From 87ed332a56212b1df852874333207110d319d0aa Mon Sep 17 00:00:00 2001
From: Arndt Brenschede <Arndt.Brenschede@web.de>
Date: Sun, 2 Feb 2014 20:37:22 +0100
Subject: [PATCH] added more cache reuse for better short-route performance

---
 .../java/btools/mapaccess/MicroCache.java     | 48 ++++++++++++++--
 .../java/btools/mapaccess/NodesCache.java     | 57 ++++++++++++++++++-
 .../main/java/btools/mapaccess/OsmFile.java   | 41 ++++++++++++-
 3 files changed, 138 insertions(+), 8 deletions(-)

diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/MicroCache.java b/brouter-mapaccess/src/main/java/btools/mapaccess/MicroCache.java
index efbbcd9..eb9911d 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/MicroCache.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/MicroCache.java
@@ -24,6 +24,11 @@ final class MicroCache
   private int aboffset;
   private int ablength;
 
+  // cache control: a virgin cache can be
+  // put to ghost state for later recovery
+  boolean virgin = true;
+  boolean ghost = false;
+
   public MicroCache( OsmFile segfile, int lonIdx80, int latIdx80, byte[] iobuffer ) throws Exception
   {
      int lonDegree = lonIdx80/80;
@@ -40,6 +45,7 @@ final class MicroCache
 
        if ( asize == 0 )
        {
+         ab = null;
          return;
        }
        if ( asize > iobuffer.length )
@@ -105,9 +111,19 @@ final class MicroCache
     return size;
   }
   
+  public int getDataSize()
+  {
+    return ab == null ? 0 : ab.length;
+  }
+
   /**
-   * @return the value for "id",
-   * Throw an exception if not contained in the map.
+   * Set the internal reader (aboffset, ablength)
+   * to the body data for the given id
+   *
+   * @return true if id was found
+   *
+   * Throws an exception if that id was already requested
+   * as an early detector for identity problems
    */
   private boolean getAndClear( long id )
   {
@@ -148,7 +164,10 @@ final class MicroCache
     return false;
   }
 
-  public void fillNode( OsmNode node, OsmNodesMap nodesMap, DistanceChecker dc )
+  /**
+   * Fill a hollow node with it's body data
+   */
+  public void fillNode( OsmNode node, OsmNodesMap nodesMap, DistanceChecker dc, boolean doCollect )
   {
     long id = node.getIdFromPos();
     if ( getAndClear( id ) )
@@ -156,8 +175,18 @@ final class MicroCache
       node.parseNodeBody( this, ablength, nodesMap, dc );
     }
 
-    if ( delcount > size / 2 ) // garbage collection
+    if ( doCollect && delcount > size / 2 ) // garbage collection
     {
+      collect();
+    }
+  }
+
+  void collect()
+  {
+    if ( delcount > 0 )
+    {
+      virgin = false;
+
       int nsize = size - delcount;
       if ( nsize == 0 )
       {
@@ -197,6 +226,17 @@ final class MicroCache
     }
   }
 
+  void unGhost()
+  {
+    ghost = false;
+    delcount = 0;
+    delbytes = 0;
+    for( int i=0; i<size; i++ )
+    {
+      fapos[i] &= 0x7fffffff; // clear deleted flags
+    }
+  }
+
   public List<OsmNode> getPositions( OsmNodesMap nodesMap )
   {
     ArrayList<OsmNode> positions = new ArrayList<OsmNode>();
diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java b/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java
index aed57f6..759af78 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java
@@ -19,13 +19,16 @@ public final class NodesCache
   private HashMap<String,PhysicalFile> fileCache;
   private byte[] iobuffer;
   
-  private OsmFile[][] fileRows = new OsmFile[180][];
+  private OsmFile[][] fileRows;
   private ArrayList<MicroCache> segmentList = new ArrayList<MicroCache>();
 
   public DistanceChecker distanceChecker;
   
   public boolean oom_carsubset_hint = false;
 
+  private long cacheSum = 0;
+  private boolean garbageCollectionEnabled = false;
+
   public NodesCache( String segmentDir, OsmNodesMap nodesMap, int lookupVersion, boolean carMode, NodesCache oldCache )
   {
     this.segmentDir = segmentDir;
@@ -38,14 +41,55 @@ public final class NodesCache
       fileCache = oldCache.fileCache;
       iobuffer = oldCache.iobuffer;
       oom_carsubset_hint = oldCache.oom_carsubset_hint;
+
+      // re-use old, virgin caches
+      fileRows = oldCache.fileRows;
+      for( OsmFile[] fileRow : fileRows )
+      {
+        if ( fileRow == null ) continue;
+        for( OsmFile osmf : fileRow )
+        {
+          cacheSum += osmf.setGhostState();
+        }
+      }
     }
     else
     {
       fileCache = new HashMap<String,PhysicalFile>(4);
+      fileRows = new OsmFile[180][];
       iobuffer = new byte[65636];
     }
   }
 
+  // if the cache sum exceeded a threshold,
+  // clean all ghosts and enable garbage collection
+  private void checkEnableCacheCleaning()
+  {
+    if ( cacheSum < 200000 || garbageCollectionEnabled ) return;
+
+    for( int i=0; i<fileRows.length; i++ )
+    {
+      OsmFile[] fileRow = fileRows[i];
+      if ( fileRow == null ) continue;
+      int nghosts = 0;
+      for( OsmFile osmf :  fileRow )
+      {
+        if ( osmf.ghost ) nghosts++;
+        else osmf.cleanAll();
+      }
+      if ( nghosts == 0 ) continue;
+      int j=0;
+      OsmFile[] frow = fileRows[fileRows.length-nghosts];
+      for( OsmFile osmf : fileRow )
+      {
+        if ( osmf.ghost ) continue;
+        frow[j++] = osmf;
+      }
+      fileRows[i] = frow;
+    }
+    garbageCollectionEnabled = true;
+  }
+
   public int loadSegmentFor( int ilon, int ilat )
   {
     MicroCache mc = getSegmentFor( ilon, ilat );
@@ -82,6 +126,7 @@ public final class NodesCache
           newFileRow[ndegrees] = osmf;
           fileRows[latDegree] = newFileRow;
         }
+        osmf.ghost = false;
         currentFileName = osmf.filename;
         if ( osmf.microCaches == null )
         {
@@ -93,10 +138,18 @@ public final class NodesCache
         {
           // nodesMap.removeCompleteNodes();
 
+          checkEnableCacheCleaning();
+
           segment = new MicroCache( osmf, lonIdx80, latIdx80, iobuffer );
+          cacheSum += segment.getDataSize();
           osmf.microCaches[subIdx] = segment;
           segmentList.add( segment );
         }
+        else if ( segment.ghost )
+        {
+          segment.unGhost();
+          segmentList.add( segment );
+        }
         return segment;
     }
     catch( RuntimeException re )
@@ -119,7 +172,7 @@ public final class NodesCache
     {
       return false;
     }
-    segment.fillNode( node, nodesMap, distanceChecker );
+    segment.fillNode( node, nodesMap, distanceChecker, garbageCollectionEnabled );
     return !node.isHollow();
   }
 
diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java b/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java
index 0f54b51..0df7ece 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java
@@ -22,6 +22,8 @@ final class OsmFile
 
   public String filename;
 
+  public boolean ghost = false;
+
   public OsmFile( PhysicalFile rafile, int tileIndex, byte[] iobuffer ) throws Exception
   {
     if ( rafile != null )
@@ -76,8 +78,43 @@ final class OsmFile
      return size;
   }
 
-  public void close()
+  // set this OsmFile to ghost-state:
+  long setGhostState()
   {
-    try { is.close(); } catch( IOException e ) { throw new RuntimeException( e ); }
+    long sum = 0;
+    ghost = true;
+    for( int i=0; i< microCaches.length; i++ )
+    {
+      MicroCache mc = microCaches[i];
+      if ( mc == null ) continue;
+      if ( mc.virgin )
+      {
+        mc.ghost = true;
+        sum += mc.getDataSize();
+      }
+      else
+      {
+        microCaches[i] = null;
+      }
+    }
+    return sum;
   }
+
+  void cleanAll()
+  {
+    for( int i=0; i< microCaches.length; i++ )
+    {
+      MicroCache mc = microCaches[i];
+      if ( mc == null ) continue;
+      if ( mc.ghost )
+      {
+        microCaches[i] = null;
+      }
+      else
+      {
+        mc.collect();
+      }
+    }
+  }
+
 }