{
    $Id$
    Copyright (c) 1998-2000 by Florian Klaempfl

    This unit implements an extended file management

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 ****************************************************************************
}
unit finput;

{$ifdef TP}
  {$V+}
{$endif}

  interface

    uses
      cutils;

    const
{$ifdef FPC}
       InputFileBufSize=32*1024;
       linebufincrease=512;
{$else}
       InputFileBufSize=1024;
       linebufincrease=64;
{$endif}

    type
{$ifdef TP}
       tlongintarr = array[0..16000] of longint;
{$else}
       tlongintarr = array[0..1000000] of longint;
{$endif}
       plongintarr = ^tlongintarr;

       pinputfile = ^tinputfile;
       tinputfile = object
         path,name : pstring;       { path and filename }
         next      : pinputfile;    { next file for reading }

         is_macro,
         endoffile,                 { still bytes left to read }
         closed       : boolean;    { is the file closed }

         buf          : pchar;      { buffer }
         bufstart,                  { buffer start position in the file }
         bufsize,                   { amount of bytes in the buffer }
         maxbufsize   : longint;    { size in memory for the buffer }

         saveinputpointer : pchar;  { save fields for scanner variables }
         savelastlinepos,
         saveline_no      : longint;

         linebuf    : plongintarr;  { line buffer to retrieve lines }
         maxlinebuf : longint;

         ref_count  : longint;      { to handle the browser refs }
         ref_index  : longint;
         ref_next   : pinputfile;

         constructor init(const fn:string);
         destructor done;
         procedure setpos(l:longint);
         procedure seekbuf(fpos:longint);
         procedure readbuf;
         function  open:boolean;
         procedure close;
         procedure tempclose;
         function  tempopen:boolean;
         procedure setmacro(p:pchar;len:longint);
         procedure setline(line,linepos:longint);
         function  getlinestr(l:longint):string;
       {$ifdef FPC}protected{$else}public{$endif}
         function fileopen(const filename: string): boolean; virtual;
         function fileseek(pos: longint): boolean; virtual;
         function fileread(var databuf; maxsize: longint): longint; virtual;
         function fileeof: boolean; virtual;
         function fileclose: boolean; virtual;
       end;

       pdosinputfile = ^tdosinputfile;
       tdosinputfile = object(tinputfile)
       {$ifdef FPC}protected{$else}public{$endif}
         function fileopen(const filename: string): boolean; virtual;
         function fileseek(pos: longint): boolean; virtual;
         function fileread(var databuf; maxsize: longint): longint; virtual;
         function fileeof: boolean; virtual;
         function fileclose: boolean; virtual;
       private
         f            : file;       { current file handle }
       end;

       pinputfilemanager = ^tinputfilemanager;
       tinputfilemanager = object
          files : pinputfile;
          last_ref_index : longint;
          cacheindex : longint;
          cacheinputfile : pinputfile;
          constructor init;
          destructor done;
          procedure register_file(f : pinputfile);
          procedure inverse_register_indexes;
          function  get_file(l:longint) : pinputfile;
          function  get_file_name(l :longint):string;
          function  get_file_path(l :longint):string;
       end;


implementation

uses
{$ifdef Delphi}
  dmisc,
{$else Delphi}
  dos,
{$endif Delphi}
  cobjects,globals;

{****************************************************************************
                                  TINPUTFILE
 ****************************************************************************}

    constructor tinputfile.init(const fn:string);
      var
        p:dirstr;
        n:namestr;
        e:extstr;
      begin
        FSplit(fn,p,n,e);
        name:=stringdup(n+e);
        path:=stringdup(p);
        next:=nil;
      { file info }
        is_macro:=false;
        endoffile:=false;
        closed:=true;
        buf:=nil;
        bufstart:=0;
        bufsize:=0;
        maxbufsize:=InputFileBufSize;
      { save fields }
        saveinputpointer:=nil;
        saveline_no:=0;
        savelastlinepos:=0;
      { indexing refs }
        ref_next:=nil;
        ref_count:=0;
        ref_index:=0;
      { line buffer }
        linebuf:=nil;
        maxlinebuf:=0;
      end;


    destructor tinputfile.done;
      begin
        if not closed then
         close;
        stringdispose(path);
        stringdispose(name);
      { free memory }
        if assigned(linebuf) then
         freemem(linebuf,maxlinebuf shl 2);
      end;


    procedure tinputfile.setpos(l:longint);
      begin
        bufstart:=l;
      end;


    procedure tinputfile.seekbuf(fpos:longint);
      begin
        if closed then
         exit;
        fileseek(fpos);
        bufstart:=fpos;
        bufsize:=0;
      end;


    procedure tinputfile.readbuf;
      begin
        if is_macro then
         endoffile:=true;
        if closed then
         exit;
        inc(bufstart,bufsize);
        bufsize:=fileread(buf^,maxbufsize-1);
        buf[bufsize]:=#0;
        endoffile:=fileeof;
      end;


    function tinputfile.open:boolean;
      begin
        open:=false;
        if not closed then
         Close;
        if not fileopen(path^+name^) then
         exit;
      { file }
        endoffile:=false;
        closed:=false;
        Getmem(buf,MaxBufsize);
        bufstart:=0;
        bufsize:=0;
        open:=true;
      end;


    procedure tinputfile.close;
      begin
        if is_macro then
         begin
           if assigned(buf) then
             Freemem(buf,maxbufsize);
           buf:=nil;
           {is_macro:=false;
           still needed for dispose in scanner PM }
           closed:=true;
           exit;
         end;
        if not closed then
         begin
           if fileclose then;
           closed:=true;
         end;
        if assigned(buf) then
          begin
             Freemem(buf,maxbufsize);
             buf:=nil;
          end;
        bufstart:=0;
      end;


    procedure tinputfile.tempclose;
      begin
        if is_macro then
         exit;
        if not closed then
         begin
           if fileclose then;
           Freemem(buf,maxbufsize);
           buf:=nil;
           closed:=true;
         end;
      end;

    function tinputfile.tempopen:boolean;
      begin
        tempopen:=false;
        if is_macro then
         begin
           { seek buffer postion to bufstart }
           if bufstart>0 then
            begin
              move(buf[bufstart],buf[0],bufsize-bufstart+1);
              bufstart:=0;
            end;
           tempopen:=true;
           exit;
         end;
        if not closed then
         exit;
        if not fileopen(path^+name^) then
         exit;
        closed:=false;
      { get new mem }
        Getmem(buf,maxbufsize);
      { restore state }
        fileseek(BufStart);
        bufsize:=0;
        readbuf;
        tempopen:=true;
      end;


    procedure tinputfile.setmacro(p:pchar;len:longint);
      begin
      { create new buffer }
        getmem(buf,len+1);
        move(p^,buf^,len);
        buf[len]:=#0;
      { reset }
        bufstart:=0;
        bufsize:=len;
        maxbufsize:=len+1;
        is_macro:=true;
        endoffile:=true;
        closed:=true;
      end;


    procedure tinputfile.setline(line,linepos:longint);
      var
        oldlinebuf  : plongintarr;
      begin
        if line<1 then
         exit;
        while (line>=maxlinebuf) do
         begin
           oldlinebuf:=linebuf;
         { create new linebuf and move old info }
           getmem(linebuf,(maxlinebuf+linebufincrease) shl 2);
           if assigned(oldlinebuf) then
            begin
              move(oldlinebuf^,linebuf^,maxlinebuf shl 2);
              freemem(oldlinebuf,maxlinebuf shl 2);
            end;
           fillchar(linebuf^[maxlinebuf],linebufincrease shl 2,0);
           inc(maxlinebuf,linebufincrease);
         end;
        linebuf^[line]:=linepos;
      end;


    function tinputfile.getlinestr(l:longint):string;
      var
        c    : char;
        i,
        fpos : longint;
        p    : pchar;
      begin
        getlinestr:='';
        if l<maxlinebuf then
         begin
           fpos:=linebuf^[l];
           { fpos is set negativ if the line was already written }
           { but we still know the correct value                 }
           if fpos<0 then
             fpos:=-fpos+1;
           if closed then
            open;
         { in current buf ? }
           if (fpos<bufstart) or (fpos>bufstart+bufsize) then
            begin
              seekbuf(fpos);
              readbuf;
            end;
         { the begin is in the buf now simply read until #13,#10 }
           i:=0;
           p:=@buf[fpos-bufstart];
           repeat
             c:=p^;
             if c=#0 then
              begin
                if endoffile then
                 break;
                readbuf;
                p:=buf;
                c:=p^;
              end;
             if c in [#10,#13] then
              break;
             inc(i);
             getlinestr[i]:=c;
             inc(longint(p));
           until (i=255);
           {$ifndef TP}
             {$ifopt H+}
               setlength(getlinestr,i);
             {$else}
               getlinestr[0]:=chr(i);
             {$endif}
           {$else}
             getlinestr[0]:=chr(i);
           {$endif}
         end;
      end;


    function tinputfile.fileopen(const filename: string): boolean;
      begin
        abstract;
        fileopen:=false;
      end;


    function tinputfile.fileseek(pos: longint): boolean;
      begin
        abstract;
        fileseek:=false;
      end;


    function tinputfile.fileread(var databuf; maxsize: longint): longint;
      begin
        abstract;
        fileread:=0;
      end;


    function tinputfile.fileeof: boolean;
      begin
        abstract;
        fileeof:=false;
      end;


    function tinputfile.fileclose: boolean;
      begin
        abstract;
        fileclose:=false;
      end;


{****************************************************************************
                                TDOSINPUTFILE
 ****************************************************************************}

    function tdosinputfile.fileopen(const filename: string): boolean;
      var
        ofm : byte;
      begin
        ofm:=filemode;
        filemode:=0;
        Assign(f,filename);
        {$I-}
         reset(f,1);
        {$I+}
        filemode:=ofm;
        fileopen:=(ioresult=0);
      end;


    function tdosinputfile.fileseek(pos: longint): boolean;
      begin
        {$I-}
         seek(f,Pos);
        {$I+}
        fileseek:=(ioresult=0);
      end;


    function tdosinputfile.fileread(var databuf; maxsize: longint): longint;
      var w: {$ifdef TP}word{$else}longint{$endif};
      begin
        blockread(f,databuf,maxsize,w);
        fileread:=w;
      end;


    function tdosinputfile.fileeof: boolean;
      begin
        fileeof:=eof(f);
      end;


    function tdosinputfile.fileclose: boolean;
      begin
        {$I-}
         system.close(f);
        {$I+}
        fileclose:=(ioresult=0);
      end;


{****************************************************************************
                                Tinputfilemanager
 ****************************************************************************}

    constructor tinputfilemanager.init;
      begin
         files:=nil;
         last_ref_index:=0;
         cacheindex:=0;
         cacheinputfile:=nil;
      end;


    destructor tinputfilemanager.done;
      var
         hp : pinputfile;
      begin
         hp:=files;
         while assigned(hp) do
          begin
            files:=files^.ref_next;
            dispose(hp,done);
            hp:=files;
          end;
         last_ref_index:=0;
      end;


    procedure tinputfilemanager.register_file(f : pinputfile);
      begin
         { don't register macro's }
         if f^.is_macro then
          exit;
         inc(last_ref_index);
         f^.ref_next:=files;
         f^.ref_index:=last_ref_index;
         files:=f;
         { update cache }
         cacheindex:=last_ref_index;
         cacheinputfile:=f;
{$ifdef FPC}
  {$ifdef heaptrc}
         writeln(stderr,f^.name^,' index ',current_module^.unit_index*100000+f^.ref_index);
  {$endif heaptrc}
{$endif FPC}
      end;


   { this procedure is necessary after loading the
     sources files from a PPU file  PM }
   procedure tinputfilemanager.inverse_register_indexes;
     var
        f : pinputfile;
     begin
        f:=files;
        while assigned(f) do
          begin
             f^.ref_index:=last_ref_index-f^.ref_index+1;
             f:=f^.ref_next;
          end;
        { reset cache }
        cacheindex:=0;
        cacheinputfile:=nil;
     end;



   function tinputfilemanager.get_file(l :longint) : pinputfile;
     var
        ff : pinputfile;
     begin
       { check cache }
       if (l=cacheindex) and assigned(cacheinputfile) then
        begin
          get_file:=cacheinputfile;
          exit;
        end;
       ff:=files;
       while assigned(ff) and (ff^.ref_index<>l) do
         ff:=ff^.ref_next;
       get_file:=ff;
     end;


   function tinputfilemanager.get_file_name(l :longint):string;
     var
       hp : pinputfile;
     begin
       hp:=get_file(l);
       if assigned(hp) then
        get_file_name:=hp^.name^
       else
        get_file_name:='';
     end;


   function tinputfilemanager.get_file_path(l :longint):string;
     var
       hp : pinputfile;
     begin
       hp:=get_file(l);
       if assigned(hp) then
        get_file_path:=hp^.path^
       else
        get_file_path:='';
     end;


end.
{
  $Log$
  Revision 1.1  2000-08-27 16:11:50  peter
    * moved some util functions from globals,cobjects to cutils
    * splitted files into finput,fmodule

}