Re: [PATCH v2] packfile: use get_be64() for large offsets
- From
SZEDER Gábor <szeder.dev@gmail.com>
- Date
- Jan 18, 2018, 14:15 UTC
- Message-ID
- <20180118141522.18294-1-szeder.dev@gmail.com>
- In-Reply-To
- <20180118110419.210006-1-dstolee@microsoft.com>
Junio,
Show 47 quoted lines
> The pack-index version 2 format uses two 4-byte integers in network-
> byte order to represent one 8-byte value. The current implementation
> has several code clones for stitching these integers together.
>
> Use get_be64() to create an 8-byte integer from two 4-byte integers
> represented this way.
>
> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
> ---
> pack-revindex.c | 6 ++----
> packfile.c | 3 +--
> 2 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/pack-revindex.c b/pack-revindex.c
> index 1b7ebd8d7e..ff5f62c033 100644
> --- a/pack-revindex.c
> +++ b/pack-revindex.c
> @@ -134,10 +134,8 @@ static void create_pack_revindex(struct packed_git *p)
> if (!(off & 0x80000000)) {
> p->revindex[i].offset = off;
> } else {
> - p->revindex[i].offset =
> - ((uint64_t)ntohl(*off_64++)) << 32;
> - p->revindex[i].offset |=
> - ntohl(*off_64++);
> + p->revindex[i].offset = get_be64(off_64);
> + off_64 += 2;
> }
> p->revindex[i].nr = i;
> }
> diff --git a/packfile.c b/packfile.c
> index 4a5fe7ab18..228ed0d59a 100644
> --- a/packfile.c
> +++ b/packfile.c
> @@ -1702,8 +1702,7 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
> return off;
> index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
> check_pack_index_ptr(p, index);
> - return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
> - ntohl(*((uint32_t *)(index + 4)));
> + return get_be64(index);
> }
> }
>
> --
> 2.15.0
> This patch can't be applied to 'maint' currently at 3013dff86 (Prepare for 2.15.2, 2017-12-06), as it is in case of 'ds/use-get-be64', because 'maint' doesn't have get_be64() yet (b2e39d006 (bswap: add 64 bit endianness helper get_be64, 2017-09-22)).
Gábor