changed: move retrieval of cache status to iocontrol instead of seek

This also changes it to a structure, so we can extend it with info on if it's full or not. (needed if we want progressive startup with limited cache size)

xbmc/cores/dvdplayer/DVDInputStreams/DVDInputStreamFile.cpp

@@ -116,10 +116,11 @@ __int64 CDVDInputStreamFile::GetLength()
 
 __int64 CDVDInputStreamFile::GetCachedBytes()
 {
-  if(!m_pFile)
+  SCacheStatus status;
+  if(m_pFile && m_pFile->IoControl(IOCTRL_CACHE_STATUS, &status) >= 0)
+    return status.forward;
+  else
     return -1;
-
-  return m_pFile->Seek(0, SEEK_BUFFERED);
 }
 
 BitstreamStats CDVDInputStreamFile::GetBitstreamStats() const

xbmc/filesystem/FileCache.cpp

@@ -284,8 +284,6 @@ int64_t CFileCache::Seek(int64_t iFilePosition, int iWhence)
     iTarget = iCurPos + iTarget;
   else if (iWhence == SEEK_POSSIBLE)
     return m_seekPossible;
-  else if (iWhence == SEEK_BUFFERED)
-    return m_pCache->WaitForData(0, 0);
   else if (iWhence != SEEK_SET)
     return -1;
 
@@ -350,3 +348,15 @@ CStdString CFileCache::GetContent()
 
   return m_source.GetImplemenation()->GetContent();
 }
+
+int CFileCache::IoControl(EIoControl request, void* param)
+{
+  if(request == IOCTRL_CACHE_STATUS)
+  {
+    SCacheStatus* status = (SCacheStatus*)param;
+    status->forward = m_pCache->WaitForData(0, 0);
+    return 0;
+  }
+
+  return -1;
+}

xbmc/filesystem/IFile.h

@@ -39,7 +39,6 @@
 #include <sys/stat.h>
 
 #define SEEK_POSSIBLE 0x10 // flag used to check if protocol allows seeks
-#define SEEK_BUFFERED 0x11 // how many bytes forward is buffered
 
 namespace XFILE
 {
@@ -50,8 +49,14 @@ struct SNativeIoControl
   void* param;
 };
 
+struct SCacheStatus
+{
+  uint64_t forward;  /**< number of bytes cached forward of current position */
+};
+
 typedef enum {
   IOCTRL_NATIVE        = 1, /**< SNativeIoControl structure, containing what should be passed to native ioctrl */
+  IOCTRL_CACHE_STATUS  = 3, /**< SCacheStatus structure */
 } EIoControl;
 
 class IFile