tags 350025 + patch
stop

The problem is caused because I have a package with a status entry
larger then 32k.

Attached is a patch which fixes the problem by the expedient of using
mmap instead of a sliding buffer, it has been tempted and works fine.

Note, the constructor still has a size argument, it's just not used.

I didn't want to change the API, I'll leave that bit of cleanup to the
apt maintainers.

Thanks.

-- 
          1024D/E65A7801 Zephaniah E. Hull <[EMAIL PROTECTED]>
           92ED 94E4 B1E6 3624 226D  5727 4453 008B E65A 7801
            CCs of replies from mailing lists are requested.

   "<green>From</yellow>"
   "Wow. The green word From is no longer yellow. That's deep, man."
 -- Marcus Meissner & Lars Balker Rasmussen in the Scary Devil Monastery
diff -ur orig/apt-0.6.43.2/apt-pkg/tagfile.cc apt-0.6.43.2/apt-pkg/tagfile.cc
--- orig/apt-0.6.43.2/apt-pkg/tagfile.cc        2005-10-19 15:19:08.000000000 
-0400
+++ apt-0.6.43.2/apt-pkg/tagfile.cc     2006-01-27 21:06:14.000000000 -0500
@@ -35,20 +35,20 @@
      Fd(*pFd),
      Size(Size)
 {
-   if (Fd.IsOpen() == false)
+   if (Fd.IsOpen() == false || Fd.Size() == 0)
    {
       Buffer = 0;
       Start = End = Buffer = 0;
-      Done = true;
       iOffset = 0;
+      Map = NULL;
       return;
    }
    
-   Buffer = new char[Size];
-   Start = End = Buffer;
-   Done = false;
+   Map = new MMap (Fd, MMap::Public | MMap::ReadOnly);
+   Buffer = (char *) Map->Data ();
+   Start = Buffer;
+   End = Buffer + Map->Size ();
    iOffset = 0;
-   Fill();
 }
                                                                        /*}}}*/
 // TagFile::~pkgTagFile - Destructor                                   /*{{{*/
@@ -56,7 +56,7 @@
 /* */
 pkgTagFile::~pkgTagFile()
 {
-   delete [] Buffer;
+   delete Map;
 }
                                                                        /*}}}*/
 // TagFile::Step - Advance to the next section                         /*{{{*/
@@ -64,14 +64,13 @@
 /* If the Section Scanner fails we refill the buffer and try again. */
 bool pkgTagFile::Step(pkgTagSection &Tag)
 {
+   if (Start == End)
+      return false;
+
    if (Tag.Scan(Start,End - Start) == false)
    {
-      if (Fill() == false)
-        return false;
-      
-      if (Tag.Scan(Start,End - Start) == false)
-        return _error->Error(_("Unable to parse package file %s (1)"),
-                             Fd.Name().c_str());
+      return _error->Error(_("Unable to parse package file %s (1)"),
+             Fd.Name().c_str());
    }
    Start += Tag.size();
    iOffset += Tag.size();
@@ -80,50 +79,6 @@
    return true;
 }
                                                                        /*}}}*/
-// TagFile::Fill - Top up the buffer                                   /*{{{*/
-// ---------------------------------------------------------------------
-/* This takes the bit at the end of the buffer and puts it at the start
-   then fills the rest from the file */
-bool pkgTagFile::Fill()
-{
-   unsigned long EndSize = End - Start;
-   unsigned long Actual = 0;
-   
-   memmove(Buffer,Start,EndSize);
-   Start = Buffer;
-   End = Buffer + EndSize;
-   
-   if (Done == false)
-   {
-      // See if only a bit of the file is left
-      if (Fd.Read(End,Size - (End - Buffer),&Actual) == false)
-        return false;
-      if (Actual != Size - (End - Buffer))
-        Done = true;
-      End += Actual;
-   }
-   
-   if (Done == true)
-   {
-      if (EndSize <= 3 && Actual == 0)
-        return false;
-      if (Size - (End - Buffer) < 4)
-        return true;
-      
-      // Append a double new line if one does not exist
-      unsigned int LineCount = 0;
-      for (const char *E = End - 1; E - End < 6 && (*E == '\n' || *E == '\r'); 
E--)
-        if (*E == '\n')
-           LineCount++;
-      for (; LineCount < 2; LineCount++)
-        *End++ = '\n';
-      
-      return true;
-   }
-   
-   return true;
-}
-                                                                       /*}}}*/
 // TagFile::Jump - Jump to a pre-recorded location in the file         /*{{{*/
 // ---------------------------------------------------------------------
 /* This jumps to a pre-recorded file location and reads the record
@@ -141,20 +96,7 @@
 
    // Reposition and reload..
    iOffset = Offset;
-   Done = false;
-   if (Fd.Seek(Offset) == false)
-      return false;
-   End = Start = Buffer;
-   
-   if (Fill() == false)
-      return false;
-
-   if (Tag.Scan(Start,End - Start) == true)
-      return true;
-   
-   // This appends a double new line (for the real eof handling)
-   if (Fill() == false)
-      return false;
+   Start = Buffer + iOffset;
    
    if (Tag.Scan(Start,End - Start) == false)
       return _error->Error(_("Unable to parse package file %s 
(2)"),Fd.Name().c_str());
@@ -181,7 +123,7 @@
    Stop = Section = Start;
    memset(AlphaIndexes,0,sizeof(AlphaIndexes));
 
-   if (Stop == 0)
+   if (Stop == 0 || MaxLength == 0)
       return false;
    
    TagCount = 0;
@@ -212,6 +154,12 @@
       Stop++;
    }
 
+   if ((Stop+1 >= End) && (End[-1] == '\n' || End[-1] == '\r'))
+   {
+       Indexes[TagCount] = (End - 1) - Section;
+       return true;
+   }
+
    return false;
 }
                                                                        /*}}}*/
diff -ur orig/apt-0.6.43.2/apt-pkg/tagfile.h apt-0.6.43.2/apt-pkg/tagfile.h
--- orig/apt-0.6.43.2/apt-pkg/tagfile.h 2005-10-19 15:19:08.000000000 -0400
+++ apt-0.6.43.2/apt-pkg/tagfile.h      2006-01-27 20:22:47.000000000 -0500
@@ -25,6 +25,7 @@
 #endif 
 
 #include <apt-pkg/fileutl.h>
+#include <apt-pkg/mmap.h>
 #include <stdio.h>
     
 class pkgTagSection
@@ -69,15 +70,13 @@
 class pkgTagFile
 {
    FileFd &Fd;
+   MMap *Map;
    char *Buffer;
    char *Start;
    char *End;
-   bool Done;
    unsigned long iOffset;
    unsigned long Size;
    
-   bool Fill();
-   
    public:
 
    bool Step(pkgTagSection &Section);

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