Seigo Nonaka | f1644f7 | 2017-11-27 22:09:49 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 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 | |
| 17 | package android.text; |
| 18 | |
| 19 | import android.annotation.IntRange; |
| 20 | import android.annotation.NonNull; |
| 21 | |
| 22 | import com.android.internal.util.ArrayUtils; |
| 23 | |
| 24 | import libcore.util.EmptyArray; |
| 25 | |
| 26 | /** |
| 27 | * Implements a growing array of int primitives. |
| 28 | * |
| 29 | * These arrays are NOT thread safe. |
| 30 | * |
| 31 | * @hide |
| 32 | */ |
| 33 | public final class AutoGrowArray { |
| 34 | private static final int MIN_CAPACITY_INCREMENT = 12; |
| 35 | private static final int MAX_CAPACITY_TO_BE_KEPT = 10000; |
| 36 | |
| 37 | /** |
| 38 | * Returns next capacity size. |
| 39 | * |
| 40 | * The returned capacity is larger than requested capacity. |
| 41 | */ |
| 42 | private static int computeNewCapacity(int currentSize, int requested) { |
| 43 | final int targetCapacity = currentSize + (currentSize < (MIN_CAPACITY_INCREMENT / 2) |
| 44 | ? MIN_CAPACITY_INCREMENT : currentSize >> 1); |
| 45 | return targetCapacity > requested ? targetCapacity : requested; |
| 46 | } |
| 47 | |
| 48 | /** |
| 49 | * An auto growing byte array. |
| 50 | */ |
| 51 | public static class ByteArray { |
| 52 | |
| 53 | private @NonNull byte[] mValues; |
| 54 | private @IntRange(from = 0) int mSize; |
| 55 | |
| 56 | /** |
| 57 | * Creates an empty ByteArray with the default initial capacity. |
| 58 | */ |
| 59 | public ByteArray() { |
| 60 | this(10); |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * Creates an empty ByteArray with the specified initial capacity. |
| 65 | */ |
| 66 | public ByteArray(@IntRange(from = 0) int initialCapacity) { |
| 67 | if (initialCapacity == 0) { |
| 68 | mValues = EmptyArray.BYTE; |
| 69 | } else { |
| 70 | mValues = ArrayUtils.newUnpaddedByteArray(initialCapacity); |
| 71 | } |
| 72 | mSize = 0; |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * Changes the size of this ByteArray. If this ByteArray is shrinked, the backing array |
| 77 | * capacity is unchanged. |
| 78 | */ |
| 79 | public void resize(@IntRange(from = 0) int newSize) { |
| 80 | if (newSize > mValues.length) { |
| 81 | ensureCapacity(newSize - mSize); |
| 82 | } |
| 83 | mSize = newSize; |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Appends the specified value to the end of this array. |
| 88 | */ |
| 89 | public void append(byte value) { |
| 90 | ensureCapacity(1); |
| 91 | mValues[mSize++] = value; |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Ensures capacity to append at least <code>count</code> values. |
| 96 | */ |
| 97 | private void ensureCapacity(@IntRange int count) { |
| 98 | final int requestedSize = mSize + count; |
| 99 | if (requestedSize >= mValues.length) { |
| 100 | final int newCapacity = computeNewCapacity(mSize, requestedSize); |
| 101 | final byte[] newValues = ArrayUtils.newUnpaddedByteArray(newCapacity); |
| 102 | System.arraycopy(mValues, 0, newValues, 0, mSize); |
| 103 | mValues = newValues; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * Removes all values from this array. |
| 109 | */ |
| 110 | public void clear() { |
| 111 | mSize = 0; |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Removes all values from this array and release the internal array object if it is too |
| 116 | * large. |
| 117 | */ |
| 118 | public void clearWithReleasingLargeArray() { |
| 119 | clear(); |
| 120 | if (mValues.length > MAX_CAPACITY_TO_BE_KEPT) { |
| 121 | mValues = EmptyArray.BYTE; |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Returns the value at the specified position in this array. |
| 127 | */ |
| 128 | public byte get(@IntRange(from = 0) int index) { |
| 129 | return mValues[index]; |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Sets the value at the specified position in this array. |
| 134 | */ |
| 135 | public void set(@IntRange(from = 0) int index, byte value) { |
| 136 | mValues[index] = value; |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Returns the number of values in this array. |
| 141 | */ |
| 142 | public @IntRange(from = 0) int size() { |
| 143 | return mSize; |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * Returns internal raw array. |
| 148 | * |
| 149 | * Note that this array may have larger size than you requested. |
| 150 | * Use size() instead for getting the actual array size. |
| 151 | */ |
| 152 | public @NonNull byte[] getRawArray() { |
| 153 | return mValues; |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | /** |
| 158 | * An auto growing int array. |
| 159 | */ |
| 160 | public static class IntArray { |
| 161 | |
| 162 | private @NonNull int[] mValues; |
| 163 | private @IntRange(from = 0) int mSize; |
| 164 | |
| 165 | /** |
| 166 | * Creates an empty IntArray with the default initial capacity. |
| 167 | */ |
| 168 | public IntArray() { |
| 169 | this(10); |
| 170 | } |
| 171 | |
| 172 | /** |
| 173 | * Creates an empty IntArray with the specified initial capacity. |
| 174 | */ |
| 175 | public IntArray(@IntRange(from = 0) int initialCapacity) { |
| 176 | if (initialCapacity == 0) { |
| 177 | mValues = EmptyArray.INT; |
| 178 | } else { |
| 179 | mValues = ArrayUtils.newUnpaddedIntArray(initialCapacity); |
| 180 | } |
| 181 | mSize = 0; |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * Changes the size of this IntArray. If this IntArray is shrinked, the backing array |
| 186 | * capacity is unchanged. |
| 187 | */ |
| 188 | public void resize(@IntRange(from = 0) int newSize) { |
| 189 | if (newSize > mValues.length) { |
| 190 | ensureCapacity(newSize - mSize); |
| 191 | } |
| 192 | mSize = newSize; |
| 193 | } |
| 194 | |
| 195 | /** |
| 196 | * Appends the specified value to the end of this array. |
| 197 | */ |
| 198 | public void append(int value) { |
| 199 | ensureCapacity(1); |
| 200 | mValues[mSize++] = value; |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * Ensures capacity to append at least <code>count</code> values. |
| 205 | */ |
| 206 | private void ensureCapacity(@IntRange(from = 0) int count) { |
| 207 | final int requestedSize = mSize + count; |
| 208 | if (requestedSize >= mValues.length) { |
| 209 | final int newCapacity = computeNewCapacity(mSize, requestedSize); |
| 210 | final int[] newValues = ArrayUtils.newUnpaddedIntArray(newCapacity); |
| 211 | System.arraycopy(mValues, 0, newValues, 0, mSize); |
| 212 | mValues = newValues; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Removes all values from this array. |
| 218 | */ |
| 219 | public void clear() { |
| 220 | mSize = 0; |
| 221 | } |
| 222 | |
| 223 | /** |
| 224 | * Removes all values from this array and release the internal array object if it is too |
| 225 | * large. |
| 226 | */ |
| 227 | public void clearWithReleasingLargeArray() { |
| 228 | clear(); |
| 229 | if (mValues.length > MAX_CAPACITY_TO_BE_KEPT) { |
| 230 | mValues = EmptyArray.INT; |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | /** |
| 235 | * Returns the value at the specified position in this array. |
| 236 | */ |
| 237 | public int get(@IntRange(from = 0) int index) { |
| 238 | return mValues[index]; |
| 239 | } |
| 240 | |
| 241 | /** |
| 242 | * Sets the value at the specified position in this array. |
| 243 | */ |
| 244 | public void set(@IntRange(from = 0) int index, int value) { |
| 245 | mValues[index] = value; |
| 246 | } |
| 247 | |
| 248 | /** |
| 249 | * Returns the number of values in this array. |
| 250 | */ |
| 251 | public @IntRange(from = 0) int size() { |
| 252 | return mSize; |
| 253 | } |
| 254 | |
| 255 | /** |
| 256 | * Returns internal raw array. |
| 257 | * |
| 258 | * Note that this array may have larger size than you requested. |
| 259 | * Use size() instead for getting the actual array size. |
| 260 | */ |
| 261 | public @NonNull int[] getRawArray() { |
| 262 | return mValues; |
| 263 | } |
| 264 | } |
| 265 | |
| 266 | /** |
| 267 | * An auto growing float array. |
| 268 | */ |
| 269 | public static class FloatArray { |
| 270 | |
| 271 | private @NonNull float[] mValues; |
| 272 | private @IntRange(from = 0) int mSize; |
| 273 | |
| 274 | /** |
| 275 | * Creates an empty FloatArray with the default initial capacity. |
| 276 | */ |
| 277 | public FloatArray() { |
| 278 | this(10); |
| 279 | } |
| 280 | |
| 281 | /** |
| 282 | * Creates an empty FloatArray with the specified initial capacity. |
| 283 | */ |
| 284 | public FloatArray(@IntRange(from = 0) int initialCapacity) { |
| 285 | if (initialCapacity == 0) { |
| 286 | mValues = EmptyArray.FLOAT; |
| 287 | } else { |
| 288 | mValues = ArrayUtils.newUnpaddedFloatArray(initialCapacity); |
| 289 | } |
| 290 | mSize = 0; |
| 291 | } |
| 292 | |
| 293 | /** |
| 294 | * Changes the size of this FloatArray. If this FloatArray is shrinked, the backing array |
| 295 | * capacity is unchanged. |
| 296 | */ |
| 297 | public void resize(@IntRange(from = 0) int newSize) { |
| 298 | if (newSize > mValues.length) { |
| 299 | ensureCapacity(newSize - mSize); |
| 300 | } |
| 301 | mSize = newSize; |
| 302 | } |
| 303 | |
| 304 | /** |
| 305 | * Appends the specified value to the end of this array. |
| 306 | */ |
| 307 | public void append(float value) { |
| 308 | ensureCapacity(1); |
| 309 | mValues[mSize++] = value; |
| 310 | } |
| 311 | |
| 312 | /** |
| 313 | * Ensures capacity to append at least <code>count</code> values. |
| 314 | */ |
| 315 | private void ensureCapacity(int count) { |
| 316 | final int requestedSize = mSize + count; |
| 317 | if (requestedSize >= mValues.length) { |
| 318 | final int newCapacity = computeNewCapacity(mSize, requestedSize); |
| 319 | final float[] newValues = ArrayUtils.newUnpaddedFloatArray(newCapacity); |
| 320 | System.arraycopy(mValues, 0, newValues, 0, mSize); |
| 321 | mValues = newValues; |
| 322 | } |
| 323 | } |
| 324 | |
| 325 | /** |
| 326 | * Removes all values from this array. |
| 327 | */ |
| 328 | public void clear() { |
| 329 | mSize = 0; |
| 330 | } |
| 331 | |
| 332 | /** |
| 333 | * Removes all values from this array and release the internal array object if it is too |
| 334 | * large. |
| 335 | */ |
| 336 | public void clearWithReleasingLargeArray() { |
| 337 | clear(); |
| 338 | if (mValues.length > MAX_CAPACITY_TO_BE_KEPT) { |
| 339 | mValues = EmptyArray.FLOAT; |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | /** |
| 344 | * Returns the value at the specified position in this array. |
| 345 | */ |
| 346 | public float get(@IntRange(from = 0) int index) { |
| 347 | return mValues[index]; |
| 348 | } |
| 349 | |
| 350 | /** |
| 351 | * Sets the value at the specified position in this array. |
| 352 | */ |
| 353 | public void set(@IntRange(from = 0) int index, float value) { |
| 354 | mValues[index] = value; |
| 355 | } |
| 356 | |
| 357 | /** |
| 358 | * Returns the number of values in this array. |
| 359 | */ |
| 360 | public @IntRange(from = 0) int size() { |
| 361 | return mSize; |
| 362 | } |
| 363 | |
| 364 | /** |
| 365 | * Returns internal raw array. |
| 366 | * |
| 367 | * Note that this array may have larger size than you requested. |
| 368 | * Use size() instead for getting the actual array size. |
| 369 | */ |
| 370 | public @NonNull float[] getRawArray() { |
| 371 | return mValues; |
| 372 | } |
| 373 | } |
| 374 | } |