SJH 3.0: Replace BiPredicate by UnionPathFilter in UnionFS and hide SecureJar impl details

Author: Technici4n

src/main/java/cpw/mods/jarhandling/JarContentsBuilder.java

@@ -53,6 +53,6 @@ public JarContentsBuilder pathFilter(@Nullable UnionPathFilter pathFilter) {
      * Builds the jar.
      */
     public JarContents build() {
-        return new JarContentsImpl(paths, defaultManifest, pathFilter == null ? null : pathFilter::test);
+        return new JarContentsImpl(paths, defaultManifest, pathFilter);
     }
 }

src/main/java/cpw/mods/jarhandling/SecureJar.java

@@ -2,6 +2,7 @@
 
 import cpw.mods.jarhandling.impl.Jar;
 import cpw.mods.jarhandling.impl.JarContentsImpl;
+import cpw.mods.niofs.union.UnionPathFilter;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.IOException;
@@ -103,7 +104,7 @@ record Provider(String serviceName, List<String> providers) {
         /**
          * Helper method to parse service provider implementations from a {@link Path}.
          */
-        public static Provider fromPath(final Path path, final BiPredicate<String, String> pkgFilter) {
+        public static Provider fromPath(Path path, @Nullable UnionPathFilter pkgFilter) {
             final var sname = path.getFileName().toString();
             try {
                 var entries = Files.readAllLines(path).stream()

src/main/java/cpw/mods/jarhandling/impl/Jar.java

@@ -32,7 +32,7 @@ public class Jar implements SecureJar {
 
     @Deprecated(forRemoval = true, since = "2.1.16")
     public Jar(final Supplier<Manifest> defaultManifest, final Function<SecureJar, JarMetadata> metadataFunction, final BiPredicate<String, String> pathfilter, final Path... paths) {
-        this.contents = new JarContentsImpl(paths, defaultManifest, pathfilter);
+        this.contents = new JarContentsImpl(paths, defaultManifest, pathfilter == null ? null : pathfilter::test);
         this.manifest = contents.getManifest();
         this.signingData = contents.signingData;
         this.filesystem = contents.filesystem;

src/main/java/cpw/mods/jarhandling/impl/JarContentsImpl.java

@@ -4,6 +4,7 @@
 import cpw.mods.jarhandling.SecureJar;
 import cpw.mods.niofs.union.UnionFileSystem;
 import cpw.mods.niofs.union.UnionFileSystemProvider;
+import cpw.mods.niofs.union.UnionPathFilter;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.IOException;
@@ -48,7 +49,7 @@ public class JarContentsImpl implements JarContents {
     // Cache for repeated getMetaInfServices calls
     private List<SecureJar.Provider> providers;
 
-    public JarContentsImpl(Path[] paths, Supplier<Manifest> defaultManifest, @Nullable BiPredicate<String, String> pathFilter) {
+    public JarContentsImpl(Path[] paths, Supplier<Manifest> defaultManifest, @Nullable UnionPathFilter pathFilter) {
         var validPaths = Arrays.stream(paths).filter(Files::exists).toArray(Path[]::new);
         if (validPaths.length == 0)
             throw new UncheckedIOException(new IOException("Invalid paths argument, contained no existing paths: " + Arrays.toString(paths)));
@@ -202,7 +203,7 @@ public List<SecureJar.Provider> getMetaInfServices() {
             if (Files.exists(services)) {
                 try (var walk = Files.walk(services)) {
                     this.providers = walk.filter(path->!Files.isDirectory(path))
-                            .map((Path path1) -> SecureJar.Provider.fromPath(path1, filesystem.getFilesystemFilter()))
+                            .map((Path path1) -> SecureJar.Provider.fromPath(path1, filesystem.getFileSystemFilter()))
                             .toList();
                 } catch (IOException e) {
                     throw new UncheckedIOException(e);

src/main/java/cpw/mods/niofs/union/UnionFileSystem.java

@@ -34,13 +34,15 @@
 import java.util.Set;
 import java.util.Spliterator;
 import java.util.Spliterators;
-import java.util.function.BiPredicate;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
+/**
+ * Can be instantiated using the public methods in {@link UnionFileSystemProvider}.
+ */
 public class UnionFileSystem extends FileSystem {
     private static final MethodHandle ZIPFS_EXISTS;
     private static final MethodHandle ZIPFS_CH;
@@ -104,15 +106,18 @@ public synchronized Throwable fillInStackTrace() {
     private final List<Path> basepaths;
     private final int lastElementIndex;
     @Nullable
-    private final BiPredicate<String, String> pathFilter;
+    private final UnionPathFilter pathFilter;
     private final Map<Path, EmbeddedFileSystemMetadata> embeddedFileSystems;
 
     public Path getPrimaryPath() {
         return basepaths.get(basepaths.size() - 1);
     }
 
+    /**
+     * {@return the filter for this file system, or null if there is none}
+     */
     @Nullable
-    public BiPredicate<String, String> getFilesystemFilter() {
+    public UnionPathFilter getFileSystemFilter() {
         return pathFilter;
     }
 
@@ -123,7 +128,7 @@ String getKey() {
     private record EmbeddedFileSystemMetadata(Path path, FileSystem fs, SeekableByteChannel fsCh) {
     }
 
-    public UnionFileSystem(final UnionFileSystemProvider provider, @Nullable BiPredicate<String, String> pathFilter, final String key, final Path... basepaths) {
+    UnionFileSystem(UnionFileSystemProvider provider, @Nullable UnionPathFilter pathFilter, String key, Path... basepaths) {
         this.pathFilter = pathFilter;
         this.provider = provider;
         this.key = key;

src/main/java/cpw/mods/niofs/union/UnionFileSystemProvider.java

@@ -11,7 +11,6 @@
 import java.nio.file.attribute.*;
 import java.nio.file.spi.FileSystemProvider;
 import java.util.*;
-import java.util.function.BiPredicate;
 import java.util.stream.Stream;
 
 public class UnionFileSystemProvider extends FileSystemProvider {
@@ -55,24 +54,7 @@ protected Path uriToPath(URI uri) {
      */
     @Override
     public FileSystem newFileSystem(final URI uri, final Map<String, ?> env) throws IOException {
-        @SuppressWarnings("unchecked")
-        var additional = ((Map<String, List<Path>>)env).getOrDefault("additional", List.<Path>of());
-        @SuppressWarnings("unchecked")
-        var filter = ((Map<String, BiPredicate<String, String>>)env).getOrDefault("filter", null);
-
-        if (filter == null && additional.isEmpty())
-            throw new IllegalArgumentException("Missing additional and/or filter");
-
-        if (filter == null)
-            filter = (p, b) -> true;
-
-        var path = uriToPath(uri);
-        var key = makeKey(path);
-        try {
-            return newFileSystemInternal(key, filter, Stream.concat(Stream.of(path), additional.stream()).toArray(Path[]::new));
-        } catch (UncheckedIOException e) {
-            throw e.getCause();
-        }
+        return newFileSystem(uriToPath(uri), env);
     }
 
     /**
@@ -87,8 +69,7 @@ public FileSystem newFileSystem(final URI uri, final Map<String, ?> env) throws
     public FileSystem newFileSystem(final Path path, final Map<String, ?> env) throws IOException {
         @SuppressWarnings("unchecked")
         var additional = ((Map<String, List<Path>>)env).getOrDefault("additional", List.<Path>of());
-        @SuppressWarnings("unchecked")
-        var filter = ((Map<String, BiPredicate<String, String>>)env).getOrDefault("filter", null);
+        var filter = readFilterFromEnv(env);
 
         if (filter == null && additional.isEmpty())
             throw new UnsupportedOperationException("Missing additional and/or filter");
@@ -101,13 +82,26 @@ public FileSystem newFileSystem(final Path path, final Map<String, ?> env) throw
         }
     }
 
-    public UnionFileSystem newFileSystem(@Nullable BiPredicate<String, String> pathfilter, final Path... paths) {
+    @Nullable
+    private static UnionPathFilter readFilterFromEnv(Map<String, ?> env) {
+        Object filter = env.get("filter");
+
+        if (filter == null) {
+            return null;
+        } else if (filter instanceof UnionPathFilter unionPathFilter) {
+            return unionPathFilter;
+        } else {
+            throw new IllegalArgumentException("Unknown type for \"filter\" UnionFileSystem env var: " + filter.getClass().getName());
+        }
+    }
+
+    public UnionFileSystem newFileSystem(@Nullable UnionPathFilter pathfilter, final Path... paths) {
         if (paths.length == 0) throw new IllegalArgumentException("Need at least one path");
         var key = makeKey(paths[0]);
         return newFileSystemInternal(key, pathfilter, paths);
     }
 
-    private UnionFileSystem newFileSystemInternal(final String key, @Nullable BiPredicate<String, String> pathfilter, final Path... paths) {
+    private UnionFileSystem newFileSystemInternal(final String key, @Nullable UnionPathFilter pathfilter, final Path... paths) {
         var normpaths = Arrays.stream(paths)
                 .map(Path::toAbsolutePath)
                 .map(Path::normalize)

src/main/java/module-info.java

@@ -4,7 +4,6 @@
 
 module cpw.mods.securejarhandler {
     exports cpw.mods.jarhandling;
-    exports cpw.mods.jarhandling.impl; // TODO - Bump version, and remove this export, you don't need our implementation
     exports cpw.mods.cl;
     exports cpw.mods.niofs.union;
     requires jdk.unsupported;