Index: dart/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/file/ElementCodec.java |
=================================================================== |
--- dart/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/file/ElementCodec.java (revision 0) |
+++ dart/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/file/ElementCodec.java (revision 0) |
@@ -0,0 +1,130 @@ |
+/* |
+ * Copyright (c) 2014, the Dart project authors. |
+ * |
+ * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html |
+ * |
+ * 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 com.google.dart.engine.internal.index.file; |
+ |
+import com.google.common.collect.Lists; |
+import com.google.dart.engine.context.AnalysisContext; |
+import com.google.dart.engine.element.Element; |
+import com.google.dart.engine.element.ElementLocation; |
+import com.google.dart.engine.internal.element.ElementLocationImpl; |
+ |
+import org.apache.commons.lang3.ArrayUtils; |
+ |
+import java.util.List; |
+ |
+/** |
+ * A helper that encodes/decodes {@link Element}s to/from integers. |
+ * |
+ * @coverage dart.engine.index |
+ */ |
+public class ElementCodec { |
+ private final StringCodec stringCodec; |
+ |
+ /** |
+ * A table mapping element locations (in form of integer arrays) into a single integer. |
+ */ |
+ private final IntArrayToIntMap pathToIndex = new IntArrayToIntMap(10000, 0.75f); |
+ |
+ /** |
+ * A list that works as a mapping of integers to element encodings (in form of integer arrays). |
+ */ |
+ private final List<int[]> indexToPath = Lists.newArrayList(); |
+ |
+ public ElementCodec(StringCodec stringCodec) { |
+ this.stringCodec = stringCodec; |
+ } |
+ |
+ /** |
+ * Returns an {@link Element} that corresponds to the given location. |
+ * |
+ * @param context the {@link AnalysisContext} to find {@link Element} in |
+ * @param index an integer corresponding to the {@link Element} |
+ * @return the {@link Element} or {@code null} |
+ */ |
+ public Element decode(AnalysisContext context, int index) { |
+ int[] path = indexToPath.get(index); |
+ String[] components = getLocationComponents(path); |
+ ElementLocation location = new ElementLocationImpl(components); |
+ return context.getElement(location); |
+ } |
+ |
+ /** |
+ * Returns a unique integer that corresponds to the given {@link Element}. |
+ */ |
+ public int encode(Element element) { |
+ int[] path = getLocationPath(element); |
+ int index = pathToIndex.get(path, -1); |
+ if (index == -1) { |
+ index = indexToPath.size(); |
+ pathToIndex.put(path, index); |
+ indexToPath.add(path); |
+ } |
+ return index; |
+ } |
+ |
+ private String[] getLocationComponents(int[] path) { |
+ int length = path.length; |
+ String[] components = new String[length]; |
+ int componentCount = 0; |
+ for (int i = 0; i < length; i++) { |
+ int componentId = path[i]; |
+ String component = stringCodec.decode(componentId); |
+ if (i < length - 1 && path[i + 1] < 0) { |
+ component += "@" + (-path[i + 1]); |
+ i++; |
+ } |
+ components[componentCount++] = component; |
+ } |
+ components = ArrayUtils.subarray(components, 0, componentCount); |
+ return components; |
+ } |
+ |
+ private int[] getLocationPath(Element element) { |
+ String[] components = element.getLocation().getComponents(); |
+ int length = components.length; |
+ if (hasLocalOffset(components)) { |
+ int[] path = new int[2 * length]; |
+ int pathLength = 0; |
+ for (String component : components) { |
+ int atOffset = component.indexOf('@'); |
+ if (atOffset == -1) { |
+ path[pathLength++] = stringCodec.encode(component); |
+ } else { |
+ String preAtString = component.substring(0, atOffset); |
+ String atString = component.substring(atOffset + 1); |
+ path[pathLength++] = stringCodec.encode(preAtString); |
+ path[pathLength++] = -1 * Integer.parseInt(atString); |
+ } |
+ } |
+ path = ArrayUtils.subarray(path, 0, pathLength); |
+ return path; |
+ } else { |
+ int[] path = new int[length]; |
+ for (int i = 0; i < length; i++) { |
+ String component = components[i]; |
+ path[i] = stringCodec.encode(component); |
+ } |
+ return path; |
+ } |
+ } |
+ |
+ private boolean hasLocalOffset(String[] components) { |
+ for (String component : components) { |
+ if (component.indexOf('@') != -1) { |
+ return true; |
+ } |
+ } |
+ return false; |
+ } |
+} |
Property changes on: dart/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/file/ElementCodec.java |
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Added: svn:eol-style |
+ LF |