efficient way of creating bytes/bytearray from each other

Author: lukasstadler

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/BuiltinConstructors.java

@@ -68,6 +68,7 @@
 import com.oracle.graal.python.builtins.objects.PNotImplemented;
 import com.oracle.graal.python.builtins.objects.bytes.BytesNodes;
 import com.oracle.graal.python.builtins.objects.bytes.BytesUtils;
+import com.oracle.graal.python.builtins.objects.bytes.PByteArray;
 import com.oracle.graal.python.builtins.objects.bytes.PBytes;
 import com.oracle.graal.python.builtins.objects.bytes.PIBytesLike;
 import com.oracle.graal.python.builtins.objects.cell.PCell;
@@ -134,6 +135,7 @@
 import com.oracle.graal.python.runtime.exception.PException;
 import com.oracle.graal.python.runtime.exception.PythonErrorType;
 import com.oracle.graal.python.runtime.sequence.PSequence;
+import com.oracle.graal.python.runtime.sequence.storage.ByteSequenceStorage;
 import com.oracle.truffle.api.CompilerAsserts;
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
@@ -166,6 +168,8 @@ protected abstract static class CreateByteOrByteArrayNode extends PythonBuiltinN
         @Child private IsIndexNode isIndexNode;
         @Child private CastToIndexNode castToIndexNode;
 
+        private final IsBuiltinClassProfile isClassProfile = IsBuiltinClassProfile.create();
+
         @SuppressWarnings("unused")
         protected Object create(PythonClass cls, byte[] barr) {
             throw new AssertionError("should not reach");
@@ -193,6 +197,24 @@ public Object fromString(PythonClass cls, String source, PNone encoding, PNone e
             throw raise(PythonErrorType.TypeError, "string argument without an encoding");
         }
 
+        protected boolean isSimpleBytes(PBytes iterable) {
+            return isClassProfile.profileObject(iterable, PythonBuiltinClassType.PBytes) && iterable.getSequenceStorage() instanceof ByteSequenceStorage;
+        }
+
+        @Specialization(guards = {"isSimpleBytes(iterable)", "isNoValue(encoding)", "isNoValue(errors)"})
+        public Object bytearray(PythonClass cls, PBytes iterable, @SuppressWarnings("unused") PNone encoding, @SuppressWarnings("unused") PNone errors) {
+            return create(cls, (byte[]) ((ByteSequenceStorage) iterable.getSequenceStorage()).getCopyOfInternalArrayObject());
+        }
+
+        protected boolean isSimpleBytes(PByteArray iterable) {
+            return isClassProfile.profileObject(iterable, PythonBuiltinClassType.PByteArray) && iterable.getSequenceStorage() instanceof ByteSequenceStorage;
+        }
+
+        @Specialization(guards = {"isSimpleBytes(iterable)", "isNoValue(encoding)", "isNoValue(errors)"})
+        public Object bytearray(PythonClass cls, PByteArray iterable, @SuppressWarnings("unused") PNone encoding, @SuppressWarnings("unused") PNone errors) {
+            return create(cls, (byte[]) ((ByteSequenceStorage) iterable.getSequenceStorage()).getCopyOfInternalArrayObject());
+        }
+
         @Specialization(guards = {"!isInt(iterable)", "!isNoValue(iterable)", "isNoValue(encoding)", "isNoValue(errors)"})
         public Object bytearray(PythonClass cls, Object iterable, @SuppressWarnings("unused") PNone encoding, @SuppressWarnings("unused") PNone errors,
                         @Cached("create()") GetIteratorNode getIteratorNode,