85 lines
2.7 KiB
Java
85 lines
2.7 KiB
Java
/*
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* Copyright (C) 2007 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package java.nio;
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import static android.annotation.SystemApi.Client.MODULE_LIBRARIES;
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import android.annotation.SystemApi;
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import android.compat.annotation.UnsupportedAppUsage;
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/**
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* This class is used via JNI by code in frameworks/base/ and
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* by the JniConstants cache in libnativehelper/.
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* @hide
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*/
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// @VisibleForTesting : was default
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@SystemApi(client = MODULE_LIBRARIES)
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public final class NIOAccess {
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private NIOAccess() {}
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/**
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* Returns the underlying native pointer to the data of the given
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* Buffer starting at the Buffer's current position, or 0 if the
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* Buffer is not backed by native heap storage.
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* @hide
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*/
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// @VisibleForTesting : was default
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@UnsupportedAppUsage
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public static long getBasePointer(Buffer b) {
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long address = b.address;
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if (address == 0L) {
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return 0L;
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}
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return address + (b.position << b._elementSizeShift);
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}
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/**
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* Returns the underlying Java array containing the data of the
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* given Buffer, or null if the Buffer is not backed by a Java array.
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*
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* @param b {@code Buffer} to get its underlying data array
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* @return underlying Java array
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*
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* @hide
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*/
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@UnsupportedAppUsage
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@SystemApi(client = MODULE_LIBRARIES)
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public static Object getBaseArray(Buffer b) {
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return b.hasArray() ? b.array() : null;
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}
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/**
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* Returns the offset in bytes from the start of the underlying
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* Java array object containing the data of the given Buffer to
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* the actual start of the data. The start of the data takes into
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* account the Buffer's current position. This method is only
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* meaningful if {@link #getBaseArray(Buffer)} returns non-null.
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*
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* @param b {@code Buffer} to get its underlying data array's base offset
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* @return underlying Java array's base offset
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*
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* @hide
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*/
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@UnsupportedAppUsage
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@SystemApi(client = MODULE_LIBRARIES)
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public static int getBaseArrayOffset(Buffer b) {
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return b.hasArray() ? ((b.arrayOffset() + b.position) << b._elementSizeShift) : 0;
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}
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}
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