Oops.

git-svn-id: https://olap4j.svn.sourceforge.net/svnroot/olap4j/trunk@554 c6a108a4-781c-0410-a6c6-c2d559e19af0

src/org/olap4j/impl/Spacer.java

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+/*
+// $Id: UnmodifiableArrayList.java 482 2012-01-05 23:27:27Z jhyde $
+//
+// Licensed to Julian Hyde under one or more contributor license
+// agreements. See the NOTICE file distributed with this work for
+// additional information regarding copyright ownership.
+//
+// Julian Hyde licenses this file to you 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 org.olap4j.impl;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.Arrays;
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * Efficiently writes strings of spaces.
+ */
+public class Spacer {
+ private static final ReentrantLock lock = new ReentrantLock();
+
+ private static char[] spaces = {' '};
+
+ private int n;
+
+ /** Creates a Spacer with zero spaces. */
+ public Spacer() {
+ this(0);
+ }
+
+ /** Creates a Spacer with a given number of spaces. */
+ public Spacer(int n) {
+ this.n = n;
+ }
+
+ /** Sets the current number of spaces. */
+ public Spacer set(int n) {
+ this.n = n;
+ return this;
+ }
+
+ /** Returns the current number of spaces. */
+ public int get() {
+ return n;
+ }
+
+ /** Increases the current number of spaces by {@code n}. */
+ public Spacer add(int n) {
+ this.n += n;
+ return this;
+ }
+
+ /** Reduces the current number of spaces by {@code n}. */
+ public Spacer subtract(int n) {
+ this.n -= n;
+ return this;
+ }
+
+ /** Returns a string of the current number of spaces. */
+ public String toString() {
+ return new String(getSpaces(n), 0, n);
+ }
+
+ /** Appends current number of spaces to a {@link StringBuilder}. */
+ public StringBuilder spaces(StringBuilder buf) {
+ buf.append(getSpaces(n), 0, n);
+ return buf;
+ }
+
+ /** Appends current number of spaces to a {@link Writer}. */
+ public Writer spaces(Writer buf) throws IOException {
+ buf.write(getSpaces(n), 0, n);
+ return buf;
+ }
+
+ /** Appends current number of spaces to a {@link StringWriter}. */
+ public StringWriter spaces(StringWriter buf) {
+ buf.write(getSpaces(n), 0, n);
+ return buf;
+ }
+
+ /** Appends current number of spaces to a {@link PrintWriter}. */
+ public PrintWriter spaces(PrintWriter buf) {
+ buf.write(getSpaces(n), 0, n);
+ return buf;
+ }
+
+ private static char[] getSpaces(int n) {
+ lock.lock();
+ try {
+ if (spaces.length < n) {
+ spaces = new char[n];
+ Arrays.fill(spaces, ' ');
+ }
+ return spaces;
+ } finally {
+ lock.unlock();
+ }
+ }
+}
+
+// End Spacer.java