From: Date: June 1 2007 5:28pm
Subject: Connector/NET commit: r749 - in branches/5.0: . Driver/Source
List-Archive: http://lists.mysql.com/commits/27937
X-Bug: 28204, 28204
Message-Id: <200706011528.l51FS3i4028295@bk-internal.mysql.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Modified:
   branches/5.0/CHANGES
   branches/5.0/Driver/Source/CompressedStream.cs
Log:
Bug #28204  	Net Connector 5.0.6/5.1.0 compression problem

Fixed a problem with compression over a network.  We were letting the inflate stream read
directly from the network stream.  Under certain situations, two bytes were being left unread
and this messed up our byte counts.  Now we are using a WeakReference to an internal buffer
that we read the compressed data into before inflating. (Bug #28204)  

Modified: branches/5.0/CHANGES
===================================================================
--- branches/5.0/CHANGES	2007-05-30 18:44:55 UTC (rev 748)
+++ branches/5.0/CHANGES	2007-06-01 15:28:02 UTC (rev 749)
@@ -1,9 +1,10 @@
 Version 5.0.8
-  Bugs fixed
-  ----------
   Bug #28706 Log messages are truncated  
+  - Fixed a problem with compression over a network.  We were letting the inflate stream read
+    directly from the network stream.  Under certain situations, two bytes were being left unread
+    and this messed up our byte counts.  Now we are using a WeakReference to an internal buffer
+    that we read the compressed data into before inflating. (Bug #28204)  
   
-  
 Version 5.0.7 5/16/2007
 
   Bugs fixed

Modified: branches/5.0/Driver/Source/CompressedStream.cs
===================================================================
--- branches/5.0/Driver/Source/CompressedStream.cs	2007-05-30 18:44:55 UTC (rev 748)
+++ branches/5.0/Driver/Source/CompressedStream.cs	2007-06-01 15:28:02 UTC (rev 749)
@@ -35,6 +35,8 @@
 
 		// reading fields
         private byte[] localByte;
+        private byte[] inBuffer;
+        private WeakReference inBufferRef;
         private int inPos;
         private int maxInPos;
         private ZInputStream zInStream;
@@ -44,16 +46,11 @@
 			this.baseStream = baseStream;
             localByte = new byte[1];
 			cache = new MemoryStream();
-		}
+            inBufferRef = new WeakReference(inBuffer, false);
+        }
 
 		#region Properties
 
-		//TODO: remove comment
-/*		public Stream BaseStream 
-		{
-			get { return baseStream; }
-		}
-*/
 		public override bool CanRead
 		{
 			get	{ return baseStream.CanRead; }
@@ -109,9 +106,8 @@
 				throw new ArgumentException(Resources.BufferNotLargeEnough, "buffer");
 
             if (inPos == maxInPos)
-            {
                 PrepareNextPacket();
-            }
+
             int countToRead = Math.Min(count, maxInPos-inPos);
             int countRead;
             if (zInStream != null)
@@ -119,6 +115,15 @@
             else
                 countRead = baseStream.Read(buffer, offset, countToRead);
             inPos += countRead;
+
+            // release the weak reference
+            if (inPos == maxInPos)
+            {
+                zInStream = null;
+                inBufferRef.Target = inBuffer;
+                inBuffer = null;
+            }
+
             return countRead;
 		}
 
@@ -141,7 +146,9 @@
             }
             else
             {
-                zInStream = new ZInputStream(baseStream);
+                ReadNextPacket(compressedLength);
+                MemoryStream ms = new MemoryStream(inBuffer);
+                zInStream = new ZInputStream(ms);
                 zInStream.maxInput = compressedLength;
             }
 
@@ -149,6 +156,21 @@
             maxInPos = unCompressedLength;
         }
 
+        private void ReadNextPacket(int len)
+        {
+            inBuffer = (byte[])inBufferRef.Target;
+            if (inBuffer == null || inBuffer.Length < len)
+                inBuffer = new byte[len];
+            int numRead = 0;
+            int numToRead = len;
+            while (numToRead > 0)
+            {
+                int read = baseStream.Read(inBuffer, numRead, numToRead);
+                numRead += read;
+                numToRead -= read;
+            }
+        }
+
         private MemoryStream CompressCache()
         {
             // small arrays almost never yeild a benefit from compressing