pq.h

   1 /* pq.h - priority queue header */
   2
   3 /* Copyright (C) 2007 Keith Rarick and Philotic Inc.
   4
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifndef q_h
  20 #define q_h
  21
  22 typedef struct pq *pq;
  23
  24 #include "job.h"
  25
  26 struct pq {
  27     unsigned int cap;
  28     unsigned int used;
  29     job_cmp_fn cmp;
  30     job *heap;
  31 };
  32
  33 /* initialize a priority queue */
  34 void pq_init(pq q, job_cmp_fn cmp);
  35
  36 void pq_clear(pq q);
  37
  38 /* return 1 if the job was inserted, else 0 */
  39 int pq_give(pq q, job j);
  40
  41 /* return a job if the queue contains jobs, else NULL */
  42 job pq_take(pq q);
  43
  44 /* return a job if the queue contains jobs, else NULL */
  45 job pq_peek(pq q);
  46
  47 /* remove and return j if the queue contains j, else return NULL */
  48 job pq_remove(pq q, job j);
  49
  50 #endif /*q_h*/