From: Pierre Ossman <ossman@cendio.se>
Date: Wed, 11 Nov 2015 12:11:09 +0000 (+0100)
Subject: Clear up ZlibInStream::reset() behaviour
X-Git-Tag: v1.6.90~95^2~20
X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=6f318e4451fcb45054408eaf568ca1c30c2d1ab6;p=tigervnc.git

Clear up ZlibInStream::reset() behaviour

It previously only did a reset of the ZlibInStream object, not the
underlying zlib stream. It also had the side effect of flushing
the underlying stream and disassociating from it.

Clear things up by changing the naming, and introducing a proper
reset function (which is needed by the Tight decoder).
---

diff --git a/common/rdr/ZlibInStream.cxx b/common/rdr/ZlibInStream.cxx
index 6f3a7d02..4053bd19 100644
--- a/common/rdr/ZlibInStream.cxx
+++ b/common/rdr/ZlibInStream.cxx
@@ -16,6 +16,8 @@
  * USA.
  */
 
+#include <assert.h>
+
 #include <rdr/ZlibInStream.h>
 #include <rdr/Exception.h>
 #include <zlib.h>
@@ -26,26 +28,16 @@ enum { DEFAULT_BUF_SIZE = 16384 };
 
 ZlibInStream::ZlibInStream(int bufSize_)
   : underlying(0), bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0),
-    bytesIn(0)
+    zs(NULL), bytesIn(0)
 {
-  zs = new z_stream;
-  zs->zalloc    = Z_NULL;
-  zs->zfree     = Z_NULL;
-  zs->opaque    = Z_NULL;
-  zs->next_in   = Z_NULL;
-  zs->avail_in  = 0;
-  if (inflateInit(zs) != Z_OK) {
-    delete zs;
-    throw Exception("ZlibInStream: inflateInit failed");
-  }
   ptr = end = start = new U8[bufSize];
+  init();
 }
 
 ZlibInStream::~ZlibInStream()
 {
+  deinit();
   delete [] start;
-  inflateEnd(zs);
-  delete zs;
 }
 
 void ZlibInStream::setUnderlying(InStream* is, int bytesIn_)
@@ -60,7 +52,7 @@ int ZlibInStream::pos()
   return offset + ptr - start;
 }
 
-void ZlibInStream::reset()
+void ZlibInStream::removeUnderlying()
 {
   ptr = end = start;
   if (!underlying) return;
@@ -72,6 +64,38 @@ void ZlibInStream::reset()
   underlying = 0;
 }
 
+void ZlibInStream::reset()
+{
+  deinit();
+  init();
+}
+
+void ZlibInStream::init()
+{
+  assert(zs == NULL);
+
+  zs = new z_stream;
+  zs->zalloc    = Z_NULL;
+  zs->zfree     = Z_NULL;
+  zs->opaque    = Z_NULL;
+  zs->next_in   = Z_NULL;
+  zs->avail_in  = 0;
+  if (inflateInit(zs) != Z_OK) {
+    delete zs;
+    zs = NULL;
+    throw Exception("ZlibInStream: inflateInit failed");
+  }
+}
+
+void ZlibInStream::deinit()
+{
+  assert(zs != NULL);
+  removeUnderlying();
+  inflateEnd(zs);
+  delete zs;
+  zs = NULL;
+}
+
 int ZlibInStream::overrun(int itemSize, int nItems, bool wait)
 {
   if (itemSize > bufSize)
diff --git a/common/rdr/ZlibInStream.h b/common/rdr/ZlibInStream.h
index c26b6d63..6bd4da4c 100644
--- a/common/rdr/ZlibInStream.h
+++ b/common/rdr/ZlibInStream.h
@@ -38,11 +38,15 @@ namespace rdr {
     virtual ~ZlibInStream();
 
     void setUnderlying(InStream* is, int bytesIn);
-    void reset();
+    void removeUnderlying();
     int pos();
+    void reset();
 
   private:
 
+    void init();
+    void deinit();
+
     int overrun(int itemSize, int nItems, bool wait);
     bool decompress(bool wait);
 
diff --git a/common/rfb/TightDecoder.cxx b/common/rfb/TightDecoder.cxx
index cab49fdf..1bfa7a9f 100644
--- a/common/rfb/TightDecoder.cxx
+++ b/common/rfb/TightDecoder.cxx
@@ -165,7 +165,7 @@ void TightDecoder::decodeRect(const Rect& r, const void* buffer,
   bufptr += 1;
   buflen -= 1;
 
-  // Flush zlib streams if we are told by the server to do so.
+  // Reset zlib streams if we are told by the server to do so.
   for (int i = 0; i < 4; i++) {
     if (comp_ctl & 1) {
       zis[i].reset();
@@ -309,8 +309,8 @@ void TightDecoder::decodeRect(const Rect& r, const void* buffer,
     netbuf = new rdr::U8[dataSize];
 
     zis[streamId].readBytes(netbuf, dataSize);
-    zis[streamId].reset();
 
+    zis[streamId].removeUnderlying();
     delete ms;
 
     bufptr = netbuf;
diff --git a/common/rfb/zrleDecode.h b/common/rfb/zrleDecode.h
index 25661711..07d6795a 100644
--- a/common/rfb/zrleDecode.h
+++ b/common/rfb/zrleDecode.h
@@ -177,7 +177,7 @@ void ZRLE_DECODE (const Rect& r, rdr::InStream* is,
     }
   }
 
-  zis->reset();
+  zis->removeUnderlying();
 }
 
 #undef ZRLE_DECODE