From: Thiago Farina <tfransosi@gmail.com>
Date: Mon, 16 May 2011 13:03:46 GMT
Subject: Re: [PATCH 08/11] streaming_write_entry(): support files with holes
Message-ID: <BANLkTi=A_vJbJ1v9NDVdh5DMNgTqHQXg6w@mail.gmail.com>
In-Reply-To: <1305505831-31587-9-git-send-email-gitster@pobox.com>

On Sun, May 15, 2011 at 9:30 PM, Junio C Hamano <gitster@pobox.com> wrote:
> One typical use of a large binary file is to hold a sparse on-disk hash
> table with a lot of holes. Help preserving the holes with lseek().
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
>  entry.c |   18 +++++++++++++++++-
>  1 files changed, 17 insertions(+), 1 deletions(-)
>
> diff --git a/entry.c b/entry.c
> index 7733a6b..d50e388 100644
> --- a/entry.c
> +++ b/entry.c
> @@ -123,6 +123,7 @@ static int streaming_write_entry(struct cache_entry *ce, char *path,
>        enum object_type type;
>        unsigned long sz;
>        int result = -1;
> +       ssize_t kept = 0;
>        int fd = -1;
>
>        st = open_istream(ce->sha1, &type, &sz);
> @@ -137,17 +138,32 @@ static int streaming_write_entry(struct cache_entry *ce, char *path,
>
>        for (;;) {
>                char buf[10240];
> -               ssize_t wrote;
> +               ssize_t wrote, holeto;
>                ssize_t readlen = read_istream(st, buf, sizeof(buf));
>
>                if (!readlen)
>                        break;
> +               for (holeto = 0; holeto < readlen; holeto++)
> +                       if (buf[holeto])
> +                               break;
> +               if (readlen == holeto) {
> +                       kept += holeto;
> +                       continue;
> +               }
>
> +               if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
> +                       goto close_and_exit;
> +               else
> +                       kept = 0;
>                wrote = write_in_full(fd, buf, readlen);
>
>                if (wrote != readlen)
>                        goto close_and_exit;
>        }
> +       if (kept &&
> +           ((  lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1)
There is an extra whitespace after ((

> +            || write(fd, "", 1) != 1))
> +               goto close_and_exit;
>        *fstat_done = fstat_output(fd, state, statbuf);
>
>  close_and_exit:
> --
> 1.7.5.1.365.g32b65
>
> --
> To unsubscribe from this list: send the line "unsubscribe git" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>