squeue.c

/* Generated by specialize genericqueue SQueue "struct State *"
 * Queues
 */

#include "system.h"

#include "squeue.h"
#include "assert.h"
#include "types.h"

/* Return a new, empty queue */
SQueue SQueueCreate()
{
  register int i;
  register SQueue q;

  q = (SQueue) vmMalloc(sizeof(SQueueRecord));
  if (q == NULL) return NULL;
  q->size = 8;
  q->count = 0;
  q->first = 0;
  q->table = (SQueueDomainType *) 
    vmMalloc((unsigned) q->size * sizeof(SQueueDomainType));
  if (q->table == NULL) {
    vmFree(q);
    return NULL;
  }
  for (i = 0; i < q->size; i++) {
    q->table[i] = NULL;
  }
  return q;
}

void SQueueDestroy(SQueue q)
{
  if (q && !ISNIL(q)) {
    vmFree((char *)q->table);
    vmFree((char *)q);
  }
}

/* Expand the array.  Each element in the table is copied 
 * in the new table.  The new space is initialized to NULL
 */
static void ExpandTable(SQueue q)
{
  register int oldTableSize = q->size, i;

  q->size = oldTableSize + oldTableSize;
  q->table = (SQueueDomainType *)
    vmRealloc(q->table, (q->size *sizeof(SQueueDomainType)));
  for (i = 0; i < q->first; i++) {
    q->table[oldTableSize + i] = q->table[i];
    q->table[i] = NULL;
  }
}

/* Insert the value in q. */
void SQueueInsert(q, value)
register SQueue q;
register SQueueDomainType value;
{
  if (q->count >= q->size) ExpandTable(q);
  q->table[q->first + q->count - (q->first + q->count >= q->size ? q->size : 0)] = value;
  q->count ++;
}

/* Insert the value in q. */
void SQueueInsertFront(q, value)
register SQueue q;
register SQueueDomainType value;
{
  if (q->count >= q->size) ExpandTable(q);
  if (--q->first < 0) q->first += q->size;
  q->table[q->first] = value;
  q->count ++;
}

/* Remove a specific element, return 1 if it was found */
int SQueueYank(SQueue q, SQueueDomainType e)
{
  int i, found = 0, x, y = 0;
  x = q->first;
  for (i = 0; i < q->count; i++) {
    if (found) {
      q->table[y] = q->table[x];
    } else if (q->table[x] == e) {
      found = 1;
    }
    y = x; x++; if (x == q->size) x = 0;
  }
  if (found) q->count --;
  return found;
}

/* Remove the value at the front of the queue */
SQueueDomainType SQueueRemove(q)
register SQueue q;
{
  SQueueDomainType r;
  if (!q || ISNIL(q) || q->count <= 0) return NULL;
  r = q->table[q->first];
  if (++q->first >= q->size) q->first = 0;
  q->count --;
  return r;
}

/* Remove the value at the front of the queue */
SQueueDomainType SQueueRemoveBack(q)
register SQueue q;
{
  SQueueDomainType r;
  int index;
  if (!q || ISNIL(q) || q->count <= 0) return NULL;
  index = q->first + q->count;
  if (index >= q->size) index -= q->size;
  r = q->table[index];
  q->count --;
  return r;
}

/* DEBUGGING: Print the q */
void SQueuePrint(q)
register SQueue q;
{
  SQueueDomainType value;
  int index;

  printf(
    "Dump of q @ 0x%05x, %d entr%s, max %d, first %d\n\
    Index\tValue\n",
    (int)q, q->count, q->count == 1 ? "y" : "ies",  q->size, q->first);
  for (index = 0; index < q->count; index++) {
    value = q->table[(q->first + index) % q->size];
    printf("%3d\t%10d\n", (q->first + index) % q->size, (int)value);
  }
}