Make the comparing update tracker a bit more flexible. It can now be in an

"auto" state where it will be enabled until we deem that the client is better
of without it (currently triggered by explicitly stating a low compression
level).

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4809 3789f03b-4d11-0410-bbf8-ca57d06f2519

diff --git a/common/rfb/ComparingUpdateTracker.cxx b/common/rfb/ComparingUpdateTracker.cxx
index 42a9e192758c422a2b6ed55394f653da4f85ce2a..43287e077af41a8c9a0d5edc64bfb49b335e000a 100644 (file)
--- a/common/rfb/ComparingUpdateTracker.cxx
+++ b/common/rfb/ComparingUpdateTracker.cxx
@@ -25,7 +25,7 @@
 using namespace rfb;
 
 ComparingUpdateTracker::ComparingUpdateTracker(PixelBuffer* buffer)
-  : fb(buffer), oldFb(fb->getPF(), 0, 0), firstCompare(true)
+  : fb(buffer), oldFb(fb->getPF(), 0, 0), firstCompare(true), enabled(true)
 {
     changed.assign_union(fb->getRect());
 }
@@ -37,35 +37,60 @@ ComparingUpdateTracker::~ComparingUpdateTracker()
 
 #define BLOCK_SIZE 16
 
-void ComparingUpdateTracker::compare()
+bool ComparingUpdateTracker::compare()
 {
   std::vector<Rect> rects;
   std::vector<Rect>::iterator i;
 
+  if (!enabled)
+    return false;
+
   if (firstCompare) {
     // NB: We leave the change region untouched on this iteration,
     // since in effect the entire framebuffer has changed.
     oldFb.setSize(fb->width(), fb->height());
+
     for (int y=0; y<fb->height(); y+=BLOCK_SIZE) {
       Rect pos(0, y, fb->width(), __rfbmin(fb->height(), y+BLOCK_SIZE));
       int srcStride;
       const rdr::U8* srcData = fb->getPixelsR(pos, &srcStride);
       oldFb.imageRect(pos, srcData, srcStride);
     }
+
     firstCompare = false;
-  } else {
-    copied.get_rects(&rects, copy_delta.x<=0, copy_delta.y<=0);
-    for (i = rects.begin(); i != rects.end(); i++)
-      oldFb.copyRect(*i, copy_delta);
 
-    changed.get_rects(&rects);
+    return false;
+  }
+
+  copied.get_rects(&rects, copy_delta.x<=0, copy_delta.y<=0);
+  for (i = rects.begin(); i != rects.end(); i++)
+    oldFb.copyRect(*i, copy_delta);
 
-    Region newChanged;
-    for (i = rects.begin(); i != rects.end(); i++)
-      compareRect(*i, &newChanged);
+  changed.get_rects(&rects);
 
-    changed = newChanged;
-  }
+  Region newChanged;
+  for (i = rects.begin(); i != rects.end(); i++)
+    compareRect(*i, &newChanged);
+
+  if (changed.equals(newChanged))
+    return false;
+
+  changed = newChanged;
+
+  return true;
+}
+
+void ComparingUpdateTracker::enable()
+{
+  enabled = true;
+}
+
+void ComparingUpdateTracker::disable()
+{
+  enabled = false;
+
+  // Make sure we update the framebuffer next time we get enabled
+  firstCompare = true;
 }
 
 void ComparingUpdateTracker::compareRect(const Rect& r, Region* newChanged)

diff --git a/common/rfb/ComparingUpdateTracker.h b/common/rfb/ComparingUpdateTracker.h
index 5d2e5edf24dc426d768d8435a765d68d7b178f76..fccc2222765c2d11a20dcbbcdd27b2887a90f651 100644 (file)
--- a/common/rfb/ComparingUpdateTracker.h
+++ b/common/rfb/ComparingUpdateTracker.h
@@ -29,14 +29,23 @@ namespace rfb {
     ~ComparingUpdateTracker();
 
     // compare() does the comparison and reduces its changed and copied regions
-    // as appropriate.
+    // as appropriate. Returns true if the regions were altered.
 
-    virtual void compare();
+    virtual bool compare();
+
+    // enable()/disable() turns the comparing functionality on/off. With it
+    // disabled, the object will behave like a dumb update tracker (i.e.
+    // compare() will be a no-op). It is harmless to repeatedly call these
+    // methods.
+
+    virtual void enable();
+    virtual void disable();
   private:
     void compareRect(const Rect& r, Region* newchanged);
     PixelBuffer* fb;
     ManagedPixelBuffer oldFb;
     bool firstCompare;
+    bool enabled;
   };
 
 }

diff --git a/common/rfb/ServerCore.cxx b/common/rfb/ServerCore.cxx
index 27e116e392aa49b4694eebb26d74058db578a3f1..ae2fd2474de5287527a48d0b64bf617264eb2498 100644 (file)
--- a/common/rfb/ServerCore.cxx
+++ b/common/rfb/ServerCore.cxx
@@ -47,10 +47,11 @@ rfb::IntParameter rfb::Server::clientWaitTimeMillis
  "The number of milliseconds to wait for a client which is no longer "
  "responding",
  20000, 0);
-rfb::BoolParameter rfb::Server::compareFB
+rfb::IntParameter rfb::Server::compareFB
 ("CompareFB",
- "Perform pixel comparison on framebuffer to reduce unnecessary updates",
- false);
+ "Perform pixel comparison on framebuffer to reduce unnecessary updates "
+ "(0: never, 1: always, 2: auto)",
+ 2);
 rfb::BoolParameter rfb::Server::protocol3_3
 ("Protocol3.3",
  "Always use protocol version 3.3 for backwards compatibility with "

diff --git a/common/rfb/ServerCore.h b/common/rfb/ServerCore.h
index 68d7b74b33bb147231e037975fab05e0bf3ab752..e12a8bc8a57e3d6b441842364406f13cb60e3265 100644 (file)
--- a/common/rfb/ServerCore.h
+++ b/common/rfb/ServerCore.h
@@ -37,7 +37,7 @@ namespace rfb {
     static IntParameter maxConnectionTime;
     static IntParameter maxIdleTime;
     static IntParameter clientWaitTimeMillis;
-    static BoolParameter compareFB;
+    static IntParameter compareFB;
     static BoolParameter protocol3_3;
     static BoolParameter alwaysShared;
     static BoolParameter neverShared;

diff --git a/common/rfb/VNCSConnectionST.cxx b/common/rfb/VNCSConnectionST.cxx
index d0cdf869943610eab32d76e791331132689950a5..466d6d5c835d72033dcbb65ed92128946dee3580 100644 (file)
--- a/common/rfb/VNCSConnectionST.cxx
+++ b/common/rfb/VNCSConnectionST.cxx
@@ -326,6 +326,16 @@ int VNCSConnectionST::checkIdleTimeout()
   return secsToMillis(timeLeft);
 }
 
+
+bool VNCSConnectionST::getComparerState()
+{
+  // We interpret a low compression level as an indication that the client
+  // wants to prioritise CPU usage over bandwidth, and hence disable the
+  // comparing update tracker.
+  return (cp.compressLevel == -1) || (cp.compressLevel > 1);
+}
+
+
 // renderedCursorChange() is called whenever the server-side rendered cursor
 // changes shape or position.  It ensures that the next update will clean up
 // the old rendered cursor and if necessary draw the new rendered cursor.

diff --git a/common/rfb/VNCSConnectionST.h b/common/rfb/VNCSConnectionST.h
index 8742fa6765ba67b810548675116dee9c6e20545d..72dc59c0e8f2c1ea9b4895a9a0f8df44a19fc46a 100644 (file)
--- a/common/rfb/VNCSConnectionST.h
+++ b/common/rfb/VNCSConnectionST.h
@@ -85,6 +85,10 @@ namespace rfb {
     // The following methods never throw exceptions nor do they ever delete the
     // SConnectionST object.
 
+    // getComparerState() returns if this client would like the framebuffer
+    // comparer to be enabled.
+    bool getComparerState();
+
     // renderedCursorChange() is called whenever the server-side rendered
     // cursor changes shape or position.  It ensures that the next update will
     // clean up the old rendered cursor and if necessary draw the new rendered

diff --git a/common/rfb/VNCServerST.cxx b/common/rfb/VNCServerST.cxx
index 5c13596983a7fac5e4cb80b032e2a3f638cfeb3a..1e3f61a08da0e5708677f326d45fdf016db277f9 100644 (file)
--- a/common/rfb/VNCServerST.cxx
+++ b/common/rfb/VNCServerST.cxx
@@ -596,10 +596,13 @@ bool VNCServerST::checkUpdate()
 
   pb->grabRegion(toCheck);
 
-  if (rfb::Server::compareFB) {
-    comparer->compare();
+  if (getComparerState())
+    comparer->enable();
+  else
+    comparer->disable();
+
+  if (comparer->compare())
     comparer->getUpdateInfo(&ui, pb->getRect());
-  }
 
   if (renderCursor) {
     pb->getImage(renderedCursor.data,
@@ -665,3 +668,19 @@ void VNCServerST::notifyScreenLayoutChange(VNCSConnectionST* requester)
     (*ci)->screenLayoutChangeOrClose(reasonOtherClient);
   }
 }
+
+bool VNCServerST::getComparerState()
+{
+  if (rfb::Server::compareFB == 0)
+    return false;
+  if (rfb::Server::compareFB != 2)
+    return true;
+
+  std::list<VNCSConnectionST*>::iterator ci, ci_next;
+  for (ci=clients.begin();ci!=clients.end();ci=ci_next) {
+    ci_next = ci; ci_next++;
+    if ((*ci)->getComparerState())
+      return true;
+  }
+  return false;
+}

diff --git a/common/rfb/VNCServerST.h b/common/rfb/VNCServerST.h
index 47a4801972a559793469ee70ba49a17f247f4421..2fed0a87f104cd64538f6061abe49245305d7db5 100644 (file)
--- a/common/rfb/VNCServerST.h
+++ b/common/rfb/VNCServerST.h
@@ -238,6 +238,8 @@ namespace rfb {
 
     void notifyScreenLayoutChange(VNCSConnectionST *requester);
 
+    bool getComparerState();
+
     QueryConnectionHandler* queryConnectionHandler;
     KeyRemapper* keyRemapper;
     bool useEconomicTranslate;