[GR-71245] Expose ByteBufferDataInput and its position

truffle/CHANGELOG.md

@@ -37,6 +37,7 @@ This changelog summarizes major changes between Truffle versions relevant to lan
 
 * GR-70086: Added `replacementOf` and `replacementMethod` attributes to `GenerateLibrary.Abstract` annotation. They enable automatic generation of legacy delegators during message library evolution, while allowing custom conversions when needed.
 * GR-70086 Deprecated `Message.resolve(Class<?>, String)`. Use `Message.resolveExact(Class<?>, String, Class<?>...)` with argument types instead. This deprecation was necessary as library messages are no longer unique by message name, if the previous message was deprecated.
+* GR-71245: Exposed `ByteBufferDataInput` as public and added a `position` method that returns the underlying buffer's position.
 
 
 ## Version 25.0

truffle/src/com.oracle.truffle.api.bytecode/snapshot.sigtest

@@ -802,6 +802,28 @@ meth public com.oracle.truffle.api.bytecode.debug.PrintInstructionTracer$Builder
 supr java.lang.Object
 hfds filter,out
 
+CLSS public final com.oracle.truffle.api.bytecode.serialization.ByteBufferDataInput
+intf java.io.DataInput
+meth public boolean readBoolean() throws java.io.IOException
+meth public byte readByte() throws java.io.IOException
+meth public char readChar() throws java.io.IOException
+meth public double readDouble() throws java.io.IOException
+meth public float readFloat() throws java.io.IOException
+meth public int position()
+meth public int readInt() throws java.io.IOException
+meth public int readUnsignedByte() throws java.io.IOException
+meth public int readUnsignedShort() throws java.io.IOException
+meth public int skipBytes(int) throws java.io.IOException
+meth public java.lang.String readLine() throws java.io.IOException
+ anno 0 java.lang.Deprecated(boolean forRemoval=false, java.lang.String since="")
+meth public java.lang.String readUTF() throws java.io.IOException
+meth public long readLong() throws java.io.IOException
+meth public short readShort() throws java.io.IOException
+meth public void readFully(byte[]) throws java.io.IOException
+meth public void readFully(byte[],int,int) throws java.io.IOException
+supr java.lang.Object
+hfds buffer,lineBuffer
+
 CLSS public abstract interface com.oracle.truffle.api.bytecode.serialization.BytecodeDeserializer
  anno 0 java.lang.FunctionalInterface()
 innr public abstract interface static DeserializerContext
@@ -986,6 +1008,23 @@ hcls Constant
 
 CLSS public abstract interface com.oracle.truffle.api.nodes.UnadoptableNode
 
+CLSS public abstract interface java.io.DataInput
+meth public abstract boolean readBoolean() throws java.io.IOException
+meth public abstract byte readByte() throws java.io.IOException
+meth public abstract char readChar() throws java.io.IOException
+meth public abstract double readDouble() throws java.io.IOException
+meth public abstract float readFloat() throws java.io.IOException
+meth public abstract int readInt() throws java.io.IOException
+meth public abstract int readUnsignedByte() throws java.io.IOException
+meth public abstract int readUnsignedShort() throws java.io.IOException
+meth public abstract int skipBytes(int) throws java.io.IOException
+meth public abstract java.lang.String readLine() throws java.io.IOException
+meth public abstract java.lang.String readUTF() throws java.io.IOException
+meth public abstract long readLong() throws java.io.IOException
+meth public abstract short readShort() throws java.io.IOException
+meth public abstract void readFully(byte[]) throws java.io.IOException
+meth public abstract void readFully(byte[],int,int) throws java.io.IOException
+
 CLSS public abstract interface java.io.Serializable
 
 CLSS public abstract interface java.lang.Cloneable

truffle/src/com.oracle.truffle.api.bytecode/src/com/oracle/truffle/api/bytecode/serialization/ByteBufferDataInput.java

@@ -53,7 +53,7 @@
  * @see SerializationUtils#createDataInput(ByteBuffer)
  * @since 24.2
  */
-final class ByteBufferDataInput implements DataInput {
+public final class ByteBufferDataInput implements DataInput {
 
     private final ByteBuffer buffer;
     private char[] lineBuffer;
@@ -84,7 +84,7 @@ public void readFully(byte[] b, int off, int len) throws IOException {
 
     @Override
     public int skipBytes(int n) throws IOException {
-        int skip = buffer.remaining() > n ? buffer.remaining() : n;
+        int skip = buffer.remaining() < n ? buffer.remaining() : n;
         buffer.position(buffer.position() + skip);
         return skip;
     }
@@ -237,4 +237,11 @@ public String readLine() throws IOException {
     public String readUTF() throws IOException {
         return DataInputStream.readUTF(this);
     }
+
+    /**
+     * Returns the position in the underlying byte buffer.
+     */
+    public int position() {
+        return buffer.position();
+    }
 }