choosing memory usage dynamically

.gitignore

@@ -3,3 +3,4 @@ node_modules/*
 yarn.lock
 tesseract.dev.js
 worker.dev.js
+*.traineddata

examples/node/basic.js

@@ -9,6 +9,6 @@ Tesseract.recognize(image)
 .catch(err => {
   console.log('catch\n', err);
 })
-.finally(data => {
-  console.log('finally\n', data.text);
+.finally(e => {
+  console.log('finally\n');
 });

src/common/worker.js

@@ -18,11 +18,15 @@ function dispatchHandlers(packet, send){
     
     latestJob = respond;
 
+    try {
         if(packet.action === 'recognize'){
             handleRecognize(packet.payload, respond)
         }else if(packet.action === 'detect'){
             handleDetect(packet.payload, respond)
         }
+    } catch (err) {
+        respond.reject(err)
+    }
 }
 exports.dispatchHandlers = dispatchHandlers;
 
@@ -32,17 +36,25 @@ exports.setAdapter = function setAdapter(impl){
 
 
 function handleInit(req, res){
-    if(!Module){
+    var MIN_MEMORY = 100663296;
+    
+    if(['chi_sim', 'chi_tra', 'jpn'].indexOf(req.options.lang) != -1){
+        MIN_MEMORY = 167772160;
+    }
+
+    if(!Module || Module.TOTAL_MEMORY < MIN_MEMORY){
         var Core = adapter.getCore(req, res);
 
         res.progress({ status: 'initializing tesseract', progress: 0 })
+
         Module = Core({
-            TOTAL_MEMORY: req.memory,
+            TOTAL_MEMORY: MIN_MEMORY,
             TesseractProgress(percent){
                 latestJob.progress({ status: 'recognizing text', progress: Math.max(0, (percent-30)/70) })
             },
             onRuntimeInitialized() {}
         })
+
         Module.FS_createPath("/", "tessdata", true, true)
         base = new Module.TessBaseAPI()
         res.progress({ status: 'initializing tesseract', progress: 1 })