X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fadt%2Fpqueue.c;h=5becefa40e58811a3dbd6d9a841ecbd165a85325;hb=f864dbddcf026827e85d49544abbb002841a5405;hp=f3ba974ad4cb81d0e82892045e7fd0835b40b976;hpb=07a060d7b4c7e0adc575f3a828e9ff16f2471ccf;p=libfirm

diff --git a/ir/adt/pqueue.c b/ir/adt/pqueue.c
index f3ba974ad..5becefa40 100644
--- a/ir/adt/pqueue.c
+++ b/ir/adt/pqueue.c
@@ -1,7 +1,32 @@
+/*
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @author  Christian Wuerdig, Matthias Braun
+ * @brief   Priority Queue implementation based on the heap datastructure
+ * @version $Id$
+ */
 #include "array.h"
 #include "pqueue.h"
 
-/**
+/*
  * Implements a heap.
  *
  * Implementation note: It might seem strange that we start indexing at 0
@@ -15,13 +40,12 @@
  * implementations or the ugly (i+1)*2 - 1 and (i+1)*2 for calculating the
  * left and right child. (At the expense that stuff easily breaks when you make
  * changes and don't think that the left child of 0 is 0 :-/)
- * @author matze
  *
  */
 
 typedef struct _pqueue_el_t {
-	void   *data;
-	double key;
+	void *data;
+	int  priority;
 } pqueue_el_t;
 
 struct _pqueue_t {
@@ -32,18 +56,19 @@ struct _pqueue_t {
  * Enforces the heap characteristics if the queue
  * starting from element at position @p pos.
  */
-static void pqueue_heapify(pqueue *q, int pos) {
-	int len = ARR_LEN(q->elems);
+static void pqueue_heapify(pqueue_t *q, unsigned pos) {
+	unsigned len = ARR_LEN(q->elems);
 
 	while (pos * 2 < len) {
 		pqueue_el_t tmp;
-		int         exchange = pos;
+		unsigned    exchange = pos;
 
-		if (q->elems[exchange].key < q->elems[pos * 2].key) {
+		if (q->elems[exchange].priority < q->elems[pos * 2].priority) {
 			exchange = pos * 2;
 		}
 
-		if ((pos * 2 + 1) < len && q->elems[exchange].key < q->elems[pos * 2 + 1].key) {
+		if ((pos * 2 + 1) < len
+				&& q->elems[exchange].priority < q->elems[pos * 2 + 1].priority) {
 			exchange = pos * 2 + 1;
 		}
 
@@ -61,8 +86,8 @@ static void pqueue_heapify(pqueue *q, int pos) {
 /**
  * Sifts up a newly inserted element at position @p pos.
  */
-static void pqueue_sift_up(pqueue *q, int pos) {
-	while(q->elems[pos].key > q->elems[pos / 2].key) {
+static void pqueue_sift_up(pqueue_t *q, unsigned pos) {
+	while(q->elems[pos].priority > q->elems[pos / 2].priority) {
 		pqueue_el_t tmp;
 
 		tmp               = q->elems[pos];
@@ -73,48 +98,29 @@ static void pqueue_sift_up(pqueue *q, int pos) {
 	}
 }
 
-/**
- * Creates a new priority queue.
- * @return A priority queue of initial length 0.
- */
-pqueue *new_pqueue(void) {
-	pqueue *res = xmalloc(sizeof(*res));
+pqueue_t *new_pqueue(void) {
+	pqueue_t *res = xmalloc(sizeof(*res));
 	res->elems = NEW_ARR_F(pqueue_el_t, 0);
 	return res;
 }
 
-/**
- * Frees all memory allocated by the priority queue.
- * @param q   The priority queue to destroy.
- */
-void del_pqueue(pqueue *q) {
+void del_pqueue(pqueue_t *q) {
 	DEL_ARR_F(q->elems);
 	free(q);
 }
 
-/**
- * Inserts a new element into a priority queue.
- * @param q      The priority queue the element should be inserted to.
- * @param data   The actual data which should be stored in the queue.
- * @param key    The priority for the data.
- */
-void pqueue_put(pqueue *q, void *data, double key) {
+void pqueue_put(pqueue_t *q, void *data, int priority) {
 	pqueue_el_t el;
 
-	el.data = data;
-	el.key  = key;
+	el.data     = data;
+	el.priority = priority;
 
 	ARR_APP1(pqueue_el_t, q->elems, el);
 
 	pqueue_sift_up(q, ARR_LEN(q->elems) - 1);
 }
 
-/**
- * Returns and removes the first element, ie. that one with the highest priority, from the queue.
- * @param q   The priority queue.
- * @return The first element of the queue. Asserts if queue is empty.
- */
-void *pqueue_get(pqueue *q) {
+void *pqueue_pop_front(pqueue_t *q) {
 	switch(ARR_LEN(q->elems)) {
 		case 0:
 			assert(0 && "Attempt to retrieve element from empty priority queue.");
@@ -137,20 +143,10 @@ void *pqueue_get(pqueue *q) {
 	}
 }
 
-/**
- * Get the length of the priority queue.
- * @param q   The priority queue.
- * @return The length of the queue.
- */
-int pqueue_length(pqueue *q) {
+int pqueue_length(const pqueue_t *q) {
 	return ARR_LEN(q->elems);
 }
 
-/**
- * Returns true if queue is empty.
- * @param q   The priority queue.
- * @return 1 if the queue is empty, 0 otherwise.
- */
-int pqueue_empty(pqueue *q) {
+int pqueue_empty(const pqueue_t *q) {
 	return ARR_LEN(q->elems) == 0;
 }