Ytai Ben-Tsvi | 335114a | 2019-11-12 12:25:38 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2019 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 | package android.os; |
| 17 | |
| 18 | import static android.system.OsConstants.MAP_SHARED; |
| 19 | import static android.system.OsConstants.PROT_READ; |
| 20 | |
| 21 | import android.annotation.NonNull; |
| 22 | import android.annotation.Nullable; |
| 23 | import android.annotation.SuppressLint; |
| 24 | import android.annotation.SystemApi; |
| 25 | import android.annotation.TestApi; |
| 26 | import android.system.ErrnoException; |
| 27 | import android.system.Os; |
| 28 | import android.util.Log; |
| 29 | |
| 30 | import com.android.internal.util.Preconditions; |
| 31 | |
| 32 | import java.nio.ByteBuffer; |
| 33 | import java.nio.DirectByteBuffer; |
| 34 | import java.util.ArrayList; |
| 35 | import java.util.List; |
| 36 | |
| 37 | /** |
| 38 | * Provides utilities for dealing with HidlMemory. |
| 39 | * |
| 40 | * @hide |
| 41 | */ |
| 42 | public final class HidlMemoryUtil { |
| 43 | static private final String TAG = "HidlMemoryUtil"; |
| 44 | |
| 45 | private HidlMemoryUtil() { |
| 46 | } |
| 47 | |
| 48 | /** |
| 49 | * Copies a byte-array into a new Ashmem region and return it as HidlMemory. |
| 50 | * The returned instance owns the underlying file descriptors, and the client should generally |
| 51 | * call close on it when no longer in use (or otherwise, when the object gets destroyed it will |
| 52 | * be closed). |
| 53 | * |
| 54 | * @param input The input byte array. |
| 55 | * @return A HidlMemory instance, containing a copy of the input. |
| 56 | */ |
| 57 | public static @NonNull |
| 58 | HidlMemory byteArrayToHidlMemory(@NonNull byte[] input) { |
| 59 | return byteArrayToHidlMemory(input, null); |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Copies a byte-array into a new Ashmem region and return it as HidlMemory. |
| 64 | * The returned instance owns the underlying file descriptors, and the client should generally |
| 65 | * call close on it when no longer in use (or otherwise, when the object gets destroyed it will |
| 66 | * be closed). |
| 67 | * |
| 68 | * @param input The input byte array. |
| 69 | * @param name An optional name for the ashmem region. |
| 70 | * @return A HidlMemory instance, containing a copy of the input. |
| 71 | */ |
| 72 | public static @NonNull |
| 73 | HidlMemory byteArrayToHidlMemory(@NonNull byte[] input, @Nullable String name) { |
| 74 | Preconditions.checkNotNull(input); |
| 75 | |
| 76 | if (input.length == 0) { |
| 77 | return new HidlMemory("ashmem", 0, null); |
| 78 | } |
| 79 | |
| 80 | try { |
| 81 | SharedMemory shmem = SharedMemory.create(name != null ? name : "", input.length); |
| 82 | ByteBuffer buffer = shmem.mapReadWrite(); |
| 83 | buffer.put(input); |
| 84 | shmem.unmap(buffer); |
| 85 | NativeHandle handle = new NativeHandle(shmem.getFileDescriptor(), true); |
| 86 | return new HidlMemory("ashmem", input.length, handle); |
| 87 | } catch (ErrnoException e) { |
| 88 | throw new RuntimeException(e); |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Copies a byte list into a new Ashmem region and return it as HidlMemory. |
| 94 | * The returned instance owns the underlying file descriptors, and the client should generally |
| 95 | * call close on it when no longer in use (or otherwise, when the object gets destroyed it will |
| 96 | * be closed). |
| 97 | * |
| 98 | * @param input The input byte list. |
| 99 | * @return A HidlMemory instance, containing a copy of the input. |
| 100 | */ |
| 101 | public static @NonNull |
| 102 | HidlMemory byteListToHidlMemory(@NonNull List<Byte> input) { |
| 103 | return byteListToHidlMemory(input, null); |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Copies a byte list into a new Ashmem region and return it as HidlMemory. |
| 108 | * The returned instance owns the underlying file descriptors, and the client should generally |
| 109 | * call close on it when no longer in use (or otherwise, when the object gets destroyed it will |
| 110 | * be closed). |
| 111 | * |
| 112 | * @param input The input byte list. |
| 113 | * @param name An optional name for the ashmem region. |
| 114 | * @return A HidlMemory instance, containing a copy of the input. |
| 115 | */ |
| 116 | public static @NonNull |
| 117 | HidlMemory byteListToHidlMemory(@NonNull List<Byte> input, @Nullable String name) { |
| 118 | Preconditions.checkNotNull(input); |
| 119 | |
| 120 | if (input.isEmpty()) { |
| 121 | return new HidlMemory("ashmem", 0, null); |
| 122 | } |
| 123 | |
| 124 | try { |
| 125 | SharedMemory shmem = SharedMemory.create(name != null ? name : "", input.size()); |
| 126 | ByteBuffer buffer = shmem.mapReadWrite(); |
| 127 | for (Byte b : input) { |
| 128 | buffer.put(b); |
| 129 | } |
| 130 | shmem.unmap(buffer); |
| 131 | NativeHandle handle = new NativeHandle(shmem.getFileDescriptor(), true); |
| 132 | return new HidlMemory("ashmem", input.size(), handle); |
| 133 | } catch (ErrnoException e) { |
| 134 | throw new RuntimeException(e); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | /** |
| 139 | * Copies all data from a HidlMemory instance into a byte array. |
| 140 | * |
| 141 | * @param mem The HidlMemory instance. Must be of name "ashmem" and of size that doesn't exceed |
| 142 | * {@link Integer#MAX_VALUE}. |
| 143 | * @return A byte array, containing a copy of the input. |
| 144 | */ |
| 145 | public static @NonNull |
| 146 | byte[] hidlMemoryToByteArray(@NonNull HidlMemory mem) { |
| 147 | Preconditions.checkNotNull(mem); |
| 148 | Preconditions.checkArgumentInRange(mem.getSize(), 0L, (long) Integer.MAX_VALUE, |
| 149 | "Memory size"); |
| 150 | Preconditions.checkArgument(mem.getSize() == 0 || mem.getName().equals("ashmem"), |
| 151 | "Unsupported memory type: %s", mem.getName()); |
| 152 | |
| 153 | if (mem.getSize() == 0) { |
| 154 | return new byte[0]; |
| 155 | } |
| 156 | |
| 157 | ByteBuffer buffer = getBuffer(mem); |
| 158 | byte[] result = new byte[buffer.remaining()]; |
| 159 | buffer.get(result); |
| 160 | return result; |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * Copies all data from a HidlMemory instance into a byte list. |
| 165 | * |
| 166 | * @param mem The HidlMemory instance. Must be of name "ashmem" and of size that doesn't exceed |
| 167 | * {@link Integer#MAX_VALUE}. |
| 168 | * @return A byte list, containing a copy of the input. |
| 169 | */ |
| 170 | @SuppressLint("ConcreteCollection") |
| 171 | public static @NonNull |
| 172 | ArrayList<Byte> hidlMemoryToByteList(@NonNull HidlMemory mem) { |
| 173 | Preconditions.checkNotNull(mem); |
| 174 | Preconditions.checkArgumentInRange(mem.getSize(), 0L, (long) Integer.MAX_VALUE, |
| 175 | "Memory size"); |
| 176 | Preconditions.checkArgument(mem.getSize() == 0 || mem.getName().equals("ashmem"), |
| 177 | "Unsupported memory type: %s", mem.getName()); |
| 178 | |
| 179 | if (mem.getSize() == 0) { |
| 180 | return new ArrayList<>(); |
| 181 | } |
| 182 | |
| 183 | ByteBuffer buffer = getBuffer(mem); |
| 184 | |
| 185 | ArrayList<Byte> result = new ArrayList<>(buffer.remaining()); |
| 186 | while (buffer.hasRemaining()) { |
| 187 | result.add(buffer.get()); |
| 188 | } |
| 189 | return result; |
| 190 | } |
| 191 | |
| 192 | private static ByteBuffer getBuffer(@NonNull HidlMemory mem) { |
| 193 | try { |
| 194 | final int size = (int) mem.getSize(); |
| 195 | |
| 196 | if (size == 0) { |
| 197 | return ByteBuffer.wrap(new byte[0]); |
| 198 | } |
| 199 | |
| 200 | NativeHandle handle = mem.getHandle(); |
| 201 | |
| 202 | final long address = Os.mmap(0, size, PROT_READ, MAP_SHARED, handle.getFileDescriptor(), |
| 203 | 0); |
| 204 | return new DirectByteBuffer(size, address, handle.getFileDescriptor(), () -> { |
| 205 | try { |
| 206 | Os.munmap(address, size); |
| 207 | } catch (ErrnoException e) { |
| 208 | Log.wtf(TAG, e); |
| 209 | } |
| 210 | }, true); |
| 211 | } catch (ErrnoException e) { |
| 212 | throw new RuntimeException(e); |
| 213 | } |
| 214 | } |
| 215 | } |