2007-01-07 Jonathan Pobst <monkey@jpobst.com>
[mono.git] / mcs / class / Managed.Windows.Forms / System.Windows.Forms / Mime.cs
index fb7839abd048830ce3021607a4a69f2c8c065316..d4e1a3e067c40ce5ed16d437e8a5949d527c6f42 100644 (file)
 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 //
-// Copyright (c) 2005 Novell, Inc. (http://www.novell.com)
+// Copyright (c) 2006 Alexander Olk
 //
 // Authors:
 //
-//  Alexander Olk      xenomorph2@onlinehome.de
+//  Alexander Olk      alex.olk@googlemail.com
 //
 
 using System;
@@ -47,13 +47,15 @@ using System.Text;
 //   string[] available = Mime.AvailableMimeTypes;
 
 // TODO:
-// - optimize
-// - little/big endian stuff for TypeHostXX
+// - optimize even more :)
 // - async callback ?!?
 // - freedesktop org file extensions can have regular expressions also, resolve them too
-// - sort match collections by magic priority ( higher = first )
-// - MimeGenerated: use indexes to point to mime type name strings instead of repeating the name string each time (in match, subclass, etc.) !?!
-// - buffer is currently hard coded to size 8192, value should be determined by MimeGenerated
+// - sort match collections by magic priority ( higher = first ) ?
+
+// internal test:
+// looking up the mime types 20 times for 2757 files in /usr/lib without caching (mime_file_cache)
+// old version: Time: 00:00:32.3791220
+// new version: Time: 00:00:16.9991810
 
 namespace System.Windows.Forms
 {
@@ -66,7 +68,7 @@ namespace System.Windows.Forms
                
                private FileStream file_stream;
                
-               private byte[] buffer = new byte[ 8192 ];
+               private byte[] buffer = null;
                
                private const string octet_stream = "application/octet-stream";
                private const string text_plain = "text/plain";
@@ -74,21 +76,66 @@ namespace System.Windows.Forms
                
                private StringDictionary mime_file_cache = new StringDictionary();
                
-               private const int mime_file_cache_max_size = 5000;
+               private const int mime_file_cache_max_size = 3000;
                
                private string search_string;
                
                private static object lock_object = new Object();
                
-               private int platform = (int) Environment.OSVersion.Platform;
+//             private int platform = (int) Environment.OSVersion.Platform;
                
                private bool is_zero_file = false;
                
-               public Mime( )
+               private int bytes_read = 0;
+               
+               private bool mime_available = false;
+               
+               public static NameValueCollection Aliases;
+               public static NameValueCollection SubClasses;
+               
+               public static NameValueCollection GlobalPatternsShort;
+               public static NameValueCollection GlobalPatternsLong;
+               public static NameValueCollection GlobalLiterals;
+               public static NameValueCollection GlobalSufPref;
+               
+               public static ArrayList Matches80Plus;
+               public static ArrayList MatchesBelow80;
+               
+               private Mime( )
                {
-                       MimeGenerated.Init( );
+#if NET_2_0
+                       Aliases = new NameValueCollection (StringComparer.CurrentCultureIgnoreCase);
+                       SubClasses = new NameValueCollection (StringComparer.CurrentCultureIgnoreCase);
+                       GlobalPatternsShort = new NameValueCollection (StringComparer.CurrentCultureIgnoreCase);
+                       GlobalPatternsLong = new NameValueCollection (StringComparer.CurrentCultureIgnoreCase);
+                       GlobalLiterals = new NameValueCollection (StringComparer.CurrentCultureIgnoreCase);
+                       GlobalSufPref = new NameValueCollection (StringComparer.CurrentCultureIgnoreCase);
+#else
+                       Aliases = new NameValueCollection (new CaseInsensitiveHashCodeProvider (), new Comparer (System.Globalization.CultureInfo.CurrentUICulture));
+                       SubClasses = new NameValueCollection (new CaseInsensitiveHashCodeProvider (), new Comparer (System.Globalization.CultureInfo.CurrentUICulture));
+                       GlobalPatternsShort = new NameValueCollection (new CaseInsensitiveHashCodeProvider (), new Comparer (System.Globalization.CultureInfo.CurrentUICulture));
+                       GlobalPatternsLong = new NameValueCollection (new CaseInsensitiveHashCodeProvider (), new Comparer (System.Globalization.CultureInfo.CurrentUICulture));
+                       GlobalLiterals = new NameValueCollection (new CaseInsensitiveHashCodeProvider (), new Comparer (System.Globalization.CultureInfo.CurrentUICulture));
+                       GlobalSufPref = new NameValueCollection (new CaseInsensitiveHashCodeProvider (), new Comparer (System.Globalization.CultureInfo.CurrentUICulture));
+#endif
+                       
+                       Matches80Plus = new ArrayList ();
+                       MatchesBelow80 = new ArrayList ();
+                       
+                       FDOMimeConfigReader fmcr = new FDOMimeConfigReader ();
+                       int buffer_length = fmcr.Init ();
                        
-//                     Console.WriteLine( "Mime Instance created..." );
+                       if (buffer_length != -1) {
+                               buffer = new byte[ buffer_length ];
+                               mime_available = true;
+                       }
+               }
+               
+               public static bool MimeAvailable
+               {
+                       get {
+                               return Instance.mime_available;
+                       }
                }
                
                public static string GetMimeTypeForFile( string filename )
@@ -124,23 +171,12 @@ namespace System.Windows.Forms
                
                public static string GetMimeAlias( string mimetype )
                {
-                       return MimeGenerated.Aliases[ mimetype ];
+                       return Aliases[ mimetype ];
                }
                
                public static string GetMimeSubClass( string mimetype )
                {
-                       return MimeGenerated.SubClasses[ mimetype ];
-               }
-               
-               public static string[] AvailableMimeTypes
-               {
-                       get {
-                               string[] result = new string[ MimeGenerated.MimeTypes.Count ];
-                               
-                               MimeGenerated.MimeTypes.Keys.CopyTo( result, 0 );
-                               
-                               return result;
-                       }
+                       return SubClasses[ mimetype ];
                }
                
                private void StartByFileName( string filename )
@@ -154,24 +190,26 @@ namespace System.Windows.Forms
                        current_file_name = filename;
                        is_zero_file = false;
                        
-                       if ( !CheckForInode( ) )
-                       {
-                               global_result = octet_stream;
-                               
-                               GoByFileName( );
-                       }
+//                     if ( !CheckForInode( ) )
+//                     {
+                       global_result = octet_stream;
                        
-                       if ( !mime_file_cache.ContainsKey( current_file_name ) )
-                               mime_file_cache.Add( current_file_name, global_result );
+                       GoByFileName( );
+//                     }
                        
-                       // not tested
-                       if ( mime_file_cache.Count > mime_file_cache_max_size )
-                       {
-                               IEnumerator enumerator = mime_file_cache.GetEnumerator);
+                       mime_file_cache.Add( current_file_name, global_result );
+                       
+                       if (mime_file_cache.Count > mime_file_cache_max_size) {
+                               IEnumerator enumerator = mime_file_cache.GetEnumerator ();
                                
-                               for ( int i = 0; i < mime_file_cache_max_size - 1000; i++ )
-                               {
-                                       mime_file_cache.Remove( enumerator.Current.ToString( ) );
+                               int counter = mime_file_cache_max_size - 1000;
+                               
+                               while (enumerator.MoveNext ()) {
+                                       mime_file_cache.Remove (enumerator.Current.ToString ());
+                                       counter--;
+                                       
+                                       if (counter == 0)
+                                               break;
                                }
                        }
                }
@@ -210,64 +248,70 @@ namespace System.Windows.Forms
                                return;
                }
                
-               private bool CheckForInode( )
-               {
-                       if ( ( platform == 4 ) || ( platform == 128 ) )
-                       {
-#if __MonoCS__
-                               // *nix platform
-                               Mono.Unix.UnixFileInfo ufi = new Mono.Unix.UnixFileInfo( current_file_name );
-                               
-                               if ( ufi.IsFile )
-                               {
-                                       return false;
-                               }
-                               else
-                               if ( ufi.IsDirectory )
-                               {
-                                       global_result = "inode/directory";
-                                       return true;
-                               }
-                               else
-                               if ( ufi.IsBlockDevice )
-                               {
-                                       global_result = "inode/blockdevice";
-                                       return true;
-                               }
-                               else
-                               if ( ufi.IsSocket )
-                               {
-                                       global_result = "inode/socket";
-                                       return true;
-                               }
-                               else
-                               if ( ufi.IsSymbolicLink )
-                               {
-                                       global_result = "inode/symlink";
-                                       return true;
-                               }
-                               else
-                               if ( ufi.IsCharacterDevice )
-                               {
-                                       global_result = "inode/chardevice";
-                                       return true;
-                               }
-                               else
-                               if ( ufi.IsFIFO )
-                               {
-                                       global_result = "inode/fifo";
-                                       return true;
-                               }
-#endif
-                       }
-                       else
-                       {
-                               // TODO!!!!
-                               // windows platform
-                       }
-                       
-                       return false;
-               }
+//             private bool CheckForInode( )
+//             {
+//                     if ( ( platform == 4 ) || ( platform == 128 ) )
+//                     {
+//#if __MonoCS__
+//                             try
+//                             {
+//                                     // *nix platform
+//                                     Mono.Unix.UnixFileInfo ufi = new Mono.Unix.UnixFileInfo( current_file_name );
+//
+//                                     if ( ufi.IsFile )
+//                                     {
+//                                             return false;
+//                                     }
+//                                     else
+//                                     if ( ufi.IsDirectory )
+//                                     {
+//                                             global_result = "inode/directory";
+//                                             return true;
+//                                     }
+//                                     else
+//                                     if ( ufi.IsBlockDevice )
+//                                     {
+//                                             global_result = "inode/blockdevice";
+//                                             return true;
+//                                     }
+//                                     else
+//                                     if ( ufi.IsSocket )
+//                                     {
+//                                             global_result = "inode/socket";
+//                                             return true;
+//                                     }
+//                                     else
+//                                     if ( ufi.IsSymbolicLink )
+//                                     {
+//                                             global_result = "inode/symlink";
+//                                             return true;
+//                                     }
+//                                     else
+//                                     if ( ufi.IsCharacterDevice )
+//                                     {
+//                                             global_result = "inode/chardevice";
+//                                             return true;
+//                                     }
+//                                     else
+//                                     if ( ufi.IsFIFO )
+//                                     {
+//                                             global_result = "inode/fifo";
+//                                             return true;
+//                                     }
+//                             } catch( Exception e )
+//                             {
+//                                     return false;
+//                             }
+//#endif
+//                     }
+//                     else
+//                     {
+//                             // TODO!!!!
+//                             // windows platform
+//                     }
+//                     
+//                     return false;
+//             }
                
                private void GoByFileName( )
                {
@@ -275,7 +319,6 @@ namespace System.Windows.Forms
                        if ( !OpenFile( ) )
                        {
                                // couldn't open the file, check globals only
-                               
                                CheckGlobalPatterns( );
                                
                                return;
@@ -309,7 +352,7 @@ namespace System.Windows.Forms
                
                private bool CheckMatch80Plus( )
                {
-                       foreach ( Match match in MimeGenerated.Matches80Plus )
+                       foreach ( Match match in Matches80Plus )
                        {
                                if ( TestMatch( match ) )
                                {
@@ -322,9 +365,75 @@ namespace System.Windows.Forms
                        return false;
                }
                
+               // this little helper method gives us a real speed improvement
+               private bool FastEndsWidth(string input, string value)
+               {
+                       if (value.Length > input.Length)
+                               return false;
+                       
+                       int z = input.Length - 1;
+                       
+                       for (int i = value.Length - 1; i > -1; i--) {
+                               if (value[i] != input[z])
+                                       return false;
+                               
+                               z--;
+                       }
+                       
+                       return true;
+               }
+               
+               private bool FastStartsWith(string input, string value)
+               {
+                       if (value.Length > input.Length)
+                               return false;
+                       
+                       for (int i = 0; i < value.Length; i++)
+                               if (value[i] != input[i])
+                                       return false;
+                       
+                       return true;
+               }
+               
+               // start always with index = 0
+               private int FastIndexOf(string input, char value)
+               {
+                       if (input.Length == 0)
+                               return -1;
+                       
+                       for (int i = 0; i < input.Length; i++)
+                               if (input[i] == value)
+                                       return i;
+                       
+                       return -1;
+               }
+               
+               private int FastIndexOf(string input, string value)
+               {
+                       if (input.Length == 0)
+                               return -1;
+                       
+                       for (int i = 0; i < input.Length - value.Length; i++) {
+                               if (input[i] == value[0]) {
+                                       int counter = 0;
+                                       for (int z = 1; z < value.Length; z++) {
+                                               if (input[i+z] != value[z])
+                                                       break;
+                                               
+                                               counter++;
+                                       }
+                                       if (counter == value.Length -1) {
+                                               return i;
+                                       }
+                               }
+                       }
+                       
+                       return -1;
+               }
+               
                private void CheckGlobalResult( )
                {
-                       int comma_index = global_result.IndexOf( "," );
+                       int comma_index = FastIndexOf(global_result, ',');
                        
                        if ( comma_index != -1 )
                        {
@@ -335,20 +444,18 @@ namespace System.Windows.Forms
                private bool CheckGlobalPatterns( )
                {
                        string filename = Path.GetFileName( current_file_name );
-                       string filename_lower = filename.ToLower( );
                        
                        // first check for literals
-                       
-                       for ( int i = 0; i < MimeGenerated.GlobalLiterals.Count; i++ )
+                       for ( int i = 0; i < GlobalLiterals.Count; i++ )
                        {
-                               string key = MimeGenerated.GlobalLiterals.GetKey( i );
+                               string key = GlobalLiterals.GetKey(i);
                                
                                // no regex char
-                               if ( key.IndexOf( '[' ) == -1 )
+                               if ( FastIndexOf(key, '[' ) == -1 )
                                {
-                                       if ( key.Equals( filename ) )
+                                       if (FastIndexOf(filename, key) != -1)
                                        {
-                                               global_result = MimeGenerated.GlobalLiterals[ i ];
+                                               global_result = GlobalLiterals[i];
                                                CheckGlobalResult( );
                                                return true;
                                        }
@@ -357,32 +464,31 @@ namespace System.Windows.Forms
                                {
                                        if ( Regex.IsMatch( filename, key ) )
                                        {
-                                               global_result = MimeGenerated.GlobalLiterals[ i ];
+                                               global_result = GlobalLiterals[ i ];
                                                CheckGlobalResult( );
                                                return true;
                                        }
                                }
                        }
                        
-                       if ( filename.IndexOf( '.' ) != -1 )
+                       if ( FastIndexOf(filename, '.' ) != -1 )
                        {
                                // check for double extension like .tar.gz
-                               
-                               for ( int i = 0; i < MimeGenerated.GlobalPatternsLong.Count; i++ )
+                               for ( int i = 0; i < GlobalPatternsLong.Count; i++ )
                                {
-                                       string key = MimeGenerated.GlobalPatternsLong.GetKey( i );
+                                       string key = GlobalPatternsLong.GetKey( i );
                                        
-                                       if ( filename.EndsWith( key ) )
+                                       if (FastEndsWidth (filename, key))
                                        {
-                                               global_result = MimeGenerated.GlobalPatternsLong[ i ];
+                                               global_result = GlobalPatternsLong[ i ];
                                                CheckGlobalResult( );
                                                return true;
                                        }
                                        else
                                        {
-                                               if ( filename_lower.EndsWith( key ) )
+                                               if ( FastEndsWidth (filename.ToLower( ), key ) )
                                                {
-                                                       global_result = MimeGenerated.GlobalPatternsLong[ i ];
+                                                       global_result = GlobalPatternsLong[ i ];
                                                        CheckGlobalResult( );
                                                        return true;
                                                }
@@ -390,25 +496,24 @@ namespace System.Windows.Forms
                                }
                                
                                // check normal extensions...
-                               
                                string extension = Path.GetExtension( current_file_name );
                                
                                if ( extension.Length != 0 )
                                {
-                                       global_result = MimeGenerated.GlobalPatternsShort[ extension ];
+                                       string global_result_tmp = GlobalPatternsShort[ extension ];
                                        
-                                       if ( global_result != null )
+                                       if ( global_result_tmp != null )
                                        {
+                                               global_result = global_result_tmp;
                                                CheckGlobalResult( );
                                                return true;
                                        }
                                        
-                                       string extension_lower = extension.ToLower( );
-                                       
-                                       global_result = MimeGenerated.GlobalPatternsShort[ extension_lower ];
+                                       global_result_tmp = GlobalPatternsShort[ extension.ToLower( ) ];
                                        
-                                       if ( global_result != null )
+                                       if ( global_result_tmp != null )
                                        {
+                                               global_result = global_result_tmp;
                                                CheckGlobalResult( );
                                                return true;
                                        }
@@ -416,25 +521,24 @@ namespace System.Windows.Forms
                        }
                        
                        // finally check if a prefix or suffix matches
-                       
-                       for ( int i = 0; i < MimeGenerated.GlobalSufPref.Count; i++ )
+                       for ( int i = 0; i < GlobalSufPref.Count; i++ )
                        {
-                               string key = MimeGenerated.GlobalSufPref.GetKey( i );
+                               string key = GlobalSufPref.GetKey( i );
                                
-                               if ( key.StartsWith( "*" ) )
+                               if ( key[0] == '*' )
                                {
-                                       if ( filename.EndsWith( key.Replace( "*", "" ) ) )
+                                       if (FastEndsWidth(filename, key.Replace( "*", String.Empty )))
                                        {
-                                               global_result = MimeGenerated.GlobalSufPref[ i ];
+                                               global_result = GlobalSufPref[ i ];
                                                CheckGlobalResult( );
                                                return true;
                                        }
                                }
                                else
                                {
-                                       if ( filename.StartsWith( key.Replace( "*", "" ) ) )
+                                       if ( FastStartsWith(filename, key.Replace( "*", String.Empty ) ) )
                                        {
-                                               global_result = MimeGenerated.GlobalSufPref[ i ];
+                                               global_result = GlobalSufPref[ i ];
                                                CheckGlobalResult( );
                                                return true;
                                        }
@@ -446,7 +550,7 @@ namespace System.Windows.Forms
                
                private bool CheckMatchBelow80( )
                {
-                       foreach ( Match match in MimeGenerated.MatchesBelow80 )
+                       foreach ( Match match in MatchesBelow80 )
                        {
                                if ( TestMatch( match ) )
                                {
@@ -477,29 +581,40 @@ namespace System.Windows.Forms
                        global_result = text_plain;
                }
                
-               private bool TestMatch( Match match )
+               private bool TestMatch (Match match)
                {
-                       bool found = false;
+                       foreach (Matchlet matchlet in match.Matchlets)
+                               if (TestMatchlet (matchlet))
+                                       return true;
                        
+                       return false;
+               }
+               
+               private bool TestMatchlet( Matchlet matchlet )
+               {
                        //  using a simple brute force search algorithm
-                       // compare each (masked) value from the buffer with the (masked) value from the match
-                       // TODO:
-                       // - to find some more speed, maybe we should use unsafe code
-                       // - check if buffer[0] and buffer[lastmatchbyte] match ByteValue[0] and ByteValue[lastmatchbyte] in a match
+                       // compare each (masked) value from the buffer with the (masked) value from the matchlet
+                       
+                       // no need to check if the offset + the bytevalue length exceed the # bytes read
+                       if (matchlet.Offset + matchlet.ByteValue.Length > bytes_read)
+                               return false;
                        
-                       for ( int offset_counter = 0; offset_counter < match.OffsetLength; offset_counter++ )
+                       for ( int offset_counter = 0; offset_counter < matchlet.OffsetLength; offset_counter++ )
                        {
-                               if ( match.Mask == null )
+                               if (matchlet.Offset + offset_counter + matchlet.ByteValue.Length > bytes_read)
+                                       return false;
+                               
+                               if ( matchlet.Mask == null )
                                {
-                                       if ( buffer[ match.Offset + offset_counter ] == match.ByteValue[ 0 ] )
+                                       if ( buffer[ matchlet.Offset + offset_counter ] == matchlet.ByteValue[ 0 ] )
                                        {
-                                               if ( match.ByteValue.Length == 1 )
+                                               if ( matchlet.ByteValue.Length == 1 )
                                                {
-                                                       if ( match.Matches.Count > 0 )
+                                                       if ( matchlet.Matchlets.Count > 0 )
                                                        {
-                                                               foreach ( Match sub_match in match.Matches )
+                                                               foreach ( Matchlet sub_matchlet in matchlet.Matchlets )
                                                                {
-                                                                       if ( TestMatch( sub_match ) )
+                                                                       if ( TestMatchlet( sub_matchlet ) )
                                                                                return true;
                                                                }
                                                        }
@@ -507,46 +622,45 @@ namespace System.Windows.Forms
                                                                return true;
                                                }
                                                
-                                               for ( int i = 1; i < match.ByteValue.Length; i++ )
-                                               {
-                                                       if ( buffer[ match.Offset + offset_counter + i ] != match.ByteValue[ i ] )
-                                                       {
-                                                               found = false;
-                                                               break;
-                                                       }
+                                               int minus = 0;
+                                               // check if the last matchlet byte value is the same as the byte value in the buffer...
+                                               if (matchlet.ByteValue.Length > 2) {
+                                                       if (buffer[ matchlet.Offset + offset_counter + matchlet.ByteValue.Length - 1 ] != matchlet.ByteValue[ matchlet.ByteValue.Length - 1 ])
+                                                               return false;
                                                        
-                                                       found = true;
+                                                       minus = 1;
                                                }
                                                
-                                               if ( found )
+                                               for ( int i = 1; i < matchlet.ByteValue.Length - minus; i++ )
                                                {
-                                                       found = false;
-                                                       
-                                                       if ( match.Matches.Count > 0 )
+                                                       if ( buffer[ matchlet.Offset + offset_counter + i ] != matchlet.ByteValue[ i ] )
+                                                               return false;
+                                               }
+                                               
+                                               if ( matchlet.Matchlets.Count > 0 )
+                                               {
+                                                       foreach ( Matchlet sub_matchlets in matchlet.Matchlets )
                                                        {
-                                                               foreach ( Match sub_match in match.Matches )
-                                                               {
-                                                                       if ( TestMatch( sub_match ) )
-                                                                               return true;
-                                                               }
+                                                               if ( TestMatchlet( sub_matchlets ) )
+                                                                       return true;
                                                        }
-                                                       else
-                                                               return true;
                                                }
+                                               else
+                                                       return true;
                                        }
                                }
                                else // with mask ( it's the same as above, only AND the byte with the corresponding mask byte
                                {
-                                       if ( ( buffer[ match.Offset + offset_counter ] & match.Mask[ 0 ] )  ==
-                                           ( match.ByteValue[ 0 ] & match.Mask[ 0 ] ) )
+                                       if ( ( buffer[ matchlet.Offset + offset_counter ] & matchlet.Mask[ 0 ] )  ==
+                                           ( matchlet.ByteValue[ 0 ] & matchlet.Mask[ 0 ] ) )
                                        {
-                                               if ( match.ByteValue.Length == 1 )
+                                               if ( matchlet.ByteValue.Length == 1 )
                                                {
-                                                       if ( match.Matches.Count > 0 )
+                                                       if ( matchlet.Matchlets.Count > 0 )
                                                        {
-                                                               foreach ( Match sub_match in match.Matches )
+                                                               foreach ( Matchlet sub_matchlets in matchlet.Matchlets )
                                                                {
-                                                                       if ( TestMatch( sub_match ) )
+                                                                       if ( TestMatchlet( sub_matchlets ) )
                                                                                return true;
                                                                }
                                                        }
@@ -554,46 +668,45 @@ namespace System.Windows.Forms
                                                                return true;
                                                }
                                                
-                                               for ( int i = 1; i < match.ByteValue.Length; i++ )
-                                               {
-                                                       if ( ( buffer[ match.Offset + offset_counter + i ]  & match.Mask[ i ] ) !=
-                                                           ( match.ByteValue[ i ] & match.Mask[ i ] ) )
-                                                       {
-                                                               found = false;
-                                                               break;
-                                                       }
+                                               int minus = 0;
+                                               // check if the last matchlet byte value is the same as the byte value in the buffer...
+                                               if (matchlet.ByteValue.Length > 2) {
                                                        
-                                                       found = true;
+                                                       if ((buffer[ matchlet.Offset + offset_counter + matchlet.ByteValue.Length - 1 ] & matchlet.Mask[ matchlet.ByteValue.Length - 1 ])
+                                                           != (matchlet.ByteValue[ matchlet.ByteValue.Length - 1 ] & matchlet.Mask[ matchlet.ByteValue.Length - 1 ]))
+                                                               return false;
+                                                       
+                                                       minus = 1;
                                                }
                                                
-                                               if ( found )
+                                               for ( int i = 1; i < matchlet.ByteValue.Length - minus; i++ )
                                                {
-                                                       found = false;
-                                                       
-                                                       if ( match.Matches.Count > 0 )
+                                                       if ( ( buffer[ matchlet.Offset + offset_counter + i ]  & matchlet.Mask[ i ] ) !=
+                                                           ( matchlet.ByteValue[ i ] & matchlet.Mask[ i ] ) )
+                                                               return false;
+                                               }
+                                               
+                                               if ( matchlet.Matchlets.Count > 0 )
+                                               {
+                                                       foreach ( Matchlet sub_matchlets in matchlet.Matchlets )
                                                        {
-                                                               foreach ( Match sub_match in match.Matches )
-                                                               {
-                                                                       if ( TestMatch( sub_match ) )
-                                                                               return true;
-                                                               }
+                                                               if ( TestMatchlet( sub_matchlets ) )
+                                                                       return true;
                                                        }
-                                                       else
-                                                               return true;
                                                }
+                                               else
+                                                       return true;
                                        }
                                }
                        }
                        
-                       return found;
+                       return false;
                }
                
                private bool OpenFile( )
                {
                        try
                        {
-                               System.Array.Clear( buffer, 0, buffer.Length );
-                               
                                file_stream = new FileStream( current_file_name, FileMode.Open, FileAccess.Read ); // FileShare ??? use BinaryReader ???
                                
                                if ( file_stream.Length == 0 )
@@ -603,12 +716,17 @@ namespace System.Windows.Forms
                                }
                                else
                                {
-                                       file_stream.Read( buffer, 0, buffer.Length );
+                                       bytes_read = file_stream.Read( buffer, 0, buffer.Length );
+                                       
+                                       // do not clear the whole buffer everytime; clear only what's needed
+                                       if (bytes_read < buffer.Length) {
+                                               System.Array.Clear( buffer, bytes_read, buffer.Length - bytes_read );
+                                       }
                                }
                                
                                file_stream.Close( );
                        }
-                       catch (Exception e)
+                       catch (Exception)
                        {
                                return false;
                        }
@@ -624,7 +742,7 @@ namespace System.Windows.Forms
                        {
                                index += 13; // Length of string "Content-type:"
                                
-                               global_result = "";
+                               global_result = String.Empty;
                                
                                while ( search_string[ index ] != ';' )
                                {
@@ -660,62 +778,394 @@ namespace System.Windows.Forms
                }
        }
        
-       internal class MimeType
-       {
-               private string comment;
-               private Hashtable commentsLanguage = new Hashtable();
+       internal class FDOMimeConfigReader {
+               bool fdo_mime_available = false;
+               StringCollection shared_mime_paths = new StringCollection ();
+               BinaryReader br;
+               
+               int max_offset_and_range = 0;
                
-               public string Comment
+               public int Init ()
                {
-                       get {
-                               return comment;
+                       CheckFDOMimePaths ();
+                       
+                       if (!fdo_mime_available)
+                               return -1;
+                       
+                       ReadMagicData ();
+                       
+                       ReadGlobsData ();
+                       
+                       ReadSubclasses ();
+                       
+                       ReadAliases ();
+                       
+                       shared_mime_paths = null;
+                       br = null;
+                       
+                       return max_offset_and_range;
+               }
+               
+               private void CheckFDOMimePaths ()
+               {
+                       if (Directory.Exists ("/usr/share/mime"))
+                               shared_mime_paths.Add ("/usr/share/mime/");
+                       else
+                       if (Directory.Exists ("/usr/local/share/mime"))
+                               shared_mime_paths.Add ("/usr/local/share/mime/");
+                       
+                       if (Directory.Exists (System.Environment.GetFolderPath (Environment.SpecialFolder.Personal) + "/.local/share/mime"))
+                               shared_mime_paths.Add (System.Environment.GetFolderPath (Environment.SpecialFolder.Personal) + "/.local/share/mime/");
+                       
+                       if (shared_mime_paths.Count == 0)
+                               return;
+                       
+                       fdo_mime_available = true;
+               }
+               
+               private void ReadMagicData ()
+               {
+                       foreach (string path in shared_mime_paths) {
+                               if (!File.Exists (path + "/magic"))
+                                       continue;
+                               
+                               try {
+                                       FileStream fs = File.OpenRead (path + "/magic");
+                                       br = new BinaryReader (fs);
+                                       
+                                       if (CheckMagicHeader ()) {
+                                               MakeMatches ();
+                                       }
+                                       
+                                       br.Close ();
+                                       fs.Close ();
+                               } catch (Exception ) {
+                               }
                        }
-                       set {
-                               comment = value;
+               }
+               
+               private void MakeMatches ()
+               {
+                       Matchlet[] matchlets = new Matchlet [30];
+                       
+                       while (br.PeekChar () != -1) {
+                               int priority = -1;
+                               string mime_type = ReadPriorityAndMimeType (ref priority);
+                               
+                               if (mime_type != null) {
+                                       Match match = new Match ();
+                                       match.Priority = priority;
+                                       match.MimeType = mime_type;
+                                       
+                                       while (true) {
+                                               int indent = 0;
+                                               // indent
+                                               char c;
+                                               if (br.PeekChar () != '>') {
+                                                       string indent_string = String.Empty;
+                                                       while (true) {
+                                                               if (br.PeekChar () == '>')
+                                                                       break;
+                                                               
+                                                               c = br.ReadChar ();
+                                                               indent_string += c;
+                                                       }
+                                                       indent = Convert.ToInt32 (indent_string);
+                                               }
+                                               
+                                               int offset = 0;
+                                               
+                                               // offset
+                                               if (br.PeekChar () == '>') {
+                                                       br.ReadChar ();
+                                                       offset = ReadValue ();
+                                               }
+                                               
+                                               int value_length = 0;
+                                               byte[] value = null;
+                                               // value length and value
+                                               if (br.PeekChar () == '=') {
+                                                       br.ReadChar ();
+                                                       
+                                                       // read 2 bytes value length (always big endian)
+                                                       byte first = br.ReadByte ();
+                                                       byte second = br.ReadByte ();
+                                                       
+                                                       value_length = first * 256 + second;
+                                                       
+                                                       value = br.ReadBytes (value_length);
+                                               }
+                                               
+                                               // mask
+                                               byte[] mask = null;
+                                               
+                                               if (br.PeekChar () == '&') {
+                                                       br.ReadChar ();
+                                                       
+                                                       mask = br.ReadBytes (value_length);
+                                               }
+                                               
+                                               // word_size
+                                               int word_size = 1;
+                                               if (br.PeekChar () == '~') {
+                                                       br.ReadChar ();
+                                                       
+                                                       c = br.ReadChar ();
+                                                       
+                                                       word_size = Convert.ToInt32 (c - 0x30);
+                                                       
+                                                       // data is stored in big endian format. 
+                                                       if (word_size > 1 && System.BitConverter.IsLittleEndian) {
+                                                               //convert the value and, if available, the mask data to little endian
+                                                               if (word_size == 2) {
+                                                                       if (value != null) {
+                                                                               for (int i = 0; i < value.Length; i += 2) {
+                                                                                       byte one = value [i];
+                                                                                       byte two = value [i + 1];
+                                                                                       value [i] = two;
+                                                                                       value [i + 1] = one;
+                                                                               }
+                                                                       }
+                                                                       if (mask != null) {
+                                                                               for (int i = 0; i < mask.Length; i += 2) {
+                                                                                       byte one = mask [i];
+                                                                                       byte two = mask [i + 1];
+                                                                                       mask [i] = two;
+                                                                                       mask [i + 1] = one;
+                                                                               }
+                                                                       }
+                                                               } else if (word_size == 4) {
+                                                                       if (value != null) {
+                                                                               for (int i = 0; i < value.Length; i += 4) {
+                                                                                       byte one = value [i];
+                                                                                       byte two = value [i + 1];
+                                                                                       byte three = value [i + 2];
+                                                                                       byte four = value [i + 3];
+                                                                                       value [i] = four;
+                                                                                       value [i + 1] = three;
+                                                                                       value [i + 2] = two;
+                                                                                       value [i + 3] = one;
+                                                                               }
+                                                                       }
+                                                                       if (mask != null) {
+                                                                               for (int i = 0; i < mask.Length; i += 4) {
+                                                                                       byte one = mask [i];
+                                                                                       byte two = mask [i + 1];
+                                                                                       byte three = mask [i + 2];
+                                                                                       byte four = mask [i + 3];
+                                                                                       mask [i] = four;
+                                                                                       mask [i + 1] = three;
+                                                                                       mask [i + 2] = two;
+                                                                                       mask [i + 3] = one;
+                                                                                       
+                                                                               }
+                                                                       }
+                                                               }
+                                                       }
+                                               }
+                                               
+                                               // range length
+                                               int range_length = 1;
+                                               if (br.PeekChar () == '+') {
+                                                       br.ReadChar ();
+                                                       range_length = ReadValue ();
+                                               }
+                                               
+                                               // read \n
+                                               br.ReadChar ();
+                                               
+                                               // create the matchlet
+                                               matchlets [indent] = new Matchlet ();
+                                               matchlets [indent].Offset = offset;
+                                               matchlets [indent].OffsetLength = range_length;
+                                               matchlets [indent].ByteValue = value;
+                                               if (mask != null)
+                                                       matchlets [indent].Mask = mask;
+                                               
+                                               if (indent == 0) {
+                                                       match.Matchlets.Add (matchlets [indent]);
+                                               } else {
+                                                       matchlets [indent - 1].Matchlets.Add (matchlets [indent]);
+                                               }
+                                               
+                                               if (max_offset_and_range < matchlets [indent].Offset + matchlets [indent].OffsetLength + matchlets [indent].ByteValue.Length + 1)
+                                                       max_offset_and_range = matchlets [indent].Offset + matchlets [indent].OffsetLength + matchlets [indent].ByteValue.Length  + 1;
+                                               
+                                               // if '[' move to next mime type
+                                               if (br.PeekChar () == '[')
+                                                       break;
+                                       }
+                                       
+                                       if (priority < 80)
+                                               Mime.MatchesBelow80.Add (match);
+                                       else
+                                               Mime.Matches80Plus.Add (match);
+                               }
                        }
                }
                
-               public Hashtable CommentsLanguage
+               private void ReadGlobsData ()
                {
-                       get {
-                               return commentsLanguage;
+                       foreach (string path in shared_mime_paths) {
+                               if (!File.Exists (path + "/globs"))
+                                       continue;
+                               
+                               try {
+                                       StreamReader sr = new StreamReader (path + "/globs");
+                                       
+                                       while (sr.Peek () != -1) {
+                                               string line = sr.ReadLine ().Trim ();
+                                               
+                                               if (line.StartsWith ("#"))
+                                                       continue;
+                                               
+                                               string[] split = line.Split (new char [] {':'});
+                                               
+                                               if (split [1].IndexOf ('*') > -1 && split [1].IndexOf ('.') == -1) {
+                                                       Mime.GlobalSufPref.Add (split [1], split [0]);
+                                               } else if (split [1]. IndexOf ('*') == -1) {
+                                                       Mime.GlobalLiterals.Add (split [1], split [0]);
+                                               } else {
+                                                       string[] split2 = split [1].Split (new char [] {'.'});
+                                                       
+                                                       if (split2.Length > 2) {
+                                                               // more than one dot
+                                                               Mime.GlobalPatternsLong.Add (split [1].Remove(0, 1), split [0]);
+                                                       } else {
+                                                               // normal
+                                                               Mime.GlobalPatternsShort.Add (split [1].Remove(0, 1), split [0]);
+                                                       }
+                                               }
+                                       }
+                                       
+                                       sr.Close ();
+                               } catch (Exception ) {
+                               }
                        }
-                       set {
-                               commentsLanguage = value;
+               }
+               
+               private void ReadSubclasses ()
+               {
+                       foreach (string path in shared_mime_paths) {
+                               if (!File.Exists (path + "/subclasses"))
+                                       continue;
+                               
+                               try {
+                                       StreamReader sr = new StreamReader (path + "/subclasses");
+                                       
+                                       while (sr.Peek () != -1) {
+                                               string line = sr.ReadLine ().Trim ();
+                                               
+                                               if (line.StartsWith ("#"))
+                                                       continue;
+                                               
+                                               string[] split = line.Split (new char [] {' '});
+                                               
+                                               Mime.SubClasses.Add (split [0], split [1]);
+                                       }
+                                       
+                                       sr.Close ();
+                               } catch (Exception ) {
+                               }
                        }
                }
-               public string GetCommentForLanguage( string language )
+               
+               private void ReadAliases ()
                {
-                       return commentsLanguage[ language ] as string;
+                       foreach (string path in shared_mime_paths) {
+                               if (!File.Exists (path + "/aliases"))
+                                       continue;
+                               
+                               try {
+                                       StreamReader sr = new StreamReader (path + "/aliases");
+                                       
+                                       while (sr.Peek () != -1) {
+                                               string line = sr.ReadLine ().Trim ();
+                                               
+                                               if (line.StartsWith ("#"))
+                                                       continue;
+                                               
+                                               string[] split = line.Split (new char [] {' '});
+                                               
+                                               Mime.Aliases.Add (split [0], split [1]);
+                                       }
+                                       
+                                       sr.Close ();
+                               } catch (Exception ) {
+                               }
+                       }
+               }
+               
+               private int ReadValue ()
+               {
+                       string result_string = String.Empty;
+                       int result = 0;
+                       char c;
+                       
+                       while (true) {
+                               if (br.PeekChar () == '=' || br.PeekChar () == '\n')
+                                       break;
+                               
+                               c = br.ReadChar ();
+                               result_string += c;
+                       }
+                       
+                       result = Convert.ToInt32 (result_string);
+                       
+                       return result;
+               }
+               
+               private string ReadPriorityAndMimeType (ref int priority)
+               {
+                       if (br.ReadChar () == '[') {
+                               string priority_string = String.Empty;
+                               while (true) {
+                                       char c = br.ReadChar ();
+                                       if (c == ':')
+                                               break;
+                                       priority_string += c;
+                               }
+                               
+                               priority = System.Convert.ToInt32 (priority_string);
+                               
+                               string mime_type_result = String.Empty;
+                               while (true) {
+                                       char c = br.ReadChar ();
+                                       if (c == ']')
+                                               break;
+                                       
+                                       mime_type_result += c;
+                               }
+                               
+                               if (br.ReadChar () == '\n')
+                                       return mime_type_result;
+                       }
+                       return null;
+               }
+               
+               private bool CheckMagicHeader ()
+               {
+                       char[] chars = br.ReadChars (10);
+                       string magic_header = new String (chars);
+                       
+                       if (magic_header != "MIME-Magic")
+                               return false;
+                       
+                       if (br.ReadByte () != 0)
+                               return false;
+                       if (br.ReadChar () != '\n')
+                               return false;
+                       
+                       return true;
                }
        }
        
-       internal enum MatchTypes
-       {
-               TypeString,
-               TypeHost16,
-               TypeHost32,
-               TypeBig16,
-               TypeBig32,
-               TypeLittle16,
-               TypeLittle32,
-               TypeByte
-       }
-       
-       internal class Match
-       {
+       internal class Match {
                string mimeType;
-               byte[] byteValue;
-               byte[] mask = null;
                int priority;
-               int offset;
-               int offsetLength;
-               int wordSize = 1;
-               MatchTypes matchType;
-               ArrayList matches = new ArrayList();
+               ArrayList matchlets = new ArrayList();
                
-               public string MimeType
-               {
+               public string MimeType {
                        set {
                                mimeType = value;
                        }
@@ -725,52 +1175,54 @@ namespace System.Windows.Forms
                        }
                }
                
-               public byte[] ByteValue
-               {
+               public int Priority {
                        set {
-                               byteValue = value;
+                               priority = value;
                        }
                        
                        get {
-                               return byteValue;
+                               return priority;
                        }
                }
                
-               public byte[] Mask
-               {
-                       set {
-                               mask = value;
-                       }
-                       
+               public ArrayList Matchlets {
                        get {
-                               return mask;
+                               return matchlets;
                        }
                }
+       }
+       
+       internal class Matchlet {
+               byte[] byteValue;
+               byte[] mask = null;
                
-               public int Priority
-               {
+               int offset;
+               int offsetLength;
+               int wordSize = 1;
+               
+               ArrayList matchlets = new ArrayList ();
+               
+               public byte[] ByteValue {
                        set {
-                               priority = value;
+                               byteValue = value;
                        }
                        
                        get {
-                               return priority;
+                               return byteValue;
                        }
                }
                
-               public ArrayList Matches
-               {
+               public byte[] Mask {
                        set {
-                               matches = value;
+                               mask = value;
                        }
                        
                        get {
-                               return matches;
+                               return mask;
                        }
                }
                
-               public int Offset
-               {
+               public int Offset {
                        set {
                                offset = value;
                        }
@@ -780,8 +1232,7 @@ namespace System.Windows.Forms
                        }
                }
                
-               public int OffsetLength
-               {
+               public int OffsetLength {
                        set {
                                offsetLength = value;
                        }
@@ -791,8 +1242,7 @@ namespace System.Windows.Forms
                        }
                }
                
-               public int WordSize
-               {
+               public int WordSize {
                        set {
                                wordSize = value;
                        }
@@ -802,14 +1252,9 @@ namespace System.Windows.Forms
                        }
                }
                
-               public MatchTypes MatchType
-               {
-                       set {
-                               matchType = value;
-                       }
-                       
+               public ArrayList Matchlets {
                        get {
-                               return matchType;
+                               return matchlets;
                        }
                }
        }