update old solc process to new process wrapper

lib/modules/solidity/solcP.js

@@ -1,11 +1,13 @@
-let solc;
-
 const fs = require('fs-extra');
 const path = require('path');
 const constants = require('../../constants');
 const Utils = require('../../utils/utils');
 
-function findImports(filename) {
+const ProcessWrapper = require('../../process/processWrapper');
+
+class SolcProcess extends ProcessWrapper {
+
+  findImports(filename) {
     if (filename.startsWith('http') || filename.startsWith('git')) {
       const fileObj = Utils.getExternalContractUrl(filename);
       filename = fileObj.filePath;
@@ -22,20 +24,35 @@ function findImports(filename) {
     return {error: 'File not found'};
   }
 
+  loadCompiler(solcLocation) {
+    this.solc = require(solcLocation);
+  }
+
+  compile(jsonObj, cb) {
+    // TODO: only available in 0.4.11; need to make versions warn about this
+    let output = this.solc.compileStandardWrapper(JSON.stringify(jsonObj), this.findImports);
+    cb(output);
+  }
+
+}
+
+let solcProcess;
+
 process.on('message', function (msg) {
+  if (msg.action === "init") {
+    solcProcess = new SolcProcess(msg.options);
+    return process.send({result: "initiated"});
+  }
+
   if (msg.action === 'loadCompiler') {
-    solc = require(msg.solcLocation);
+    solcProcess.loadCompiler(msg.requirePath);
     process.send({result: "loadedCompiler"});
   }
 
   if (msg.action === 'compile') {
-    // TODO: only available in 0.4.11; need to make versions warn about this
-    let output = solc.compileStandardWrapper(JSON.stringify(msg.jsonObj), findImports);
+    solcProcess.compile(msg.jsonObj, (output) => {
       process.send({result: "compilation", output: output});
+    });
   }
 });
 
-process.on('exit', function () {
-  process.exit(0);
-});
-

lib/modules/solidity/solcW.js

@@ -1,58 +1,59 @@
 let utils = require('../../utils/utils.js');
 let fs = require('../../core/fs.js');
-let solcProcess;
-let compilerLoaded = false;
 let currentSolcVersion = require('../../../package.json').dependencies.solc;
+const ProcessLauncher = require('../../process/processLauncher');
 
 class SolcW {
 
   constructor(options) {
     this.logger = options.logger;
     this.events = options.events;
+    this.compilerLoaded = false;
+    this.solcProcess = null;
   }
 
   load_compiler(done) {
     const self = this;
-    if (compilerLoaded) {
+    if (this.compilerLoaded) {
       done();
     }
-    solcProcess = require('child_process').fork(utils.joinPath(__dirname, '/solcP.js'));
-    solcProcess.once('message', function (msg) {
-      if (msg.result !== 'loadedCompiler') {
-        return;
-      }
-      compilerLoaded = true;
+    this.solcProcess = new ProcessLauncher({
+      modulePath: utils.joinPath(__dirname, 'solcP.js'),
+      logger: self.logger,
+      events: self.events
+    });
+    this.solcProcess.send({action: "init", options: {}});
+
+    this.solcProcess.subscribeTo('result', 'loadedCompiler', () => {
+      self.compilerLoaded = true;
       done();
     });
 
     this.events.request("version:get:solc", function(solcVersion) {
       if (solcVersion === currentSolcVersion) {
-        solcProcess.send({action: 'loadCompiler', solcLocation: 'solc'});
+        self.solcProcess.send({action: 'loadCompiler', requirePath: 'solc'});
       } else {
         self.events.request("version:getPackageLocation", "solc", solcVersion, function(err, location) {
           if (err) {
             return done(err);
           }
           let requirePath = fs.dappPath(location);
-          solcProcess.send({action: 'loadCompiler', solcLocation: requirePath});
+          self.solcProcess.send({action: 'loadCompiler', requirePath: requirePath});
         });
-
       }
     });
   }
 
   isCompilerLoaded() {
-    return (compilerLoaded === true);
+    return (this.compilerLoaded === true);
   }
 
   compile(jsonObj,  done) {
-    solcProcess.once('message', function (msg) {
-      if (msg.result !== 'compilation') {
-        return;
-      }
+    this.solcProcess.subscribeTo('result', 'compilation', (msg) => {
       done(JSON.parse(msg.output));
     });
-    solcProcess.send({action: 'compile', jsonObj: jsonObj});
+
+    this.solcProcess.send({action: 'compile', jsonObj: jsonObj});
   }
 }