HDFS-13168. XmlImageVisitor - Prefer Array over LinkedList. Contributed by BELUGA BEHR.

This commit is contained in:
Inigo Goiri 2018-02-20 15:16:01 -08:00
parent 9028ccaf83
commit 17c592e6cf

View File

@ -18,16 +18,17 @@
package org.apache.hadoop.hdfs.tools.offlineImageViewer;
import java.io.IOException;
import java.util.LinkedList;
import java.util.ArrayDeque;
import java.util.Deque;
import org.apache.hadoop.hdfs.util.XMLUtils;
/**
* An XmlImageVisitor walks over an fsimage structure and writes out
* an equivalent XML document that contains the fsimage's components.
*/
public class XmlImageVisitor extends TextWriterImageVisitor {
final private LinkedList<ImageElement> tagQ =
new LinkedList<ImageElement>();
final private Deque<ImageElement> tagQ = new ArrayDeque<>();
public XmlImageVisitor(String filename) throws IOException {
super(filename, false);
@ -51,9 +52,10 @@ void finishAbnormally() throws IOException {
@Override
void leaveEnclosingElement() throws IOException {
if(tagQ.size() == 0)
if (tagQ.isEmpty()) {
throw new IOException("Tried to exit non-existent enclosing element " +
"in FSImage file");
}
ImageElement element = tagQ.pop();
write("</" + element.toString() + ">\n");
@ -71,7 +73,7 @@ void visit(ImageElement element, String value) throws IOException {
@Override
void visitEnclosingElement(ImageElement element) throws IOException {
write("<" + element.toString() + ">\n");
write('<' + element.toString() + ">\n");
tagQ.push(element);
}
@ -79,12 +81,12 @@ void visitEnclosingElement(ImageElement element) throws IOException {
void visitEnclosingElement(ImageElement element,
ImageElement key, String value)
throws IOException {
write("<" + element.toString() + " " + key + "=\"" + value +"\">\n");
write('<' + element.toString() + ' ' + key + "=\"" + value +"\">\n");
tagQ.push(element);
}
private void writeTag(String tag, String value) throws IOException {
write("<" + tag + ">" +
write('<' + tag + '>' +
XMLUtils.mangleXmlString(value, true) + "</" + tag + ">\n");
}
}