Re: [PATCH v2 16/21] read-cache: unlink old sharedindex files

[Christian Couder <christian.couder@gmail.com>]

On Mon, Dec 19, 2016 at 12:58 PM, Duy Nguyen <pclouds@gmail.com> wrote:
> On Sat, Dec 17, 2016 at 03:55:42PM +0100, Christian Couder wrote:
>> +static int clean_shared_index_files(const char *current_hex)
>> +{
>> +     struct dirent *de;
>> +     DIR *dir = opendir(get_git_dir());
>> +
>> +     if (!dir)
>> +             return error_errno(_("unable to open git dir: %s"), get_git_dir());
>> +
>> +     while ((de = readdir(dir)) != NULL) {
>> +             const char *sha1_hex;
>> +             if (!skip_prefix(de->d_name, "sharedindex.", &sha1_hex))
>> +                     continue;
>> +             if (!strcmp(sha1_hex, current_hex))
>
> fspathcmp since we're dealing fs paths?
>
> In theory we should be ok using strcmp, even on Windows because case
> is preserved, I think. It's only a problem when we write path 'abc'
> down and read 'ABC' back.
>
> Oh well.. your call because if you go with fspathcmp, skip_prefix can't
> be used either. A lot more changes for a very rare case.

I'd rather keep using skip_prefix() and strcmp().

I could find no place in the code where fspathcmp() is used to compare
dir entries, but a few where other *cmp() functions are used:

$ git grep '>d_name' | grep cmp
builtin/repack.c:               if (strncmp(e->d_name, buf.buf +
dirlen, prefixlen))
dir.c:  if (is_dot_or_dotdot(de->d_name) || !strcmp(de->d_name, ".git"))
sha1_name.c:                    if (memcmp(de->d_name, ds->hex_pfx +
2, ds->len - 2))

and also a few where skip_prefix() is used:

$ git grep -n '>d_name' | grep prefix
builtin/repack.c:60:            if (strncmp(e->d_name, buf.buf +
dirlen, prefixlen))
help.c:147:             if (!skip_prefix(de->d_name, prefix, &ent))

so I think it is ok to use skip_prefix() and strcmp().

>> +                     continue;
>> +             if (can_delete_shared_index(sha1_hex) > 0 &&
>
> Probably shorter to pass full d->name here so you don't have to do
> another git_path() in can_delete_

Yeah, you are right, I will do that.