[resolver] Added a URI resolver interface

Sometimes the standard template or default URL calculation is not sufficient. When a URI resolver is set, it takes over and it can calculate any URI based on the file under consideration.

Signed-off-by: Peter Kriens <peter.kriens@aqute.biz>

org.osgi.impl.bundle.repoindex.lib/src/org/osgi/service/indexer/impl/BundleAnalyzer.java

@@ -3,6 +3,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URI;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
@@ -189,6 +190,26 @@ private String calculateLocation(Resource resource) throws IOException {
 
 		GeneratorState state = getStateLocal();
 		if (state != null) {
+
+			//
+			// Check if a resolver was specified
+			// If so, we give that preference over the automatic
+			// and template calculation
+			//
+
+			URLResolver resolver = state.getResolver();
+			if (resolver != null) {
+				try {
+					URI uri = resolver.resolver(path);
+					if (uri != null)
+						return uri.toString();
+				}
+				catch (Exception e) {
+					if (log != null)
+						log.log(LogService.LOG_ERROR, "Resolver failed on " + path + ", falling back to old method");
+				}
+			}
+
 			String rootUrl = state.getRootUrl().toString();
 			if (!rootUrl.endsWith("/"))
 				rootUrl += "/";

org.osgi.impl.bundle.repoindex.lib/src/org/osgi/service/indexer/impl/GeneratorState.java

@@ -6,10 +6,12 @@ class GeneratorState {
 
 	private final URL rootUrl;
 	private final String urlTemplate;
+	private URLResolver		resolver;
 
-	public GeneratorState(URL rootUrl, String urlTemplate) {
+	public GeneratorState(URL rootUrl, String urlTemplate, URLResolver resolver) {
 		this.rootUrl = rootUrl;
 		this.urlTemplate = urlTemplate;
+		this.resolver = resolver;
 	}
 
 	public URL getRootUrl() {
@@ -56,4 +58,7 @@ public String toString() {
 		return "GeneratorState [rootUrl=" + rootUrl + ", urlTemplate=" + urlTemplate + "]";
 	}
 
+	public URLResolver getResolver() {
+		return resolver;
+	}
 }

org.osgi.impl.bundle.repoindex.lib/src/org/osgi/service/indexer/impl/RepoIndex.java

@@ -66,6 +66,8 @@ public class RepoIndex implements ResourceIndexer {
 	 */
 	private final List<Pair<ResourceAnalyzer, Filter>> analyzers = new LinkedList<Pair<ResourceAnalyzer, Filter>>();
 
+	private URLResolver									resolver;
+
 	/**
 	 * Construct a default instance that uses a console logger.
 	 */
@@ -249,7 +251,7 @@ private Tag generateResource(File file, Map<String, String> config) throws Excep
 					rootURL = new File(System.getProperty("user.dir")).toURI().toURL();
 
 				String urlTemplate = config.get(ResourceIndexer.URL_TEMPLATE);
-				bundleAnalyzer.setStateLocal(new GeneratorState(rootURL, urlTemplate));
+				bundleAnalyzer.setStateLocal(new GeneratorState(rootURL, urlTemplate, resolver));
 			} else {
 				bundleAnalyzer.setStateLocal(null);
 			}
@@ -363,4 +365,13 @@ private long getSignature() {
 		}
 		return value;
 	}
+
+	/**
+	 * Set a URL resolver that calculates the reference to the file
+	 */
+
+	public void setURLResolver(URLResolver resolver) {
+		this.resolver = resolver;
+	}
+
 }

org.osgi.impl.bundle.repoindex.lib/src/org/osgi/service/indexer/impl/URLResolver.java

@@ -0,0 +1,22 @@
+package org.osgi.service.indexer.impl;
+
+import java.io.File;
+import java.net.URI;
+
+/**
+ * Override the calculation of the URL with a specific function.
+ */
+public interface URLResolver {
+
+	/**
+	 * Calculate the URL for the given artifact. If this returns null or throws
+	 * an exception, the automatic calculation will be used. Exceptions are
+	 * logged so should not be used for flow control.
+	 * 
+	 * @param artifact
+	 *            The artifact being analyzed
+	 * @return Either a URI to be used in the content capability or null if the
+	 *         default method should be used
+	 */
+	URI resolver(File artifact) throws Exception;
+}

org.osgi.impl.bundle.repoindex.lib/test/org/osgi/service/indexer/impl/TestIndexer.java

@@ -11,14 +11,18 @@
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.IOException;
 import java.io.StringWriter;
+import java.net.URI;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import junit.framework.TestCase;
 
@@ -34,6 +38,66 @@
 
 public class TestIndexer extends TestCase {
 
+	/**
+	 * Test if the resolver is not affected if we use a dummy resolver
+	 */
+	public void testResolverUnaffected() throws Exception {
+
+		RepoIndex indexer = new RepoIndex();
+		String without = index(indexer);
+
+		indexer = new RepoIndex();
+		indexer.setURLResolver(new URLResolver() {
+
+			@Override
+			public URI resolver(File artifact) throws Exception {
+				return null;
+			}
+		});
+
+		String with = index(indexer);
+
+		assertEquals("Should be the same without a resolver or a resolver that returns null", without, with);
+
+		indexer = new RepoIndex();
+		indexer.setURLResolver(new URLResolver() {
+
+			@Override
+			public URI resolver(File artifact) throws Exception {
+				throw new Exception();
+			}
+		});
+
+		with = index(indexer);
+		assertEquals("Should be the same without a resolver or a resolver that returns null", without, with);
+	}
+
+	/**
+	 * Test if the resolver can change the URLs
+	 * 
+	 */
+	public void testResolverEffect() throws Exception {
+
+		RepoIndex indexer = new RepoIndex();
+		indexer.setURLResolver(new URLResolver() {
+
+			@Override
+			public URI resolver(File artifact) throws Exception {
+				return new URI("xyz://FOOBAR/" + artifact.getName());
+			}
+		});
+
+		String with = index(indexer);
+
+		Pattern p = Pattern.compile("xyz://FOOBAR/(03-export.jar|06-requirebundle.jar)(?:\"|')");
+		Matcher m = p.matcher(with);
+		int n = 0;
+		while (m.find()) {
+			n++;
+		}
+		assertEquals("There are two files indexed", 2, n);
+	}
+
 	public void testFragmentBsnVersion() throws Exception {
 		assertFragmentMatch("testdata/fragment-01.txt", "testdata/01-bsn+version.jar");
 	}
@@ -146,6 +210,14 @@ public void testEmptyIndex() throws Exception {
 	public void testFullIndex() throws Exception {
 		RepoIndex indexer = new RepoIndex();
 
+		String decompressed = index(indexer);
+
+		String unpackedXML = Utils.readStream(new FileInputStream("testdata/unpacked.xml"));
+		String expected = unpackedXML.replaceAll("\\r?\\n|\\t", "");
+		assertEquals(expected, decompressed);
+	}
+
+	private String index(RepoIndex indexer) throws Exception, IOException {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		Set<File> files = new LinkedHashSet<File>();
 		files.add(new File("testdata/03-export.jar"));
@@ -156,9 +228,8 @@ public void testFullIndex() throws Exception {
 		config.put(ResourceIndexer.REPOSITORY_NAME, "full-c+f");
 		indexer.index(files, out, config);
 
-		String unpackedXML = Utils.readStream(new FileInputStream("testdata/unpacked.xml"));
-		String expected = unpackedXML.replaceAll("\\r?\\n|\\t", "");
-		assertEquals(expected, Utils.decompress(out.toByteArray()));
+		String decompressed = Utils.decompress(out.toByteArray());
+		return decompressed;
 	}
 
 	public void testFullIndexPrettyCompressedPermutations() throws Exception {