Try an optimisation based on flamegraphs

lib/collector.js

@@ -22,9 +22,7 @@ class DataCollector {
     try {
       if (this.validOpcodes[info.opcode.name] && info.stack.length > 0){
         const idx = info.stack.length - 1;
-        let hash = web3Utils.toHex(info.stack[idx]).toString();
+        let hash = "0x" + info.stack[idx].toString(16,64);
-        hash = this._normalizeHash(hash);
-
         if(this.instrumentationData[hash]){
           this.instrumentationData[hash].hits++;
         }
@@ -32,23 +30,6 @@ class DataCollector {
     } catch (err) { /*Ignore*/ };
   }
 
-  /**
-   * Left-pads zero prefixed bytes 32 hashes to length 66. The '59' in the
-   * comparison below is arbitrary. It provides a margin for recurring zeros
-   * but prevents left-padding shorter irrelevant hashes (like fn sigs)
-   *
-   * @param  {String} hash  data hash from evm stack.
-   * @return {String}       0x prefixed hash of length 66.
-   */
-  _normalizeHash(hash){
-    if (hash.length < 66 && hash.length > 59){
-      hash = hash.slice(2);
-      while(hash.length < 64) hash = '0' + hash;
-      hash = '0x' + hash
-    }
-    return hash;
-  }
-
   /**
    * Unit test helper
    * @param {Object} data  Instrumenter.instrumentationData
@@ -58,4 +39,4 @@ class DataCollector {
   }
 }
 
-module.exports = DataCollector;
+module.exports = DataCollector;