1 /*
 2  * Copyright (c) 2024, 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.  Oracle designates this
 8  * particular file as subject to the "Classpath" exception as provided
 9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 package optkl.ifacemapper;
26 
27 import optkl.codebuilders.CodeBuilder;
28 
29 import java.lang.foreign.MemoryLayout;
30 import java.lang.foreign.PaddingLayout;
31 import java.lang.foreign.SequenceLayout;
32 import java.lang.foreign.StructLayout;
33 import java.lang.foreign.UnionLayout;
34 import java.lang.foreign.ValueLayout;
35 import java.nio.ByteOrder;
36 
37 public class SchemaBuilder extends CodeBuilder<SchemaBuilder> {
38     static String valueLayoutToSchemaString(ValueLayout valueLayout) {
39         String descriptor = valueLayout.carrier().descriptorString();
40         String schema = switch (descriptor) {
41             case "Z" -> "Z";
42             case "B" -> "S";
43             case "C" -> "U";
44             case "S" -> "S";
45             case "I" -> "S";
46             case "F" -> "F";
47             case "D" -> "D";
48             case "J" -> "S";
49             default -> throw new IllegalStateException("Unexpected value: " + descriptor);
50         } + valueLayout.byteSize() * 8;
51         return (valueLayout.order().equals(ByteOrder.LITTLE_ENDIAN)) ? schema.toLowerCase() : schema;
52     }
53 
54     SchemaBuilder layout(MemoryLayout layout) {
55         either(layout.name().isPresent(), (_) -> identifier(layout.name().get()), (_) -> questionMark()).colon();
56         switch (layout) {
57             case StructLayout structLayout ->
58                 brace(_ ->
59                         commaSeparated(
60                                 structLayout.memberLayouts(),
61                                 this::layout
62                         )
63                 );
64             case UnionLayout unionLayout ->
65                 chevron(_ ->
66                         barSeparated(
67                                 unionLayout.memberLayouts(),
68                                 this::layout
69                         )
70                 );
71             case ValueLayout valueLayout ->
72                 literal(valueLayoutToSchemaString(valueLayout));
73             case PaddingLayout paddingLayout ->
74                 literal("x").literal(paddingLayout.byteSize());
75             case SequenceLayout sequenceLayout ->
76                 sbrace((_) -> literal(sequenceLayout.elementCount()).colon().layout(sequenceLayout.elementLayout()));
77         }
78         return this;
79     }
80 
81     public static String schema(Buffer buffer) {
82             return new SchemaBuilder().literal(MappableIface.getMemorySegment(buffer).byteSize())
83                     .hash().layout(MappableIface.getLayout(buffer)).toString();
84     }
85 }