• MGW (15/15) Jan 03 2020 Need help:
• Alex (5/21) Jan 03 2020 As far as I know, there isn't any native in D. Maybe I overlooked
• =?UTF-8?Q?Ali_=c3=87ehreli?= (8/25) Jan 04 2020 How long are the lines? If 1K bytes, 100M would fit in memory just fine....

MGW <mgw yandex.ru> writes:

Need help:
There' s a large text file (hundreds of thousands of lines).
The structure is as follows:
2345|wedwededwedwedwe ......
872625|rfrferwewweww .....
23|rergrferfefer ....
................

It is necessary to sort this file by the first field having 
received:
23|rergrferfefer.......
2345|wedwededwedwedwe.......
872625|rfrferwewweww.......

There are also N CPU (from 4 to 8) and 16 Gb of Memory. Necessary
come up with an algorithm in D for fast sorting using 
multithreading.

Alex <sascha.orlov gmail.com> writes:

On Saturday, 4 January 2020 at 07:51:49 UTC, MGW wrote:
 Need help:
 There' s a large text file (hundreds of thousands of lines).
 The structure is as follows:
 2345|wedwededwedwedwe ......
 872625|rfrferwewweww .....
 23|rergrferfefer ....
 ................

 It is necessary to sort this file by the first field having 
 received:
 23|rergrferfefer.......
 2345|wedwededwedwedwe.......
 872625|rfrferwewweww.......

 There are also N CPU (from 4 to 8) and 16 Gb of Memory. 
 Necessary
 come up with an algorithm in D for fast sorting using 
 multithreading.

As far as I know, there isn't any native in D. Maybe I overlooked 
some at code.dlang.org. But there are plenty out there in the 
wild. Found this on the first shoot:
https://stackoverflow.com/questions/23531625/multithreaded-sorting-application/23532317

=?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:

On 1/3/20 11:51 PM, MGW wrote:
 Need help:
 There' s a large text file (hundreds of thousands of lines).

How long are the lines? If 1K bytes, 100M would fit in memory just fine. 
There is a parallel quick sort example on the std.parallelism page:

   https://dlang.org/phobos/std_parallelism.html

 The structure is as follows:
 2345|wedwededwedwedwe ......
 872625|rfrferwewweww .....
 23|rergrferfefer ....
 .................
 
 It is necessary to sort this file by the first field having received:
 23|rergrferfefer.......
 2345|wedwededwedwedwe.......
 872625|rfrferwewweww.......

Are you going to write the result back to a file? Then you would hardly 
notice any improvement from parallelism because relative slowness of I/O 
would determine the overall performance.

 
 There are also N CPU (from 4 to 8) and 16 Gb of Memory. Necessary
 come up with an algorithm in D for fast sorting using multithreading.
 
 

Ali