diff options
Diffstat (limited to 'lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java')
| -rw-r--r-- | lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java | 687 |
1 files changed, 0 insertions, 687 deletions
diff --git a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java deleted file mode 100644 index 0556371273..0000000000 --- a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java +++ /dev/null @@ -1,687 +0,0 @@ -/*******************************************************************************. - * Copyright (c) 2011, 2014 Ericsson, Ecole Polytechnique de Montreal and others - * - * All rights reserved. This program and the accompanying materials are made - * available under the terms of the Eclipse Public License v1.0 which - * accompanies this distribution, and is available at - * http://www.eclipse.org/legal/epl-v10.html - * - * Contributors: - * Matthew Khouzam - Initial Design and implementation + overhaul - * Francis Giraldeau - Initial API and implementation - * Philippe Proulx - Some refinement and optimization - * Etienne Bergeron <Etienne.Bergeron@gmail.com> - fix zero size read + cleanup - *******************************************************************************/ - -package org.eclipse.linuxtools.ctf.core.event.io; - -import java.nio.BufferUnderflowException; -import java.nio.ByteBuffer; -import java.nio.ByteOrder; - -import org.eclipse.jdt.annotation.NonNull; -import org.eclipse.linuxtools.ctf.core.trace.CTFReaderException; - -/** - * <b><u>BitBuffer</u></b> - * <p> - * A bitwise buffer capable of accessing fields with bit offsets. - * - * @since 2.0 - */ -public final class BitBuffer { - - // ------------------------------------------------------------------------ - // Constants - // ------------------------------------------------------------------------ - - /* default bit width */ - /** 8 bits to a char */ - public static final int BIT_CHAR = 8; - /** 16 bits to a short */ - public static final int BIT_SHORT = 16; - /** 32 bits to an int */ - public static final int BIT_INT = 32; - /** 32 bits to a float */ - public static final int BIT_FLOAT = 32; - /** 64 bits to a long */ - public static final int BIT_LONG = 64; - - // ------------------------------------------------------------------------ - // Attributes - // ------------------------------------------------------------------------ - - private final @NonNull ByteBuffer fBuffer; - private final long fBitCapacity; - - /** - * Bit-buffer's position, maximum value = Integer.MAX_VALUE * 8 - */ - private long fPosition; - private ByteOrder fByteOrder; - - // ------------------------------------------------------------------------ - // Constructors - // ------------------------------------------------------------------------ - /** - * Default constructor, makes a big-endian buffer - */ - @SuppressWarnings("null") - public BitBuffer() { - this(ByteBuffer.allocateDirect(0), ByteOrder.BIG_ENDIAN); - } - - /** - * Constructor, makes a big-endian buffer - * - * @param buf - * the bytebuffer to read - */ - public BitBuffer(@NonNull ByteBuffer buf) { - this(buf, ByteOrder.BIG_ENDIAN); - } - - /** - * Constructor that is fully parameterizable - * - * @param buf - * the buffer to read - * @param order - * the byte order (big-endian, little-endian, network?) - */ - public BitBuffer(@NonNull ByteBuffer buf, ByteOrder order) { - fBuffer = buf; - setByteOrder(order); - resetPosition(); - fBitCapacity = fBuffer.capacity() * BIT_CHAR; - } - - private void resetPosition() { - fPosition = 0; - } - - // ------------------------------------------------------------------------ - // 'Get' operations on buffer - // ------------------------------------------------------------------------ - - /** - * Relative <i>get</i> method for reading 32-bit integer. - * - * Reads next four bytes from the current bit position according to current - * byte order. - * - * @return The int value (signed) read from the buffer - * @throws CTFReaderException - * An error occurred reading the long. This exception can be - * raised if the buffer tries to read out of bounds - */ - public int getInt() throws CTFReaderException { - return getInt(BIT_INT, true); - } - - /** - * Relative <i>get</i> method for reading 64-bit integer. - * - * Reads next eight bytes from the current bit position according to current - * byte order. - * - * @return The long value (signed) read from the buffer - * @throws CTFReaderException - * An error occurred reading the long. This exception can be - * raised if the buffer tries to read out of bounds - * @since 3.0 - */ - public long getLong() throws CTFReaderException { - return get(BIT_LONG, true); - } - - /** - * Relative <i>get</i> method for reading long of <i>length</i> bits. - * - * Reads <i>length</i> bits starting at the current position. The result is - * signed extended if <i>signed</i> is true. The current position is - * increased of <i>length</i> bits. - * - * @param length - * The length in bits of this integer - * @param signed - * The sign extended flag - * @return The long value read from the buffer - * @throws CTFReaderException - * An error occurred reading the data. If more than 64 bits at a - * time are read, or the buffer is read beyond its end, this - * exception will be raised. - * @since 3.0 - */ - public long get(int length, boolean signed) throws CTFReaderException { - if (length > BIT_LONG) { - throw new CTFReaderException("Cannot read a long longer than 64 bits. Rquested: " + length); //$NON-NLS-1$ - } - if (length > BIT_INT) { - final int highShift = length - BIT_INT; - long a = getInt(); - long b = getInt(highShift, false); - long retVal; - /* Cast the signed-extended int into a unsigned int. */ - a &= 0xFFFFFFFFL; - b &= (1L << highShift) - 1L; - - retVal = (fByteOrder == ByteOrder.BIG_ENDIAN) ? ((a << highShift) | b) : ((b << BIT_INT) | a); - /* sign extend */ - if (signed) { - int signExtendBits = BIT_LONG - length; - retVal = (retVal << signExtendBits) >> signExtendBits; - } - return retVal; - } - long retVal = getInt(length, signed); - return (signed ? retVal : (retVal & 0xFFFFFFFFL)); - } - - /** - * Relative bulk <i>get</i> method. - * - * <p> - * This method transfers <strong>bytes</strong> from this buffer into the - * given destination array. This method currently only supports reads - * aligned to 8 bytes. It is up to the developer to shift the bits in - * post-processing to do unaligned reads. - * - * @param dst - * the bytes to write to - * @throws BufferUnderflowException - * - If there are fewer than length bytes remaining in this - * buffer - * @since 3.1 - */ - public void get(@NonNull byte[] dst) { - fBuffer.position((int) (fPosition / 8)); - fBuffer.get(dst); - fPosition += dst.length * 8; - } - - /** - * Relative <i>get</i> method for reading integer of <i>length</i> bits. - * - * Reads <i>length</i> bits starting at the current position. The result is - * signed extended if <i>signed</i> is true. The current position is - * increased of <i>length</i> bits. - * - * @param length - * The length in bits of this integer - * @param signed - * The sign extended flag - * @return The int value read from the buffer - * @throws CTFReaderException - * An error occurred reading the data. When the buffer is read - * beyond its end, this exception will be raised. - */ - private int getInt(int length, boolean signed) throws CTFReaderException { - - /* Nothing to read. */ - if (length == 0) { - return 0; - } - - /* Validate that the buffer has enough bits. */ - if (!canRead(length)) { - throw new CTFReaderException("Cannot read the integer, " + //$NON-NLS-1$ - "the buffer does not have enough remaining space. " + //$NON-NLS-1$ - "Requested:" + length); //$NON-NLS-1$ - } - - /* Get the value from the byte buffer. */ - int val = 0; - boolean gotIt = false; - - /* - * Try a fast read when the position is byte-aligned by using - * java.nio.ByteBuffer's native methods - */ - /* - * A faster alignment detection as the compiler cannot guaranty that pos - * is always positive. - */ - if ((fPosition & (BitBuffer.BIT_CHAR - 1)) == 0) { - switch (length) { - case BitBuffer.BIT_CHAR: - // Byte - val = fBuffer.get((int) (fPosition / 8)); - if (!signed) { - val = val & 0xff; - } - gotIt = true; - break; - - case BitBuffer.BIT_SHORT: - // Word - val = fBuffer.getShort((int) (fPosition / 8)); - if (!signed) { - val = val & 0xffff; - } - gotIt = true; - break; - - case BitBuffer.BIT_INT: - // Double word - val = fBuffer.getInt((int) (fPosition / 8)); - gotIt = true; - break; - - default: - break; - } - } - - /* When not byte-aligned, fall-back to a general decoder. */ - if (!gotIt) { - // Nothing read yet: use longer methods - if (fByteOrder == ByteOrder.LITTLE_ENDIAN) { - val = getIntLE(fPosition, length, signed); - } else { - val = getIntBE(fPosition, length, signed); - } - } - fPosition += length; - - return val; - } - - private int getIntBE(long index, int length, boolean signed) { - if ((length <= 0) || (length > BIT_INT)) { - throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ - } - long end = index + length; - int startByte = (int) (index / BIT_CHAR); - int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); - int currByte, lshift, cshift, mask, cmask, cache; - int value = 0; - - currByte = startByte; - cache = fBuffer.get(currByte) & 0xFF; - boolean isNeg = (cache & (1 << (BIT_CHAR - (index % BIT_CHAR) - 1))) != 0; - if (signed && isNeg) { - value = ~0; - } - if (startByte == (endByte - 1)) { - cmask = cache >>> ((BIT_CHAR - (end % BIT_CHAR)) % BIT_CHAR); - if (((length) % BIT_CHAR) > 0) { - mask = ~((~0) << length); - cmask &= mask; - } - value <<= length; - value |= cmask; - return value; - } - cshift = (int) (index % BIT_CHAR); - if (cshift > 0) { - mask = ~((~0) << (BIT_CHAR - cshift)); - cmask = cache & mask; - lshift = BIT_CHAR - cshift; - value <<= lshift; - value |= cmask; - currByte++; - } - for (; currByte < (endByte - 1); currByte++) { - value <<= BIT_CHAR; - value |= fBuffer.get(currByte) & 0xFF; - } - lshift = (int) (end % BIT_CHAR); - if (lshift > 0) { - mask = ~((~0) << lshift); - cmask = fBuffer.get(currByte) & 0xFF; - cmask >>>= BIT_CHAR - lshift; - cmask &= mask; - value <<= lshift; - value |= cmask; - } else { - value <<= BIT_CHAR; - value |= fBuffer.get(currByte) & 0xFF; - } - return value; - } - - private int getIntLE(long index, int length, boolean signed) { - if ((length <= 0) || (length > BIT_INT)) { - throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ - } - long end = index + length; - int startByte = (int) (index / BIT_CHAR); - int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); - int currByte, lshift, cshift, mask, cmask, cache, mod; - int value = 0; - - currByte = endByte - 1; - cache = fBuffer.get(currByte) & 0xFF; - mod = (int) (end % BIT_CHAR); - lshift = (mod > 0) ? mod : BIT_CHAR; - boolean isNeg = (cache & (1 << (lshift - 1))) != 0; - if (signed && isNeg) { - value = ~0; - } - if (startByte == (endByte - 1)) { - cmask = cache >>> (index % BIT_CHAR); - if (((length) % BIT_CHAR) > 0) { - mask = ~((~0) << length); - cmask &= mask; - } - value <<= length; - value |= cmask; - return value; - } - cshift = (int) (end % BIT_CHAR); - if (cshift > 0) { - mask = ~((~0) << cshift); - cmask = cache & mask; - value <<= cshift; - value |= cmask; - currByte--; - } - for (; currByte >= (startByte + 1); currByte--) { - value <<= BIT_CHAR; - value |= fBuffer.get(currByte) & 0xFF; - } - lshift = (int) (index % BIT_CHAR); - if (lshift > 0) { - mask = ~((~0) << (BIT_CHAR - lshift)); - cmask = fBuffer.get(currByte) & 0xFF; - cmask >>>= lshift; - cmask &= mask; - value <<= (BIT_CHAR - lshift); - value |= cmask; - } else { - value <<= BIT_CHAR; - value |= fBuffer.get(currByte) & 0xFF; - } - return value; - } - - // ------------------------------------------------------------------------ - // 'Put' operations on buffer - // ------------------------------------------------------------------------ - - /** - * Relative <i>put</i> method to write signed 32-bit integer. - * - * Write four bytes starting from current bit position in the buffer - * according to the current byte order. The current position is increased of - * <i>length</i> bits. - * - * @param value - * The int value to write - * @throws CTFReaderException - * An error occurred writing the data. If the buffer is written - * beyond its end, this exception will be raised. - */ - public void putInt(int value) throws CTFReaderException { - putInt(BIT_INT, value); - } - - /** - * Relative <i>put</i> method to write <i>length</i> bits integer. - * - * Writes <i>length</i> lower-order bits from the provided <i>value</i>, - * starting from current bit position in the buffer. Sequential bytes are - * written according to the current byte order. The sign bit is carried to - * the MSB if signed is true. The sign bit is included in <i>length</i>. The - * current position is increased of <i>length</i>. - * - * @param length - * The number of bits to write - * @param value - * The value to write - * @throws CTFReaderException - * An error occurred writing the data. If the buffer is written - * beyond its end, this exception will be raised. - */ - public void putInt(int length, int value) throws CTFReaderException { - final long curPos = fPosition; - - if (!canRead(length)) { - throw new CTFReaderException("Cannot write to bitbuffer, " //$NON-NLS-1$ - + "insufficient space. Requested: " + length); //$NON-NLS-1$ - } - if (length == 0) { - return; - } - if (fByteOrder == ByteOrder.LITTLE_ENDIAN) { - putIntLE(curPos, length, value); - } else { - putIntBE(curPos, length, value); - } - fPosition += length; - } - - private void putIntBE(long index, int length, int value) { - if ((length <= 0) || (length > BIT_INT)) { - throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ - } - long end = index + length; - int startByte = (int) (index / BIT_CHAR); - int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); - int currByte, lshift, cshift, mask, cmask; - int correctedValue = value; - - /* - * mask v high bits. Works for unsigned and two complement signed - * numbers which value do not overflow on length bits. - */ - - if (length < BIT_INT) { - correctedValue &= ~(~0 << length); - } - - /* sub byte */ - if (startByte == (endByte - 1)) { - lshift = (int) ((BIT_CHAR - (end % BIT_CHAR)) % BIT_CHAR); - mask = ~((~0) << lshift); - if ((index % BIT_CHAR) > 0) { - mask |= (~(0)) << (BIT_CHAR - (index % BIT_CHAR)); - } - cmask = correctedValue << lshift; - /* - * low bits are cleared because of left-shift and high bits are - * already cleared - */ - cmask &= ~mask; - int b = fBuffer.get(startByte) & 0xFF; - fBuffer.put(startByte, (byte) ((b & mask) | cmask)); - return; - } - - /* head byte contains MSB */ - currByte = endByte - 1; - cshift = (int) (end % BIT_CHAR); - if (cshift > 0) { - lshift = BIT_CHAR - cshift; - mask = ~((~0) << lshift); - cmask = correctedValue << lshift; - cmask &= ~mask; - int b = fBuffer.get(currByte) & 0xFF; - fBuffer.put(currByte, (byte) ((b & mask) | cmask)); - correctedValue >>>= cshift; - currByte--; - } - - /* middle byte(s) */ - for (; currByte >= (startByte + 1); currByte--) { - fBuffer.put(currByte, (byte) correctedValue); - correctedValue >>>= BIT_CHAR; - } - /* end byte contains LSB */ - if ((index % BIT_CHAR) > 0) { - mask = (~0) << (BIT_CHAR - (index % BIT_CHAR)); - cmask = correctedValue & ~mask; - int b = fBuffer.get(currByte) & 0xFF; - fBuffer.put(currByte, (byte) ((b & mask) | cmask)); - } else { - fBuffer.put(currByte, (byte) correctedValue); - } - } - - private void putIntLE(long index, int length, int value) { - if ((length <= 0) || (length > BIT_INT)) { - throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ - } - long end = index + length; - int startByte = (int) (index / BIT_CHAR); - int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); - int currByte, lshift, cshift, mask, cmask; - int correctedValue = value; - - /* - * mask v high bits. Works for unsigned and two complement signed - * numbers which value do not overflow on length bits. - */ - - if (length < BIT_INT) { - correctedValue &= ~(~0 << length); - } - - /* sub byte */ - if (startByte == (endByte - 1)) { - lshift = (int) (index % BIT_CHAR); - mask = ~((~0) << lshift); - if ((end % BIT_CHAR) > 0) { - mask |= (~(0)) << (end % BIT_CHAR); - } - cmask = correctedValue << lshift; - /* - * low bits are cleared because of left-shift and high bits are - * already cleared - */ - cmask &= ~mask; - int b = fBuffer.get(startByte) & 0xFF; - fBuffer.put(startByte, (byte) ((b & mask) | cmask)); - return; - } - - /* head byte */ - currByte = startByte; - cshift = (int) (index % BIT_CHAR); - if (cshift > 0) { - mask = ~((~0) << cshift); - cmask = correctedValue << cshift; - cmask &= ~mask; - int b = fBuffer.get(currByte) & 0xFF; - fBuffer.put(currByte, (byte) ((b & mask) | cmask)); - correctedValue >>>= BIT_CHAR - cshift; - currByte++; - } - - /* middle byte(s) */ - for (; currByte < (endByte - 1); currByte++) { - fBuffer.put(currByte, (byte) correctedValue); - correctedValue >>>= BIT_CHAR; - } - /* end byte */ - if ((end % BIT_CHAR) > 0) { - mask = (~0) << (end % BIT_CHAR); - cmask = correctedValue & ~mask; - int b = fBuffer.get(currByte) & 0xFF; - fBuffer.put(currByte, (byte) ((b & mask) | cmask)); - } else { - fBuffer.put(currByte, (byte) correctedValue); - } - } - - // ------------------------------------------------------------------------ - // Buffer attributes handling - // ------------------------------------------------------------------------ - - /** - * Can this buffer be read for thus amount of bits? - * - * @param length - * the length in bits to read - * @return does the buffer have enough room to read the next "length" - */ - public boolean canRead(int length) { - return ((fPosition + length) <= fBitCapacity); - } - - /** - * Sets the order of the buffer. - * - * @param order - * The order of the buffer. - */ - public void setByteOrder(ByteOrder order) { - fByteOrder = order; - fBuffer.order(order); - } - - /** - * Sets the order of the buffer. - * - * @return The order of the buffer. - */ - public ByteOrder getByteOrder() { - return fByteOrder; - } - - /** - * Sets the position in the buffer. - * - * @param newPosition - * The new position of the buffer. - * @throws CTFReaderException - * Thrown on out of bounds exceptions - * @since 3.0 - */ - public void position(long newPosition) throws CTFReaderException { - - - if (newPosition > fBitCapacity) { - throw new CTFReaderException("Out of bounds exception on a position move, attempting to access position: " + newPosition); //$NON-NLS-1$ - } - fPosition = newPosition; - } - - /** - * - * Sets the position in the buffer. - * - * @return order The position of the buffer. - * @since 3.0 - */ - public long position() { - return fPosition; - } - - /** - * Sets the byte buffer - * - * @param buf - * the byte buffer - */ - @Deprecated - public void setByteBuffer(ByteBuffer buf) { - /* - * to avoid "The method setByteBuffer(ByteBuffer) from the type - * BitBuffer can be declared as static" - */ - long data = fPosition; - fPosition = data; - throw new UnsupportedOperationException("Bytebuffers are now final"); //$NON-NLS-1$ - - } - - /** - * Gets the byte buffer - * - * @return The byte buffer - */ - public ByteBuffer getByteBuffer() { - return fBuffer; - } - - /** - * Resets the bitbuffer. - */ - public void clear() { - resetPosition(); - fBuffer.clear(); - } - -} |