[mkgmap-dev] [PATCH 10/14] Switch to using an ArrayList instead of hash table for Tags.

Thu Sep 9 21:12:10 BST 2010

From: Scott Crosby <scrosby at cs.rice.edu>

---
 src/uk/me/parabola/splitter/Element.java   |   57 +++++++++++++---------------
 src/uk/me/parabola/splitter/OSMWriter.java |    4 +-
 2 files changed, 28 insertions(+), 33 deletions(-)

diff --git a/src/uk/me/parabola/splitter/Element.java b/src/uk/me/parabola/splitter/Element.java
index 94a3265..d3f4a57 100644
--- a/src/uk/me/parabola/splitter/Element.java
+++ b/src/uk/me/parabola/splitter/Element.java
@@ -12,18 +12,15 @@
  */
 package uk.me.parabola.splitter;
 
-import java.util.HashMap;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Iterator;
-import java.util.Map;
-import java.util.NoSuchElementException;
 
 /**
  * @author Steve Ratcliffe
  */
 public class Element {
-	private static final Iterator<Map.Entry<String, String>> EMPTY_ITERATOR = new EmptyIterator();
-
-	private Map<String, String> tags;
+	private ArrayList<Tag> tags; 
 	private int id;
 
 	protected void setId(int id) {
@@ -36,43 +33,41 @@ public class Element {
 
 	public void reset() {
 		this.id = 0;
-		tags = null;
+		tags.clear();
 	}
 
+	class Tag {
+		public Tag(String key,String value) {
+			this.key = key;
+			this.value = value;
+		}
+		public String getKey() {
+			return key;
+		}
+		public String getValue() {
+			return value;
+		}
+		final public String key,value;
+	}
+	
 	public void addTag(String key, String value) {
 		if (key.equals("created_by"))
 			return;
 		// Most elements are nodes. Most nodes have no tags. Create the tag table lazily
-		if (tags == null) {
-			tags = new HashMap<String, String>(4);
-		}
-		tags.put(key, value);
+		if (tags == null)
+			tags = new ArrayList<Tag>(4);
+
+		tags.add(new Tag(key, value));
 	}
 
 	public boolean hasTags() {
 		return tags != null;
 	}
 
-	public Iterator<Map.Entry<String, String>> tagsIterator() {
-		if (tags == null) {
-			return EMPTY_ITERATOR;
-		}
-		return tags.entrySet().iterator();
-	}
-
-	private static class EmptyIterator implements Iterator<Map.Entry<String, String>>
-	{
-		public boolean hasNext()
-		{
-			return false;
-		}
+	public Iterator<Tag> tagsIterator() {
+		if (tags == null)
+			return Collections.EMPTY_LIST.iterator();
 
-		public Map.Entry<String, String> next() {
-			throw new NoSuchElementException();
-		}
-
-		public void remove() {
-			throw new UnsupportedOperationException();
-		}
+		return tags.iterator();
 	}
 }
diff --git a/src/uk/me/parabola/splitter/OSMWriter.java b/src/uk/me/parabola/splitter/OSMWriter.java
index 701a639..8cd0740 100644
--- a/src/uk/me/parabola/splitter/OSMWriter.java
+++ b/src/uk/me/parabola/splitter/OSMWriter.java
@@ -145,9 +145,9 @@ public class OSMWriter {
 	}
 
 	private void writeTags(Element element) throws IOException {
-		Iterator<Map.Entry<String, String>> it = element.tagsIterator();
+		Iterator<Element.Tag> it = element.tagsIterator();
 		while (it.hasNext()) {
-			Map.Entry<String, String> entry = it.next();
+			Element.Tag entry = it.next();
 			writeString("<tag k='");
 			writeAttribute(entry.getKey());
 			writeString("' v='");
-- 
1.7.2.3


