File	Doc	Category	Size	Date	Package
DoubleBuffer.java	API Doc	Java SE 6 API	28850	Tue Jun 10 01:17:44 BST 2008	java.nio

DoubleBuffer

• java.lang.Object
  • java.nio.Buffer

Fields Summary
final double[]	hb
final int	offset
boolean	isReadOnly

Constructors Summary
DoubleBuffer(int mark, int pos, int lim, int cap, double[] hb, int offset) super(mark, pos, lim, cap); this.hb = hb; this.offset = offset;
DoubleBuffer(int mark, int pos, int lim, int cap) // package-private this(mark, pos, lim, cap, null, 0);

Methods Summary
public static java.nio.DoubleBuffer	allocate(int capacity) Allocates a new double buffer. The new buffer's position will be zero, its limit will be its capacity, and its mark will be undefined. It will have a {@link #array backing array}, and its {@link #arrayOffset array offset} will be zero. param capacity The new buffer's capacity, in doubles return The new double buffer throws IllegalArgumentException If the capacity is a negative integer if (capacity < 0) throw new IllegalArgumentException(); return new HeapDoubleBuffer(capacity, capacity);
public final double[]	array() Returns the double array that backs this buffer  (optional operation). Modifications to this buffer's content will cause the returned array's content to be modified, and vice versa. Invoke the {@link #hasArray hasArray} method before invoking this method in order to ensure that this buffer has an accessible backing array. return The array that backs this buffer throws ReadOnlyBufferException If this buffer is backed by an array but is read-only throws UnsupportedOperationException If this buffer is not backed by an accessible array if (hb == null) throw new UnsupportedOperationException(); if (isReadOnly) throw new ReadOnlyBufferException(); return hb;
public final int	arrayOffset() Returns the offset within this buffer's backing array of the first element of the buffer  (optional operation). If this buffer is backed by an array then buffer position p corresponds to array index p + arrayOffset(). Invoke the {@link #hasArray hasArray} method before invoking this method in order to ensure that this buffer has an accessible backing array. return The offset within this buffer's array of the first element of the buffer throws ReadOnlyBufferException If this buffer is backed by an array but is read-only throws UnsupportedOperationException If this buffer is not backed by an accessible array if (hb == null) throw new UnsupportedOperationException(); if (isReadOnly) throw new ReadOnlyBufferException(); return offset;
public abstract java.nio.DoubleBuffer	asReadOnlyBuffer() Creates a new, read-only double buffer that shares this buffer's content. The content of the new buffer will be that of this buffer. Changes to this buffer's content will be visible in the new buffer; the new buffer itself, however, will be read-only and will not allow the shared content to be modified. The two buffers' position, limit, and mark values will be independent. The new buffer's capacity, limit, position, and mark values will be identical to those of this buffer. If this buffer is itself read-only then this method behaves in exactly the same way as the {@link #duplicate duplicate} method. return The new, read-only double buffer
public abstract java.nio.DoubleBuffer	compact() Compacts this buffer  (optional operation). The doubles between the buffer's current position and its limit, if any, are copied to the beginning of the buffer. That is, the double at index p = position() is copied to index zero, the double at index p + 1 is copied to index one, and so forth until the double at index limit() - 1 is copied to index n = limit() - 1 - p. The buffer's position is then set to n+1 and its limit is set to its capacity. The mark, if defined, is discarded. The buffer's position is set to the number of doubles copied, rather than to zero, so that an invocation of this method can be followed immediately by an invocation of another relative put method. return This buffer throws ReadOnlyBufferException If this buffer is read-only
public int	compareTo(java.nio.DoubleBuffer that) Compares this buffer to another. Two double buffers are compared by comparing their sequences of remaining elements lexicographically, without regard to the starting position of each sequence within its corresponding buffer. A double 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 int n = this.position() + Math.min(this.remaining(), that.remaining()); for (int i = this.position(), j = that.position(); i < n; i++, j++) { double v1 = this.get(i); double 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();
public abstract java.nio.DoubleBuffer	duplicate() Creates a new double buffer that shares this buffer's content. The content of the new buffer will be that of this buffer. 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. The new buffer's capacity, limit, position, and mark values will be identical to those of this buffer. 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. return The new double buffer
public boolean	equals(java.lang.Object ob) Tells whether or not this buffer is equal to another object. Two double buffers are equal if, and only if, They have the same element type, They have the same number of remaining elements, and The two sequences of remaining elements, considered independently of their starting positions, are pointwise equal. A double buffer is not equal to any other type of object. param ob The object to which this buffer is to be compared return true if, and only if, this buffer is equal to the given object if (!(ob instanceof DoubleBuffer)) return false; DoubleBuffer that = (DoubleBuffer)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--) { double v1 = this.get(i); double v2 = that.get(j); if (v1 != v2) { if ((v1 != v1) && (v2 != v2)) // For float and double continue; return false; } } return true;
public abstract double	get(int index) Absolute get method. Reads the double at the given index. param index The index from which the double will be read return The double at the given index throws IndexOutOfBoundsException If index is negative or not smaller than the buffer's limit
public java.nio.DoubleBuffer	get(double[] dst, int offset, int length) Relative bulk get method. This method transfers doubles from this buffer into the given destination array. If there are fewer doubles remaining in the buffer than are required to satisfy the request, that is, if length > remaining(), then no doubles are transferred and a {@link BufferUnderflowException} is thrown. Otherwise, this method copies length doubles 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 length. In other words, an invocation of this method of the form src.get(dst, off, len) has exactly the same effect as the loop for (int i = off; i < off + len; i++) dst[i] = src.get(); except that it first checks that there are sufficient doubles in this buffer and it is potentially much more efficient. param dst The array into which doubles are to be written param offset The offset within the array of the first double to be written; must be non-negative and no larger than dst.length param length The maximum number of doubles to be written to the given array; must be non-negative and no larger than dst.length - offset return This buffer throws BufferUnderflowException If there are fewer than length doubles remaining in this buffer throws IndexOutOfBoundsException If the preconditions on the offset and length parameters do not hold checkBounds(offset, length, dst.length); if (length > remaining()) throw new BufferUnderflowException(); int end = offset + length; for (int i = offset; i < end; i++) dst[i] = get(); return this;
public java.nio.DoubleBuffer	get(double[] dst) Relative bulk get method. This method transfers doubles from this buffer into the given destination array. An invocation of this method of the form src.get(a) behaves in exactly the same way as the invocation src.get(a, 0, a.length) return This buffer throws BufferUnderflowException If there are fewer than length doubles remaining in this buffer return get(dst, 0, dst.length);
public abstract double	get() Relative get method. Reads the double at this buffer's current position, and then increments the position. return The double at the buffer's current position throws BufferUnderflowException If the buffer's current position is not smaller than its limit
public final boolean	hasArray() Tells whether or not this buffer is backed by an accessible double array. If this method returns true then the {@link #array() array} and {@link #arrayOffset() arrayOffset} methods may safely be invoked. return true if, and only if, this buffer is backed by an array and is not read-only return (hb != null) && !isReadOnly;
public int	hashCode() Returns the current hash code of this buffer. The hash code of a double buffer depends only upon its remaining elements; that is, upon the elements from position() up to, and including, the element at limit() - 1. 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. return The current hash code of this buffer int h = 1; int p = position(); for (int i = limit() - 1; i >= p; i--) h = 31 * h + (int)get(i); return h;
public abstract boolean	isDirect() Tells whether or not this double buffer is direct. return true if, and only if, this buffer is direct
public abstract java.nio.ByteOrder	order() Retrieves this buffer's byte order. The byte order of a double buffer created by allocation or by wrapping an existing double array is the {@link ByteOrder#nativeOrder native order} of the underlying hardware. The byte order of a double buffer created as a view of a byte buffer is that of the byte buffer at the moment that the view is created. return This buffer's byte order
public abstract java.nio.DoubleBuffer	put(double d) Relative put method  (optional operation). Writes the given double into this buffer at the current position, and then increments the position. param d The double 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
public abstract java.nio.DoubleBuffer	put(int index, double d) Absolute put method  (optional operation). Writes the given double into this buffer at the given index. param index The index at which the double will be written param d The double value to be written return This buffer throws IndexOutOfBoundsException If index is negative or not smaller than the buffer's limit throws ReadOnlyBufferException If this buffer is read-only
public java.nio.DoubleBuffer	put(java.nio.DoubleBuffer src) Relative bulk put method  (optional operation). This method transfers the doubles remaining in the given source buffer into this buffer. If there are more doubles remaining in the source buffer than in this buffer, that is, if src.remaining() > remaining(), then no doubles are transferred and a {@link BufferOverflowException} is thrown. Otherwise, this method copies n = src.remaining() doubles from the given buffer into this buffer, starting at each buffer's current position. The positions of both buffers are then incremented by n. In other words, an invocation of this method of the form dst.put(src) has exactly the same effect as the loop while (src.hasRemaining()) dst.put(src.get()); except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient. param src The source buffer from which doubles 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 doubles in the source buffer throws IllegalArgumentException If the source buffer is this buffer throws ReadOnlyBufferException If this buffer is read-only if (src == this) throw new IllegalArgumentException(); int n = src.remaining(); if (n > remaining()) throw new BufferOverflowException(); for (int i = 0; i < n; i++) put(src.get()); return this;
public java.nio.DoubleBuffer	put(double[] src, int offset, int length) Relative bulk put method  (optional operation). This method transfers doubles into this buffer from the given source array. If there are more doubles to be copied from the array than remain in this buffer, that is, if length > remaining(), then no doubles are transferred and a {@link BufferOverflowException} is thrown. Otherwise, this method copies length doubles 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 length. In other words, an invocation of this method of the form dst.put(src, off, len) has exactly the same effect as the loop for (int i = off; i < off + len; i++) dst.put(a[i]); except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient. param src The array from which doubles are to be read param offset The offset within the array of the first double to be read; must be non-negative and no larger than array.length param length The number of doubles to be read from the given array; must be non-negative and no larger than array.length - offset return This buffer throws BufferOverflowException If there is insufficient space in this buffer throws IndexOutOfBoundsException If the preconditions on the offset and length parameters do not hold throws ReadOnlyBufferException If this buffer is read-only checkBounds(offset, length, src.length); if (length > remaining()) throw new BufferOverflowException(); int end = offset + length; for (int i = offset; i < end; i++) this.put(src[i]); return this;
public final java.nio.DoubleBuffer	put(double[] src) Relative bulk put method  (optional operation). This method transfers the entire content of the given source double array into this buffer. An invocation of this method of the form dst.put(a) behaves in exactly the same way as the invocation dst.put(a, 0, a.length) return This buffer throws BufferOverflowException If there is insufficient space in this buffer throws ReadOnlyBufferException If this buffer is read-only return put(src, 0, src.length);
public abstract java.nio.DoubleBuffer	slice() Creates a new double buffer whose content is a shared subsequence of this buffer's content. 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. The new buffer's position will be zero, its capacity and its limit will be the number of doubles 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. return The new double buffer
public java.lang.String	toString() Returns a string summarizing the state of this buffer. return A summary string StringBuffer sb = new StringBuffer(); sb.append(getClass().getName()); sb.append("[pos="); sb.append(position()); sb.append(" lim="); sb.append(limit()); sb.append(" cap="); sb.append(capacity()); sb.append("]"); return sb.toString();
public static java.nio.DoubleBuffer	wrap(double[] array, int offset, int length) Wraps a double array into a buffer. The new buffer will be backed by the given double array; that is, modifications to the buffer will cause the array to be modified and vice versa. The new buffer's capacity will be array.length, its position will be offset, its limit will be offset + length, and its mark will be undefined. Its {@link #array backing array} will be the given array, and its {@link #arrayOffset array offset} will be zero. 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 array.length. 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 array.length - offset. The new buffer's limit will be set to offset + length. return The new double buffer throws IndexOutOfBoundsException If the preconditions on the offset and length parameters do not hold try { return new HeapDoubleBuffer(array, offset, length); } catch (IllegalArgumentException x) { throw new IndexOutOfBoundsException(); }
public static java.nio.DoubleBuffer	wrap(double[] array) Wraps a double array into a buffer. The new buffer will be backed by the given double 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 array.length, its position will be zero, and its mark will be undefined. Its {@link #array backing array} will be the given array, and its {@link #arrayOffset array offset} will be zero. param array The array that will back this buffer return The new double buffer return wrap(array, 0, array.length);