ios code refactor

src/ios/RNFetchBlob/RNFetchBlob.m

                   body:(NSString *)body callback:(RCTResponseSenderBlock)callback)
 {
     NSString *cType = [headers valueForKey:@"content-type"];
-//	if (cType != nil && cType == @"application/x-www-form-urlencoded") {
-//		[RNFetchBlobReqBuilder buildEncodedRequest:options taskId:taskId method:method url:url headers:headers body:body onComplete:^(NSURLRequest *req, long bodyLength) {
-//	        // send HTTP request
-//	        RNFetchBlobNetwork * utils = [[RNFetchBlobNetwork alloc] init];
-//	        [utils sendRequest:options contentLength:bodyLength bridge:self.bridge taskId:taskId withRequest:req callback:callback];
-//	        utils = nil;
-//	    }];
-//	} else {
-		[RNFetchBlobReqBuilder buildOctetRequest:options taskId:taskId method:method url:url headers:headers body:body onComplete:^(NSURLRequest *req, long bodyLength) {
-	        // send HTTP request
-	        RNFetchBlobNetwork * utils = [[RNFetchBlobNetwork alloc] init];
-	        [utils sendRequest:options contentLength:bodyLength bridge:self.bridge taskId:taskId withRequest:req callback:callback];
-	        utils = nil;
-	    }];
-//	}
+    
+    [RNFetchBlobReqBuilder buildOctetRequest:options taskId:taskId method:method url:url headers:headers body:body onComplete:^(NSURLRequest *req, long bodyLength) {
+        // send HTTP request
+        RNFetchBlobNetwork * utils = [[RNFetchBlobNetwork alloc] init];
+        [utils sendRequest:options contentLength:bodyLength bridge:self.bridge taskId:taskId withRequest:req callback:callback];
+        utils = nil;
+    }];
 }
 
 RCT_EXPORT_METHOD(createFile:(NSString *)path data:(NSString *)data encoding:(NSString *)encoding callback:(RCTResponseSenderBlock)callback) {
 
 RCT_EXPORT_METHOD(writeArrayChunk:(NSString *)streamId withArray:(NSArray *)dataArray callback:(RCTResponseSenderBlock) callback) {
     RNFetchBlobFS *fs = [[RNFetchBlobFS getFileStreams] valueForKey:streamId];
-//    char bytes[[dataArray count]];
     char * bytes = (char *) malloc([dataArray count]);
     for(int i = 0; i < dataArray.count; i++) {
         bytes[i] = [[dataArray objectAtIndex:i] charValue];

src/ios/RNFetchBlobNetwork.m

 @implementation RNFetchBlobNetwork
 
 NSOperationQueue *taskQueue;
-
 @synthesize taskId;
 @synthesize expectedBytes;
 @synthesize receivedBytes;
     self = [super init];
     if(taskQueue == nil) {
         taskQueue = [[NSOperationQueue alloc] init];
+        taskQueue.maxConcurrentOperationCount = 10;
     }
     if(taskTable == nil) {
         taskTable = [[NSMutableDictionary alloc] init];
     // the session trust any SSL certification
 
     NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
-    session = [NSURLSession sessionWithConfiguration:defaultConfigObject delegate:self delegateQueue:[NSOperationQueue mainQueue]];
+    session = [NSURLSession sessionWithConfiguration:defaultConfigObject delegate:self delegateQueue:taskQueue];
 
     if(path != nil || [self.options valueForKey:CONFIG_USE_TEMP]!= nil)
     {
 
     if(respFile == YES)
     {
-        NSFileManager * fm = [NSFileManager defaultManager];
-        NSString * folder = [destPath stringByDeletingLastPathComponent];
-        if(![fm fileExistsAtPath:folder]) {
-            [fm createDirectoryAtPath:folder withIntermediateDirectories:YES attributes:NULL error:nil];
+        @try{
+            NSFileManager * fm = [NSFileManager defaultManager];
+            NSString * folder = [destPath stringByDeletingLastPathComponent];
+            if(![fm fileExistsAtPath:folder]) {
+                [fm createDirectoryAtPath:folder withIntermediateDirectories:YES attributes:NULL error:nil];
+            }
+            [fm createFileAtPath:destPath contents:[[NSData alloc] init] attributes:nil];
+            writeStream = [[NSOutputStream alloc] initToFileAtPath:destPath append:YES];
+            [writeStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
+            [writeStream open];
+        }
+        @catch(NSException * ex)
+        {
+            NSLog(@"write file error");
         }
-        [fm createFileAtPath:destPath contents:[[NSData alloc] init] attributes:nil];
-        writeStream = [[NSOutputStream alloc] initToFileAtPath:destPath append:YES];
-        [writeStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
-        [writeStream open];
     }
     completionHandler(NSURLSessionResponseAllow);
 }
     
     if(respFile == YES)
     {
+        if(error != nil) {
+            NSLog([error localizedDescription]);
+        }
         [writeStream close];
         callback(@[error == nil ? [NSNull null] : [error localizedDescription],
                    respInfo == nil ? [NSNull null] : respInfo,