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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.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 
slice()57     public FloatBuffer 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 << 2) + offset;
63         assert (off >= 0);
64         return new ByteBufferAsFloatBuffer(bb, -1, 0, rem, rem, off, order);
65     }
66 
duplicate()67     public FloatBuffer duplicate() {
68         return new ByteBufferAsFloatBuffer(bb,
69                 markValue(),
70                 position(),
71                 limit(),
72                 capacity(),
73                 offset,
74                 order);
75     }
76 
asReadOnlyBuffer()77     public FloatBuffer asReadOnlyBuffer() {
78         return new ByteBufferAsFloatBuffer(bb.asReadOnlyBuffer(),
79                 markValue(),
80                 position(),
81                 limit(),
82                 capacity(),
83                 offset,
84                 order);
85     }
86 
ix(int i)87     protected int ix(int i) {
88         return (i << 2) + offset;
89     }
90 
get()91     public float get() {
92         return get(nextGetIndex());
93     }
94 
get(int i)95     public float get(int i) {
96         return bb.getFloatUnchecked(ix(checkIndex(i)));
97     }
98 
get(float[] dst, int offset, int length)99     public FloatBuffer get(float[] 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 
put(float x)108     public FloatBuffer put(float x) {
109         put(nextPutIndex(), x);
110         return this;
111     }
112 
put(int i, float x)113     public FloatBuffer put(int i, float x) {
114         if (isReadOnly) {
115             throw new ReadOnlyBufferException();
116         }
117         bb.putFloatUnchecked(ix(checkIndex(i)), x);
118         return this;
119     }
120 
put(float[] src, int offset, int length)121     public FloatBuffer put(float[] 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 
compact()130     public FloatBuffer 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 << 2);
140         } else {
141             Memory.memmove(this, ix(0), this, ix(pos), rem << 2);
142         }
143         position(rem);
144         limit(capacity());
145         discardMark();
146         return this;
147     }
148 
isDirect()149     public boolean isDirect() {
150         return bb.isDirect();
151     }
152 
isReadOnly()153     public boolean isReadOnly() {
154         return isReadOnly;
155     }
156 
order()157     public ByteOrder order() {
158         return order;
159     }
160 }
161