J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005-2007 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.java2d.pipe; |
| 27 | |
| 28 | import sun.misc.Unsafe; |
| 29 | |
| 30 | /** |
| 31 | * The RenderBuffer class is a simplified, high-performance, Unsafe wrapper |
| 32 | * used for buffering rendering operations in a single-threaded rendering |
| 33 | * environment. It's functionality is similar to the ByteBuffer and related |
| 34 | * NIO classes. However, the methods in this class perform little to no |
| 35 | * alignment or bounds checks for performance reasons. Therefore, it is |
| 36 | * the caller's responsibility to ensure that all put() calls are properly |
| 37 | * aligned and within bounds: |
| 38 | * - int and float values must be aligned on 4-byte boundaries |
| 39 | * - long and double values must be aligned on 8-byte boundaries |
| 40 | * |
| 41 | * This class only includes the bare minimum of methods to support |
| 42 | * single-threaded rendering. For example, there is no put(double[]) method |
| 43 | * because we currently have no need for such a method in the STR classes. |
| 44 | */ |
| 45 | public class RenderBuffer { |
| 46 | |
| 47 | /** |
| 48 | * These constants represent the size of various data types (in bytes). |
| 49 | */ |
| 50 | protected static final long SIZEOF_BYTE = 1L; |
| 51 | protected static final long SIZEOF_SHORT = 2L; |
| 52 | protected static final long SIZEOF_INT = 4L; |
| 53 | protected static final long SIZEOF_FLOAT = 4L; |
| 54 | protected static final long SIZEOF_LONG = 8L; |
| 55 | protected static final long SIZEOF_DOUBLE = 8L; |
| 56 | |
| 57 | /** |
| 58 | * Represents the number of elements at which we have empirically |
| 59 | * determined that the average cost of a JNI call exceeds the expense |
| 60 | * of an element by element copy. In other words, if the number of |
| 61 | * elements in an array to be copied exceeds this value, then we should |
| 62 | * use the copyFromArray() method to complete the bulk put operation. |
| 63 | * (This value can be adjusted if the cost of JNI downcalls is reduced |
| 64 | * in a future release.) |
| 65 | */ |
| 66 | private static final int COPY_FROM_ARRAY_THRESHOLD = 28; |
| 67 | |
| 68 | protected final Unsafe unsafe; |
| 69 | protected final long baseAddress; |
| 70 | protected final long endAddress; |
| 71 | protected long curAddress; |
| 72 | protected final int capacity; |
| 73 | |
| 74 | protected RenderBuffer(int numBytes) { |
| 75 | unsafe = Unsafe.getUnsafe(); |
| 76 | curAddress = baseAddress = unsafe.allocateMemory(numBytes); |
| 77 | endAddress = baseAddress + numBytes; |
| 78 | capacity = numBytes; |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * Allocates a fresh buffer using the machine endianness. |
| 83 | */ |
| 84 | public static RenderBuffer allocate(int numBytes) { |
| 85 | return new RenderBuffer(numBytes); |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Returns the base address of the underlying memory buffer. |
| 90 | */ |
| 91 | public final long getAddress() { |
| 92 | return baseAddress; |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Copies length bytes from the Java-level srcArray to the native |
| 97 | * memory located at dstAddr. Note that this method performs no bounds |
| 98 | * checking. Verification that the copy will not result in memory |
| 99 | * corruption should be done by the caller prior to invocation. |
| 100 | * |
| 101 | * @param srcArray the source array |
| 102 | * @param srcPos the starting position of the source array (in bytes) |
| 103 | * @param dstAddr pointer to the destination block of native memory |
| 104 | * @param length the number of bytes to copy from source to destination |
| 105 | */ |
| 106 | private static native void copyFromArray(Object srcArray, long srcPos, |
| 107 | long dstAddr, long length); |
| 108 | |
| 109 | /** |
| 110 | * The behavior (and names) of the following methods are nearly |
| 111 | * identical to their counterparts in the various NIO Buffer classes. |
| 112 | */ |
| 113 | |
| 114 | public final int capacity() { |
| 115 | return capacity; |
| 116 | } |
| 117 | |
| 118 | public final int remaining() { |
| 119 | return (int)(endAddress - curAddress); |
| 120 | } |
| 121 | |
| 122 | public final int position() { |
| 123 | return (int)(curAddress - baseAddress); |
| 124 | } |
| 125 | |
| 126 | public final void position(long numBytes) { |
| 127 | curAddress = baseAddress + numBytes; |
| 128 | } |
| 129 | |
| 130 | public final void clear() { |
| 131 | curAddress = baseAddress; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * putByte() methods... |
| 136 | */ |
| 137 | |
| 138 | public final RenderBuffer putByte(byte x) { |
| 139 | unsafe.putByte(curAddress, x); |
| 140 | curAddress += SIZEOF_BYTE; |
| 141 | return this; |
| 142 | } |
| 143 | |
| 144 | public RenderBuffer put(byte[] x) { |
| 145 | return put(x, 0, x.length); |
| 146 | } |
| 147 | |
| 148 | public RenderBuffer put(byte[] x, int offset, int length) { |
| 149 | if (length > COPY_FROM_ARRAY_THRESHOLD) { |
| 150 | long offsetInBytes = offset * SIZEOF_BYTE; |
| 151 | long lengthInBytes = length * SIZEOF_BYTE; |
| 152 | copyFromArray(x, offsetInBytes, curAddress, lengthInBytes); |
| 153 | position(position() + lengthInBytes); |
| 154 | } else { |
| 155 | int end = offset + length; |
| 156 | for (int i = offset; i < end; i++) { |
| 157 | putByte(x[i]); |
| 158 | } |
| 159 | } |
| 160 | return this; |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * putShort() methods... |
| 165 | */ |
| 166 | |
| 167 | public final RenderBuffer putShort(short x) { |
| 168 | // assert (position() % SIZEOF_SHORT == 0); |
| 169 | unsafe.putShort(curAddress, x); |
| 170 | curAddress += SIZEOF_SHORT; |
| 171 | return this; |
| 172 | } |
| 173 | |
| 174 | public RenderBuffer put(short[] x) { |
| 175 | return put(x, 0, x.length); |
| 176 | } |
| 177 | |
| 178 | public RenderBuffer put(short[] x, int offset, int length) { |
| 179 | // assert (position() % SIZEOF_SHORT == 0); |
| 180 | if (length > COPY_FROM_ARRAY_THRESHOLD) { |
| 181 | long offsetInBytes = offset * SIZEOF_SHORT; |
| 182 | long lengthInBytes = length * SIZEOF_SHORT; |
| 183 | copyFromArray(x, offsetInBytes, curAddress, lengthInBytes); |
| 184 | position(position() + lengthInBytes); |
| 185 | } else { |
| 186 | int end = offset + length; |
| 187 | for (int i = offset; i < end; i++) { |
| 188 | putShort(x[i]); |
| 189 | } |
| 190 | } |
| 191 | return this; |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * putInt() methods... |
| 196 | */ |
| 197 | |
| 198 | public final RenderBuffer putInt(int pos, int x) { |
| 199 | // assert (baseAddress + pos % SIZEOF_INT == 0); |
| 200 | unsafe.putInt(baseAddress + pos, x); |
| 201 | return this; |
| 202 | } |
| 203 | |
| 204 | public final RenderBuffer putInt(int x) { |
| 205 | // assert (position() % SIZEOF_INT == 0); |
| 206 | unsafe.putInt(curAddress, x); |
| 207 | curAddress += SIZEOF_INT; |
| 208 | return this; |
| 209 | } |
| 210 | |
| 211 | public RenderBuffer put(int[] x) { |
| 212 | return put(x, 0, x.length); |
| 213 | } |
| 214 | |
| 215 | public RenderBuffer put(int[] x, int offset, int length) { |
| 216 | // assert (position() % SIZEOF_INT == 0); |
| 217 | if (length > COPY_FROM_ARRAY_THRESHOLD) { |
| 218 | long offsetInBytes = offset * SIZEOF_INT; |
| 219 | long lengthInBytes = length * SIZEOF_INT; |
| 220 | copyFromArray(x, offsetInBytes, curAddress, lengthInBytes); |
| 221 | position(position() + lengthInBytes); |
| 222 | } else { |
| 223 | int end = offset + length; |
| 224 | for (int i = offset; i < end; i++) { |
| 225 | putInt(x[i]); |
| 226 | } |
| 227 | } |
| 228 | return this; |
| 229 | } |
| 230 | |
| 231 | /** |
| 232 | * putFloat() methods... |
| 233 | */ |
| 234 | |
| 235 | public final RenderBuffer putFloat(float x) { |
| 236 | // assert (position() % SIZEOF_FLOAT == 0); |
| 237 | unsafe.putFloat(curAddress, x); |
| 238 | curAddress += SIZEOF_FLOAT; |
| 239 | return this; |
| 240 | } |
| 241 | |
| 242 | public RenderBuffer put(float[] x) { |
| 243 | return put(x, 0, x.length); |
| 244 | } |
| 245 | |
| 246 | public RenderBuffer put(float[] x, int offset, int length) { |
| 247 | // assert (position() % SIZEOF_FLOAT == 0); |
| 248 | if (length > COPY_FROM_ARRAY_THRESHOLD) { |
| 249 | long offsetInBytes = offset * SIZEOF_FLOAT; |
| 250 | long lengthInBytes = length * SIZEOF_FLOAT; |
| 251 | copyFromArray(x, offsetInBytes, curAddress, lengthInBytes); |
| 252 | position(position() + lengthInBytes); |
| 253 | } else { |
| 254 | int end = offset + length; |
| 255 | for (int i = offset; i < end; i++) { |
| 256 | putFloat(x[i]); |
| 257 | } |
| 258 | } |
| 259 | return this; |
| 260 | } |
| 261 | |
| 262 | /** |
| 263 | * putLong() methods... |
| 264 | */ |
| 265 | |
| 266 | public final RenderBuffer putLong(long x) { |
| 267 | // assert (position() % SIZEOF_LONG == 0); |
| 268 | unsafe.putLong(curAddress, x); |
| 269 | curAddress += SIZEOF_LONG; |
| 270 | return this; |
| 271 | } |
| 272 | |
| 273 | public RenderBuffer put(long[] x) { |
| 274 | return put(x, 0, x.length); |
| 275 | } |
| 276 | |
| 277 | public RenderBuffer put(long[] x, int offset, int length) { |
| 278 | // assert (position() % SIZEOF_LONG == 0); |
| 279 | if (length > COPY_FROM_ARRAY_THRESHOLD) { |
| 280 | long offsetInBytes = offset * SIZEOF_LONG; |
| 281 | long lengthInBytes = length * SIZEOF_LONG; |
| 282 | copyFromArray(x, offsetInBytes, curAddress, lengthInBytes); |
| 283 | position(position() + lengthInBytes); |
| 284 | } else { |
| 285 | int end = offset + length; |
| 286 | for (int i = offset; i < end; i++) { |
| 287 | putLong(x[i]); |
| 288 | } |
| 289 | } |
| 290 | return this; |
| 291 | } |
| 292 | |
| 293 | /** |
| 294 | * putDouble() method(s)... |
| 295 | */ |
| 296 | |
| 297 | public final RenderBuffer putDouble(double x) { |
| 298 | // assert (position() % SIZEOF_DOUBLE == 0); |
| 299 | unsafe.putDouble(curAddress, x); |
| 300 | curAddress += SIZEOF_DOUBLE; |
| 301 | return this; |
| 302 | } |
| 303 | } |