fix 104: make RandomAccessSequenceAdapter.readBytes(int) always make … (

#171)

Signed-off-by: Anthony Petrov <anthony@swirldslabs.com>

pbj-core/pbj-runtime/src/main/java/com/hedera/pbj/runtime/Codec.java

@@ -43,7 +43,7 @@ public interface Codec<T /*extends Record*/> {
      *     input
      */
     @NonNull default T parse(@NonNull Bytes bytes) throws IOException {
-        return parse(bytes.toCopyingReadableSequentialData());
+        return parse(bytes.toReadableSequentialData());
     }
 
     /**
@@ -77,7 +77,7 @@ public interface Codec<T /*extends Record*/> {
      *     input
      */
     @NonNull default T parseStrict(@NonNull Bytes bytes) throws IOException {
-        return parseStrict(bytes.toCopyingReadableSequentialData());
+        return parseStrict(bytes.toReadableSequentialData());
     }
 
     /**

pbj-core/pbj-runtime/src/main/java/com/hedera/pbj/runtime/io/buffer/Bytes.java

@@ -321,17 +321,6 @@ public ReadableSequentialData toReadableSequentialData() {
         return new RandomAccessSequenceAdapter(this);
     }
 
-    /**
-     * Create and return a new {@link ReadableSequentialData} that is backed by this {@link Bytes}
-     * and that returns a replicated Bytes object upon a call to readBytes(int length).
-     *
-     * @return A {@link ReadableSequentialData} backed by this {@link Bytes}.
-     */
-    @NonNull
-    public ReadableSequentialData toCopyingReadableSequentialData() {
-        return new RandomAccessSequenceAdapter(this, true);
-    }
-
     /**
      * Exposes this {@link Bytes} as an {@link InputStream}. This is a zero-copy operation.
      *

pbj-core/pbj-runtime/src/main/java/com/hedera/pbj/runtime/io/buffer/RandomAccessSequenceAdapter.java

@@ -15,9 +15,6 @@ final class RandomAccessSequenceAdapter implements ReadableSequentialData {
     /** The delegate {@link RandomAccessData} instance */
     private final RandomAccessData delegate;
 
-    /** The `Bytes readBytes(int length)` will replicate the return value if true. */
-    private final boolean copyingBytes;
-
     /**
      * The capacity of this sequence will be the difference between the <b>initial</b> position and the
      * length of the delegate
@@ -39,15 +36,6 @@ final class RandomAccessSequenceAdapter implements ReadableSequentialData {
         this.capacity = delegate.length();
         this.start = 0;
         this.limit = this.capacity;
-        this.copyingBytes = false;
-    }
-
-    RandomAccessSequenceAdapter(@NonNull final RandomAccessData delegate, final boolean copyingBytes) {
-        this.delegate = delegate;
-        this.capacity = delegate.length();
-        this.start = 0;
-        this.limit = this.capacity;
-        this.copyingBytes = copyingBytes;
     }
 
     /**
@@ -60,7 +48,6 @@ final class RandomAccessSequenceAdapter implements ReadableSequentialData {
         this.start = start;
         this.capacity = delegate.length() - start;
         this.limit = this.capacity;
-        this.copyingBytes = false;
 
         if (this.start > delegate.length()) {
             throw new IllegalArgumentException("Start " + start + " is greater than the delegate length " + delegate.length());
@@ -179,9 +166,13 @@ public Bytes readBytes(final int length) {
         }
 
         var bytes = delegate.getBytes(start + position, length);
-        if (copyingBytes) {
-            bytes = bytes.replicate();
-        }
+
+        // Always create a copy because Bytes.getBytes() returns a view
+        // and the RandomAccessSequenceAdapter.readBytes(int) method is unaware of
+        // the underlying buffer ownership, but users of Bytes assume it's immutable.
+        // We could make this conditional on `delegate instanceof Bytes` if we have to.
+        bytes = bytes.replicate();
+
         position += bytes.length();
         return bytes;
     }