[GR-17457] Prevent flattening LazyIntRope from modifying its bytes.

PullRequest: truffleruby/1762

Author: bjfish

src/main/java/org/truffleruby/core/rope/LazyIntRope.java

@@ -10,12 +10,13 @@
 package org.truffleruby.core.rope;
 
 
+import com.oracle.truffle.api.CompilerDirectives;
 import org.jcodings.Encoding;
 import org.jcodings.specific.USASCIIEncoding;
 
-import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 
-public class LazyIntRope extends LazyRope {
+public class LazyIntRope extends ManagedRope {
 
     final int value;
 
@@ -24,7 +25,7 @@ public LazyIntRope(int value) {
     }
 
     protected LazyIntRope(int value, Encoding encoding, int length) {
-        super(encoding, length, length);
+        super(encoding, CodeRange.CR_7BIT, length, length, 1, null);
         this.value = value;
         assert Integer.toString(value).length() == length;
     }
@@ -63,16 +64,24 @@ Rope withBinaryEncoding() {
         throw new UnsupportedOperationException("Must only be called for CR_VALID Strings");
     }
 
+
     @Override
-    public byte[] fulfill() {
-        if (bytes == null) {
-            bytes = RopeOperations.encodeAsciiBytes(Integer.toString(value));
-        }
+    protected byte[] getBytesSlow() {
+        return RopeOperations.encodeAsciiBytes(valueToString(value));
+    }
 
-        return bytes;
+    @TruffleBoundary
+    private String valueToString(int value) {
+        return Integer.toString(value);
     }
 
     public int getValue() {
         return value;
     }
+
+    @Override
+    protected byte getByteSlow(int index) {
+        return getBytes()[index];
+    }
+
 }

src/main/java/org/truffleruby/core/rope/LazyRope.java

@@ -154,7 +154,7 @@ private Rope substringRepeatingRopeWithEncoding(Encoding encoding, RepeatingRope
         }
 
         @Specialization(guards = { "byteLength > 1", "!sameAsBase(base, byteLength)" })
-        protected Rope substringLazyRope(LazyRope base, int byteOffset, int byteLength,
+        protected Rope substringLazyRope(LazyIntRope base, int byteOffset, int byteLength,
                 @Cached MakeSubstringRopeNode makeSubstringRopeNode) {
             return makeSubstringRopeNode.executeMake(base.getEncoding(), base, byteOffset, byteLength);
         }
@@ -1142,7 +1142,7 @@ protected int getByte(NativeRope rope, int index) {
         }
 
         @Specialization(guards = "rope.getRawBytes() == null")
-        protected int getByte(LazyRope rope, int index) {
+        protected int getByte(LazyIntRope rope, int index) {
             return rope.getBytes()[index] & 0xff;
         }
 

src/main/java/org/truffleruby/core/rope/RopeNodes.java

@@ -329,15 +329,17 @@ public static byte[] flattenBytes(Rope rope) {
                 continue;
             }
 
-            // Force lazy ropes
-            if (current instanceof LazyRope) {
-                ((LazyRope) current).fulfill();
+            final byte[] rawBytes;
+            if (current instanceof LazyIntRope) {
+                rawBytes = current.getBytesSlow();
+            } else {
+                rawBytes = current.getRawBytes();
             }
 
-            if (current.getRawBytes() != null) {
+            if (rawBytes != null) {
                 // In the absence of any SubstringRopes, we always take the full contents of the current rope.
                 if (substringLengths.isEmpty()) {
-                    System.arraycopy(current.getRawBytes(), byteOffset, buffer, bufferPosition, current.byteLength());
+                    System.arraycopy(rawBytes, byteOffset, buffer, bufferPosition, current.byteLength());
                     bufferPosition += current.byteLength();
                 } else {
                     int bytesToCopy = substringLengths.pop();
@@ -352,7 +354,7 @@ public static byte[] flattenBytes(Rope rope) {
                         currentBytesToCopy = bytesToCopy;
                     }
 
-                    System.arraycopy(current.getRawBytes(), byteOffset, buffer, bufferPosition, currentBytesToCopy);
+                    System.arraycopy(rawBytes, byteOffset, buffer, bufferPosition, currentBytesToCopy);
                     bufferPosition += currentBytesToCopy;
                     bytesToCopy -= currentBytesToCopy;
 
@@ -561,7 +563,7 @@ public static int hashForRange(Rope rope, int startingHashCode, int offset, int
             }
 
             return hash;
-        } else if (rope instanceof LazyRope) {
+        } else if (rope instanceof LazyIntRope) {
             return Hashing.stringHash(rope.getBytes(), startingHashCode, offset, length);
         } else if (rope instanceof NativeRope) {
             return Hashing.stringHash(rope.getBytes(), startingHashCode, offset, length);