Author: chirino
Date: Fri Sep 12 11:23:29 2008
New Revision: 694765
URL: http://svn.apache.org/viewvc?rev=694765&view=rev
Log:
Exposing a getLast() and getFirst() method on the index.
Modified:
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java
Modified:
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java
URL:
http://svn.apache.org/viewvc/activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java?rev=694765&r1=694764&r2=694765&view=diff
==============================================================================
---
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java
(original)
+++
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeIndex.java
Fri Sep 12 11:23:29 2008
@@ -223,10 +223,14 @@
getRoot(tx).visit(tx, visitor);
}
- synchronized Value getFirst(Transaction tx) throws IOException {
+ synchronized public Map.Entry<Key,Value> getFirst(Transaction tx) throws
IOException {
return getRoot(tx).getFirst(tx);
}
+ synchronized public Map.Entry<Key,Value> getLast(Transaction tx) throws
IOException {
+ return getRoot(tx).getLast(tx);
+ }
+
///////////////////////////////////////////////////////////////////
// Internal implementation methods
///////////////////////////////////////////////////////////////////
Modified:
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java
URL:
http://svn.apache.org/viewvc/activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java?rev=694765&r1=694764&r2=694765&view=diff
==============================================================================
---
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java
(original)
+++
activemq/sandbox/kahadb/src/main/java/org/apache/kahadb/index/BTreeNode.java
Fri Sep 12 11:23:29 2008
@@ -55,7 +55,31 @@
// The next leaf node after this one. Used for fast iteration of the
entries.
private long next = -1;
+ private final class KeyValueEntry implements Map.Entry<Key, Value> {
+ private final Key key;
+ private final Value value;
+
+ public KeyValueEntry(Key key, Value value) {
+ this.key = key;
+ this.value = value;
+ }
+
+ public Key getKey() {
+ return key;
+ }
+
+ public Value getValue() {
+ return value;
+ }
+
+ public Value setValue(Value value) {
+ throw new UnsupportedOperationException();
+ }
+
+ }
+
private final class BTreeIterator implements Iterator<Map.Entry<Key,
Value>> {
+
private final Transaction tx;
BTreeNode<Key,Value> current;
int nextIndex;
@@ -83,20 +107,7 @@
break;
}
} else {
- nextEntry = new Map.Entry<Key, Value>() {
- private final Key key = current.keys[nextIndex];
- private final Value value =
current.values[nextIndex];
-
- public Key getKey() {
- return key;
- }
- public Value getValue() {
- return value;
- }
- public Value setValue(Value value) {
- throw new UnsupportedOperationException();
- }
- };
+ nextEntry = new KeyValueEntry(current.keys[nextIndex],
current.values[nextIndex]);
nextIndex++;
break;
}
@@ -524,13 +535,26 @@
}
}
- public Value getFirst(Transaction tx) throws IOException {
+ public Map.Entry<Key,Value> getFirst(Transaction tx) throws IOException {
BTreeNode<Key, Value> node = this;
while( node .isBranch() ) {
node = node.getChild(tx, 0);
}
if( node.values.length>0 ) {
- return node.values[0];
+ return new KeyValueEntry(keys[0], values[0]);
+ } else {
+ return null;
+ }
+ }
+
+ public Map.Entry<Key,Value> getLast(Transaction tx) throws IOException {
+ BTreeNode<Key, Value> node = this;
+ while( node.isBranch() ) {
+ node = node.getChild(tx, children.length-1);
+ }
+ if( node.values.length>0 ) {
+ int idx = values.length-1;
+ return new KeyValueEntry(keys[idx], values[idx]);
} else {
return null;
}
