#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);

}