how get all patterns that match that given subject string

[perfgao]

Hi,

I noticed that The Match_Tmpl not supports MV_ALL_MATCHES.

if (state->is_term) {
     if (variant == MV_FIRST_MATCH) {
         ac_result_t r;
         r.match_begin = idx - state->depth;
         r.match_end = idx - 1;
         r.pattern_idx = state->is_term - 1;
         return r;
     }

     if (variant == MV_LEFT_LONGEST) {
         int match_begin = idx - state->depth;
         int match_end = idx - 1;

         if (r.match_begin == -1 ||
             match_end - match_begin > r.match_end - r.match_begin) {
             r.match_begin = match_begin;
             r.match_end = match_end;
             r.pattern_idx = state->is_term - 1;
         }
         continue;
     }

     ASSERT(false && "NYI");
 }

What should I do if i want get all patterns that match that given subject
string? Why not implement variant == MV_ALL_MATCHES?

[yangshuxin]

Why not implement variant == MV_ALL_MATCHES?

Simply because there were no such need during the time I were with Cloudflare. There were only one matching-variant by the time I implemented this code; later on I added left-longest variant as one of my ex-coworker needed it.

It's not difficult the to implement the all-match variant. Just need to be pretty careful with the data structure and efficiency. BTW, if you are trying to implement this variant, please use separate (c++) template instead of adding the implementation on top of existing template -- I believe it would degrade other variants' performance and/or make the code difficult to maintain.

[perfgao]

There is no question that an exact match lookup will be less efficient than the current lookup. I try to achieve an efficiency within the acceptable range.