Re: stat() on Windows might cause error if target file is larger than 4GB

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Michael Paquier <michael(at)paquier(dot)xyz>
Cc: "Higuchi, Daisuke" <higuchi(dot)daisuke(at)jp(dot)fujitsu(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: stat() on Windows might cause error if target file is larger than 4GB
Date: 2018-09-12 03:27:08
Message-ID: 1513.1536722828@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Michael Paquier <michael(at)paquier(dot)xyz> writes:
> At the end, I have finally been able to put my hands on a Windows VM
> which uses VS2015, and I am able to see the problem. In short, Windows
> definition of stat() is an utter mess as this documentation page, which
> is the latest one available, nicely summarizes:
> https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/stat-functions?view=vs-2017

Egad.

> It is possible to get away with the error by using _stat64(), which
> returns as result a _stat64 structure. Still, it has one difference
> with the native result returned by stat() (which maps to _stat64i32) as
> st_size is a 32-bit integer in _stat64i32, and a 64-bit integer with
> _stat64. This mess is mixed also with the fact that pgwin32_safestat
> relies on a result stored in _stat, so we'd lose the 32 high bits from
> the size if we only do a direct mapping, which is bad.

Could we fix things so that Postgres thinks that struct stat is
struct __stat64? That is, act as though that variant is the native
stat structure?

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Michael Paquier 2018-09-12 03:47:31 Re: stat() on Windows might cause error if target file is larger than 4GB
Previous Message Michael Paquier 2018-09-12 02:25:10 Re: stat() on Windows might cause error if target file is larger than 4GB