experimental removal of synchronization. This should work for all cases

where the size() and isEmpty() method is used only for statistics, which
happens at many locations in YaCy. If these methods are used for
structual reasons (like accessing the last element in an array) then it
may fail or cause other problems. As far as visible, this is not the
case.

source/net/yacy/kelondro/blob/Heap.java

@@ -113,7 +113,7 @@ public final class Heap extends HeapModifier implements BLOB {
      * @return the number of BLOBs in the heap
      */
     @Override
-    public synchronized int size() {
+    public int size() {
         return super.size() + ((this.buffer == null) ? 0 : this.buffer.size());
     }
 

source/net/yacy/kelondro/index/RAMIndex.java

@@ -325,7 +325,7 @@ public final class RAMIndex implements Index, Iterable<Row.Entry> {
     }
 
     @Override
-    public final synchronized int size() {
+    public final int size() {
         if (this.index0 != null && this.index1 == null) {
             return this.index0.size();
         }
@@ -337,7 +337,7 @@ public final class RAMIndex implements Index, Iterable<Row.Entry> {
     }
 
     @Override
-    public final synchronized boolean isEmpty() {
+    public final boolean isEmpty() {
         if (this.index0 != null && this.index1 == null) {
             return this.index0.isEmpty();
         }

source/net/yacy/kelondro/index/RAMIndexCluster.java

@@ -337,26 +337,20 @@ public final class RAMIndexCluster implements Index, Iterable<Row.Entry>, Clonea
     @Override
     public final int size() {
         int c = 0;
-        synchronized (this.cluster) {
-            for (final RAMIndex i: this.cluster) if (i != null) c += i.size();
-        }
+        for (final RAMIndex i: this.cluster) if (i != null) c += i.size();
         return c;
     }
 
     @Override
     public long mem() {
         long m = 0;
-        synchronized (this.cluster) {
-            for (final RAMIndex i: this.cluster) if (i != null)  m += i.mem();
-        }
+        for (final RAMIndex i: this.cluster) if (i != null)  m += i.mem();
         return m;
     }
 
     @Override
     public final boolean isEmpty() {
-        synchronized (this.cluster) {
-            for (final RAMIndex i: this.cluster) if (i != null && !i.isEmpty()) return false;
-        }
+        for (final RAMIndex i: this.cluster) if (i != null && !i.isEmpty()) return false;
         return true;
     }