Patrick Steinhardt <ps@xxxxxx> writes:
>> +static int check_collision(const char *filename_a, const char *filename_b)
>> +{
>> ...
>> + return ret;
>> +}
>> +
>> /*
>> * Move the just written object into its final resting place.
>> */
>
> This function compares the exact contents, but isn't that wrong? The
> contents may differ even though the object is the same because the
> object hash is derived from the uncompressed data, whereas we store
> compressed data on disk.
Very true. So check_collision is *not* a good name for this helper
function.
For .pack files, a collision means two resulting files have the
identical contents, so the above function, perhaps renamed to
"compare_files()" or something, is a very appropriate helper to
detect a collision once you get two files that claim to be the same
.pack file.
For loose object files, a collision means the contents before
compression are the same, so if we wanted to check collisions within
the same framework, we'd need "compare_files_after_inflating()" or
something, that opens both files and compare their contents while
"inflating" via zlib.
Thanks.
