 32, hash) |
214 | } |
215 | |
216 | /** |
217 | * Gets the block’s beneficiary address and loads into memory. |
218 | * @param offset |
219 | */ |
220 | coinbase (offset) { |
221 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.coinbase) |
222 | } |
223 | |
224 | /** |
225 | * Get the block’s timestamp. |
226 | * @return {integer} |
227 | */ |
228 | timestamp () { |
229 | return this.environment.timestamp |
230 | } |
231 | |
232 | /** |
233 | * Get the block’s number. |
234 | * @return {integer} |
235 | */ |
236 | number () { |
237 | return this.environment.number |
238 | } |
239 | |
240 | /** |
241 | * Get the block’s difficulty. |
242 | * @return {integer} |
243 | */ |
244 | difficulty () { |
245 | return this.environment.difficulty |
246 | } |
247 | |
248 | /** |
249 | * Get the block’s gas limit. |
250 | * @return {integer} |
251 | */ |
252 | gasLimit () { |
253 | return this.environment.gasLimit |
254 | } |
255 | |
256 | /** |
257 | * Creates a new log in the current environment |
258 | * @param {integer} dataOffset the offset in memory to load the memory |
259 | * @param {integer} length the data length |
260 | * TODO: replace with variadic |
261 | */ |
262 | log (dataOffset, length, topic1, topic2, topic3, topic4, topic5) { |
263 | const data = this.getMemory(dataOffset, length) |
264 | this.environment.logs.push({ |
265 | data: data, |
266 | topics: [topic1, topic2, topic3, topic4, topic5] |
267 | }) |
268 | } |
269 | |
270 | /** |
271 | * Creates a new contract with a given value. |
272 | * @param {integer} valueOffset the offset in memory to the value from |
273 | * @param {integer} dataOffset the offset to load the code for the new contract from |
274 | * @param {integer} length the data length |
275 | */ |
276 | create (valueOffset, dataOffset, length) { |
277 | const value = this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES) |
278 | const data = this.getMemory(dataOffset, length) |
279 | const result = this.environment.create(value, data) |
280 | return result |
281 | } |
282 | |
283 | /** |
284 | * Sends a message with arbiatary data to a given address path |
285 | * @param {integer} addressOffset the offset to load the address path from |
286 | * @param {integer} valueOffset the offset to load the value from |
287 | * @param {integer} dataOffset the offset to load data from |
288 | * @param {integer} dataLength the length of data |
289 | * @param {integer} resultOffset the offset to store the result data at |
290 | * @param {integer} resultLength |
291 | * @param {integer} gas |
292 | * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not |
293 | * TODO: add proper gas counting |
294 | */ |
295 | call (addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength, gas) { |
296 | if (gas === undefined) { |
297 | gas = this.gasLeft() |
298 | } |
299 | // Load the params from mem |
300 | const address = this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES) |
301 | const value = this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES) |
302 | const data = this.getMemory(dataOffset, dataLength) |
303 | // Run the call |
304 | const [result, errorCode] = this.environment.call(gas, address, value, data) |
305 | this.setMemory(resultOffset, resultLength, result) |
306 | |
307 | return errorCode |
308 | } |
309 | |
310 | /** |
311 | * Message-call into this account with an alternative account’s code, but |
312 | * persisting the current values for sender and value. |
313 | * @param {integer} gas |
314 | * @param {integer} addressOffset the offset to load the address path from |
315 | * @param {integer} valueOffset the offset to load the value from |
316 | * @param {integer} dataOffset the offset to load data from |
317 | * @param {integer} dataLength the length of data |
318 | * @param {integer} resultOffset the offset to store the result data at |
319 | * @param {integer} resultLength |
320 | * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not |
321 | */ |
322 | callDelegate (gas, addressOffset, dataOffset, dataLength, resultOffset, resultLength) { |
323 | const data = this.getMemory(dataOffset, dataLength) |
324 | const address = this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES) |
325 | const [result, errorCode] = this.environment.callDelegate(gas, address, data) |
326 | this.setMemory(resultOffset, resultLength, result) |
327 | |
328 | return errorCode |
329 | } |
330 | |
331 | /** |
332 | * store a value at a given path in long term storage which are both loaded |
333 | * from Memory |
334 | * @param {interger} pathOffest the memory offset to load the the path from |
335 | * @param {interger} valueOffset the memory offset to load the value from |
336 | */ |
337 | sstore (pathOffset, valueOffset) { |
338 | const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex') |
339 | // copy the value |
340 | const value = this.getMemory(valueOffset, 32).slice(0) |
341 | const oldValue = this.environment.state.get(path) |
342 | const valIsZero = value.every((i) => i === 0) |
343 | |
344 | // write |
345 | if (!valIsZero && !oldValue) { |
346 | this.environment.gasLimit -= 15000 |
347 | } |
348 | |
349 | // delete |
350 | if (valIsZero && oldValue) { |
351 | this.environment.gasRefund += 15000 |
352 | this.environment.state.delete(path) |
353 | } else { |
354 | this.environment.state.set(path, value) |
355 | } |
356 | } |
357 | |
358 | /** |
359 | * reterives a value at a given path in long term storage |
360 | * @param {interger} pathOffest the memory offset to load the the path from |
361 | * @param {interger} resultOffset the memory offset to load the value from |
362 | */ |
363 | sload (pathOffset, resultOffset) { |
364 | const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex') |
365 | const result = this.environment.state.get(path) |
366 | this.setMemory(resultOffset, 32, result) |
367 | } |
368 | |
369 | /** |
370 | * Halt execution returning output data. |
371 | * @param {integer} offset the offset of the output data. |
372 | * @param {integer} length the length of the output data. |
373 | */ |
374 | return (offset, length) { |
375 | this.environment.returnValue = this.getMemory(offset, length) |
376 | } |
377 | |
378 | /** |
379 | * Halt execution and register account for later deletion giving the remaining |
380 | * balance to an address path |
381 | * @param {integer} offset the offset to load the address from |
382 | */ |
383 | suicide (addressOffset) { |
384 | this.environment.suicideAddress = this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES) |
385 | } |
386 | |
387 | getMemory (offset, length) { |
388 | return new Uint8Array(this.module.exports.memory, offset, length) |
389 | } |
390 | |
391 | setMemory (offset, length, value) { |
392 | const memory = new Uint8Array(this.module.exports.memory, offset, length) |
393 | memory.set(value) |
394 | } |
395 | } |
396 | |
397 | // |
398 | // Polyfill required unless this is sorted: https://bugs.chromium.org/p/chromium/issues/detail?id=633895 |
399 | // |
400 | // Polyfill from: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind |
401 | // |
402 | Function.prototype.bind = function (oThis) { // eslint-disable-line |
403 | if (typeof this !== 'function') { |
404 | // closest thing possible to the ECMAScript 5 |
405 | // internal IsCallable function |
406 | throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable') |
407 | } |
408 | |
409 | var aArgs = Array.prototype.slice.call(arguments, 1) |
410 | var fToBind = this |
411 | var fNOP = function () {} |
412 | var fBound = function () { |
413 | return fToBind.apply(this instanceof fNOP ? this : oThis, |
414 | aArgs.concat(Array.prototype.slice.call(arguments))) |
415 | } |
416 | |
417 | if (this.prototype) { |
418 | // Function.prototype doesn't have a prototype property |
419 | fNOP.prototype = this.prototype |
420 | } |
421 | |
422 | fBound.prototype = new fNOP() // eslint-disable-line new-cap |
423 | |
424 | return fBound |
425 | } |
426 |
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