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      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 ByteBufferAsLongBuffer extends LongBuffer {                 // package-private
     31 
     32     protected final ByteBuffer bb;
     33     protected final int offset;
     34     private final ByteOrder order;
     35 
     36     ByteBufferAsLongBuffer(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.duplicate();
     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.bb.order(order);
     53         this.order = order;
     54         offset = off;
     55     }
     56 
     57     public LongBuffer slice() {
     58         int pos = this.position();
     59         int lim = this.limit();
     60         assert (pos <= lim);
     61         int rem = (pos <= lim ? lim - pos : 0);
     62         int off = (pos << 3) + offset;
     63         assert (off >= 0);
     64         return new ByteBufferAsLongBuffer(bb, -1, 0, rem, rem, off, order);
     65     }
     66 
     67     public LongBuffer duplicate() {
     68         return new ByteBufferAsLongBuffer(bb,
     69                 this.markValue(),
     70                 this.position(),
     71                 this.limit(),
     72                 this.capacity(),
     73                 offset,
     74                 order);
     75     }
     76 
     77     public LongBuffer asReadOnlyBuffer() {
     78         return new ByteBufferAsLongBuffer(bb.asReadOnlyBuffer(),
     79                 this.markValue(),
     80                 this.position(),
     81                 this.limit(),
     82                 this.capacity(),
     83                 offset,
     84                 order);
     85     }
     86 
     87     protected int ix(int i) {
     88         return (i << 3) + offset;
     89     }
     90 
     91     public long get() {
     92         return get(nextGetIndex());
     93     }
     94 
     95     public long get(int i) {
     96         return bb.getLongUnchecked(ix(checkIndex(i)));
     97     }
     98 
     99     public LongBuffer get(long[] dst, int offset, int length) {
    100         checkBounds(offset, length, dst.length);
    101         if (length > remaining())
    102             throw new BufferUnderflowException();
    103         bb.getUnchecked(ix(position), dst, offset, length);
    104         position += length;
    105         return this;
    106     }
    107 
    108     public LongBuffer put(long x) {
    109         put(nextPutIndex(), x);
    110         return this;
    111     }
    112 
    113     public LongBuffer put(int i, long x) {
    114         if (isReadOnly) {
    115             throw new ReadOnlyBufferException();
    116         }
    117         bb.putLongUnchecked(ix(checkIndex(i)), x);
    118         return this;
    119     }
    120 
    121     public LongBuffer put(long[] src, int offset, int length) {
    122         checkBounds(offset, length, src.length);
    123         if (length > remaining())
    124             throw new BufferOverflowException();
    125         bb.putUnchecked(ix(position), src, offset, length);
    126         position += length;
    127         return this;
    128     }
    129 
    130     public LongBuffer compact() {
    131         if (isReadOnly) {
    132             throw new ReadOnlyBufferException();
    133         }
    134         int pos = position();
    135         int lim = limit();
    136         assert (pos <= lim);
    137         int rem = (pos <= lim ? lim - pos : 0);
    138         if (!(bb instanceof DirectByteBuffer)) {
    139             System.arraycopy(bb.array(), ix(pos), bb.array(), ix(0), rem << 3);
    140         } else {
    141             Memory.memmove(this, ix(0), this, ix(pos), rem << 3);
    142         }
    143         position(rem);
    144         limit(capacity());
    145         discardMark();
    146         return this;
    147     }
    148 
    149     public boolean isDirect() {
    150         return bb.isDirect();
    151     }
    152 
    153     public boolean isReadOnly() {
    154         return isReadOnly;
    155     }
    156 
    157     public ByteOrder order() {
    158         return order;
    159     }
    160 }
    161