Candidate release of source code.

Ghidra/Framework/DB/src/main/java/db/VarKeyNode.java

@@ -0,0 +1,151 @@
+/* ###
+ * IP: GHIDRA
+ * REVIEWED: YES
+ *
+ * Licensed 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 db;
+
+import java.io.IOException;
+
+import db.buffers.DataBuffer;
+
+/**
+ * <code>VarKeyNode</code> is an abstract implementation of a BTree node
+ * which utilizes variable-length Field key values.
+ */
+abstract class VarKeyNode implements BTreeNode {
+
+	private static final int KEY_TYPE_SIZE = 1;
+	private static final int KEY_COUNT_SIZE = 4;
+
+	private static final int KEY_TYPE_OFFSET = NodeMgr.NODE_HEADER_SIZE;
+	private static final int KEY_COUNT_OFFSET = KEY_TYPE_OFFSET + KEY_TYPE_SIZE;
+
+	static final int VARKEY_NODE_HEADER_SIZE = NodeMgr.NODE_HEADER_SIZE + KEY_TYPE_SIZE +
+		KEY_COUNT_SIZE;
+
+	protected final Field keyType;
+	protected final int maxKeyLength;
+
+	protected NodeMgr nodeMgr;
+	protected DataBuffer buffer;
+	protected VarKeyInteriorNode parent;
+	protected int keyCount;
+
+	/**
+	 * Construct an existing variable-length-key node.
+	 * @param nodeMgr table node manager instance
+	 * @param buf node buffer
+	 */
+	VarKeyNode(NodeMgr nodeMgr, DataBuffer buf) {
+		this.nodeMgr = nodeMgr;
+		this.buffer = buf;
+		keyType = Field.getField(buf.getByte(KEY_TYPE_OFFSET));
+		keyCount = buffer.getInt(KEY_COUNT_OFFSET);
+		maxKeyLength = VarKeyInteriorNode.getMaxKeyLength(buffer.length());
+		nodeMgr.addNode(this);
+	}
+
+	/**
+	 * Construct a new variable-length-key node.
+	 * @param nodeMgr table node manager.
+	 * @param nodeType node type
+	 * @param keyType key Field type
+	 * @throws IOException thrown if IO error occurs
+	 */
+	VarKeyNode(NodeMgr nodeMgr, byte nodeType, Field keyType) throws IOException {
+		this.nodeMgr = nodeMgr;
+		this.buffer = nodeMgr.getBufferMgr().createBuffer();
+		NodeMgr.setNodeType(buffer, nodeType);
+		this.keyType = keyType.newField();
+		buffer.putByte(KEY_TYPE_OFFSET, keyType.getFieldType());
+		setKeyCount(0);
+		maxKeyLength = VarKeyInteriorNode.getMaxKeyLength(buffer.length());
+		nodeMgr.addNode(this);
+	}
+
+	/*
+	 * @see ghidra.framework.store.db.BTreeNode#getBufferId()
+	 */
+	@Override
+	public int getBufferId() {
+		return buffer.getId();
+	}
+
+	/*
+	 * @see ghidra.framework.store.db.BTreeNode#getBuffer()
+	 */
+	@Override
+	public DataBuffer getBuffer() {
+		return buffer;
+	}
+
+	/**
+	 * Get the root for this node.  If setParent has not been invoked, this node
+	 * is assumed to be the root.
+	 * @return TableNode
+	 */
+	VarKeyNode getRoot() {
+		if (parent != null)
+			return parent.getRoot();
+		return this;
+	}
+
+	/*
+	 * @see ghidra.framework.store.db.BTreeNode#getKeyCount()
+	 */
+	@Override
+	public int getKeyCount() {
+		return keyCount;
+	}
+
+	/*
+	 * @see ghidra.framework.store.db.BTreeNode#setKeyCount(int)
+	 */
+	@Override
+	public void setKeyCount(int cnt) {
+		keyCount = cnt;
+		buffer.putInt(KEY_COUNT_OFFSET, keyCount);
+	}
+
+	/**
+	 * Get the key value at a specific index.
+	 * @param index key index
+	 * @return key value
+	 * @throws IOException thrown if an IO error occurs
+	 */
+	abstract Field getKey(int index) throws IOException;
+
+	/**
+	 * Get the leaf node which contains the specified key.
+	 * @param key key value
+	 * @return leaf node
+	 * @throws IOException thrown if an IO error occurs
+	 */
+	abstract VarKeyRecordNode getLeafNode(Field key) throws IOException;
+
+	/**
+	 * Get the left-most leaf node within the tree.
+	 * @return left-most leaf node.
+	 * @throws IOException thrown if IO error occurs
+	 */
+	abstract VarKeyRecordNode getLeftmostLeafNode() throws IOException;
+
+	/*
+	 * @see ghidra.framework.store.db.BTreeNode#delete()
+	 */
+	@Override
+	public abstract void delete() throws IOException;
+
+}