1 /*
 2  * Copyright (c) 2021, 2022, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.
 8  *
 9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 package org.openjdk.bench.java.lang.foreign.pointers;
25 
26 
27 import java.lang.foreign.MemorySegment;
28 import java.lang.foreign.SegmentAllocator;
29 
30 public class Pointer<X> {
31 
32     final MemorySegment segment;
33 
34     Pointer(MemorySegment segment) {
35         this.segment = segment;
36     }
37 
38     public <Z extends NativeType.OfInt<X>> int get(Z type, long index) {
39         return segment.getAtIndex(type.layout(), index);
40     }
41 
42     public <Z extends NativeType.OfDouble<X>> double get(Z type, long index) {
43         return segment.getAtIndex(type.layout(), index);
44     }
45 
46     public <Z extends NativeType.OfStruct<X>> X get(Z type, long index) {
47         return type.make(addOffset(index * type.layout().byteSize()));
48     }
49 
50     public Pointer<X> addOffset(long offset) {
51         return new Pointer<>(segment.asSlice(offset));
52     }
53 
54     @SuppressWarnings("unchecked")
55     public <Z extends NativeType.OfPointer<X>> X get(Z type, long index) {
56         MemorySegment address = segment.getAtIndex(type.layout(), index);
57         return (X)new Pointer<>(address);
58     }
59 
60     @SuppressWarnings("unchecked")
61     public X get(NativeType<X> type, long offset) {
62         if (type instanceof NativeType.OfInt intType) {
63             return (X) (Object) get(intType, offset);
64         } else if (type instanceof NativeType.OfDouble doubleType) {
65             return (X) (Object) get(doubleType, offset);
66         } else {
67             throw new UnsupportedOperationException();
68         }
69     }
70 
71     public MemorySegment segment() {
72         return segment;
73     }
74 
75     public static <X> Pointer<X> allocate(NativeType<X> type, SegmentAllocator allocator) {
76         MemorySegment segment = allocator.allocate(type.layout());
77         return new Pointer<>(segment);
78     }
79 
80     public static <X> Pointer<X> allocate(NativeType<X> type, long size, SegmentAllocator allocator) {
81         MemorySegment segment = allocator.allocate(type.layout(), size);
82         return new Pointer<>(segment);
83     }
84 
85     public static <X> Pointer<X> wrap(NativeType<X> type, MemorySegment segment) {
86         return new Pointer<>(segment);
87     }
88 }