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From: Ole-Hjalmar Kristensen <ole-hjalmar.kristensen@substitute_employer_here.com>
Subject: Re: Ada Shootout program for K-Nucleotide (patches)
Date: 01 Sep 2009 12:16:54 +0200
Date: 2009-09-01T12:16:54+02:00	[thread overview]
Message-ID: <wvbr7hwjc6ll.fsf@sun.com> (raw)
In-Reply-To: wvbrbplvccnc.fsf@sun.com

Or you could use the Unix read system call and roll your own get_line function
along these lines. It will read 1000000 lines of 60 characters line by line in about a second.

with Interfaces.C_Streams; use Interfaces.C_Streams;
with Ada.Text_Io;

procedure Get_Line_Test is
   In_Buf : String(1..8192);
   for In_Buf'Alignment use 8192;

   First: Integer := In_Buf'last;
   Last: Integer := 0;
   N : Size_T := 1;

   function Read(Fd : Int; Buffer : Voids; Nbyte : Size_T) return Size_T;
   pragma Import(C,read);

   function Empty_Buffer return Boolean is
   begin
      return First > Last;
   end Empty_Buffer;
   pragma  Inline(Empty_Buffer);

   function End_File return Boolean is
   begin
      return N <= 0;
   end End_File;
   pragma  Inline(End_File);
   
   -- Get line from stdin, return "" if end of file
   function Get_Line return String is
   begin
      -- Get buffer from file if empty
      if Empty_buffer then
         N := Read(0,In_Buf(1)'Address, Size_T(In_Buf'Last));
         First := 1;
         Last := Integer(N);
      end if;
      if Empty_Buffer then
         return "";
      end if;

      -- Look for end of line and return it
      for I in First..Last loop
         if In_Buf(I) = Ascii.LF then
            declare
               Start : Integer := First;
            begin
               First := I + 1;
               return In_Buf(Start..I-1);
            end;
         end if;
      end loop;

      -- Did not find end of line, seek further
      declare
         Copy: string := In_Buf(First..Last);
      begin
         Last := 0;
         return Copy & Get_Line;
      end;
   end Get_Line;
   pragma Inline(Get_Line);

begin
   while not End_File loop
      declare
         Line : String := Get_Line;
      begin
         -- Do something with line here
         null;
      end;
   end loop;
end Get_Line_Test;

astra06:~/ada/div-ada> uname -a
SunOS astra06 5.10 Generic_137137-09 sun4u sparc SUNW,Sun-Fire-V440
astra06:~/ada/div-ada> ls -l x.txt
-rw-------   1 ok145024 clustra  60000000 Sep  1 12:03 x.txt
astra06:~/ada/div-ada> time ./get_line_test < x.txt
0.49u 0.09s 0:00.59 98.3%

-- 
   C++: The power, elegance and simplicity of a hand grenade.



  parent reply	other threads:[~2009-09-01 10:16 UTC|newest]

Thread overview: 116+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-01 12:21 Ada Shootout program for K-Nucleotide (patches) Georg Bauhaus
2009-08-01 12:59 ` Ludovic Brenta
2009-08-01 13:59   ` Georg Bauhaus
2009-08-01 13:50 ` Gautier write-only
2009-08-01 15:21 ` Ludovic Brenta
2009-08-01 15:37   ` Gautier write-only
2009-08-02 12:55   ` Georg Bauhaus
2009-08-27 11:17     ` Ole-Hjalmar Kristensen
2009-08-27 12:25       ` Georg Bauhaus
2009-09-01  8:06         ` Ole-Hjalmar Kristensen
2009-09-01  9:29           ` Georg Bauhaus
2009-09-01 10:48             ` Ole-Hjalmar Kristensen
2009-09-01 10:16           ` Ole-Hjalmar Kristensen [this message]
2009-09-01 11:34             ` Georg Bauhaus
2009-09-01 12:11               ` Ole-Hjalmar Kristensen
2009-09-01 14:36                 ` Georg Bauhaus
2009-09-03  8:49                   ` Ole-Hjalmar Kristensen
2009-09-02  8:44                 ` Georg Bauhaus
2009-09-02 11:07                   ` Ole-Hjalmar Kristensen
2009-09-03  8:13                   ` Ole-Hjalmar Kristensen
2009-09-03 10:39                     ` Georg Bauhaus
2009-08-03  8:56   ` Jacob Sparre Andersen
2009-08-03 11:43     ` Georg Bauhaus
2009-08-03 12:36       ` Jacob Sparre Andersen
2009-08-03 18:31         ` Isaac Gouy
2009-08-03 20:29           ` Robert A Duff
2009-08-04 15:43             ` Isaac Gouy
2009-08-04 16:06               ` Isaac Gouy
2009-08-04 17:08                 ` Georg Bauhaus
2009-08-05 15:58                   ` Isaac Gouy
2009-08-05 21:18                     ` Georg Bauhaus
2009-08-05 22:04                       ` Ludovic Brenta
2009-08-05 22:31                         ` Georg Bauhaus
2009-08-05 23:44                           ` Jeffrey R. Carter
2009-08-06  8:38                             ` Georg Bauhaus
2009-08-06 21:39                               ` Georg Bauhaus
2009-08-06 22:42                                 ` Jeffrey R. Carter
2009-08-07  8:53                                   ` Georg Bauhaus
2009-08-07  9:21                                     ` Jacob Sparre Andersen
2009-08-07  9:23                                       ` Jacob Sparre Andersen
2009-08-09 19:17                                       ` Georg Bauhaus
2009-08-13 20:56                                 ` jonathan
2009-08-13 21:30                                   ` jonathan
2009-08-13 22:08                                   ` Georg Bauhaus
2009-08-14 15:31                                     ` jonathan
2009-08-06  7:51                           ` Dmitry A. Kazakov
2009-08-06  0:07                       ` Isaac Gouy
2009-08-06  8:36                         ` Georg Bauhaus
2009-08-06  9:09                           ` Dmitry A. Kazakov
2009-08-06 10:34                             ` Georg Bauhaus
2009-08-06 10:49                               ` Dmitry A. Kazakov
2009-08-06 15:21                                 ` Isaac Gouy
2009-08-03 20:47           ` Ludovic Brenta
2009-08-01 17:07 ` jonathan
2009-08-01 17:59 ` jonathan
2009-08-02 11:39   ` Georg Bauhaus
2009-08-02 16:00     ` jonathan
2009-08-02 16:42       ` jonathan
2009-09-03 13:44     ` Olivier Scalbert
2009-09-03 14:08       ` Ludovic Brenta
2009-09-03 15:13         ` Olivier Scalbert
2009-09-03 19:11           ` sjw
2009-09-04  6:11             ` Olivier Scalbert
2009-09-04  8:18               ` Ludovic Brenta
2009-09-04 10:17                 ` Olivier Scalbert
2009-09-04 12:37                   ` Ludovic Brenta
2009-09-04 13:50                     ` Olivier Scalbert
2009-09-04 12:50                   ` Ludovic Brenta
2009-09-04 16:22                     ` Georg Bauhaus
2009-09-04 16:29                       ` Georg Bauhaus
2009-09-04 16:38                         ` Ludovic Brenta
2009-09-04 17:58                           ` Georg Bauhaus
2009-09-04 18:12                             ` Georg Bauhaus
2009-09-05 20:16                             ` Georg Bauhaus
2009-09-07  7:45                           ` Olivier Scalbert
2009-09-07  9:19                             ` Georg Bauhaus
2009-09-07 13:31                               ` Olivier Scalbert
2009-09-07 14:38                                 ` jonathan
2009-09-07 15:03                                   ` Olivier Scalbert
2009-09-07 17:31                                     ` jonathan
2009-09-07 17:54                                       ` Olivier Scalbert
2009-09-07 18:07                                     ` Georg Bauhaus
2009-09-08  0:22                                 ` Georg Bauhaus
2009-09-04 17:56                     ` Martin
2009-09-04 18:26                       ` Georg Bauhaus
2009-09-04 21:51                         ` Robert A Duff
2009-09-04 18:51                       ` Ludovic Brenta
2009-09-04  9:27               ` Georg Bauhaus
2009-09-03 15:28       ` Georg Bauhaus
2009-09-04  1:24         ` Georg Bauhaus
2009-08-04  8:23 ` Martin
2009-08-16 15:20 ` jonathan
2009-08-17 15:46   ` Georg Bauhaus
2009-08-18 16:59     ` jonathan
2009-08-19 14:52       ` Georg Bauhaus
2009-08-19 16:40         ` Martin
2009-08-19 18:24           ` Robert A Duff
2009-08-19 22:15             ` jonathan
2009-08-19 23:50               ` Georg Bauhaus
2009-08-20 19:47                 ` jonathan
2009-08-20 22:15                   ` Georg Bauhaus
2009-08-21 21:43                     ` jonathan
2009-08-22 22:35                       ` Georg Bauhaus
2009-08-23 22:21                         ` jonathan
2009-08-20 19:55                 ` jonathan
2009-08-19 21:37           ` Georg Bauhaus
2009-08-19 19:22         ` jonathan
2009-08-19 19:27         ` jonathan
2009-08-27  9:05 ` Martin
2009-08-27  9:08   ` Martin
2009-08-27 10:01     ` Georg Bauhaus
2009-10-07 11:44 ` Olivier Scalbert
2009-10-07 12:04   ` Georg Bauhaus
2009-10-07 13:22   ` Martin
2009-10-07 14:15     ` Olivier Scalbert
2009-10-08  9:54       ` Georg Bauhaus
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