diff --git a/platform/vcs-api/src/com/intellij/openapi/vcs/Ring.java b/platform/vcs-api/src/com/intellij/openapi/vcs/Ring.java
deleted file mode 100644
index 9ef9cbb044b0..000000000000
--- a/platform/vcs-api/src/com/intellij/openapi/vcs/Ring.java
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Copyright 2000-2010 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.intellij.openapi.vcs;
-
-import com.intellij.openapi.util.text.StringUtil;
-import com.intellij.util.Function;
-
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-
-/**
- * @author irengrig
- */
-public abstract class Ring<T extends Comparable<T>> {
-  protected final LinkedList<T> myFreeNumbers;
-  protected final T myFirst;
-  protected T myNextAvailable;
-
-  public Ring(final T first) {
-    myFreeNumbers = new LinkedList<>();
-    myNextAvailable = first;
-    myFirst = first;
-  }
-
-  public Ring(final T first, final List<T> used) {
-    this(first);
-    for (T t : used) {
-      minus(t);
-    }
-  }
-
-  public void reset() {
-    myFreeNumbers.clear();
-    myNextAvailable = myFirst;
-  }
-
-  public void back(final T number) {
-    final int idx = Collections.binarySearch(myFreeNumbers, number);
-    // todo remove
-    if (idx >= 0) {
-      System.out.println("* " + number);
-    }
-    assert idx < 0 || idx >= myFreeNumbers.size();
-    myFreeNumbers.add(- idx - 1, number);
-  }
-  
-  // todo debug
-  public boolean haveInFree(final T t) {
-    return myFreeNumbers.contains(t);
-  }
-
-  public boolean minus(final T t) {
-    while (myNextAvailable.compareTo(t) <= 0) {
-      myFreeNumbers.add(myNextAvailable);
-      myNextAvailable = getNext(myNextAvailable);
-    }
-    return myFreeNumbers.remove(t);
-  }
-
-  public List<T> getUsed() {
-    final List<T> result = new LinkedList<>();
-
-    T current = myFirst;
-    final Iterator<T> iterator = myFreeNumbers.iterator();
-    T currentUsed = iterator.hasNext() ? iterator.next() : null;
-    while (current.compareTo(myNextAvailable) < 0) {
-      final int compResult = (currentUsed == null) ? -1 : current.compareTo(currentUsed);
-      if (compResult < 0) {
-        result.add(current);
-      } else if (compResult == 0) {
-        if (iterator.hasNext()) {
-          currentUsed = iterator.next();
-        } else {
-          currentUsed = null;
-        }
-      }
-      current = getNext(current);
-    }
-    return result;
-  }
-
-  public T getMaxNumber() {
-    return myNextAvailable;
-  }
-
-  protected abstract T getNext(final T t);
-
-  public T getFree() {
-    if (myFreeNumbers.isEmpty()) {
-      final T tmp = myNextAvailable;
-      myNextAvailable = getNext(myNextAvailable);
-      return tmp;
-    }
-    return myFreeNumbers.removeFirst();
-  }
-  
-  public static class IntegerRing extends Ring<Integer> {
-    public IntegerRing() {
-      super(0);
-    }
-
-    public IntegerRing(final List<Integer> used) {
-      super(0, used);
-    }
-
-    @Override
-    protected Integer getNext(Integer integer) {
-      return integer + 1;
-    }
-
-    public int size() {
-      return myNextAvailable - myFreeNumbers.size();
-    }
-
-    public boolean isNumUsed(final int num) {
-      return (num < myNextAvailable) && (! myFreeNumbers.contains(num));
-    }
-  }
-
-  @Override
-  public String toString() {
-    return "Ring{" +
-           "myFreeNumbers=" + StringUtil.join(myFreeNumbers, new Function<T, String>() {
-      @Override
-      public String fun(T t) {
-        return t.toString();
-      }
-    }, ",") +
-           ", myFirst=" + myFirst +
-           ", myNextAvailable=" + myNextAvailable +
-           '}';
-  }
-}