/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.nio;
import java.util.Arrays;
/**
* A buffer of floats.
* <p>
* A float buffer can be created in either of the following ways:
* <ul>
* <li>{@link #allocate(int) Allocate} a new float array and create a buffer
* based on it;</li>
* <li>{@link #wrap(float[]) Wrap} an existing float array to create a new
* buffer;</li>
* <li>Use {@link java.nio.ByteBuffer#asFloatBuffer() ByteBuffer.asFloatBuffer}
* to create a float buffer based on a byte buffer.</li>
* </ul>
*/
public abstract class FloatBuffer extends Buffer implements
Comparable<FloatBuffer> {
/**
* Creates a float buffer based on a newly allocated float array.
*
* @param capacity
* the capacity of the new buffer.
* @return the created float buffer.
* @throws IllegalArgumentException
* if {@code capacity} is less than zero.
*/
public static FloatBuffer allocate(int capacity) {
if (capacity < 0) {
throw new IllegalArgumentException("capacity < 0: " + capacity);
}
return new FloatArrayBuffer(new float[capacity]);
}
/**
* Creates a new float buffer by wrapping the given float array.
* <p>
* Calling this method has the same effect as
* {@code wrap(array, 0, array.length)}.
*
* @param array
* the float array which the new buffer will be based on.
* @return the created float buffer.
*/
public static FloatBuffer wrap(float[] array) {
return wrap(array, 0, array.length);
}
/**
* Creates a new float buffer by wrapping the given float array.
* <p>
* The new buffer's position will be {@code start}, limit will be
* {@code start + floatCount}, capacity will be the length of the array.
*
* @param array
* the float array which the new buffer will be based on.
* @param start
* the start index, must not be negative and not greater than
* {@code array.length}.
* @param floatCount
* the length, must not be negative and not greater than
* {@code array.length - start}.
* @return the created float buffer.
* @throws IndexOutOfBoundsException
* if either {@code start} or {@code floatCount} is invalid.
* @throws NullPointerException
* if {@code array} is null.
*/
public static FloatBuffer wrap(float[] array, int start, int floatCount) {
Arrays.checkOffsetAndCount(array.length, start, floatCount);
FloatBuffer buf = new FloatArrayBuffer(array);
buf.position = start;
buf.limit = start + floatCount;
return buf;
}
FloatBuffer(int capacity, long effectiveDirectAddress) {
super(2, capacity, effectiveDirectAddress);
}
public final float[] array() {
return protectedArray();
}
public final int arrayOffset() {
return protectedArrayOffset();
}
/**
* Returns a read-only buffer that shares its content with this buffer.
* <p>
* The returned buffer is guaranteed to be a new instance, even if this
* buffer is read-only itself. The new buffer's position, limit, capacity
* and mark are the same as this buffer.
* <p>
* The new buffer shares its content with this buffer, which means this
* buffer's change of content will be visible to the new buffer. The two
* buffer's position, limit and mark are independent.
*
* @return a read-only version of this buffer.
*/
public abstract FloatBuffer asReadOnlyBuffer();
/**
* Compacts this float buffer.
* <p>
* The remaining floats will be moved to the head of the buffer, starting
* from position zero. Then the position is set to {@code remaining()}; the
* limit is set to capacity; the mark is cleared.
*
* @return this buffer.
* @throws ReadOnlyBufferException
* if no changes may be made to the contents of this buffer.
*/
public abstract FloatBuffer compact();
/**
* Compare the remaining floats of this buffer to another float buffer's
* remaining floats.
*
* @param otherBuffer
* another float buffer.
* @return a negative value if this is less than {@code otherBuffer}; 0 if
* this equals to {@code otherBuffer}; a positive value if this is
* greater than {@code otherBuffer}.
* @throws ClassCastException
* if {@code otherBuffer} is not a float buffer.
*/
public int compareTo(FloatBuffer otherBuffer) {
int compareRemaining = (remaining() < otherBuffer.remaining()) ? remaining()
: otherBuffer.remaining();
int thisPos = position;
int otherPos = otherBuffer.position;
float thisFloat, otherFloat;
while (compareRemaining > 0) {
thisFloat = get(thisPos);
otherFloat = otherBuffer.get(otherPos);
// checks for float and NaN inequality
if ((thisFloat != otherFloat)
&& ((thisFloat == thisFloat) || (otherFloat == otherFloat))) {
return thisFloat < otherFloat ? -1 : 1;
}
thisPos++;
otherPos++;
compareRemaining--;
}
return remaining() - otherBuffer.remaining();
}
/**
* Returns a duplicated buffer that shares its content with this buffer.
* <p>
* The duplicated buffer's position, limit, capacity and mark are the same
* as this buffer. The duplicated buffer's read-only property and byte order
* are same as this buffer too.
* <p>
* The new buffer shares its content with this buffer, which means either
* buffer's change of content will be visible to the other. The two buffers'
* position, limit and mark are independent.
*/
public abstract FloatBuffer duplicate();
/**
* Checks whether this float buffer is equal to another object. If {@code
* other} is not a {@code FloatBuffer} then {@code false} is returned.
*
* <p>Two float buffers are equal if their remaining floats are equal.
* Position, limit, capacity and mark are not considered.
*
* <p>This method considers two floats {@code a} and {@code b} to be equal
* if {@code a == b} or if {@code a} and {@code b} are both {@code NaN}.
* Unlike {@link Float#equals}, this method considers {@code -0.0} and
* {@code +0.0} to be equal.
*
* @param other
* the object to compare with this float buffer.
* @return {@code true} if this float buffer is equal to {@code other},
* {@code false} otherwise.
*/
@Override
public boolean equals(Object other) {
if (!(other instanceof FloatBuffer)) {
return false;
}
FloatBuffer otherBuffer = (FloatBuffer) other;
if (remaining() != otherBuffer.remaining()) {
return false;
}
int myPosition = position;
int otherPosition = otherBuffer.position;
boolean equalSoFar = true;
while (equalSoFar && (myPosition < limit)) {
float a = get(myPosition++);
float b = otherBuffer.get(otherPosition++);
equalSoFar = a == b || (a != a && b != b);
}
return equalSoFar;
}
/**
* Returns the float at the current position and increases the position by
* 1.
*
* @return the float at the current position.
* @throws BufferUnderflowException
* if the position is equal or greater than limit.
*/
public abstract float get();
/**
* Reads floats from the current position into the specified float array and
* increases the position by the number of floats read.
* <p>
* Calling this method has the same effect as
* {@code get(dst, 0, dst.length)}.
*
* @param dst
* the destination float array.
* @return this buffer.
* @throws BufferUnderflowException
* if {@code dst.length} is greater than {@code remaining()}.
*/
public FloatBuffer get(float[] dst) {
return get(dst, 0, dst.length);
}
/**
* Reads floats from the current position into the specified float array,
* starting from the specified offset, and increases the position by the
* number of floats read.
*
* @param dst
* the target float array.
* @param dstOffset
* the offset of the float array, must not be negative and no
* greater than {@code dst.length}.
* @param floatCount
* the number of floats to read, must be no less than zero and no
* greater than {@code dst.length - dstOffset}.
* @return this buffer.
* @throws IndexOutOfBoundsException
* if either {@code dstOffset} or {@code floatCount} is invalid.
* @throws BufferUnderflowException
* if {@code floatCount} is greater than {@code remaining()}.
*/
public FloatBuffer get(float[] dst, int dstOffset, int floatCount) {
Arrays.checkOffsetAndCount(dst.length, dstOffset, floatCount);
if (floatCount > remaining()) {
throw new BufferUnderflowException();
}
for (int i = dstOffset; i < dstOffset + floatCount; ++i) {
dst[i] = get();
}
return this;
}
/**
* Returns a float at the specified index; the position is not changed.
*
* @param index
* the index, must not be negative and less than limit.
* @return a float at the specified index.
* @throws IndexOutOfBoundsException
* if index is invalid.
*/
public abstract float get(int index);
public final boolean hasArray() {
return protectedHasArray();
}
/**
* Calculates this buffer's hash code from the remaining chars. The
* position, limit, capacity and mark don't affect the hash code.
*
* @return the hash code calculated from the remaining floats.
*/
@Override
public int hashCode() {
int myPosition = position;
int hash = 0;
while (myPosition < limit) {
hash = hash + Float.floatToIntBits(get(myPosition++));
}
return hash;
}
/**
* Indicates whether this buffer is direct. A direct buffer will try its
* best to take advantage of native memory APIs and it may not stay in the
* Java heap, so it is not affected by garbage collection.
* <p>
* A float buffer is direct if it is based on a byte buffer and the byte
* buffer is direct.
*
* @return {@code true} if this buffer is direct, {@code false} otherwise.
*/
public abstract boolean isDirect();
/**
* Returns the byte order used by this buffer when converting floats from/to
* bytes.
* <p>
* If this buffer is not based on a byte buffer, then always return the
* platform's native byte order.
*
* @return the byte order used by this buffer when converting floats from/to
* bytes.
*/
public abstract ByteOrder order();
/**
* Child class implements this method to realize {@code array()}.
*
* @return see {@code array()}
*/
abstract float[] protectedArray();
/**
* Child class implements this method to realize {@code arrayOffset()}.
*
* @return see {@code arrayOffset()}
*/
abstract int protectedArrayOffset();
/**
* Child class implements this method to realize {@code hasArray()}.
*
* @return see {@code hasArray()}
*/
abstract boolean protectedHasArray();
/**
* Writes the given float to the current position and increases the position
* by 1.
*
* @param f
* the float to write.
* @return this buffer.
* @throws BufferOverflowException
* if position is equal or greater than limit.
* @throws ReadOnlyBufferException
* if no changes may be made to the contents of this buffer.
*/
public abstract FloatBuffer put(float f);
/**
* Writes floats from the given float array to the current position and
* increases the position by the number of floats written.
* <p>
* Calling this method has the same effect as
* {@code put(src, 0, src.length)}.
*
* @param src
* the source float array.
* @return this buffer.
* @throws BufferOverflowException
* if {@code remaining()} is less than {@code src.length}.
* @throws ReadOnlyBufferException
* if no changes may be made to the contents of this buffer.
*/
public final FloatBuffer put(float[] src) {
return put(src, 0, src.length);
}
/**
* Writes floats from the given float array, starting from the specified
* offset, to the current position and increases the position by the number
* of floats written.
*
* @param src
* the source float array.
* @param srcOffset
* the offset of float array, must not be negative and not
* greater than {@code src.length}.
* @param floatCount
* the number of floats to write, must be no less than zero and
* no greater than {@code src.length - srcOffset}.
* @return this buffer.
* @throws BufferOverflowException
* if {@code remaining()} is less than {@code floatCount}.
* @throws IndexOutOfBoundsException
* if either {@code srcOffset} or {@code floatCount} is invalid.
* @throws ReadOnlyBufferException
* if no changes may be made to the contents of this buffer.
*/
public FloatBuffer put(float[] src, int srcOffset, int floatCount) {
Arrays.checkOffsetAndCount(src.length, srcOffset, floatCount);
if (floatCount > remaining()) {
throw new BufferOverflowException();
}
for (int i = srcOffset; i < srcOffset + floatCount; ++i) {
put(src[i]);
}
return this;
}
/**
* Writes all the remaining floats of the {@code src} float buffer to this
* buffer's current position, and increases both buffers' position by the
* number of floats copied.
*
* @param src
* the source float buffer.
* @return this buffer.
* @throws BufferOverflowException
* if {@code src.remaining()} is greater than this buffer's
* {@code remaining()}.
* @throws IllegalArgumentException
* if {@code src} is this buffer.
* @throws ReadOnlyBufferException
* if no changes may be made to the contents of this buffer.
*/
public FloatBuffer put(FloatBuffer src) {
if (isReadOnly()) {
throw new ReadOnlyBufferException();
}
if (src == this) {
throw new IllegalArgumentException("src == this");
}
if (src.remaining() > remaining()) {
throw new BufferOverflowException();
}
float[] contents = new float[src.remaining()];
src.get(contents);
put(contents);
return this;
}
/**
* Writes a float to the specified index of this buffer; the position is not
* changed.
*
* @param index
* the index, must not be negative and less than the limit.
* @param f
* the float to write.
* @return this buffer.
* @throws IndexOutOfBoundsException
* if index is invalid.
* @throws ReadOnlyBufferException
* if no changes may be made to the contents of this buffer.
*/
public abstract FloatBuffer put(int index, float f);
/**
* Returns a sliced buffer that shares its content with this buffer.
* <p>
* The sliced buffer's capacity will be this buffer's {@code remaining()},
* and its zero position will correspond to this buffer's current position.
* The new buffer's position will be 0, limit will be its capacity, and its
* mark is cleared. The new buffer's read-only property and byte order are
* same as this buffer's.
* <p>
* The new buffer shares its content with this buffer, which means either
* buffer's change of content will be visible to the other. The two buffers'
* position, limit and mark are independent.
*/
public abstract FloatBuffer slice();
}