Fix performance regression in CanonicalTreeParser

Change-Id: I14046559fddb9656d890d3099010117e84cd9439

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/CanonicalTreeParser.java b/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/CanonicalTreeParser.java
index df31558ff9915351e8804b3568b50176e92f9a10..c24efe20aadb27ff4f4980442bc62ba864a5e5f8 100644 (file)
--- a/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/CanonicalTreeParser.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/CanonicalTreeParser.java
@@ -64,11 +64,11 @@ import org.eclipse.jgit.util.RawParseUtils;
 
 /** Parses raw Git trees from the canonical semi-text/semi-binary format. */
 public class CanonicalTreeParser extends AbstractTreeIterator {
-       private static final int ATTRIBUTESLENGTH = Constants.DOT_GIT_ATTRIBUTES
-                       .getBytes().length;
-
        private static final byte[] EMPTY = {};
 
+       private static final byte[] ATTRS = Constants
+                       .encode(Constants.DOT_GIT_ATTRIBUTES);
+
        private byte[] raw;
 
        /** First offset within {@link #raw} of the prior entry. */
@@ -375,11 +375,9 @@ public class CanonicalTreeParser extends AbstractTreeIterator {
                nextPtr = ptr + Constants.OBJECT_ID_LENGTH;
 
                // Check if this entry is a .gitattributes file
-               if (RawParseUtils.match(path, pathOffset,
-                               Constants.DOT_GIT_ATTRIBUTES.getBytes()) == ATTRIBUTESLENGTH)
-                       attributesNode = new LazyLoadingAttributesNode(
-                                       ObjectId.fromRaw(idBuffer(), idOffset()));
-
+               if (path[pathOffset] == '.'
+                               && RawParseUtils.match(path, pathOffset, ATTRS) > 0)
+                       attributesNode = new LazyLoadingAttributesNode(idOffset());
        }
 
        /**
@@ -402,18 +400,18 @@ public class CanonicalTreeParser extends AbstractTreeIterator {
        /**
         * {@link AttributesNode} implementation that provides lazy loading
         */
-       private static class LazyLoadingAttributesNode extends AttributesNode {
-               final ObjectId objectId;
+       private class LazyLoadingAttributesNode extends AttributesNode {
+               private final int idOffset;
 
-               LazyLoadingAttributesNode(ObjectId objectId) {
+               LazyLoadingAttributesNode(int idOffset) {
                        super(Collections.<AttributesRule> emptyList());
-                       this.objectId = objectId;
-
+                       this.idOffset = idOffset;
                }
 
                AttributesNode load(ObjectReader reader) throws IOException {
                        AttributesNode r = new AttributesNode();
-                       ObjectLoader loader = reader.open(objectId);
+                       ObjectId id = ObjectId.fromRaw(raw, idOffset);
+                       ObjectLoader loader = reader.open(id);
                        if (loader != null) {
                                InputStream in = loader.openStream();
                                try {
@@ -425,5 +423,4 @@ public class CanonicalTreeParser extends AbstractTreeIterator {
                        return r.getRules().isEmpty() ? null : r;
                }
        }
-
 }