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 SimpleLookupTable implements Cloneable {
-// to avoid using Enumerations, walk the individual tables skipping nulls
-public Object[] keyTable;
-public Object[] valueTable;
-public int elementSize; // number of elements in the table
-public int threshold;
+ // to avoid using Enumerations, walk the individual tables skipping nulls
+ public Object[] keyTable;
-public SimpleLookupTable() {
- this(13);
-}
+ public Object[] valueTable;
-public SimpleLookupTable(int size) {
- if (size < 3) size = 3;
- this.elementSize = 0;
- this.threshold = size + 1; // size is the expected number of elements
- int tableLength = 2 * size + 1;
- this.keyTable = new Object[tableLength];
- this.valueTable = new Object[tableLength];
-}
+ public int elementSize; // number of elements in the table
-public Object clone() throws CloneNotSupportedException {
- SimpleLookupTable result = (SimpleLookupTable) super.clone();
- result.elementSize = this.elementSize;
- result.threshold = this.threshold;
+ public int threshold;
- int length = this.keyTable.length;
- result.keyTable = new Object[length];
- System.arraycopy(this.keyTable, 0, result.keyTable, 0, length);
+ public SimpleLookupTable() {
+ this(13);
+ }
- length = this.valueTable.length;
- result.valueTable = new Object[length];
- System.arraycopy(this.valueTable, 0, result.valueTable, 0, length);
- return result;
-}
+ public SimpleLookupTable(int size) {
+ if (size < 3)
+ size = 3;
+ this.elementSize = 0;
+ this.threshold = size + 1; // size is the expected number of elements
+ int tableLength = 2 * size + 1;
+ this.keyTable = new Object[tableLength];
+ this.valueTable = new Object[tableLength];
+ }
+
+ public Object clone() throws CloneNotSupportedException {
+ SimpleLookupTable result = (SimpleLookupTable) super.clone();
+ result.elementSize = this.elementSize;
+ result.threshold = this.threshold;
+
+ int length = this.keyTable.length;
+ result.keyTable = new Object[length];
+ System.arraycopy(this.keyTable, 0, result.keyTable, 0, length);
-public boolean containsKey(Object key) {
- int length = keyTable.length;
- int index = (key.hashCode() & 0x7FFFFFFF) % length;
- Object currentKey;
- while ((currentKey = keyTable[index]) != null) {
- if (currentKey.equals(key)) return true;
- if (++index == length) index = 0;
+ length = this.valueTable.length;
+ result.valueTable = new Object[length];
+ System.arraycopy(this.valueTable, 0, result.valueTable, 0, length);
+ return result;
}
- return false;
-}
-public Object get(Object key) {
- int length = keyTable.length;
- int index = (key.hashCode() & 0x7FFFFFFF) % length;
- Object currentKey;
- while ((currentKey = keyTable[index]) != null) {
- if (currentKey.equals(key)) return valueTable[index];
- if (++index == length) index = 0;
+ public boolean containsKey(Object key) {
+ int length = keyTable.length;
+ int index = (key.hashCode() & 0x7FFFFFFF) % length;
+ Object currentKey;
+ while ((currentKey = keyTable[index]) != null) {
+ if (currentKey.equals(key))
+ return true;
+ if (++index == length)
+ index = 0;
+ }
+ return false;
}
- return null;
-}
-public Object keyForValue(Object valueToMatch) {
- if (valueToMatch != null)
- for (int i = 0, l = valueTable.length; i < l; i++)
- if (valueToMatch.equals(valueTable[i]))
- return keyTable[i];
- return null;
-}
+ public Object get(Object key) {
+ int length = keyTable.length;
+ int index = (key.hashCode() & 0x7FFFFFFF) % length;
+ Object currentKey;
+ while ((currentKey = keyTable[index]) != null) {
+ if (currentKey.equals(key))
+ return valueTable[index];
+ if (++index == length)
+ index = 0;
+ }
+ return null;
+ }
-public Object put(Object key, Object value) {
- int length = keyTable.length;
- int index = (key.hashCode() & 0x7FFFFFFF) % length;
- Object currentKey;
- while ((currentKey = keyTable[index]) != null) {
- if (currentKey.equals(key)) return valueTable[index] = value;
- if (++index == length) index = 0;
+ public Object keyForValue(Object valueToMatch) {
+ if (valueToMatch != null)
+ for (int i = 0, l = valueTable.length; i < l; i++)
+ if (valueToMatch.equals(valueTable[i]))
+ return keyTable[i];
+ return null;
}
- keyTable[index] = key;
- valueTable[index] = value;
- // assumes the threshold is never equal to the size of the table
- if (++elementSize > threshold) rehash();
- return value;
-}
+ public Object put(Object key, Object value) {
+ int length = keyTable.length;
+ int index = (key.hashCode() & 0x7FFFFFFF) % length;
+ Object currentKey;
+ while ((currentKey = keyTable[index]) != null) {
+ if (currentKey.equals(key))
+ return valueTable[index] = value;
+ if (++index == length)
+ index = 0;
+ }
+ keyTable[index] = key;
+ valueTable[index] = value;
-public Object removeKey(Object key) {
- int length = keyTable.length;
- int index = (key.hashCode() & 0x7FFFFFFF) % length;
- Object currentKey;
- while ((currentKey = keyTable[index]) != null) {
- if (currentKey.equals(key)) {
- elementSize--;
- Object oldValue = valueTable[index];
- keyTable[index] = null;
- valueTable[index] = null;
- if (keyTable[index + 1 == length ? 0 : index + 1] != null)
- rehash(); // only needed if a possible collision existed
- return oldValue;
+ // assumes the threshold is never equal to the size of the table
+ if (++elementSize > threshold)
+ rehash();
+ return value;
+ }
+
+ public Object removeKey(Object key) {
+ int length = keyTable.length;
+ int index = (key.hashCode() & 0x7FFFFFFF) % length;
+ Object currentKey;
+ while ((currentKey = keyTable[index]) != null) {
+ if (currentKey.equals(key)) {
+ elementSize--;
+ Object oldValue = valueTable[index];
+ keyTable[index] = null;
+ valueTable[index] = null;
+ if (keyTable[index + 1 == length ? 0 : index + 1] != null)
+ rehash(); // only needed if a possible collision existed
+ return oldValue;
+ }
+ if (++index == length)
+ index = 0;
}
- if (++index == length) index = 0;
+ return null;
}
- return null;
-}
-public void removeValue(Object valueToRemove) {
- boolean rehash = false;
- for (int i = 0, l = valueTable.length; i < l; i++) {
- Object value = valueTable[i];
- if (value != null && value.equals(valueToRemove)) {
- elementSize--;
- keyTable[i] = null;
- valueTable[i] = null;
- if (!rehash && keyTable[i + 1 == l ? 0 : i + 1] != null)
- rehash = true; // only needed if a possible collision existed
+ public void removeValue(Object valueToRemove) {
+ boolean rehash = false;
+ for (int i = 0, l = valueTable.length; i < l; i++) {
+ Object value = valueTable[i];
+ if (value != null && value.equals(valueToRemove)) {
+ elementSize--;
+ keyTable[i] = null;
+ valueTable[i] = null;
+ if (!rehash && keyTable[i + 1 == l ? 0 : i + 1] != null)
+ rehash = true; // only needed if a possible collision
+ // existed
+ }
}
+ if (rehash)
+ rehash();
}
- if (rehash) rehash();
-}
-private void rehash() {
- SimpleLookupTable newLookupTable = new SimpleLookupTable(elementSize * 2); // double the number of expected elements
- Object currentKey;
- for (int i = keyTable.length; --i >= 0;)
- if ((currentKey = keyTable[i]) != null)
- newLookupTable.put(currentKey, valueTable[i]);
-
- this.keyTable = newLookupTable.keyTable;
- this.valueTable = newLookupTable.valueTable;
- this.elementSize = newLookupTable.elementSize;
- this.threshold = newLookupTable.threshold;
-}
+ private void rehash() {
+ SimpleLookupTable newLookupTable = new SimpleLookupTable(
+ elementSize * 2); // double the number of expected elements
+ Object currentKey;
+ for (int i = keyTable.length; --i >= 0;)
+ if ((currentKey = keyTable[i]) != null)
+ newLookupTable.put(currentKey, valueTable[i]);
+
+ this.keyTable = newLookupTable.keyTable;
+ this.valueTable = newLookupTable.valueTable;
+ this.elementSize = newLookupTable.elementSize;
+ this.threshold = newLookupTable.threshold;
+ }
-public String toString() {
- String s = ""; //$NON-NLS-1$
- Object object;
- for (int i = 0, l = valueTable.length; i < l; i++)
- if ((object = valueTable[i]) != null)
- s += keyTable[i].toString() + " -> " + object.toString() + "\n"; //$NON-NLS-2$ //$NON-NLS-1$
- return s;
-}
+ public String toString() {
+ String s = ""; //$NON-NLS-1$
+ Object object;
+ for (int i = 0, l = valueTable.length; i < l; i++)
+ if ((object = valueTable[i]) != null)
+ s += keyTable[i].toString() + " -> " + object.toString() + "\n"; //$NON-NLS-2$ //$NON-NLS-1$
+ return s;
+ }
}
git://git.phpeclipse.com / phpeclipse.git / blobdiff