1 /* 2 * Copyright (c) 2000, 2008, Oracle and/or its affiliates. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.nio; 27 28 import libcore.io.Memory; 29 30 class ByteBufferAsFloatBuffer extends FloatBuffer { // package-private 31 32 protected final ByteBuffer bb; 33 protected final int offset; 34 private final ByteOrder order; 35 ByteBufferAsFloatBuffer(ByteBuffer bb, int mark, int pos, int lim, int cap, int off, ByteOrder order)36 ByteBufferAsFloatBuffer(ByteBuffer bb, 37 int mark, int pos, int lim, int cap, 38 int off, ByteOrder order) { 39 super(mark, pos, lim, cap); 40 this.bb = bb; 41 this.isReadOnly = bb.isReadOnly; 42 // There are only two possibilities for the type of ByteBuffer "bb", viz, DirectByteBuffer and 43 // HeapByteBuffer. We only have to initialize the field when bb is an instance of 44 // DirectByteBuffer. 45 // The address field is used by NIOAccess#getBasePointer and GetDirectBufferAddress method 46 // in art which return the address of the first usable byte of the underlying memory, i.e, 47 // the position of parent buffer. Therefore, value of "off" will be equal to parent buffer's 48 // position when the method is called from either HeapByteBuffer or DirectByteBuffer. 49 if (bb instanceof DirectByteBuffer) { 50 this.address = bb.address + off; 51 } 52 this.order = order; 53 offset = off; 54 } 55 slice()56 public FloatBuffer slice() { 57 int pos = this.position(); 58 int lim = this.limit(); 59 assert (pos <= lim); 60 int rem = (pos <= lim ? lim - pos : 0); 61 int off = (pos << 2) + offset; 62 assert (off >= 0); 63 return new ByteBufferAsFloatBuffer(bb, -1, 0, rem, rem, off, order); 64 } 65 duplicate()66 public FloatBuffer duplicate() { 67 return new ByteBufferAsFloatBuffer(bb, 68 markValue(), 69 position(), 70 limit(), 71 capacity(), 72 offset, 73 order); 74 } 75 asReadOnlyBuffer()76 public FloatBuffer asReadOnlyBuffer() { 77 return new ByteBufferAsFloatBuffer(bb.asReadOnlyBuffer(), 78 markValue(), 79 position(), 80 limit(), 81 capacity(), 82 offset, 83 order); 84 } 85 ix(int i)86 protected int ix(int i) { 87 return (i << 2) + offset; 88 } 89 get()90 public float get() { 91 return get(nextGetIndex()); 92 } 93 get(int i)94 public float get(int i) { 95 return bb.getFloatUnchecked(ix(checkIndex(i))); 96 } 97 get(float[] dst, int offset, int length)98 public FloatBuffer get(float[] dst, int offset, int length) { 99 checkBounds(offset, length, dst.length); 100 if (length > remaining()) 101 throw new BufferUnderflowException(); 102 bb.getUnchecked(ix(position), dst, offset, length); 103 position += length; 104 return this; 105 } 106 put(float x)107 public FloatBuffer put(float x) { 108 put(nextPutIndex(), x); 109 return this; 110 } 111 put(int i, float x)112 public FloatBuffer put(int i, float x) { 113 if (isReadOnly) { 114 throw new ReadOnlyBufferException(); 115 } 116 bb.putFloatUnchecked(ix(checkIndex(i)), x); 117 return this; 118 } 119 put(float[] src, int offset, int length)120 public FloatBuffer put(float[] src, int offset, int length) { 121 checkBounds(offset, length, src.length); 122 if (length > remaining()) 123 throw new BufferOverflowException(); 124 bb.putUnchecked(ix(position), src, offset, length); 125 position += length; 126 return this; 127 } 128 compact()129 public FloatBuffer compact() { 130 if (isReadOnly) { 131 throw new ReadOnlyBufferException(); 132 } 133 int pos = position(); 134 int lim = limit(); 135 assert (pos <= lim); 136 int rem = (pos <= lim ? lim - pos : 0); 137 if (!(bb instanceof DirectByteBuffer)) { 138 System.arraycopy(bb.array(), ix(pos), bb.array(), ix(0), rem << 2); 139 } else { 140 Memory.memmove(this, ix(0), this, ix(pos), rem << 2); 141 } 142 position(rem); 143 limit(capacity()); 144 discardMark(); 145 return this; 146 } 147 isDirect()148 public boolean isDirect() { 149 return bb.isDirect(); 150 } 151 isReadOnly()152 public boolean isReadOnly() { 153 return isReadOnly; 154 } 155 order()156 public ByteOrder order() { 157 return order; 158 } 159 } 160