Merge pull request #1513 from ratnikov/null-file-resource

Introduce EmptyfileResource that should replace the JRubyNotFoundFile.NOT_FOUND

core/src/main/java/org/jruby/util/EmptyFileResource.java

@@ -0,0 +1,85 @@
+package org.jruby.util;
+
+import jnr.posix.FileStat;
+import jnr.posix.POSIX;
+import org.jruby.exceptions.RaiseException;
+import org.jruby.runtime.ThreadContext;
+
+class EmptyFileResource implements FileResource {
+    // All empty resources are the same and immutable, so may as well
+    // cache the instance
+    private static final EmptyFileResource INSTANCE = new EmptyFileResource();
+
+    public static EmptyFileResource create(String pathname) {
+        return (pathname == null || "".equals(pathname)) ?
+            INSTANCE : null;
+    }
+
+    @Override
+    public String absolutePath() {
+        return "";
+    }
+
+    @Override
+    public boolean exists() {
+        return false;
+    }
+
+    @Override
+    public boolean isDirectory() {
+        return false;
+    }
+
+    @Override
+    public boolean isFile() {
+        return false;
+    }
+
+    @Override
+    public boolean canRead() {
+        return false;
+    }
+
+    @Override
+    public boolean canWrite() {
+        return false;
+    }
+
+    @Override
+    public boolean isSymLink() {
+        return false;
+    }
+
+    @Override
+    public String[] list() {
+        return new String[0];
+    }
+
+    @Override
+    public long lastModified() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public long length() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public FileStat stat(POSIX posix) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public FileStat lstat(POSIX posix) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public JRubyFile hackyGetJRubyFile() {
+        // It is somewhat weird that we're returning the NOT_EXIST instance that this resource is
+        // intending to replace. However, that should go away once we get rid of the hacky method, so
+        // should be okay for now.
+        return JRubyNonExistentFile.NOT_EXIST;
+    }
+}

core/src/main/java/org/jruby/util/JRubyFile.java

@@ -67,12 +67,11 @@ public static FileResource createResource(Ruby runtime, String pathname) {
     }
 
     public static FileResource createResource(String cwd, String pathname) {
-        if (pathname == null) {
-            // null pathnames do not exist
-            return new RegularFileResource(JRubyNonExistentFile.NOT_EXIST);
+        FileResource emptyResource = EmptyFileResource.create(pathname);
+        if (emptyResource != null) {
+            return emptyResource;
         }
 
-        // Try as a jar resource first
         FileResource jarResource = JarResource.create(pathname);
         if (jarResource != null) {
             return jarResource;
@@ -81,6 +80,8 @@ public static FileResource createResource(String cwd, String pathname) {
         if (pathname.startsWith("file:")) {
             pathname = pathname.substring(5);
         }
+
+        // If any other special resource types fail, count it as a filesystem backed resource.
         return new RegularFileResource(create(cwd, pathname));
     }
 

core/src/main/java/org/jruby/util/JRubyNonExistentFile.java

@@ -37,6 +37,7 @@
 /**
  * @author nicksieger
  */
+@Deprecated // Replaced now with EmptyFileResource
 public class JRubyNonExistentFile extends JRubyFile {
     static final JRubyNonExistentFile NOT_EXIST = new JRubyNonExistentFile();
     private JRubyNonExistentFile() {
@@ -124,4 +125,4 @@ public File[] listFiles(final FileFilter filter) {
     public File[] listFiles(final FilenameFilter filter) {
         return new File[0];
     }
-}
+}