[Truffle] Add Dir#{pos,rewind,seek,tell}.

Author: bjfish

spec/truffle/tags/core/dir/each_tags.txt

@@ -1,2 +1 @@
-fails:Dir#each returns the directory which remains open
 fails:Dir#each raises an IOError when called on a closed Dir instance

spec/truffle/tags/core/dir/pos_tags.txt

@@ -1,4 +1 @@
-fails:Dir#pos returns an Integer representing the current position in the directory
-fails:Dir#pos returns a different Integer if moved from previous position
 fails:Dir#pos raises an IOError when called on a closed Dir instance
-fails:Dir#pos= moves the read position to a previously obtained position

spec/truffle/tags/core/dir/rewind_tags.txt

@@ -1,3 +1 @@
-fails:Dir#rewind resets the next read to start from the first entry
-fails:Dir#rewind returns the Dir instance
 fails:Dir#rewind raises an IOError when called on a closed Dir instance

spec/truffle/tags/core/dir/seek_tags.txt

@@ -1,3 +1 @@
-fails:Dir#tell returns an Integer representing the current position in the directory
-fails:Dir#tell returns a different Integer if moved from previous position
 fails:Dir#tell raises an IOError when called on a closed Dir instance

spec/truffle/tags/core/dir/tell_tags.txt

@@ -6,6 +6,34 @@
  * Eclipse Public License version 1.0
  * GNU General Public License version 2
  * GNU Lesser General Public License version 2.1
+ *
+ * Some of the code in this class is transliterated from C++ code in Rubinius.
+ *
+ * Copyright (c) 2007-2014, Evan Phoenix and contributors
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of Rubinius nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 package org.jruby.truffle.nodes.rubinius;
 
@@ -136,6 +164,44 @@ public Object read(RubyBasicObject dir) {
 
     }
 
+
+    @RubiniusPrimitive(name = "dir_control")
+    public static abstract class DirControlPrimitiveNode extends RubiniusPrimitiveNode {
+
+        @Child private ReadHeadObjectFieldNode readPositionNode;
+        @Child private WriteHeadObjectFieldNode writePositionNode;
+
+        public DirControlPrimitiveNode(RubyContext context, SourceSection sourceSection) {
+            super(context, sourceSection);
+            readPositionNode = new ReadHeadObjectFieldNode(positionKey);
+            writePositionNode = new WriteHeadObjectFieldNode(positionKey);
+        }
+
+        @CompilerDirectives.TruffleBoundary
+        @Specialization
+        public Object control(RubyBasicObject dir, int kind, int position) {
+            switch (kind) {
+                case 0:
+                    writePositionNode.execute(dir, position);
+                    return true;
+                case 1:
+                    writePositionNode.execute(dir, -2);
+                    return true;
+                case 2:
+                    try {
+                        return readPositionNode.executeInteger(dir);
+                    } catch (UnexpectedResultException e) {
+                        throw new IllegalStateException();
+                    }
+
+            }
+            return nil();
+        }
+
+    }
+
+
+
     @RubiniusPrimitive(name = "dir_close")
     public static abstract class DirClosePrimitiveNode extends RubiniusPrimitiveNode {
 

truffle/src/main/java/org/jruby/truffle/nodes/rubinius/DirPrimitiveNodes.java

@@ -183,6 +183,34 @@ def each
     self
   end
 
+  SeekKind = 0
+  RewindKind = 1
+  TellKind = 2
+
+  def pos
+    control TellKind, 0
+  end
+
+  alias_method :tell, :pos
+
+  def pos=(position)
+    seek(position)
+
+    position
+  end
+
+  def seek(position)
+    control SeekKind, position
+
+    self
+  end
+
+  def rewind
+    control RewindKind, 0
+
+    self
+  end
+
   class << self
     alias_method :pwd, :getwd
     alias_method :delete, :rmdir