cgewecke
5 years ago
parent
503c300993
commit
556d2d2e58
@ -1,37 +1,61 @@ |
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const web3Utils = require('web3-utils') |
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|
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/** |
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* Writes data from the VM step to the in-memory |
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* coverage map constructed by the Instrumenter. |
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*/ |
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class DataCollector { |
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constructor(instrumentationData={}){ |
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this.instrumentationData = instrumentationData; |
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|
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this.validOpcodes = { |
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"PUSH1": true, |
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} |
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} |
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|
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/** |
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* VM step event handler. Detects instrumentation hashes when they are pushed to the |
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* top of the stack. This runs millions of times - trying to keep it fast. |
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* @param {Object} info vm step info |
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*/ |
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step(info){ |
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const self = this; |
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if (typeof info !== 'object' || !info.opcode ) return; |
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|
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if (info.opcode.name.includes("PUSH1") && info.stack.length > 0){ |
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const idx = info.stack.length - 1; |
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let hash = web3Utils.toHex(info.stack[idx]).toString(); |
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hash = self._normalizeHash(hash); |
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try { |
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if (this.validOpcodes[info.opcode.name] && info.stack.length > 0){ |
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const idx = info.stack.length - 1; |
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let hash = web3Utils.toHex(info.stack[idx]).toString(); |
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hash = this._normalizeHash(hash); |
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|
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if(self.instrumentationData[hash]){ |
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self.instrumentationData[hash].hits++; |
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if(this.instrumentationData[hash]){ |
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this.instrumentationData[hash].hits++; |
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} |
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} |
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} |
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} |
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|
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_setInstrumentationData(data){ |
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this.instrumentationData = data; |
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} catch (err) { /*Ignore*/ }; |
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} |
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|
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/** |
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* Left-pads zero prefixed bytes 32 hashes to length 66. The '59' in the |
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* comparison below is arbitrary. It provides a margin for recurring zeros |
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* but prevents left-padding shorter irrelevant hashes (like fn sigs) |
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* |
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* @param {String} hash data hash from evm stack. |
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* @return {String} 0x prefixed hash of length 66. |
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*/ |
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_normalizeHash(hash){ |
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if (hash.length < 66 && hash.length > 52){ |
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if (hash.length < 66 && hash.length > 59){ |
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hash = hash.slice(2); |
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while(hash.length < 64) hash = '0' + hash; |
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hash = '0x' + hash |
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} |
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return hash; |
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} |
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|
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/** |
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* Unit test helper |
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* @param {Object} data Instrumenter.instrumentationData |
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*/ |
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_setInstrumentationData(data){ |
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this.instrumentationData = data; |
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} |
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} |
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|
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module.exports = DataCollector; |
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