Make a find function for the peek command.

pq.c

@@ -100,3 +100,12 @@ pq_take(pq q)
  delete_min(q);
  return j;
 }
+
+job
+pq_find(pq q, unsigned long long int id)
+{
+ unsigned int i;
+
+ for (i = 0; i < q->used; i++) if (q->heap[i]->id == id) return q->heap[i];
+ return NULL;
+}

pq.h

@@ -20,4 +20,8 @@ int pq_give(pq q, job j);
 /* return a job if the queue contains jobs, else NULL */
 job pq_take(pq q);
 
+/* return a job that matches the given id, else NULL */
+/* This is O(n), so don't do it much. */
+job pq_find(pq q, unsigned long long int id);
+
 #endif /*q_h*/

tests/test_pq.c

@@ -111,6 +111,30 @@ __CUT__pq_test_fifo_property()
  ASSERT(j == j3c, "j3c should come out third.");
 }
 
+void
+__CUT__pq_test_find_match()
+{
+ job j;
+
+ q = make_pq(2);
+ pq_give(q, j1);
+
+ j = pq_find(q, j1->id);
+ ASSERT(j == j1, "j1 should come out.");
+}
+
+void
+__CUT__pq_test_find_miss()
+{
+ job j;
+
+ q = make_pq(2);
+ pq_give(q, j1);
+
+ j = pq_find(q, j1->id + 1);
+ ASSERT(j == NULL, "no job should match.");
+}
+
 void
 __CUT_TAKEDOWN__pq()
 {