Browse thread
[Caml-list] using BigArray to mmap huge binary file
[
Home
]
[ Index:
by date
|
by threads
]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: | 2006-11-09 (19:12) |
From: | malc <av1474@c...> |
Subject: | Re: [Caml-list] using BigArray to mmap huge binary file |
On Thu, 9 Nov 2006, Richard Jones wrote: > On Thu, Nov 09, 2006 at 06:30:50PM +0000, D?rio Abdulrehman wrote: >> I have a huge binary data file that I would like to memory map for intensive >> reading (no writing) with the best possible performance. >> I read some discussions about using BigArrays to achieve this in Ocaml. I >> would like to know how this solution compares with the C language mmap. >> Please bear in mind I am a total newbie to Ocaml but I have good Common Lisp >> experience. > > We use Bigarray to map geographical data. It works. As far as I'm > aware ArrayX.map_file is really just a wrapper around mmap, and read > accesses are just indirections on a pointer. I beg to differ, to the best of my knowlege every reference to bigarray is bounds checked, even with -unsafe. So, while map_file does indeed look like a wrapper around mmap, read/write is a bit more than an indirected memory fetch. -- vale