MetadataMarshalClass.java revision 2f1a2e423e0fbb64467d6fcfa4e82c6384f31210 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.hardware.camera2.impl;
18
19import java.nio.ByteBuffer;
20
21public interface MetadataMarshalClass<T> {
22
23    /**
24     * Marshal the specified object instance (value) into a byte buffer.
25     *
26     * @param value the value of type T that we wish to write into the byte buffer
27     * @param buffer the byte buffer into which the marshalled object will be written
28     * @param nativeType the native type, e.g.
29     *        {@link android.hardware.camera2.CameraMetadata#TYPE_BYTE TYPE_BYTE}.
30     *        Guaranteed to be one for which isNativeTypeSupported returns true.
31     * @param sizeOnly if this is true, don't write to the byte buffer. calculate the size only.
32     * @return the size that needs to be written to the byte buffer
33     */
34    int marshal(T value, ByteBuffer buffer, int nativeType, boolean sizeOnly);
35
36    /**
37     * Unmarshal a new object instance from the byte buffer.
38     * @param buffer the byte buffer, from which we will read the object
39     * @param nativeType the native type, e.g.
40     *        {@link android.hardware.camera2.CameraMetadata#TYPE_BYTE TYPE_BYTE}.
41     *        Guaranteed to be one for which isNativeTypeSupported returns true.
42     * @return a new instance of type T read from the byte buffer
43     */
44    T unmarshal(ByteBuffer buffer, int nativeType);
45
46    Class<T> getMarshalingClass();
47
48    /**
49     * Determines whether or not this marshaller supports this native type. Most marshallers
50     * will are likely to only support one type.
51     *
52     * @param nativeType the native type, e.g.
53     *        {@link android.hardware.camera2.CameraMetadata#TYPE_BYTE TYPE_BYTE}
54     * @return true if it supports, false otherwise
55     */
56    boolean isNativeTypeSupported(int nativeType);
57
58    public static int NATIVE_SIZE_DYNAMIC = -1;
59
60    /**
61     * How many bytes T will take up if marshalled to/from nativeType
62     * @param nativeType the native type, e.g.
63     *        {@link android.hardware.camera2.CameraMetadata#TYPE_BYTE TYPE_BYTE}
64     * @return a size in bytes, or NATIVE_SIZE_DYNAMIC if the size is dynamic
65     */
66    int getNativeSize(int nativeType);
67}
68