[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] pc: Use fstat in get_file_size()
From: |
Michael Tokarev |
Subject: |
Re: [Qemu-devel] [PATCH] pc: Use fstat in get_file_size() |
Date: |
Sun, 5 Jun 2016 10:15:07 +0300 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.8.0 |
Please direct all patches to qemu-devel@ too, don't use ONLY
qemu-trivial. Thanks.
01.06.2016 17:23, Fabien Siron wrote:
> As mentioned in the comment, fstat is quite simpler than playing with
> ftell() and fseek().
>
> Signed-off-by: Fabien Siron <address@hidden>
> ---
> hw/i386/pc.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 99437e0..fecb067 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -801,16 +801,13 @@ static FWCfgState *bochs_bios_init(AddressSpace *as,
> PCMachineState *pcms)
>
> static long get_file_size(FILE *f)
> {
> - long where, size;
> + struct stat stat;
> + int fd;
>
> - /* XXX: on Unix systems, using fstat() probably makes more sense */
> + fd = fileno(f);
> + fstat(fd, &stat);
There's no need to introduce fd variable here, it is perfectly
sane to use fstat(fileno(f), &stat) here.
> - where = ftell(f);
> - fseek(f, 0, SEEK_END);
> - size = ftell(f);
> - fseek(f, where, SEEK_SET);
> -
> - return size;
> + return stat.st_size;
Note there's no error checking in this function, neither in the
original nor in the new implementation. But old function, in case
of error, will most likely return -1 (error result of ftell()),
while new function will return some random value.
So the body should look something like:
struct stat st;
return fstat(fileno(f), &st) < 0 ? -1 : st.st_size;
Thanks,
/mjt
- Re: [Qemu-devel] [PATCH] pc: Use fstat in get_file_size(),
Michael Tokarev <=