jruby · Mar 10, 2016 · Mar 10, 2016
diff --git a/truffle/src/main/java/org/jruby/truffle/core/encoding/EncodingOperations.java b/truffle/src/main/java/org/jruby/truffle/core/encoding/EncodingOperations.java
@@ -26,6 +26,8 @@ public static Encoding getEncoding(DynamicObject rubyEncoding) {
         Encoding encoding = Layouts.ENCODING.getEncoding(rubyEncoding);
 
         if (encoding == null) {
+            CompilerDirectives.transferToInterpreter();
+
             final ByteList name = Layouts.ENCODING.getName(rubyEncoding);
             encoding = loadEncoding(name);
             Layouts.ENCODING.setEncoding(rubyEncoding, encoding);

diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/AsciiOnlyLeafRope.java b/truffle/src/main/java/org/jruby/truffle/core/rope/AsciiOnlyLeafRope.java
@@ -10,6 +10,7 @@
 
 package org.jruby.truffle.core.rope;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import org.jcodings.Encoding;
 
 public class AsciiOnlyLeafRope extends LeafRope {
@@ -18,4 +19,13 @@ public AsciiOnlyLeafRope(byte[] bytes, Encoding encoding) {
         super(bytes, encoding, CodeRange.CR_7BIT, true, bytes.length);
     }
 
+    @Override
+    public Rope withEncoding(Encoding newEncoding, CodeRange newCodeRange) {
+        if (newCodeRange != getCodeRange()) {
+            CompilerDirectives.transferToInterpreter();
+            throw new UnsupportedOperationException("Cannot fast-path updating encoding with different code range.");
+        }
+
+        return new AsciiOnlyLeafRope(getRawBytes(), newEncoding);
+    }
 }
diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/ConcatRope.java b/truffle/src/main/java/org/jruby/truffle/core/rope/ConcatRope.java
@@ -9,6 +9,7 @@
  */
 package org.jruby.truffle.core.rope;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import org.jcodings.Encoding;
 
@@ -18,6 +19,10 @@ public class ConcatRope extends Rope {
     private final Rope right;
 
     public ConcatRope(Rope left, Rope right, Encoding encoding, CodeRange codeRange, boolean singleByteOptimizable, int depth) {
+        this(left, right, encoding, codeRange, singleByteOptimizable, depth, null);
+    }
+
+    private ConcatRope(Rope left, Rope right, Encoding encoding, CodeRange codeRange, boolean singleByteOptimizable, int depth, byte[] bytes) {
         super(encoding,
                 codeRange,
                 singleByteOptimizable,
@@ -30,6 +35,16 @@ public ConcatRope(Rope left, Rope right, Encoding encoding, CodeRange codeRange,
         this.right = right;
     }
 
+    @Override
+    public Rope withEncoding(Encoding newEncoding, CodeRange newCodeRange) {
+        if (newCodeRange != getCodeRange()) {
+            CompilerDirectives.transferToInterpreter();
+            throw new UnsupportedOperationException("Cannot fast-path updating encoding with different code range.");
+        }
+
+        return new ConcatRope(getLeft(), getRight(), newEncoding, newCodeRange, isSingleByteOptimizable(), depth(), getRawBytes());
+    }
+
     @Override
     @TruffleBoundary
     public byte getByteSlow(int index) {

diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/InvalidLeafRope.java b/truffle/src/main/java/org/jruby/truffle/core/rope/InvalidLeafRope.java
@@ -10,6 +10,7 @@
 
 package org.jruby.truffle.core.rope;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import org.jcodings.Encoding;
 
 public class InvalidLeafRope extends LeafRope {
@@ -18,4 +19,13 @@ public InvalidLeafRope(byte[] bytes, Encoding encoding) {
         super(bytes, encoding, CodeRange.CR_BROKEN, false, bytes.length);
     }
 
+    @Override
+    public Rope withEncoding(Encoding newEncoding, CodeRange newCodeRange) {
+        if (newCodeRange != getCodeRange()) {
+            CompilerDirectives.transferToInterpreter();
+            throw new UnsupportedOperationException("Cannot fast-path updating encoding with different code range.");
+        }
+
+        return new InvalidLeafRope(getRawBytes(), newEncoding);
+    }
 }
diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/Rope.java b/truffle/src/main/java/org/jruby/truffle/core/rope/Rope.java
@@ -36,6 +36,8 @@ protected Rope(Encoding encoding, CodeRange codeRange, boolean singleByteOptimiz
         this.bytes = bytes;
     }
 
+    public abstract Rope withEncoding(Encoding newEncoding, CodeRange newCodeRange);
+
     public final int characterLength() {
         return characterLength;
     }

diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/RopeOperations.java b/truffle/src/main/java/org/jruby/truffle/core/rope/RopeOperations.java
@@ -82,6 +82,14 @@ public static Rope withEncoding(Rope originalRope, Encoding newEncoding, CodeRan
             return originalRope;
         }
 
+        if (originalRope.getCodeRange() == newCodeRange) {
+            return originalRope.withEncoding(newEncoding, newCodeRange);
+        }
+
+        if ((originalRope.getCodeRange() == CR_7BIT) && newEncoding.isAsciiCompatible()) {
+            return originalRope.withEncoding(newEncoding, CR_7BIT);
+        }
+
         return create(originalRope.getBytes(), newEncoding, newCodeRange);
     }
 

diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/SubstringRope.java b/truffle/src/main/java/org/jruby/truffle/core/rope/SubstringRope.java
@@ -10,18 +10,36 @@
 
 package org.jruby.truffle.core.rope;
 
+import com.oracle.truffle.api.CompilerDirectives;
+import org.jcodings.Encoding;
+
 public class SubstringRope extends Rope {
 
     private final Rope child;
     private final int offset;
 
     public SubstringRope(Rope child, int offset, int byteLength, int characterLength, CodeRange codeRange) {
         // TODO (nirvdrum 07-Jan-16) Verify that this rope is only used for character substrings and not arbitrary byte slices. The former should always have the child's code range while the latter may not.
-        super(child.getEncoding(), codeRange, child.isSingleByteOptimizable(), byteLength, characterLength, child.depth() + 1, null);
+        this(child, child.getEncoding(), offset, byteLength, characterLength, codeRange);
+    }
+
+    private SubstringRope(Rope child, Encoding encoding, int offset, int byteLength, int characterLength, CodeRange codeRange) {
+        // TODO (nirvdrum 07-Jan-16) Verify that this rope is only used for character substrings and not arbitrary byte slices. The former should always have the child's code range while the latter may not.
+        super(encoding, codeRange, child.isSingleByteOptimizable(), byteLength, characterLength, child.depth() + 1, null);
         this.child = child;
         this.offset = offset;
     }
 
+    @Override
+    public Rope withEncoding(Encoding newEncoding, CodeRange newCodeRange) {
+        if (newCodeRange != getCodeRange()) {
+            CompilerDirectives.transferToInterpreter();
+            throw new UnsupportedOperationException("Cannot fast-path updating encoding with different code range.");
+        }
+
+        return new SubstringRope(getChild(), newEncoding, getOffset(), byteLength(), characterLength(), newCodeRange);
+    }
+
     @Override
     public byte getByteSlow(int index) {
         return child.getByteSlow(index + offset);

diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/ValidLeafRope.java b/truffle/src/main/java/org/jruby/truffle/core/rope/ValidLeafRope.java
@@ -10,6 +10,7 @@
 
 package org.jruby.truffle.core.rope;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import org.jcodings.Encoding;
 
 public class ValidLeafRope extends LeafRope {
@@ -18,4 +19,14 @@ public ValidLeafRope(byte[] bytes, Encoding encoding, int characterLength) {
         super(bytes, encoding, CodeRange.CR_VALID, encoding.isSingleByte(), characterLength);
     }
 
+    @Override
+    public Rope withEncoding(Encoding newEncoding, CodeRange newCodeRange) {
+        if (newCodeRange != getCodeRange()) {
+            CompilerDirectives.transferToInterpreter();
+            throw new UnsupportedOperationException("Cannot fast-path updating encoding with different code range.");
+        }
+
+        // TODO (nirvdrum 08-Mar-16): This should recalculate the character length since the new encoding may treat the bytes differently.
+        return new ValidLeafRope(getRawBytes(), newEncoding, characterLength());
+    }
 }