/* * 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; import libcore.io.Memory; /** * A buffer for bytes. *
* A byte buffer can be created in either one of the following ways: *
* Calling this method has the same effect as * {@code wrap(array, 0, array.length)}. * * @param array * the byte array which the new buffer will be based on * @return the created byte buffer. */ public static ByteBuffer wrap(byte[] array) { return new ReadWriteHeapByteBuffer(array); } /** * Creates a new byte buffer by wrapping the given byte array. *
* The new buffer's position will be {@code start}, limit will be * {@code start + byteCount}, capacity will be the length of the array. * * @param array * the byte 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 byteCount * the length, must not be negative and not greater than * {@code array.length - start}. * @return the created byte buffer. * @exception IndexOutOfBoundsException * if either {@code start} or {@code byteCount} is invalid. */ public static ByteBuffer wrap(byte[] array, int start, int byteCount) { Arrays.checkOffsetAndCount(array.length, start, byteCount); ByteBuffer buf = new ReadWriteHeapByteBuffer(array); buf.position = start; buf.limit = start + byteCount; return buf; } /** * The byte order of this buffer, default is {@code BIG_ENDIAN}. */ ByteOrder order = ByteOrder.BIG_ENDIAN; ByteBuffer(int capacity, MemoryBlock block) { super(0, capacity, block); } /** * Returns the byte array which this buffer is based on, if there is one. * * @return the byte array which this buffer is based on. * @exception ReadOnlyBufferException * if this buffer is based on a read-only array. * @exception UnsupportedOperationException * if this buffer is not based on an array. */ public final byte[] array() { return protectedArray(); } /** * Returns the offset of the byte array which this buffer is based on, if * there is one. *
* The offset is the index of the array which corresponds to the zero * position of the buffer. * * @return the offset of the byte array which this buffer is based on. * @exception ReadOnlyBufferException * if this buffer is based on a read-only array. * @exception UnsupportedOperationException * if this buffer is not based on an array. */ public final int arrayOffset() { return protectedArrayOffset(); } /** * Returns a char buffer which is based on the remaining content of this * byte buffer. *
* The new buffer's position is zero, its limit and capacity is the number * of remaining bytes divided by two, and its mark is not set. The new * buffer's read-only property and byte order are the same as this buffer's. * The new buffer is direct if this byte buffer is direct. *
* 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 buffer's * position, limit and mark are independent. * * @return a char buffer which is based on the content of this byte buffer. */ public abstract CharBuffer asCharBuffer(); /** * Returns a double buffer which is based on the remaining content of this * byte buffer. *
* The new buffer's position is zero, its limit and capacity is the number * of remaining bytes divided by eight, and its mark is not set. The new * buffer's read-only property and byte order are the same as this buffer's. * The new buffer is direct if this byte buffer is direct. *
* 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 buffer's * position, limit and mark are independent. * * @return a double buffer which is based on the content of this byte * buffer. */ public abstract DoubleBuffer asDoubleBuffer(); /** * Returns a float buffer which is based on the remaining content of this * byte buffer. *
* The new buffer's position is zero, its limit and capacity is the number * of remaining bytes divided by four, and its mark is not set. The new * buffer's read-only property and byte order are the same as this buffer's. * The new buffer is direct if this byte buffer is direct. *
* 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 buffer's * position, limit and mark are independent. * * @return a float buffer which is based on the content of this byte buffer. */ public abstract FloatBuffer asFloatBuffer(); /** * Returns a int buffer which is based on the remaining content of this byte * buffer. *
* The new buffer's position is zero, its limit and capacity is the number * of remaining bytes divided by four, and its mark is not set. The new * buffer's read-only property and byte order are the same as this buffer's. * The new buffer is direct if this byte buffer is direct. *
* 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 buffer's * position, limit and mark are independent. * * @return a int buffer which is based on the content of this byte buffer. */ public abstract IntBuffer asIntBuffer(); /** * Returns a long buffer which is based on the remaining content of this * byte buffer. *
* The new buffer's position is zero, its limit and capacity is the number * of remaining bytes divided by eight, and its mark is not set. The new * buffer's read-only property and byte order are the same as this buffer's. * The new buffer is direct if this byte buffer is direct. *
* 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 buffer's * position, limit and mark are independent. * * @return a long buffer which is based on the content of this byte buffer. */ public abstract LongBuffer asLongBuffer(); /** * Returns a read-only buffer that shares its content with this buffer. *
* 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. *
* 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 ByteBuffer asReadOnlyBuffer(); /** * Returns a short buffer which is based on the remaining content of this * byte buffer. *
* The new buffer's position is zero, its limit and capacity is the number * of remaining bytes divided by two, and its mark is not set. The new * buffer's read-only property and byte order are the same as this buffer's. * The new buffer is direct if this byte buffer is direct. *
* 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 buffer's * position, limit and mark are independent. * * @return a short buffer which is based on the content of this byte buffer. */ public abstract ShortBuffer asShortBuffer(); /** * Compacts this byte buffer. *
* The remaining bytes 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 {@code this} * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer compact(); /** * Compares the remaining bytes of this buffer to another byte buffer's * remaining bytes. * * @param otherBuffer * another byte buffer. * @return a negative value if this is less than {@code other}; 0 if this * equals to {@code other}; a positive value if this is greater * than {@code other}. * @exception ClassCastException * if {@code other} is not a byte buffer. */ public int compareTo(ByteBuffer otherBuffer) { int compareRemaining = (remaining() < otherBuffer.remaining()) ? remaining() : otherBuffer.remaining(); int thisPos = position; int otherPos = otherBuffer.position; byte thisByte, otherByte; while (compareRemaining > 0) { thisByte = get(thisPos); otherByte = otherBuffer.get(otherPos); if (thisByte != otherByte) { return thisByte < otherByte ? -1 : 1; } thisPos++; otherPos++; compareRemaining--; } return remaining() - otherBuffer.remaining(); } /** * Returns a duplicated buffer that shares its content with this buffer. *
* The duplicated buffer's position, limit, capacity and mark are the same * as this buffer's. The duplicated buffer's read-only property and byte * order are the same as this buffer's too. *
* 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 buffer's * position, limit and mark are independent. * * @return a duplicated buffer that shares its content with this buffer. */ public abstract ByteBuffer duplicate(); /** * Checks whether this byte buffer is equal to another object. *
* If {@code other} is not a byte buffer then {@code false} is returned. Two * byte buffers are equal if and only if their remaining bytes are exactly * the same. Position, limit, capacity and mark are not considered. * * @param other * the object to compare with this byte buffer. * @return {@code true} if this byte buffer is equal to {@code other}, * {@code false} otherwise. */ @Override public boolean equals(Object other) { if (!(other instanceof ByteBuffer)) { return false; } ByteBuffer otherBuffer = (ByteBuffer) other; if (remaining() != otherBuffer.remaining()) { return false; } int myPosition = position; int otherPosition = otherBuffer.position; boolean equalSoFar = true; while (equalSoFar && (myPosition < limit)) { equalSoFar = get(myPosition++) == otherBuffer.get(otherPosition++); } return equalSoFar; } /** * Returns the byte at the current position and increases the position by 1. * * @return the byte at the current position. * @exception BufferUnderflowException * if the position is equal or greater than limit. */ public abstract byte get(); /** * Reads bytes from the current position into the specified byte array and * increases the position by the number of bytes read. *
* Calling this method has the same effect as * {@code get(dst, 0, dst.length)}. * * @param dst * the destination byte array. * @return {@code this} * @exception BufferUnderflowException * if {@code dst.length} is greater than {@code remaining()}. */ public ByteBuffer get(byte[] dst) { return get(dst, 0, dst.length); } /** * Reads bytes from the current position into the specified byte array, * starting at the specified offset, and increases the position by the * number of bytes read. * * @param dst * the target byte array. * @param dstOffset * the offset of the byte array, must not be negative and * not greater than {@code dst.length}. * @param byteCount * the number of bytes to read, must not be negative and not * greater than {@code dst.length - dstOffset} * @return {@code this} * @exception IndexOutOfBoundsException if {@code dstOffset < 0 || byteCount < 0} * @exception BufferUnderflowException if {@code byteCount > remaining()} */ public ByteBuffer get(byte[] dst, int dstOffset, int byteCount) { Arrays.checkOffsetAndCount(dst.length, dstOffset, byteCount); if (byteCount > remaining()) { throw new BufferUnderflowException(); } for (int i = dstOffset; i < dstOffset + byteCount; ++i) { dst[i] = get(); } return this; } /** * Returns the byte at the specified index and does not change the position. * * @param index * the index, must not be negative and less than limit. * @return the byte at the specified index. * @exception IndexOutOfBoundsException * if index is invalid. */ public abstract byte get(int index); /** * Returns the char at the current position and increases the position by 2. *
* The 2 bytes starting at the current position are composed into a char * according to the current byte order and returned. * * @return the char at the current position. * @exception BufferUnderflowException * if the position is greater than {@code limit - 2}. */ public abstract char getChar(); /** * Returns the char at the specified index. *
* The 2 bytes starting from the specified index are composed into a char * according to the current byte order and returned. The position is not * changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 2}. * @return the char at the specified index. * @exception IndexOutOfBoundsException * if {@code index} is invalid. */ public abstract char getChar(int index); /** * Returns the double at the current position and increases the position by * 8. *
* The 8 bytes starting from the current position are composed into a double * according to the current byte order and returned. * * @return the double at the current position. * @exception BufferUnderflowException * if the position is greater than {@code limit - 8}. */ public abstract double getDouble(); /** * Returns the double at the specified index. *
* The 8 bytes starting at the specified index are composed into a double * according to the current byte order and returned. The position is not * changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 8}. * @return the double at the specified index. * @exception IndexOutOfBoundsException * if {@code index} is invalid. */ public abstract double getDouble(int index); /** * Returns the float at the current position and increases the position by * 4. *
* The 4 bytes starting at the current position are composed into a float * according to the current byte order and returned. * * @return the float at the current position. * @exception BufferUnderflowException * if the position is greater than {@code limit - 4}. */ public abstract float getFloat(); /** * Returns the float at the specified index. *
* The 4 bytes starting at the specified index are composed into a float * according to the current byte order and returned. The position is not * changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 4}. * @return the float at the specified index. * @exception IndexOutOfBoundsException * if {@code index} is invalid. */ public abstract float getFloat(int index); /** * Returns the int at the current position and increases the position by 4. *
* The 4 bytes starting at the current position are composed into a int * according to the current byte order and returned. * * @return the int at the current position. * @exception BufferUnderflowException * if the position is greater than {@code limit - 4}. */ public abstract int getInt(); /** * Returns the int at the specified index. *
* The 4 bytes starting at the specified index are composed into a int * according to the current byte order and returned. The position is not * changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 4}. * @return the int at the specified index. * @exception IndexOutOfBoundsException * if {@code index} is invalid. */ public abstract int getInt(int index); /** * Returns the long at the current position and increases the position by 8. *
* The 8 bytes starting at the current position are composed into a long * according to the current byte order and returned. * * @return the long at the current position. * @exception BufferUnderflowException * if the position is greater than {@code limit - 8}. */ public abstract long getLong(); /** * Returns the long at the specified index. *
* The 8 bytes starting at the specified index are composed into a long * according to the current byte order and returned. The position is not * changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 8}. * @return the long at the specified index. * @exception IndexOutOfBoundsException * if {@code index} is invalid. */ public abstract long getLong(int index); /** * Returns the short at the current position and increases the position by 2. *
* The 2 bytes starting at the current position are composed into a short * according to the current byte order and returned. * * @return the short at the current position. * @exception BufferUnderflowException * if the position is greater than {@code limit - 2}. */ public abstract short getShort(); /** * Returns the short at the specified index. *
* The 2 bytes starting at the specified index are composed into a short * according to the current byte order and returned. The position is not * changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 2}. * @return the short at the specified index. * @exception IndexOutOfBoundsException * if {@code index} is invalid. */ public abstract short getShort(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 bytes. */ @Override public int hashCode() { int myPosition = position; int hash = 0; while (myPosition < limit) { hash = hash + get(myPosition++); } return hash; } /** * Indicates whether this 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 bytes from/to * other primitive types. *
* The default byte order of byte buffer is always * {@link ByteOrder#BIG_ENDIAN BIG_ENDIAN} * * @return the byte order used by this buffer when converting bytes from/to * other primitive types. */ public final ByteOrder order() { return order; } /** * Sets the byte order of this buffer. * * @param byteOrder * the byte order to set. If {@code null} then the order * will be {@link ByteOrder#LITTLE_ENDIAN LITTLE_ENDIAN}. * @return {@code this} * @see ByteOrder */ public final ByteBuffer order(ByteOrder byteOrder) { orderImpl(byteOrder); return this; } /** * Subverts the fact that order(ByteOrder) is final, for the benefit of MappedByteBufferAdapter. */ void orderImpl(ByteOrder byteOrder) { if (byteOrder == null) { byteOrder = ByteOrder.LITTLE_ENDIAN; } order = byteOrder; } /** * Child class implements this method to realize {@code array()}. * * @see #array() */ abstract byte[] protectedArray(); /** * Child class implements this method to realize {@code arrayOffset()}. * * @see #arrayOffset() */ abstract int protectedArrayOffset(); /** * Child class implements this method to realize {@code hasArray()}. * * @see #hasArray() */ abstract boolean protectedHasArray(); /** * Writes the given byte to the current position and increases the position * by 1. * * @param b * the byte to write. * @return {@code this} * @exception BufferOverflowException * if position is equal or greater than limit. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer put(byte b); /** * Writes bytes in the given byte array to the current position and * increases the position by the number of bytes written. *
* Calling this method has the same effect as * {@code put(src, 0, src.length)}. * * @param src * the source byte array. * @return {@code this} * @exception BufferOverflowException * if {@code remaining()} is less than {@code src.length}. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public final ByteBuffer put(byte[] src) { return put(src, 0, src.length); } /** * Writes bytes in the given byte array, starting from the specified offset, * to the current position and increases the position by the number of bytes * written. * * @param src * the source byte array. * @param srcOffset * the offset of byte array, must not be negative and not greater * than {@code src.length}. * @param byteCount * the number of bytes to write, must not be negative and not * greater than {@code src.length - srcOffset}. * @return {@code this} * @exception BufferOverflowException * if {@code remaining()} is less than {@code byteCount}. * @exception IndexOutOfBoundsException * if either {@code srcOffset} or {@code byteCount} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public ByteBuffer put(byte[] src, int srcOffset, int byteCount) { Arrays.checkOffsetAndCount(src.length, srcOffset, byteCount); if (byteCount > remaining()) { throw new BufferOverflowException(); } for (int i = srcOffset; i < srcOffset + byteCount; ++i) { put(src[i]); } return this; } /** * Writes all the remaining bytes of the {@code src} byte buffer to this * buffer's current position, and increases both buffers' position by the * number of bytes copied. * * @param src * the source byte buffer. * @return {@code this} * @exception BufferOverflowException * if {@code src.remaining()} is greater than this buffer's * {@code remaining()}. * @exception IllegalArgumentException * if {@code src} is this buffer. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public ByteBuffer put(ByteBuffer src) { if (src == this) { throw new IllegalArgumentException("src == this"); } int srcByteCount = src.remaining(); if (srcByteCount > remaining()) { throw new BufferOverflowException(); } Object srcObject = src.isDirect() ? src : NioUtils.unsafeArray(src); int srcOffset = src.position(); if (!src.isDirect()) { srcOffset += NioUtils.unsafeArrayOffset(src); } ByteBuffer dst = this; Object dstObject = dst.isDirect() ? dst : NioUtils.unsafeArray(dst); int dstOffset = dst.position(); if (!dst.isDirect()) { dstOffset += NioUtils.unsafeArrayOffset(dst); } Memory.memmove(dstObject, dstOffset, srcObject, srcOffset, srcByteCount); src.position(src.limit()); dst.position(dst.position() + srcByteCount); return this; } /** * Write a byte to the specified index of this buffer without changing the * position. * * @param index * the index, must not be negative and less than the limit. * @param b * the byte to write. * @return {@code this} * @exception IndexOutOfBoundsException * if {@code index} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer put(int index, byte b); /** * Writes the given char to the current position and increases the position * by 2. *
* The char is converted to bytes using the current byte order. * * @param value * the char to write. * @return {@code this} * @exception BufferOverflowException * if position is greater than {@code limit - 2}. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putChar(char value); /** * Writes the given char to the specified index of this buffer. *
* The char is converted to bytes using the current byte order. The position * is not changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 2}. * @param value * the char to write. * @return {@code this} * @exception IndexOutOfBoundsException * if {@code index} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putChar(int index, char value); /** * Writes the given double to the current position and increases the position * by 8. *
* The double is converted to bytes using the current byte order. * * @param value * the double to write. * @return {@code this} * @exception BufferOverflowException * if position is greater than {@code limit - 8}. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putDouble(double value); /** * Writes the given double to the specified index of this buffer. *
* The double is converted to bytes using the current byte order. The * position is not changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 8}. * @param value * the double to write. * @return {@code this} * @exception IndexOutOfBoundsException * if {@code index} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putDouble(int index, double value); /** * Writes the given float to the current position and increases the position * by 4. *
* The float is converted to bytes using the current byte order. * * @param value * the float to write. * @return {@code this} * @exception BufferOverflowException * if position is greater than {@code limit - 4}. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putFloat(float value); /** * Writes the given float to the specified index of this buffer. *
* The float is converted to bytes using the current byte order. The * position is not changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 4}. * @param value * the float to write. * @return {@code this} * @exception IndexOutOfBoundsException * if {@code index} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putFloat(int index, float value); /** * Writes the given int to the current position and increases the position by * 4. *
* The int is converted to bytes using the current byte order. * * @param value * the int to write. * @return {@code this} * @exception BufferOverflowException * if position is greater than {@code limit - 4}. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putInt(int value); /** * Writes the given int to the specified index of this buffer. *
* The int is converted to bytes using the current byte order. The position * is not changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 4}. * @param value * the int to write. * @return {@code this} * @exception IndexOutOfBoundsException * if {@code index} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putInt(int index, int value); /** * Writes the given long to the current position and increases the position * by 8. *
* The long is converted to bytes using the current byte order. * * @param value * the long to write. * @return {@code this} * @exception BufferOverflowException * if position is greater than {@code limit - 8}. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putLong(long value); /** * Writes the given long to the specified index of this buffer. *
* The long is converted to bytes using the current byte order. The position * is not changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 8}. * @param value * the long to write. * @return {@code this} * @exception IndexOutOfBoundsException * if {@code index} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putLong(int index, long value); /** * Writes the given short to the current position and increases the position * by 2. *
* The short is converted to bytes using the current byte order. * * @param value * the short to write. * @return {@code this} * @exception BufferOverflowException * if position is greater than {@code limit - 2}. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putShort(short value); /** * Writes the given short to the specified index of this buffer. *
* The short is converted to bytes using the current byte order. The * position is not changed. * * @param index * the index, must not be negative and equal or less than * {@code limit - 2}. * @param value * the short to write. * @return {@code this} * @exception IndexOutOfBoundsException * if {@code index} is invalid. * @exception ReadOnlyBufferException * if no changes may be made to the contents of this buffer. */ public abstract ByteBuffer putShort(int index, short value); /** * Returns a sliced buffer that shares its content with this buffer. *
* The sliced buffer's capacity will be this buffer's * {@code remaining()}, and it's 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 the same as this buffer's. *
* 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 buffer's * position, limit and mark are independent. * * @return a sliced buffer that shares its content with this buffer. */ public abstract ByteBuffer slice(); }