From 86c860c0f43a9130e4121072620961fc892ed83f Mon Sep 17 00:00:00 2001
From: Francois Fleuret <francois@fleuret.org>
Date: Wed, 19 Dec 2012 21:25:34 +0100
Subject: [PATCH] Moved the heap-related methods in the Vertex class, made them
 inline.

---
 mtp_graph.cc | 83 ++++++++++++++++++++++++++--------------------------
 mtp_graph.h  |  3 --
 2 files changed, 42 insertions(+), 44 deletions(-)

diff --git a/mtp_graph.cc b/mtp_graph.cc
index 660e659..33d5a4f 100644
--- a/mtp_graph.cc
+++ b/mtp_graph.cc
@@ -52,6 +52,8 @@ public:
 
   inline void add_leaving_edge(Edge *e);
   inline void del_leaving_edge(Edge *e);
+  inline void decrease_distance_in_heap(Vertex **heap);
+  inline void increase_distance_in_heap(Vertex **heap, int heap_size);
 };
 
 //////////////////////////////////////////////////////////////////////
@@ -91,6 +93,41 @@ void Vertex::del_leaving_edge(Edge *e) {
   }
 }
 
+void Vertex::decrease_distance_in_heap(Vertex **heap) {
+  Vertex **p, **h;
+  // There is some beauty in that
+  h = heap_slot;
+  while(h > heap &&
+        (p = heap + (h - heap + 1) / 2 - 1,
+         (*p)->distance_from_source > (*h)->distance_from_source)) {
+    swap(*p, *h);
+    swap((*p)->heap_slot, (*h)->heap_slot);
+    h = p;
+  }
+}
+
+void Vertex::increase_distance_in_heap(Vertex **heap, int heap_size) {
+  Vertex **c1, **c2, **h;
+  // omg, that's beautiful
+  h = heap_slot;
+  while(c1 = heap + 2 * (h - heap + 1) - 1, c2 = c1 + 1,
+        (c1 < heap + heap_size && (*c1)->distance_from_source < (*h)->distance_from_source)
+        ||
+        (c2 < heap + heap_size && (*c2)->distance_from_source < (*h)->distance_from_source)
+        ) {
+    if(c1 < heap + heap_size &&
+     !(c2 < heap + heap_size && (*c2)->distance_from_source < (*c1)->distance_from_source)){
+      swap(*c1, *h);
+      swap((*c1)->heap_slot, (*h)->heap_slot);
+      h = c1;
+    } else {
+      swap(*c2, *h);
+      swap((*c2)->heap_slot, (*h)->heap_slot);
+      h = c2;
+    }
+  }
+}
+
 //////////////////////////////////////////////////////////////////////
 
 static int compare_vertex(const void *v1, const void *v2) {
@@ -275,41 +312,6 @@ int MTPGraph::compute_dp_distances() {
   return nb_active == 0;
 }
 
-void MTPGraph::decrease_distance_in_heap(Vertex *v) {
-  Vertex **p, **h;
-  // There is some beauty in that
-  h = v->heap_slot;
-  while(h > _heap &&
-        (p = _heap + (h - _heap + 1) / 2 - 1,
-         (*p)->distance_from_source > (*h)->distance_from_source)) {
-    swap(*p, *h);
-    swap((*p)->heap_slot, (*h)->heap_slot);
-    h = p;
-  }
-}
-
-void MTPGraph::increase_distance_in_heap(Vertex *v) {
-  Vertex **c1, **c2, **h;
-  // omg, that's beautiful
-  h = v->heap_slot;
-  while(c1 = _heap + 2 * (h - _heap + 1) - 1, c2 = c1 + 1,
-        (c1 < _heap + _heap_size && (*c1)->distance_from_source < (*h)->distance_from_source)
-        ||
-        (c2 < _heap + _heap_size && (*c2)->distance_from_source < (*h)->distance_from_source)
-        ) {
-    if(c1 < _heap + _heap_size &&
-     !(c2 < _heap + _heap_size && (*c2)->distance_from_source < (*c1)->distance_from_source)){
-      swap(*c1, *h);
-      swap((*c1)->heap_slot, (*h)->heap_slot);
-      h = c1;
-    } else {
-      swap(*c2, *h);
-      swap((*c2)->heap_slot, (*h)->heap_slot);
-      h = c2;
-    }
-  }
-}
-
 void MTPGraph::dp_compute_distances() {
   Vertex *v, *tv;
   Edge *e;
@@ -330,7 +332,7 @@ void MTPGraph::dp_compute_distances() {
       if(d < tv->distance_from_source) {
         tv->distance_from_source = d;
         tv->pred_edge_toward_source = e;
-        decrease_distance_in_heap(tv);
+        tv->decrease_distance_in_heap(_heap);
       }
     }
   }
@@ -352,7 +354,7 @@ void MTPGraph::find_shortest_path() {
 
   _heap_size = _nb_vertices;
   _source->distance_from_source = 0;
-  decrease_distance_in_heap(_source);
+  _source->decrease_distance_in_heap(_heap);
 
   do {
     // Get the closest to the source
@@ -364,7 +366,7 @@ void MTPGraph::find_shortest_path() {
     a = _heap;
     b = _heap + _heap_size;
     swap(*a, *b); swap((*a)->heap_slot, (*b)->heap_slot);
-    increase_distance_in_heap(_heap[0]);
+    _heap[0]->increase_distance_in_heap(_heap, _heap_size);
 
     // Now update the neighbors of the currently closest to the source
     for(e = v->leaving_edges; e; e = e->next_leaving_edge) {
@@ -374,7 +376,7 @@ void MTPGraph::find_shortest_path() {
         ASSERT(tv->heap_slot - _heap < _heap_size);
         tv->distance_from_source = d;
         tv->pred_edge_toward_source = e;
-        decrease_distance_in_heap(tv);
+        tv->decrease_distance_in_heap(_heap);
       }
     }
   } while(_heap_size > 0);
@@ -391,8 +393,7 @@ void MTPGraph::find_best_paths(scalar_t *lengths) {
     _edges[e].positivized_length = _edges[e].length;
   }
 
-  // Update the distance to the source in "good order"
-
+  // Update the distances to the source in "good order"
   dp_compute_distances();
 
   do {
diff --git a/mtp_graph.h b/mtp_graph.h
index 84c9ce6..ff15830 100644
--- a/mtp_graph.h
+++ b/mtp_graph.h
@@ -49,9 +49,6 @@ class MTPGraph {
   // the total correction when compiled in VERBOSE mode.
   void force_positivized_lengths();
 
-  void decrease_distance_in_heap(Vertex *v);
-  void increase_distance_in_heap(Vertex *v);
-
   // Visit the vertices according to _dp_order and simply update their
   // distance to the source
   void dp_compute_distances();
-- 
2.39.5