Bug 515268 - Shared JDT Index folder among different workspaces.S4_14_0_RC2aS4_14_0_RC2R4_14I20191210-0610I20191204-1800I20191204-0600R4_14_maintenance

- Allow enablement of this feature using jdt.core.sharedIndexLocation
  property
- Index entries not present in the common location will still cause the
  index manager to fall back to creating the index in the normal workspace
  location

Change-Id: I0a2d41a3abf23c64f98c8b3060c281dc71e48509

2 files changed, 87 insertions, 2 deletions

diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/JavaIndexTests.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/JavaIndexTests.java
index f29622ff8b..ddfaa7ac6e 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/JavaIndexTests.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/JavaIndexTests.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2012 IBM Corporation and others.
+ * Copyright (c) 2012, 2019 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -16,6 +16,9 @@ package org.eclipse.jdt.core.tests.model;
 import java.io.File;
 import java.io.IOException;
 import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.zip.CRC32;
 
 import junit.framework.Test;
 
@@ -34,6 +37,7 @@ import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.jdt.core.index.*;
 import org.eclipse.jdt.core.search.SearchEngine;
 import org.eclipse.jdt.core.tests.util.Util;
+import org.eclipse.jdt.internal.core.ClasspathEntry;
 import org.eclipse.jdt.internal.core.JavaModelManager;
 import org.eclipse.jdt.internal.core.UserLibraryClasspathContainer;
 import org.osgi.service.prefs.BackingStoreException;
@@ -50,6 +54,7 @@ public class JavaIndexTests extends AbstractJavaSearchTests  {
 	public static Test suite() {
 		return buildModelTestSuite(JavaIndexTests.class);
 	}
+
 	// Test that the index file is really generated.
 	public void testGenerateIndex() throws IOException {
 		String indexFilePath = getExternalResourcePath("Test.index");
@@ -866,4 +871,56 @@ public class JavaIndexTests extends AbstractJavaSearchTests  {
 			deleteProject("ForIndex");
 		}
 	}
+
+	// Test shared index location functionality
+	public void testSharedIndexLocation() throws CoreException, IOException {
+		// Create temporary testing folder
+		String sharedIndexDir = Files.createTempDirectory("shared_index").toFile().getCanonicalPath();
+		// enable shared index
+		ClasspathEntry.setSharedIndexLocation(sharedIndexDir, getClass());
+		// path of library must be platform neutral
+		String jarFilePath = Path.fromOSString(Paths.get(sharedIndexDir, "Test.jar").toString()).toPortableString();
+		// compute index file
+		CRC32 checksumCalculator = new CRC32();
+		checksumCalculator.update(jarFilePath.getBytes());
+		String fileName = Long.toString(checksumCalculator.getValue()) + ".index";
+		String indexFilePath = Paths.get(sharedIndexDir, fileName).toString();
+		try {
+			createJar(new String[] {
+					"pkg/Test.java",
+					"package pkg;\n" +
+					"public class Test {\n" +
+					"  protected Test(int i) {}\n" +
+					"}"}, jarFilePath);
+
+			JavaIndexer.generateIndexForJar(jarFilePath, indexFilePath);
+			assertTrue(new File(indexFilePath).exists());
+			long modified = new File(indexFilePath).lastModified();
+
+			IJavaProject p = createJavaProject("P");
+			Path libPath = new Path(jarFilePath);
+			IClasspathEntry entry = JavaCore.newLibraryEntry(libPath, null, null, null, null, false);
+			setClasspath(p, new IClasspathEntry[] { entry });
+
+			waitUntilIndexesReady();
+
+			// Test that search works properly
+			search("Test", TYPE, DECLARATIONS, EXACT_RULE,
+					SearchEngine.createJavaSearchScope(new IJavaElement[] { p }));
+			assertSearchResults(Paths.get(sharedIndexDir, "Test.jar").toString() + " pkg.Test");
+
+			// Test that specified index file is really used
+			java.io.File indexFile = JavaModelManager.getIndexManager().getIndex(libPath, false, false).getIndexFile();
+			assertEquals("Specified index file is not being used", indexFilePath, indexFile.toString());
+
+			// Ensure that the index file is not modified
+			assertEquals(modified, new File(indexFilePath).lastModified());
+		} finally {
+			deleteProject("P");
+			new File(indexFilePath).delete();
+			new File(jarFilePath).delete();
+			new File(sharedIndexDir).delete();
+			ClasspathEntry.setSharedIndexLocation(null, getClass());
+		}
+	}
 }
diff --git a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathEntry.java b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathEntry.java
index dc3de3704c..374d128034 100644
--- a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathEntry.java
+++ b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathEntry.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corporation and others.
+ * Copyright (c) 2000, 2019 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -31,6 +31,7 @@ import java.io.OutputStreamWriter;
 import java.io.UnsupportedEncodingException;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -38,6 +39,7 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.zip.CRC32;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
@@ -122,6 +124,9 @@ public class ClasspathEntry implements IClasspathEntry {
 	public static final String TAG_DISCOURAGED = "discouraged"; //$NON-NLS-1$
 	public static final String TAG_IGNORE_IF_BETTER = "ignoreifbetter"; //$NON-NLS-1$
 
+	// common index location for all workspaces
+	private static String SHARED_INDEX_LOCATION = System.getProperty("jdt.core.sharedIndexLocation"); //$NON-NLS-1$
+
 	/**
 	 * Describes the kind of classpath entry - one of
 	 * CPE_PROJECT, CPE_LIBRARY, CPE_SOURCE, CPE_VARIABLE or CPE_CONTAINER
@@ -1757,6 +1762,18 @@ public class ClasspathEntry implements IClasspathEntry {
 	public URL getLibraryIndexLocation() {
 		switch(getEntryKind()) {
 			case IClasspathEntry.CPE_LIBRARY :
+				if (SHARED_INDEX_LOCATION != null) {
+					try {
+						String pathString = getPath().toPortableString();
+						CRC32 checksumCalculator = new CRC32();
+						checksumCalculator.update(pathString.getBytes());
+						String fileName = Long.toString(checksumCalculator.getValue()) + ".index"; //$NON-NLS-1$
+						return new URL("file", null, Paths.get(SHARED_INDEX_LOCATION, fileName).toString()); //$NON-NLS-1$
+					} catch (MalformedURLException e1) {
+						Util.log(e1); // should not happen if protocol known (eg. 'file')
+					}
+				}
+				break;
 			case IClasspathEntry.CPE_VARIABLE :
 				break;
 			default :
@@ -2523,4 +2540,15 @@ public class ClasspathEntry implements IClasspathEntry {
 		}
 		return JavaModelStatus.VERIFIED_OK;
 	}
+
+	/*
+	 * For testing shared index location in JavaIndexTests only
+	 */
+	public static void setSharedIndexLocation(String value, Class<?> clazz) throws IllegalArgumentException{
+		if (clazz != null && "org.eclipse.jdt.core.tests.model.JavaIndexTests".equals(clazz.getName())) { //$NON-NLS-1$
+			SHARED_INDEX_LOCATION = value;
+		} else {
+			throw new IllegalArgumentException("Cannot set index location for specified test class"); //$NON-NLS-1$
+		}
+	}
 }