shithub: asif

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pheap: fix another problem in cutting pairs from the graph + debugging

--- a/asif.h

+++ b/asif.h

@@ -75,6 +75,7 @@

 	Pairheap *left;

 	Pairheap *right;

 };

+void	printqueue(Pairheap**);

 void	nukequeue(Pairheap**);

 Pairheap*	popqueue(Pairheap**);

 void	decreasekey(Pairheap*, double, Pairheap**);

@@ -96,6 +97,7 @@

 	Lognone,

 	Logdebug,

 	Logtrace,

+	Logparanoid,

 };

 extern int debuglevel;

--- a/pheap.c

+++ b/pheap.c

@@ -7,9 +7,23 @@

  * (1986).  */

 static void

+checkheap(Pairheap *p, Pairheap *queue)

+{

+	Pairheap *q;

+

+	if(p == nil || queue == nil)

+		return;

+	if(p == queue)

+		fprint(2, "pheap::checkheap %#p\n", p);

+	assert(p == queue || p->parent != nil && p->parent != p);

+	for(q=p; q!=nil; q=q->right)

+		checkheap(q->left, queue);

+}

+

+static void

 printright(Pairheap *p, int level)

 {

-	int i, j;

+	int i;

 	Pairheap *q;

 	if(p == nil)

@@ -17,7 +31,7 @@

 	fprint(2, "(\n");

 	for(i=0; i<level; i++)

 		fprint(2, "\t");

-	for(q=p, j=0; q!=nil; q=q->right, j++){

+	for(q=p; q!=nil; q=q->right){

 		fprint(2, "[%#p,%.5f]", q, q->n);

 		printright(q->left, level+1);

 	}

@@ -26,21 +40,30 @@

 		fprint(2, "\t");

 	fprint(2, ")");

 }

-static void

-printqueue(Pairheap *p)

+void

+printqueue(Pairheap **queue)

 {

-	if(debuglevel == 0)

+	if(queue == nil)

 		return;

-	if(p == nil)

-		return;

-	fprint(2, "pheap ");

-	printright(p, 1);

+	fprint(2, "pheap::printqueue %#p ", *queue);

+	printright(*queue, 1);

 	fprint(2, "\n");

 }

+static void

+debugqueue(Pairheap **queue)

+{

+	if(debuglevel < Logtrace || queue == nil)

+		return;

+	printqueue(queue);

+	checkheap(*queue, *queue);

+}

+

 static Pairheap *

 mergequeue(Pairheap *a, Pairheap *b)

 {

+	dprint(Logtrace, "pheap::mergequeue %#p %.6f b %#p %.6f\n",

+		a, a->n, b, b!=nil ? b->n : NaN());

 	if(b == nil)

 		return a;

 	else if(a->n < b->n){

@@ -57,21 +80,27 @@

 }

 static Pairheap *

-mergepairs(Pairheap *a)

+mergepairs(Pairheap *a, Pairheap *q)

 {

 	Pairheap *b, *c;

 	if(a == nil)

 		return nil;

+	if(a->parent != nil && a->parent->left == a)

+		a->parent->left = nil;

 	a->parent = nil;

+	assert(a->parent == nil || a->parent->left != a);

 	b = a->right;

 	if(b == nil)

 		return a;

 	a->right = nil;

+	if(b->parent != nil && b->parent->left == b)

+		b->parent->left = nil;

 	b->parent = nil;

+	assert(b->parent == nil || b->parent->left != b);

 	c = b->right;

 	b->right = nil;

-	return mergequeue(mergequeue(a, b), mergepairs(c));

+	return mergequeue(mergequeue(a, b), mergepairs(c, q));

 }

 void

@@ -79,8 +108,11 @@

 {

 	Pairheap *p;

-	while((p = popqueue(queue)) != nil)

+	dprint(Logtrace, "pheap::nukequeue %#p\n", queue);

+	while((p = popqueue(queue)) != nil){

+		debugqueue(&p);

 		free(p);

+	}

 }

 Pairheap *

@@ -92,7 +124,8 @@

 	if(p == nil)

 		return nil;

 	dprint(Logtrace, "pheap::popqueue %#p %.6f\n", p, p->n);

-	*queue = mergepairs(p->left);

+	*queue = mergepairs(p->left, p);

+	debugqueue(queue);

 	return p;

 }

@@ -104,16 +137,19 @@

 	dprint(Logtrace, "pheap::decreasekey %#p %.6f Δ %.6f\n", p, p->n, Δ);

 	p->n -= Δ;

 	if(p->parent != nil && p->n < p->parent->n){

+		assert(p->parent->left != nil);

 		if(p->parent->left == p)

-			p->parent->left = nil;

+			p->parent->left = p->right;

 		else{

-			for(q=p->parent->left; q->right!=p; q=q->right)

-				;

+			for(q=p->parent->left; q!=nil && q!=p; q=q->right)

+				if(q->right == p)

+					break;

 			assert(q != nil);

 			q->right = p->right;

 		}

 		p->parent = nil;

 		*queue = mergequeue(p, *queue);

+		debugqueue(queue);

 	}

 }

@@ -125,7 +161,8 @@

 	p = emalloc(sizeof *p);

 	p->n = n;

 	p->aux = aux;

-	*queue = mergequeue(p, *queue);

 	dprint(Logtrace, "pheap::pushqueue %#p %.6f\n", p, p->n);

+	*queue = mergequeue(p, *queue);

+	debugqueue(queue);

 	return p;

 }