Duy Nguyen <pclouds@xxxxxxxxx> writes:
> On Mon, Aug 19, 2013 at 2:42 AM, Thomas Gummerer <t.gummerer@xxxxxxxxx> wrote:
>> +static int read_entry(struct cache_entry **ce, char *pathname, size_t pathlen,
>> + void *mmap, unsigned long mmap_size,
>> + unsigned int first_entry_offset,
>> + unsigned int foffsetblock)
>> +{
>> + int len, offset_to_offset;
>> + char *name;
>> + uint32_t foffsetblockcrc, *filecrc, *beginning, *end, entry_offset;
>> + struct ondisk_cache_entry *disk_ce;
>> +
>> + beginning = ptr_add(mmap, foffsetblock);
>> + end = ptr_add(mmap, foffsetblock + 4);
>> + len = ntoh_l(*end) - ntoh_l(*beginning) - sizeof(struct ondisk_cache_entry) - 5;
>> + entry_offset = first_entry_offset + ntoh_l(*beginning);
>> + name = ptr_add(mmap, entry_offset);
>> + disk_ce = ptr_add(mmap, entry_offset + len + 1);
>> + *ce = cache_entry_from_ondisk(disk_ce, pathname, name, len, pathlen);
>> + filecrc = ptr_add(mmap, entry_offset + len + 1 + sizeof(*disk_ce));
>> + offset_to_offset = htonl(foffsetblock);
>> + foffsetblockcrc = crc32(0, (Bytef*)&offset_to_offset, 4);
>> + if (!check_crc32(foffsetblockcrc,
>> + ptr_add(mmap, entry_offset), len + 1 + sizeof(*disk_ce),
>> + ntoh_l(*filecrc)))
>> + return -1;
>> +
>> + return 0;
>> +}
>
> Last thought before book+bed time. I wonder if moving the name part to
> the end of the entry (i.e. chaging on disk format) would simplify this
> code. The new ondisk_cache_entry would be something like this
>
> struct ondisk_cache_entry {
> uint16_t flags;
> uint16_t mode;
> struct cache_time mtime;
> uint32_t size;
> int stat_crc;
> unsigned char sha1[20];
> char name[FLEX_ARRAY];
> };
I think it simplifies it a bit, but not too much, the only thing I see
avoiding the use of the name variable. I think it will also simplify
the writing code a bit. The only negative part would be for bisecting
the index, but that would still be possible, and only slightly more
complicated. I'll give it a try tomorrow and check if it's worth it.
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