#include "constmap.h"
#include "alloc.h"
#include "case.h"

static constmap_hash hash(s,len)
char *s;
int len;
{
 unsigned char ch;
 constmap_hash h;
 h = 5381;
 while (len > 0)
  {
   ch = *s++ - 'A';
   if (ch <= 'Z' - 'A') ch += 'a' - 'A';
   h = ((h << 5) + h) ^ ch;
   --len;
  }
 return h;
}

char *constmap(cm,s,len)
struct constmap *cm;
char *s;
int len;
{
 constmap_hash h;
 int pos;
 h = hash(s,len);
 pos = cm->first[h & cm->mask];
 while (pos != -1)
  {
   if (h == cm->hash[pos])
     if (len == cm->inputlen[pos])
       if (!case_diffb(cm->input[pos],len,s))
	 return cm->input[pos] + cm->inputlen[pos] + 1;
   pos = cm->next[pos];
  }
 return 0;
}

int constmap_init(cm,s,len,flagcolon)
struct constmap *cm;
char *s;
int len;
int flagcolon;
{
 int i;
 int j;
 int k;
 int pos;
 constmap_hash h;

 cm->num = 0;
 for (j = 0;j < len;++j) if (!s[j]) ++cm->num;

 h = 64;
 while (h && (h < cm->num)) h += h;
 cm->mask = h - 1;

 cm->first = (int *) alloc(sizeof(int) * h);
 if (cm->first)
  {
   cm->input = (char **) alloc(sizeof(char *) * cm->num);
   if (cm->input)
    {
     cm->inputlen = (int *) alloc(sizeof(int) * cm->num);
     if (cm->inputlen)
      {
       cm->hash = (constmap_hash *) alloc(sizeof(constmap_hash) * cm->num);
       if (cm->hash)
	{
	 cm->next = (int *) alloc(sizeof(int) * cm->num);
	 if (cm->next)
	  {
	   for (h = 0;h <= cm->mask;++h)
	     cm->first[h] = -1;
           pos = 0;
           i = 0;
           for (j = 0;j < len;++j)
             if (!s[j])
              {
	       k = j - i;
	       if (flagcolon)
		{
		 for (k = i;k < j;++k)
		   if (s[k] == ':')
		     break;
		 if (k >= j) { i = j + 1; continue; }
		 k -= i;
		}
               cm->input[pos] = s + i;
               cm->inputlen[pos] = k;
               h = hash(s + i,k);
               cm->hash[pos] = h;
               h &= cm->mask;
               cm->next[pos] = cm->first[h];
               cm->first[h] = pos;
               ++pos;
               i = j + 1;
              }
           return 1;
	  }
	 alloc_free(cm->hash);
	}
       alloc_free(cm->inputlen);
      }
     alloc_free(cm->input);
    }
   alloc_free(cm->first);
  }
 return 0;
}

void constmap_free(cm)
struct constmap *cm;
{
 alloc_free(cm->next);
 alloc_free(cm->hash);
 alloc_free(cm->inputlen);
 alloc_free(cm->input);
 alloc_free(cm->first);
}