package

lib/src/Net/NetworkBuffer.dart

@@ -0,0 +1,134 @@
+/*
+ 
+Copyright (c) 2019 Ahmed Kh. Zamil
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+
+import '../Data/DC.dart';
+import 'dart:core';
+
+class NetworkBuffer
+{
+    DC _data;
+
+    int _neededDataLength = 0;
+    
+    NetworkBuffer()
+    {
+        _data = new DC(0);
+    }
+
+    bool get protected => _neededDataLength > _data.length;
+        
+    int get available => _data.length;
+    
+
+
+    void holdForNextWrite(DC src, int offset, int size)
+    {
+        holdFor(src, offset, size, size + 1);
+    }
+
+
+    void holdFor(DC src, int offset, int size, int needed)
+    {
+        //lock (syncLock)
+        //{
+            if (size >= needed)
+                throw new Exception("Size >= Needed !");
+
+            //trim = true;
+            _data = DC.combine(src, offset, size, _data, 0, _data.length);
+            _neededDataLength = needed;
+
+        //}
+    }
+
+    void holdForNeeded(DC src, int needed)
+    {
+        holdFor(src, 0, src.length, needed);
+    }
+
+    bool protect(DC data, int offset, int needed)
+    {
+        int dataLength = _data.length - offset;
+
+        // protection
+        if (dataLength < needed)
+        {
+            holdFor(data, offset, dataLength, needed);
+            return true;
+        }
+        else
+            return false;
+    }
+
+
+
+    void write(DC src, int offset, int length)
+    {
+        //lock(syncLock)
+        _data.append(src, offset, length);
+    }
+
+    bool get canRead
+    {
+        if (_data.length == 0)
+            return false;
+        if (_data.length < _neededDataLength)
+            return false;
+
+        return true;
+    }
+
+    DC read()
+    {
+        //lock (syncLock)
+        //{
+        if (_data.length == 0)
+            return null;
+
+        DC rt = null;
+
+        if (_neededDataLength == 0)
+        {
+            rt = _data;
+            _data = new DC(0);
+        }
+        else
+        {
+            if (_data.length >= _neededDataLength)
+            {
+                rt = _data;
+                _data = new DC(0);
+                _neededDataLength = 0;
+                return rt;
+            }
+            else
+            {
+                return null;
+            }
+        }
+        //}
+
+        return rt;
+      }
+}