package net.sourceforge.phpdt.internal.core.util;
/**
- * A simple lookup table is a non-synchronized Hashtable, whose keys
- * and values are Objects. It also uses linear probing to resolve collisions
- * rather than a linked list of hash table entries.
+ * A simple lookup table is a non-synchronized Hashtable, whose keys and values
+ * are Objects. It also uses linear probing to resolve collisions rather than a
+ * linked list of hash table entries.
*/
public final class SimpleSet implements Cloneable {
-// to avoid using Enumerations, walk the individual values skipping nulls
-public Object[] values;
-public int elementSize; // number of elements in the table
-public int threshold;
+ // to avoid using Enumerations, walk the individual values skipping nulls
+ public Object[] values;
-public SimpleSet() {
- this(13);
-}
+ public int elementSize; // number of elements in the table
-public SimpleSet(int size) {
- if (size < 3) size = 3;
- this.elementSize = 0;
- this.threshold = size + 1; // size is the expected number of elements
- this.values = new Object[2 * size + 1];
-}
+ public int threshold;
-public Object add(Object object) {
- int length = values.length;
- int index = (object.hashCode() & 0x7FFFFFFF) % length;
- Object current;
- while ((current = values[index]) != null) {
- if (current.equals(object)) return values[index] = object;
- if (++index == length) index = 0;
+ public SimpleSet() {
+ this(13);
}
- values[index] = object;
- // assumes the threshold is never equal to the size of the table
- if (++elementSize > threshold) rehash();
- return object;
-}
+ public SimpleSet(int size) {
+ if (size < 3)
+ size = 3;
+ this.elementSize = 0;
+ this.threshold = size + 1; // size is the expected number of elements
+ this.values = new Object[2 * size + 1];
+ }
-public Object clone() throws CloneNotSupportedException {
- SimpleSet result = (SimpleSet) super.clone();
- result.elementSize = this.elementSize;
- result.threshold = this.threshold;
+ public Object add(Object object) {
+ int length = values.length;
+ int index = (object.hashCode() & 0x7FFFFFFF) % length;
+ Object current;
+ while ((current = values[index]) != null) {
+ if (current.equals(object))
+ return values[index] = object;
+ if (++index == length)
+ index = 0;
+ }
+ values[index] = object;
- int length = this.values.length;
- result.values = new Object[length];
- System.arraycopy(this.values, 0, result.values, 0, length);
- return result;
-}
+ // assumes the threshold is never equal to the size of the table
+ if (++elementSize > threshold)
+ rehash();
+ return object;
+ }
-public boolean includes(Object object) {
- int length = values.length;
- int index = (object.hashCode() & 0x7FFFFFFF) % length;
- Object current;
- while ((current = values[index]) != null) {
- if (current.equals(object)) return true;
- if (++index == length) index = 0;
+ public Object clone() throws CloneNotSupportedException {
+ SimpleSet result = (SimpleSet) super.clone();
+ result.elementSize = this.elementSize;
+ result.threshold = this.threshold;
+
+ int length = this.values.length;
+ result.values = new Object[length];
+ System.arraycopy(this.values, 0, result.values, 0, length);
+ return result;
}
- return false;
-}
-public Object remove(Object object) {
- int length = values.length;
- int index = (object.hashCode() & 0x7FFFFFFF) % length;
- Object current;
- while ((current = values[index]) != null) {
- if (current.equals(object)) {
- elementSize--;
- Object oldValue = values[index];
- values[index] = null;
- if (values[index + 1 == length ? 0 : index + 1] != null)
- rehash(); // only needed if a possible collision existed
- return oldValue;
+ public boolean includes(Object object) {
+ int length = values.length;
+ int index = (object.hashCode() & 0x7FFFFFFF) % length;
+ Object current;
+ while ((current = values[index]) != null) {
+ if (current.equals(object))
+ return true;
+ if (++index == length)
+ index = 0;
}
- if (++index == length) index = 0;
+ return false;
}
- return null;
-}
-private void rehash() {
- SimpleSet newSet = new SimpleSet(elementSize * 2); // double the number of expected elements
- Object current;
- for (int i = values.length; --i >= 0;)
- if ((current = values[i]) != null)
- newSet.add(current);
+ public Object remove(Object object) {
+ int length = values.length;
+ int index = (object.hashCode() & 0x7FFFFFFF) % length;
+ Object current;
+ while ((current = values[index]) != null) {
+ if (current.equals(object)) {
+ elementSize--;
+ Object oldValue = values[index];
+ values[index] = null;
+ if (values[index + 1 == length ? 0 : index + 1] != null)
+ rehash(); // only needed if a possible collision existed
+ return oldValue;
+ }
+ if (++index == length)
+ index = 0;
+ }
+ return null;
+ }
- this.values = newSet.values;
- this.elementSize = newSet.elementSize;
- this.threshold = newSet.threshold;
-}
+ private void rehash() {
+ SimpleSet newSet = new SimpleSet(elementSize * 2); // double the number
+ // of expected
+ // elements
+ Object current;
+ for (int i = values.length; --i >= 0;)
+ if ((current = values[i]) != null)
+ newSet.add(current);
-public String toString() {
- String s = ""; //$NON-NLS-1$
- Object object;
- for (int i = 0, l = values.length; i < l; i++)
- if ((object = values[i]) != null)
- s += object.toString() + "\n"; //$NON-NLS-1$
- return s;
-}
+ this.values = newSet.values;
+ this.elementSize = newSet.elementSize;
+ this.threshold = newSet.threshold;
+ }
+
+ public String toString() {
+ String s = ""; //$NON-NLS-1$
+ Object object;
+ for (int i = 0, l = values.length; i < l; i++)
+ if ((object = values[i]) != null)
+ s += object.toString() + "\n"; //$NON-NLS-1$
+ return s;
+ }
}