On 16/01/2010, bay...@apache.org <bay...@apache.org> wrote: > Author: bayard > Date: Sat Jan 16 07:58:11 2010 > New Revision: 899895 > > URL: http://svn.apache.org/viewvc?rev=899895&view=rev > Log: > Adding String lazy caching > > Modified: > > commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/Range.java > > Modified: > commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/Range.java > URL: > http://svn.apache.org/viewvc/commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/Range.java?rev=899895&r1=899894&r2=899895&view=diff > > ============================================================================== > --- > commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/Range.java > (original) > +++ > commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/Range.java > Sat Jan 16 07:58:11 2010 > @@ -28,13 +28,33 @@ > */ > public final class Range<T> implements Serializable { > > + /** > + * Required for serialization support. > + * > + * @see java.io.Serializable > + */ > private static final long serialVersionUID = 1L; > > + /** > + * The ordering scheme used in this range. > + */ > private final Comparator<T> comparator; > + > + /** > + * The minimum value in this range (inclusive). > + */ > private final T minimum; > + /** > + * The maximum value in this range (inclusive). > + */ > private final T maximum; > > /** > + * Cached output toString (class is immutable). > + */ > + private transient String toString = null; > + > + /** > * <p>Constructs a new <code>Range</code> using the specified > * element as both the minimum and maximum in this range.</p> > * <p>The range uses the natural ordering of the elements to > @@ -320,16 +340,18 @@ > */ > @Override > public String toString() { > - StringBuilder buf = new StringBuilder(32); > - buf.append("Range["); > - buf.append(this.minimum); > - buf.append(','); > - buf.append(this.maximum); > - buf.append(']'); > - return buf.toString(); > + if (toString == null) { > + StringBuilder buf = new StringBuilder(32); > + buf.append("Range["); > + buf.append(this.minimum); > + buf.append(','); > + buf.append(this.maximum); > + buf.append(']'); > + toString = buf.toString(); > + } > + return toString;
There's some doubt as to whether fetching the toString class variable twice is thread-safe. See long thread in Harmony [1] and [2] [1] http://harmony.markmail.org/message/ud3c6ngyfjeymdga?q=data+reordering+hashCode [2] http://jeremymanson.blogspot.com/2008/12/benign-data-races-in-java.html Also HARMONY-6404. It would be safer to use a temp. local String and return that. > } > > - > // Taken from Commons Collections - documentation removed as not a > public class > private static class ComparableComparator<E extends Comparable<? super > E>> implements Comparator<E>, Serializable { > > > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
