From 46a6d089b741482ddf6e4056af17a243d9f0b275 Mon Sep 17 00:00:00 2001
From: Maxim Pimenov <m@maps.me>
Date: Fri, 10 Apr 2015 22:33:33 +0300
Subject: [PATCH] [routing] Support cancelling of route search requests.

---
 routing/astar_router.cpp    | 14 ++++++++++++--
 routing/dijkstra_router.cpp | 12 ++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/routing/astar_router.cpp b/routing/astar_router.cpp
index ebe02078e4..592bc8a191 100644
--- a/routing/astar_router.cpp
+++ b/routing/astar_router.cpp
@@ -8,8 +8,9 @@
 
 namespace routing
 {
-static double const kMaxSpeedMPS = 5000.0 / 3600;
-static double const kEpsilon = 1e-6;
+double const kMaxSpeedMPS = 5000.0 / 3600;
+double const kEpsilon = 1e-6;
+int const kCancelledPollPeriod = 100;
 
 namespace
 {
@@ -117,8 +118,17 @@ IRouter::ResultCode AStarRouter::CalculateRouteM2M(vector<RoadPos> const & start
     queue.push(Vertex(rp, 0.0));
   }
 
+  int steps = 0;
+
   while (!queue.empty())
   {
+    ++steps;
+    if (steps % kCancelledPollPeriod == 0)
+    {
+      if (IsCancelled())
+        return IRouter::Cancelled;
+    }
+
     Vertex const v = queue.top();
     queue.pop();
 
diff --git a/routing/dijkstra_router.cpp b/routing/dijkstra_router.cpp
index dd41186b2b..17dad8baa6 100644
--- a/routing/dijkstra_router.cpp
+++ b/routing/dijkstra_router.cpp
@@ -10,6 +10,8 @@
 
 namespace routing
 {
+int const kCancelledPollPeriod = 100;
+
 namespace
 {
 template <typename E>
@@ -76,10 +78,20 @@ IRouter::ResultCode DijkstraRouter::CalculateRouteM2M(vector<RoadPos> const & st
   for (auto const & p : dist)
     queue.push(Vertex(p.first, 0.0 /* distance */));
 
+  int steps = 0;
+
   while (!queue.empty())
   {
+    ++steps;
+    if (steps % kCancelledPollPeriod == 0)
+    {
+      if (IsCancelled())
+        return IRouter::Cancelled;
+    }
+
     Vertex const v = queue.top();
     queue.pop();
+
     if (v.dist > dist[v.pos])
       continue;