/*
* Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package java.nio;
import com.sun.jsr239.BufferManager;
/**
* A byte buffer.
*
* <p> This class is provided as part of the JSR 239 NIO Buffer
* building block. It is a subset of the
* <code>java.nio.ByteBuffer</code> class in Java(TM) Standard Edition
* version 1.4.2. Differences are noted in <b><i>bold italic</i></b>.
* The class documentation may make reference to classes that are not
* present in the building block.
*
* <p><b><i> I/O channels, marking and resetting, and read-only buffers
* are not supported. Allocation of non-direct byte buffers,
* compaction, and duplication are not supported. The
* <code>char</code>, <code>long</code>, and <code>double</code>
* datatypes are not supported. The following methods are omitted:
*
* <ul>
* <li><code>ByteBuffer allocate(int capacity)</code></li>
* <li><code>ByteBuffer compact()</code></li>
* <li><code>ByteBuffer duplicate()</code></li>
* <li><code>Buffer mark()</code></li>
* <li><code>Buffer reset()</code></li>
* <li><code>boolean isReadOnly()</code></li>
* <li><code>ByteBuffer asReadOnlyBuffer()</code></li>
* <li><code>CharBuffer asCharBuffer()</code></li>
* <li><code>LongBuffer asLongBuffer()</code></li>
* <li><code>DoubleBuffer asDoubleBuffer()</code></li>
* <li><code>char getChar()</code></li>
* <li><code>char getChar(int index)</code></li>
* <li><code>long getLong()</code></li>
* <li><code>long getLong(int index)</code></li>
* <li><code>double getDouble()</code></li>
* <li><code>double getDouble(int index)</code></li>
* <li><code>ByteBuffer putChar(char value)</code></li>
* <li><code>ByteBuffer putChar(int index, char value)</code></li>
* <li><code>ByteBuffer putLong(int index, long value)</code></li>
* <li><code>ByteBuffer putLong(long value)</code></li>
* <li><code>ByteBuffer putDouble(double value)</code></li>
* <li><code>ByteBuffer putDouble(int index, double value)</code></li>
* </ul>
* </i></b>
*
* <p> This class defines six categories of operations upon
* byte buffers:
*
* <ul>
*
* <li><p> Absolute and relative <A
* HREF="ByteBuffer.html#get()"><CODE></code><i>get</i><code></CODE></A>
* and <A
* HREF="ByteBuffer.html#put(byte)"><CODE></code><i>put</i><code></CODE></A>
* methods that read and write single bytes; </p></li>
*
* <li><p> Relative <A
* HREF="ByteBuffer.html#get(byte[])"><CODE></code><i>bulk
* get</i><code></CODE></A> methods that transfer contiguous
* sequences of bytes from this buffer into an array; </p></li>
*
* <li><p> Relative <A
* HREF="ByteBuffer.html#put(byte[])"><CODE></code><i>bulk
* put</i><code></CODE></A> methods that transfer contiguous
* sequences of bytes from a byte array or some other byte buffer
* into this buffer; </p></li>
*
* <li><p> Absolute and relative <i>get</i> and <i>put</i> methods
* that read and write values of other primitive types, translating
* them to and from sequences of bytes in a particular byte order;
* <b><i>JSR 239 does not support certain multi-byte </i>get<i> and
* </i>put<i> methods.</i></b> </p></li>
*
* <li><p> Methods for creating <i><a href="#views">view
* buffers</a></i>, which allow a byte buffer to be viewed as a
* buffer containing values of some other primitive type; and
* </p></li>
*
* <li><p> Methods for compacting, duplicating, and <A
* HREF="ByteBuffer.html#slice()"><CODE></code>slicing<code></CODE></A>
* a byte buffer. <b><i>JSR 239 does not support compacting and
* duplicating buffers.</i></b> </p></li>
*
* </ul>
*
* <p> Byte buffers can be created either by <A
* HREF="ByteBuffer.html#allocateDirect(int)"><CODE></code><i>allocation</i><code></CODE></A>,
* which allocates space for the buffer's content, or by <A
* HREF="ByteBuffer.html#wrap(byte[])"><CODE></code><i>wrapping</i><code></CODE></A>
* an existing byte array into a buffer.
*
* <a name="direct">
* <h4> Direct <i>vs.</i> non-direct buffers </h4>
*
* <p> A byte buffer is either <i>direct</i> or <i>non-direct</i>.
* Given a direct byte buffer, the Java virtual machine will make a
* best effort to perform native I/O operations directly upon it.
* That is, it will attempt to avoid copying the buffer's content to
* (or from) an intermediate buffer before (or after) each invocation
* of one of the underlying operating system's native I/O operations.
*
* <p> A direct byte buffer may be created by invoking the <A
* HREF="ByteBuffer.html#allocateDirect(int)"><CODE>allocateDirect</CODE></A>
* factory method of this class. The buffers returned by this method
* typically have somewhat higher allocation and deallocation costs
* than non-direct buffers. The contents of direct buffers may reside
* outside of the normal garbage-collected heap, and so their impact
* upon the memory footprint of an application might not be obvious.
* It is therefore recommended that direct buffers be allocated
* primarily for large, long-lived buffers that are subject to the
* underlying system's native I/O operations. In general it is best
* to allocate direct buffers only when they yield a measureable gain
* in program performance. <b><i>Certain JSR 239 methods require the
* use of direct buffers.</i></b>
*
* <b><i>JSR 239 does not support the techniques described in the
* remainder of this paragraph.</i></b>
* <p> A direct byte buffer may also be created by mapping a region of
* a file directly into memory. An implementation of the Java
* platform may optionally support the creation of direct byte buffers
* from native code via JNI. If an instance of one of these kinds of
* buffers refers to an inaccessible region of memory then an attempt
* to access that region will not change the buffer's content and will
* cause an unspecified exception to be thrown either at the time of
* the access or at some later time.
*
* <p> Whether a byte buffer is direct or non-direct may be determined
* by invoking its <A
* HREF="ByteBuffer.html#isDirect()"><CODE>isDirect</CODE></A>
* method. This method is provided so that explicit buffer management
* can be done in performance-critical code.
*
* <a name="bin">
* <h4> Access to binary data </h4>
*
* <p> This class defines methods for reading and writing values of
* all other primitive types, except <tt>boolean</tt>,
* <b><i><code>char</code>, <code>long</code>, and
* <code>double</code></i></b>. Primitive values are translated to
* (or from) sequences of bytes according to the buffer's current byte
* order, which may be retrieved and modified via the
* <CODE>order</CODE> methods. Specific byte orders are represented
* by instances of the <CODE>ByteOrder</CODE> class. The initial
* order of a byte buffer is always <CODE>BIG_ENDIAN</CODE>. <b><i>JSR
* 239 does not support the <code>ByteOrder</code> class or the
* <code>order</code> methods. The inital order of a byte buffer is
* the platform byte order.</i></b>
*
* <p> For access to heterogenous binary data, that is, sequences of
* values of different types, this class defines a family of absolute
* and relative <i>get</i> and <i>put</i> methods for each type. For
* 32-bit floating-point values, for example, this class defines:
*
* <blockquote><pre>
*
* float <A HREF="ByteBuffer.html#getFloat()"><CODE>getFloat()</CODE></A>
* float <A HREF="ByteBuffer.html#getFloat(int)"><CODE>getFloat(int index)</CODE></A>
* void <A HREF="ByteBuffer.html#putFloat(float)"><CODE>putFloat(float f)</CODE></A>
* void <A HREF="ByteBuffer.html#putFloat(int, float)"><CODE>putFloat(int index, float f)</CODE></A></pre></blockquote>
*
* <p> Corresponding methods are defined for the types <tt>char</tt>,
* <tt>short</tt>, <tt>int</tt>, <tt>long</tt>, and <tt>double</tt>.
* <b><i>JSR 239 does not define the <code>char</code>,
* <code>long</code>, or <code>double</code> methods.</b></i> The
* index parameters of the absolute <i>get</i> and <i>put</i> methods
* are in terms of bytes rather than of the type being read or
* written.
*
* <a name="views">
*
* <p> For access to homogeneous binary data, that is, sequences of
* values of the same type, this class defines methods that can create
* <i>views</i> of a given byte buffer. A <i>view buffer</i> is
* simply another buffer whose content is backed by the byte buffer.
* Changes to the byte buffer's content will be visible in the view
* buffer, and vice versa; the two buffers' position, limit, and mark
* values are independent. The <A
* HREF="ByteBuffer.html#asFloatBuffer()"><CODE>asFloatBuffer</CODE></A>
* method, for example, creates an instance of the <A
* HREF="FloatBuffer.html" title="class in
* java.nio"><CODE>FloatBuffer</CODE></A> class that is backed by the
* byte buffer upon which the method is invoked. Corresponding
* view-creation methods are defined for the types <tt>char</tt>,
* <tt>short</tt>, <tt>int</tt>, <tt>long</tt>, and
* <tt>double</tt>. <b><i>JSR 239 does not define views of type
* <code>char</code>, <code>long</code>, or
* <code>double</code>.</i></b>
*
* <p> View buffers have three important advantages over the families of
* type-specific <i>get</i> and <i>put</i> methods described above:
*
* <ul>
*
* <li><p> A view buffer is indexed not in terms of bytes but rather
* in terms of the type-specific size of its values; </p></li>
*
* <li><p> A view buffer provides relative bulk <i>get</i> and
* <i>put</i> methods that can transfer contiguous sequences of
* values between a buffer and an array or some other buffer of the
* same type; and </p></li>
*
* <li><p> A view buffer is potentially much more efficient because
* it will be direct if, and only if, its backing byte buffer is
* direct. </p></li>
*
* </ul>
*
* <p> The byte order of a view buffer is fixed to be that of its byte
* buffer at the time that the view is created. </p>
*
* <h4> Invocation chaining </h4>
*
* <p> Methods in this class that do not otherwise have a value to
* return are specified to return the buffer upon which they are
* invoked. This allows method invocations to be chained.
*
* <p> The sequence of statements
*
* <blockquote><pre>
* bb.putInt(0xCAFEBABE);
* bb.putShort(3);
* bb.putShort(45);
* </pre></blockquote>
* can, for example, be replaced by the single statement
*
* <blockquote><pre>
* bb.putInt(0xCAFEBABE).putShort(3).putShort(45);
* </pre></blockquote>
*/
public abstract class ByteBuffer extends Buffer implements Comparable {
byte[] array;
int arrayOffset;
boolean isDirect;
boolean disposed = false;
/**
* Buffers created by <code>allocateDirect</code> have an
* accosiated buffer allocated in the native Heap. A user may
* create a slice <code>Buffer</code> from a direct "parent"
* <code>Buffer</code> (<code>Buffer.slice()</code>). The "slice" and
* "parent" <code>Buffer</code> share the same native buffer. Native
* buffer is released when the parent <code>Buffer</code> is collected.
* <code>directParent</code> is a reference from slice object to the
* parent. It guarantees that parent object is collected (and shared
* buffer is released) only after all its slice objects are collected.
*/
Buffer directParent;
/**
* Constructs a new <code>ByteBuffer</code>.
*/
ByteBuffer() {}
/**
* Allocates a new direct byte buffer.
*
* <p> The new buffer's position will be zero, its limit will be
* its capacity, and its mark will be undefined. Whether or not it
* has a backing array is unspecified. <b><i>For JSR 239, the mark
* is undefined, and no backing array will be present.</i></b>.
*
* @param capacity The new buffer's capacity, in bytes.
*
* @return The new byte buffer.
*
* @throws IllegalArgumentException If the <code>capacity</code> is
* a negative integer.
*/
public static ByteBuffer allocateDirect(int capacity) {
if (capacity < 0) {
throw new IllegalArgumentException();
}
int nativeAddress = ByteBufferImpl._allocNative(capacity);
ByteBuffer buf = new ByteBufferImpl(capacity, null, nativeAddress,
null /*directParent is null if direct buffer is a parent itself*/);
// Record the address of this buffer along with a weak
// reference; if the weak reference becomes null,
// we will free the native heap memory.
BufferManager.newBuffer(buf, nativeAddress);
return buf;
}
/**
* Wraps a byte array into a buffer.
*
* <p> The new buffer will be backed by the the given byte array;
* that is, modifications to the buffer will cause the array to be
* modified and vice versa. The new buffer's capacity will be
* <tt>array.length</tt>, its position will be <tt>offset</tt>,
* its limit will be <tt>offset + length</tt>, and its mark will
* be undefined. Its <A
* HREF="ByteBuffer.html#array()"><CODE></code>backing
* array<code></CODE></A> will be the given array, and its <A
* HREF="ByteBuffer.html#arrayOffset()"><CODE></code>array
* offset<code></CODE></A> will be zero. </p>
*
* @param array The array that will back the new buffer
* @param offset The offset of the subarray to be used; must be
* non-negative and no larger than <tt>array.length</tt>. The new
* buffer's position will be set to this value.
* @param length The length of the subarray to be used; must be
* non-negative and no larger than <tt>array.length - offset</tt>.
* The new buffer's limit will be set to <tt>offset + length</tt>.
*
* @return The new byte buffer.
*
* @throws IndexOutOfBoundsException If the preconditions on the
* <tt>offset</tt> and <tt>length</tt> parameters do not hold.
*/
public static ByteBuffer wrap(byte[] array, int offset, int length) {
if (offset < 0 || offset > array.length ||
length < 0 || length > array.length - offset) {
throw new IndexOutOfBoundsException();
}
ByteBufferImpl bbi = new ByteBufferImpl(array.length, array, 0,
null /*directParent is null for all nondirect buffers*/);
bbi.position(offset);
bbi.limit(offset + length);
return bbi;
}
/**
* Wraps a byte array into a buffer.
*
* <p> The new buffer will be backed by the the given byte array;
* that is, modifications to the buffer will cause the array to be
* modified and vice versa. The new buffer's capacity and limit
* will be <tt>array.length</tt>, its position will be zero, and
* its mark will be undefined. Its <A
* HREF="ByteBuffer.html#array()"><CODE></code>backing
* array<code></CODE></A> will be the given array, and its <A
* HREF="ByteBuffer.html#arrayOffset()"><CODE></code>array
* offset<code></CODE></A> will be zero. </p>
*
* @param array The array that will back this buffer.
*
* @return The new byte buffer.
*/
public static ByteBuffer wrap(byte[] array) {
return wrap(array, 0, array.length);
}
/**
* Creates a new byte buffer whose content is a shared
* subsequence of this buffer's content.
*
* <p> The content of the new buffer will start at this buffer's
* current position. Changes to this buffer's content will be
* visible in the new buffer, and vice versa; the two buffers'
* position, limit, and mark values will be independent. <b><i>JSR
* 239 does not support the mark.</i></b>
*
* <p> The new buffer's position will be zero, its capacity and
* its limit will be the number of bytes remaining in this
* buffer, and its mark will be undefined. The new buffer will be
* direct if, and only if, this buffer is direct, and it will be
* read-only if, and only if, this buffer is read-only. <b><i>JSR
* 239 does not support the mark or read-only buffers.</i></b>
* </p>
*
* @return The new byte buffer.
*/
public abstract ByteBuffer slice();
/**
* Relative <i>get</i> method. Reads the byte at this
* buffer's current position, and then increments the
* position. </p>
*
* @return The byte at the buffer's current position.
*
* @throws BufferUnderflowException If the buffer's current
* position is not smaller than its limit.
*/
public abstract byte get();
/**
* Relative <i>put</i> method <i>(optional
* operation)</i>.
*
* <p> Writes the given byte into this buffer at the current
* position, and then increments the position. </p>
*
* @param b The byte to be written.
*
* @return This buffer.
*
* @throws BufferOverflowException If this buffer's current
* position is not smaller than its limit.
*
* @throws ReadOnlyBufferException If this buffer is
* read-only. <b><i>JSR 239 does not support read-only buffer or
* the <code>ReadOnlyBufferException</code> class.</i></b>
*/
public abstract ByteBuffer put(byte b);
/**
* Absolute <i>get</i> method. Reads the byte at the given
* index. </p>
*
* @param index The index from which the byte will be read.
*
* @return The byte at the given index.
*
* @throws IndexOutOfBoundsException If <tt>index</tt> is negative
* or not smaller than the buffer's limit.
*/
public abstract byte get(int index);
/**
* Absolute <i>put</i> method <i>(optional operation)</i>.
*
* <p> Writes the given byte into this buffer at the given
* index. </p>
*
* @param index The index at which the byte will be written.
*
* @param b The byte value to be written.
*
* @return This buffer.
*
* @throws IndexOutOfBoundsException If <tt>index</tt> is negative
* or not smaller than the buffer's limit.
*
* @throws ReadOnlyBufferException If this buffer is
* read-only. <b><i>JSR 239 does not support read-only buffer or
* the <code>ReadOnlyBufferException</code> class.</i></b>
*/
public abstract ByteBuffer put(int index, byte b);
/**
* Relative bulk <i>get</i> method.
*
* <p> This method transfers bytes from this buffer into the
* given destination array. If there are fewer bytes
* remaining in the buffer than are required to satisfy the
* request, that is, if
* <tt>length</tt> <tt>></tt> <tt>remaining()</tt>,
* then no bytes are transferred and a {@link
* BufferUnderflowException} is thrown.
*
* <p> Otherwise, this method copies <tt>length</tt> bytes
* from this buffer into the given array, starting at the current
* position of this buffer and at the given offset in the array.
* The position of this buffer is then incremented by
* <tt>length</tt>.
*
* <p> In other words, an invocation of this method of the form
* <tt>src.get(dst, off, len)</tt> has exactly the same
* effect as the loop
*
* <pre>
* for (int i = off; i < off + len; i++)
* dst[i] = src.get(); </pre>
*
* except that it first checks that there are sufficient
* bytes in this buffer and it is potentially much more
* efficient. </p>
*
* @param dst The array into which bytes are to be written.
*
* @param offset The offset within the array of the first
* byte to be written; must be non-negative and no larger
* than <tt>dst.length</tt>.
*
* @param length The maximum number of bytes to be written
* to the given array; must be non-negative and no larger than
* <tt>dst.length - offset</tt>.
*
* @return This buffer.
*
* @throws BufferUnderflowException If there are fewer than
* <tt>length</tt> bytes remaining in this buffer.
*
* @throws IndexOutOfBoundsException If the preconditions on the
* <tt>offset</tt> and <tt>length</tt> parameters do not hold.
*/
public ByteBuffer get(byte[] dst, int offset, int length) {
if (offset < 0 || offset > dst.length ||
length < 0 || length > dst.length - offset) {
throw new IndexOutOfBoundsException();
}
if (limit - position < length) {
throw new BufferUnderflowException();
}
if (isDirect) {
ByteBufferImpl._getBytes(arrayOffset + position,
dst, offset, length);
} else {
System.arraycopy(array, arrayOffset + position,
dst, offset, length);
}
position += length;
return this;
}
/**
* Relative bulk <i>get</i> method.
*
* <p> This method transfers bytes from this buffer into the
* given destination array. An invocation of this method of the
* form <tt>src.get(a)</tt> behaves in exactly the same way as the
* invocation
*
* <pre>
* src.get(a, 0, a.length) </pre>
*
* @return This buffer.
*
* @throws BufferUnderflowException If there are fewer than
* <tt>dst.length</tt> bytes remaining in this buffer.
*/
public ByteBuffer get(byte[] dst) {
return get(dst, 0, dst.length);
}
/**
* Relative bulk <i>put</i> method <i>(optional
* operation)</i>.
*
* <p> This method transfers the bytes remaining in the
* given source buffer into this buffer. If there are more
* bytes remaining in the source buffer than in this buffer,
* that is, if
* <tt>src.remaining()</tt> <tt>></tt> <tt>remaining()</tt>,
* then no bytes are transferred and a {@link
* BufferOverflowException} is thrown.
*
* <p> Otherwise, this method copies
* <i>n</i> = <tt>src.remaining()</tt> bytes from
* the given buffer into this buffer, starting at each buffer's
* current position. The positions of both buffers are then
* incremented by <i>n</i>.
*
* <p> In other words, an invocation of this method of the form
* <tt>dst.put(src)</tt> has exactly the same effect as the loop
*
* <pre>
* while (src.hasRemaining())
* dst.put(src.get()); </pre>
*
* except that it first checks that there is sufficient space in
* this buffer and it is potentially much more efficient. </p>
*
* @param src The source buffer from which bytes are to be
* read; must not be this buffer.
*
* @return This buffer.
*
* @throws BufferOverflowException If there is insufficient space
* in this buffer for the remaining bytes in the source
* buffer.
*
* @throws IllegalArgumentException If the source buffer is this buffer.
*
* @throws ReadOnlyBufferException If this buffer is
* read-only. <b><i>JSR 239 does not support read-only buffer or
* the <code>ReadOnlyBufferException</code> class.</i></b>
*/
public ByteBuffer put(ByteBuffer src) {
if (src == this) {
throw new IllegalArgumentException();
}
ByteBufferImpl srci = (ByteBufferImpl)src;
int length = srci.limit - srci.position;
if (length > this.limit - this.position) {
throw new BufferOverflowException();
}
if (isDirect && srci.isDirect) {
ByteBufferImpl._copyBytes(srci.arrayOffset + srci.position,
this.arrayOffset + this.position,
length);
} else if (isDirect && !srci.isDirect) {
ByteBufferImpl._putBytes(this.arrayOffset + this.position,
srci.array,
srci.arrayOffset + srci.position,
length);
} else if (!isDirect && srci.isDirect) {
ByteBufferImpl._getBytes(srci.arrayOffset + srci.position,
this.array,
this.arrayOffset + this.position,
length);
} else if (!isDirect && !srci.isDirect) {
System.arraycopy(srci.array, srci.arrayOffset + srci.position,
this.array, this.arrayOffset + this.position,
length);
}
srci.position += length;
this.position += length;
return this;
}
/**
* Relative bulk <i>put</i> method <i>(optional
* operation)</i>.
*
* <p> This method transfers bytes into this buffer from the
* given source array. If there are more bytes to be copied
* from the array than remain in this buffer, that is, if
* <tt>length</tt> <tt>></tt> <tt>remaining()</tt>,
* then no bytes are transferred and a {@link
* BufferOverflowException} is thrown.
*
* <p> Otherwise, this method copies <tt>length</tt> bytes
* from the given array into this buffer, starting at the given
* offset in the array and at the current position of this buffer.
* The position of this buffer is then incremented by
* <tt>length</tt>.
*
* <p> In other words, an invocation of this method of the form
* <tt>dst.put(src, off, len)</tt> has exactly the same
* effect as the loop
*
* <pre>
* for (int i = off; i < off + len; i++)
* dst.put(a[i]); </pre>
*
* except that it first checks that there is sufficient space in
* this buffer and it is potentially much more efficient. </p>
*
* @param src The array from which bytes are to be read.
*
* @param offset The offset within the array of the first
* byte to be read; must be non-negative and no larger than
* <tt>array.length</tt>.
*
* @param length The number of bytes to be read from the
* given array; must be non-negative and no larger than
* <tt>array.length - offset</tt>.
*
* @return This buffer.
*
* @throws BufferOverflowException If there is insufficient space
* in this buffer.
*
* @throws IndexOutOfBoundsException If the preconditions on the
* <tt>offset</tt> and <tt>length</tt> parameters do not hold.
*
* @throws ReadOnlyBufferException If this buffer is
* read-only. <b><i>JSR 239 does not support read-only buffer or
* the <code>ReadOnlyBufferException</code> class.</i></b>
*/
public ByteBuffer put(byte[] src, int offset, int length) {
// need revisit -- overlapping backing store?
if (offset < 0 || offset > src.length ||
length < 0 || length > src.length - offset) {
throw new IndexOutOfBoundsException();
}
if (length > limit - position) {
throw new BufferOverflowException();
}
if (isDirect) {
ByteBufferImpl._putBytes(arrayOffset + position,
src, offset, length);
} else {
System.arraycopy(src, offset,
array, arrayOffset + position, length);
}
position += length;
return this;
}
/**
* Relative bulk <i>put</i> method <i>(optional operation)</i>.
*
* <p> This method transfers the entire content of the given
* source byte array into this buffer. An invocation of
* this method of the form <tt>dst.put(a)</tt> behaves in exactly
* the same way as the invocation
*
* <pre>
* dst.put(a, 0, a.length) </pre>
*
* @return This buffer.
*
* @throws BufferOverflowException If there is insufficient space
* in this buffer.
*
* @throws ReadOnlyBufferException If this buffer is
* read-only. <b><i>JSR 239 does not support read-only buffer or
* the <code>ReadOnlyBufferException</code> class.</i></b>
*/
public final ByteBuffer put(byte[] src) {
return put(src, 0, src.length);
}
/**
* Tells whether or not this buffer is backed by an accessible
* byte array.
*
* <p> If this method returns <tt>true</tt> then the {@link
* #array() array} and {@link #arrayOffset() arrayOffset} methods
* may safely be invoked. </p>
*
* @return <tt>true</tt> if, and only if, this buffer is backed by
* an array and is not read-only. <b><i>JSR 239 does not support
* read-only buffers.</i></b>
*/
public final boolean hasArray() {
return !isDirect;
}
/**
* Returns the byte array that backs this
* buffer <i>(optional operation)</i>.
*
* <p> Modifications to this buffer's content will cause the returned
* array's content to be modified, and vice versa.
*
* <p> Invoke the {@link #hasArray hasArray} method before
* invoking this method in order to ensure that this buffer has an
* accessible backing array. </p>
*
* @return The array that backs this buffer.
*
* @throws ReadOnlyBufferException If this buffer is
* read-only. <b><i>JSR 239 does not support read-only buffer or
* the <code>ReadOnlyBufferException</code> class.</i></b>
*
* @throws UnsupportedOperationException If this buffer is not
* backed by an accessible array.
*/
public final byte[] array() {
if (isDirect) {
throw new UnsupportedOperationException();
}
return array;
}
/**
* Returns the offset within this buffer's backing array of the
* first element of the buffer <i>(optional
* operation)</i>.
*
* <p> If this buffer is backed by an array then buffer position
* <i>p</i> corresponds to array index
* <i>p</i> + <tt>arrayOffset()</tt>.
*
* <p> Invoke the {@link #hasArray hasArray} method before
* invoking this method in order to ensure that this buffer has an
* accessible backing array. </p>
*
* @return The offset within this buffer's array of the first
* element of the buffer.
*
* @throws ReadOnlyBufferException If this buffer is
* read-only. <b><i>JSR 239 does not support read-only buffer or
* the <code>ReadOnlyBufferException</code> class.</i></b>
*
* @throws UnsupportedOperationException If this buffer is not
* backed by an accessible array.
*/
public final int arrayOffset() {
if (isDirect) {
throw new UnsupportedOperationException();
}
return arrayOffset;
}
/**
* Tells whether or not this byte buffer is direct. </p>
*
* @return <tt>true</tt> if, and only if, this buffer is direct.
*/
public abstract boolean isDirect();
/**
* Returns a string summarizing the state of this buffer.
*
* @return A summary string
*/
public String toString() {
return "java.nio.ByteBuffer[" +
"pos=" + position() +
"lim=" + limit() +
"cap=" + capacity() +
"]";
}
/**
* Returns the current hash code of this buffer.
*
* <p> The hash code of a byte buffer depends only upon its remaining
* elements; that is, upon the elements from <tt>position()</tt> up to, and
* including, the element at <tt>limit()</tt> - <tt>1</tt>.
*
* <p> Because buffer hash codes are content-dependent, it is inadvisable
* to use buffers as keys in hash maps or similar data structures unless it
* is known that their contents will not change. </p>
*
* @return The current hash code of this buffer.
*/
public int hashCode() {
int h = 1;
int p = position();
for (int i = limit() - 1; i >= p; i--)
h = 31 * h + (int)get(i);
return h;
}
/**
* Tells whether or not this buffer is equal to another object.
*
* <p> Two byte buffers are equal if, and only if,
*
* <p><ol>
*
* <li><p> They have the same element type, </p></li>
*
* <li><p> They have the same number of remaining elements, and
* </p></li>
*
* <li><p> The two sequences of remaining elements, considered
* independently of their starting positions, are pointwise equal.
* </p></li>
*
* </ol>
*
* <p> A byte buffer is not equal to any other type of object. </p>
*
* @param ob The object to which this buffer is to be compared.
*
* @return <tt>true</tt> if, and only if, this buffer is equal to the
* given object.
*/
public boolean equals(Object ob) {
if (!(ob instanceof ByteBuffer))
return false;
ByteBuffer that = (ByteBuffer)ob;
if (this.remaining() != that.remaining())
return false;
int p = this.position();
for (int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j--) {
byte v1 = this.get(i);
byte v2 = that.get(j);
if (v1 != v2) {
if ((v1 != v1) && (v2 != v2)) // For float and double
continue;
return false;
}
}
return true;
}
/**
* Compares this buffer to another.
*
* <p> Two byte buffers are compared by comparing their sequences of
* remaining elements lexicographically, without regard to the starting
* position of each sequence within its corresponding buffer.
*
* <p> A byte buffer is not comparable to any other type of object.
*
* @return A negative integer, zero, or a positive integer as this buffer
* is less than, equal to, or greater than the given buffer.
* @throws ClassCastException If the argument is not a byte buffer.
*/
public int compareTo(Object ob) {
ByteBuffer that = (ByteBuffer)ob;
int n = this.position() + Math.min(this.remaining(), that.remaining());
for (int i = this.position(), j = that.position(); i < n; i++, j++) {
byte v1 = this.get(i);
byte v2 = that.get(j);
if (v1 == v2)
continue;
if ((v1 != v1) && (v2 != v2)) // For float and double
continue;
if (v1 < v2)
return -1;
return +1;
}
return this.remaining() - that.remaining();
}
/**
* Relative <i>get</i> method for reading a short value.
*
* <p> Reads the next two bytes at this buffer's current position,
* composing them into a short value according to the current byte order,
* and then increments the position by two. </p>
*
* @return The short value at the buffer's current position
*
* @throws BufferUnderflowException
* If there are fewer than two bytes
* remaining in this buffer
*/
public abstract short getShort();
/**
* Relative <i>put</i> method for writing a short
* value <i>(optional operation)</i>.
*
* <p> Writes two bytes containing the given short value, in the
* current byte order, into this buffer at the current position, and then
* increments the position by two. </p>
*
* @param value
* The short value to be written
*
* @return This buffer
*
* @throws BufferOverflowException
* If there are fewer than two bytes
* remaining in this buffer
*
* @throws ReadOnlyBufferException
* If this buffer is read-only
*/
public abstract ByteBuffer putShort(short value);
/**
* Absolute <i>get</i> method for reading a short value.
*
* <p> Reads two bytes at the given index, composing them into a
* short value according to the current byte order. </p>
*
* @param index
* The index from which the bytes will be read
*
* @return The short value at the given index
*
* @throws IndexOutOfBoundsException
* If <tt>index</tt> is negative
* or not smaller than the buffer's limit,
* minus one
*/
public abstract short getShort(int index);
/**
* Absolute <i>put</i> method for writing a short
* value <i>(optional operation)</i>.
*
* <p> Writes two bytes containing the given short value, in the
* current byte order, into this buffer at the given index. </p>
*
* @param index
* The index at which the bytes will be written
*
* @param value
* The short value to be written
*
* @return This buffer
*
* @throws IndexOutOfBoundsException
* If <tt>index</tt> is negative
* or not smaller than the buffer's limit,
* minus one
*
* @throws ReadOnlyBufferException
* If this buffer is read-only
*/
public abstract ByteBuffer putShort(int index, short value);
/**
* Creates a view of this byte buffer as a short buffer.
*
* <p> The content of the new buffer will start at this buffer's
* current position. Changes to this buffer's content will be
* visible in the new buffer, and vice versa; the two buffers'
* position, limit, and mark values will be independent. <b><i>JSR
* 239 does not support the mark.</i></b>
*
* <p> The new buffer's position will be zero, its capacity and
* its limit will be the number of bytes remaining in this buffer
* divided by two, and its mark will be undefined. The new buffer
* will be direct if, and only if, this buffer is direct, and it
* will be read-only if, and only if, this buffer is read-only.
* <b><i>JSR 239 does not support the mark or read-only
* buffers.</i></b>
*
* @return A new short buffer.
*/
public abstract ShortBuffer asShortBuffer();
/**
* Relative <i>get</i> method for reading an int value.
*
* <p> Reads the next four bytes at this buffer's current position,
* composing them into an int value according to the current byte order,
* and then increments the position by four. </p>
*
* @return The int value at the buffer's current position
*
* @throws BufferUnderflowException
* If there are fewer than four bytes
* remaining in this buffer
*/
public abstract int getInt();
/**
* Relative <i>put</i> method for writing an int
* value <i>(optional operation)</i>.
*
* <p> Writes four bytes containing the given int value, in the
* current byte order, into this buffer at the current position, and then
* increments the position by four. </p>
*
* @param value
* The int value to be written
*
* @return This buffer
*
* @throws BufferOverflowException
* If there are fewer than four bytes
* remaining in this buffer
*
* @throws ReadOnlyBufferException
* If this buffer is read-only
*/
public abstract ByteBuffer putInt(int value);
/**
* Absolute <i>get</i> method for reading an int value.
*
* <p> Reads four bytes at the given index, composing them into a
* int value according to the current byte order. </p>
*
* @param index
* The index from which the bytes will be read
*
* @return The int value at the given index
*
* @throws IndexOutOfBoundsException
* If <tt>index</tt> is negative
* or not smaller than the buffer's limit,
* minus three
*/
public abstract int getInt(int index);
/**
* Absolute <i>put</i> method for writing an int
* value <i>(optional operation)</i>.
*
* <p> Writes four bytes containing the given int value, in the
* current byte order, into this buffer at the given index. </p>
*
* @param index
* The index at which the bytes will be written
*
* @param value
* The int value to be written
*
* @return This buffer
*
* @throws IndexOutOfBoundsException
* If <tt>index</tt> is negative
* or not smaller than the buffer's limit,
* minus three
*
* @throws ReadOnlyBufferException
* If this buffer is read-only
*/
public abstract ByteBuffer putInt(int index, int value);
/**
* Creates a view of this byte buffer as an int buffer.
*
* <p> The content of the new buffer will start at this buffer's
* current position. Changes to this buffer's content will be
* visible in the new buffer, and vice versa; the two buffers'
* position, limit, and mark values will be independent. <b><i>JSR
* 239 does not support the mark.</i></b>
*
* <p> The new buffer's position will be zero, its capacity and
* its limit will be the number of bytes remaining in this buffer
* divided by four, and its mark will be undefined. The new buffer
* will be direct if, and only if, this buffer is direct, and it
* will be read-only if, and only if, this buffer is read-only.
* <b><i>JSR 239 does not support the mark or read-only
* buffers.</i></b>
*
* @return A new int buffer.
*/
public abstract IntBuffer asIntBuffer();
/**
* Relative <i>get</i> method for reading a float value.
*
* <p> Reads the next four bytes at this buffer's current position,
* composing them into a float value according to the current byte order,
* and then increments the position by four. </p>
*
* @return The float value at the buffer's current position
*
* @throws BufferUnderflowException
* If there are fewer than four bytes
* remaining in this buffer
*/
public abstract float getFloat();
/**
* Relative <i>put</i> method for writing a float
* value <i>(optional operation)</i>.
*
* <p> Writes four bytes containing the given float value, in the
* current byte order, into this buffer at the current position, and then
* increments the position by four. </p>
*
* @param value
* The float value to be written
*
* @return This buffer
*
* @throws BufferOverflowException
* If there are fewer than four bytes
* remaining in this buffer
*
* @throws ReadOnlyBufferException
* If this buffer is read-only
*/
public abstract ByteBuffer putFloat(float value);
/**
* Absolute <i>get</i> method for reading a float value.
*
* <p> Reads four bytes at the given index, composing them into a
* float value according to the current byte order. </p>
*
* @param index
* The index from which the bytes will be read
*
* @return The float value at the given index
*
* @throws IndexOutOfBoundsException
* If <tt>index</tt> is negative
* or not smaller than the buffer's limit,
* minus three
*/
public abstract float getFloat(int index);
/**
* Absolute <i>put</i> method for writing a float
* value <i>(optional operation)</i>.
*
* <p> Writes four bytes containing the given float value, in the
* current byte order, into this buffer at the given index. </p>
*
* @param index
* The index at which the bytes will be written
*
* @param value
* The float value to be written
*
* @return This buffer
*
* @throws IndexOutOfBoundsException
* If <tt>index</tt> is negative
* or not smaller than the buffer's limit,
* minus three
*
* @throws ReadOnlyBufferException
* If this buffer is read-only
*/
public abstract ByteBuffer putFloat(int index, float value);
/**
* Creates a view of this byte buffer as a float buffer.
*
* <p> The content of the new buffer will start at this buffer's
* current position. Changes to this buffer's content will be
* visible in the new buffer, and vice versa; the two buffers'
* position, limit, and mark values will be independent. <b><i>JSR
* 239 does not support the mark.</i></b>
*
* <p> The new buffer's position will be zero, its capacity and
* its limit will be the number of bytes remaining in this buffer
* divided by four, and its mark will be undefined. The new buffer
* will be direct if, and only if, this buffer is direct, and it
* will be read-only if, and only if, this buffer is read-only.
* <b><i>JSR 239 does not support the mark or read-only
* buffers.</i></b>
*
* @return A new float buffer.
*/
public abstract FloatBuffer asFloatBuffer();
}
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