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authorKarsten Blees <blees@dcon.de>2014-11-27 00:24:01 -0500
committerJunio C Hamano <gitster@pobox.com>2014-11-30 18:07:34 -0800
commitb5007211b6582fc38647ff695b5ac51541ea9de8 (patch)
tree4208da1ac8c0929519656f951f43384e8970fa5c /pack-bitmap.c
parent68f4e1fc6abd332726dd281c76dd63ce7d13d7a1 (diff)
downloadgit-b5007211b6582fc38647ff695b5ac51541ea9de8.tar.gz
pack-bitmap: do not use gcc packed attribute
The "__attribute__" flag may be a noop on some compilers. That's OK as long as the code is correct without the attribute, but in this case it is not. We would typically end up with a struct that is 2 bytes too long due to struct padding, breaking both reading and writing of bitmaps. Instead of marshalling the data in a struct, let's just provide helpers for reading and writing the appropriate types. Besides being correct on all platforms, the result is more efficient and simpler to read. Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'pack-bitmap.c')
-rw-r--r--pack-bitmap.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 91e4101531..9f8b909811 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -197,13 +197,24 @@ static struct stored_bitmap *store_bitmap(struct bitmap_index *index,
return stored;
}
+static inline uint32_t read_be32(const unsigned char *buffer, size_t *pos)
+{
+ uint32_t result = get_be32(buffer + *pos);
+ (*pos) += sizeof(result);
+ return result;
+}
+
+static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos)
+{
+ return buffer[(*pos)++];
+}
+
static int load_bitmap_entries_v1(struct bitmap_index *index)
{
static const size_t MAX_XOR_OFFSET = 160;
uint32_t i;
struct stored_bitmap **recent_bitmaps;
- struct bitmap_disk_entry *entry;
recent_bitmaps = xcalloc(MAX_XOR_OFFSET, sizeof(struct stored_bitmap));
@@ -214,15 +225,12 @@ static int load_bitmap_entries_v1(struct bitmap_index *index)
uint32_t commit_idx_pos;
const unsigned char *sha1;
- entry = (struct bitmap_disk_entry *)(index->map + index->map_pos);
- index->map_pos += sizeof(struct bitmap_disk_entry);
+ commit_idx_pos = read_be32(index->map, &index->map_pos);
+ xor_offset = read_u8(index->map, &index->map_pos);
+ flags = read_u8(index->map, &index->map_pos);
- commit_idx_pos = ntohl(entry->object_pos);
sha1 = nth_packed_object_sha1(index->pack, commit_idx_pos);
- xor_offset = (int)entry->xor_offset;
- flags = (int)entry->flags;
-
bitmap = read_bitmap_1(index);
if (!bitmap)
return -1;