[Rpm-maint] [PATCH] Add RPMTAG_IDENTITY calculation as tag extension

[Panu Matilainen]

On 04/04/2018 11:01 AM, Panu Matilainen wrote:
[...]
>> +static int identityTag(Header h, rpmtd td, headerGetFlags hgflags)
>> +{
>> +    int rc = 1;
>> +    unsigned int bsize;
>> +    void * hb;
>> +    DIGEST_CTX ctx;
>> +    char * identity = NULL;
>> +
>> +    struct rpmtd_s ttd;
>> +    Header ih = headerNew();
>> +    HeaderIterator hi = headerInitIterator(h);
>> +
>> +    while (headerNext(hi, &ttd) && rc) {
>> +    if (rpmtdCount(&ttd) > 0) {
>> +        if (!identityFilter(ttd.tag))
>> +        rc = headerPut(ih, &ttd, HEADERPUT_DEFAULT);
>> +    }
>> +    rpmtdFreeData(&ttd);
>> +    }
>> +    headerFreeIterator(hi);
>> +
>> +    if (!rc)
>> +    return 0;
>> +
>> +    hb = headerExport(ih, &bsize);

Forgot to bring this up on the first round: another question is whether 
it actually makes sense to go through all this trouble of copying the 
header, then exporting it and calculating the digest from that.

It'd be considerably cheaper to calculate a digest on the go while 
iterating over the data (from the immutable region, see my other email). 
A newly imported header is guaranteed to be sorted (by tags) so it's 
consistent.

	- Panu -