/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
|
* or http://forgerock.org/license/CDDLv1.0.html.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at legal-notices/CDDLv1_0.txt.
|
* If applicable, add the following below this CDDL HEADER, with the
|
* fields enclosed by brackets "[]" replaced with your own identifying
|
* information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2009-2010 Sun Microsystems, Inc.
|
* Portions Copyright 2013-2015 ForgeRock AS.
|
*/
|
package org.opends.server.backends.jeb;
|
|
import static org.opends.server.backends.jeb.Importer.*;
|
import static org.opends.server.util.StaticUtils.*;
|
|
import java.io.ByteArrayOutputStream;
|
import java.io.DataOutputStream;
|
import java.io.IOException;
|
import java.nio.ByteBuffer;
|
|
import com.sleepycat.util.PackedInteger;
|
|
/**
|
* This class represents a index buffer used to store the keys and entry IDs
|
* processed from the LDIF file during phase one of an import, or rebuild index
|
* process. Each key and ID is stored in a record in the buffer.
|
* <p>
|
* The records in the buffer are eventually sorted, based on the key, when the
|
* maximum size of the buffer is reached and no more records will fit into the
|
* buffer. The buffer is scheduled to be flushed to an index scratch file and
|
* then re-cycled by the import, or rebuild-index process.
|
* </p>
|
* <p>
|
* The structure of a record in the buffer is the following:
|
*
|
* <pre>
|
* +-------------+-------------+---------+---------+------------+-----------+
|
* | record size | INS/DEL bit | indexID | entryID | key length | key bytes |
|
* +-------------+-------------+---------+---------+------------+-----------+
|
* </pre>
|
*
|
* The record size is used for fast seeks to quickly "jump" over records.
|
* </p>
|
* <p>
|
* The records are packed as much as possible, to optimize the buffer space.<br>
|
* This class is not thread safe.
|
* </p>
|
*/
|
final class IndexOutputBuffer implements Comparable<IndexOutputBuffer> {
|
|
/** Enumeration used when sorting a buffer. */
|
private enum CompareOp {
|
LT, GT, LE, GE, EQ
|
}
|
|
/**
|
* The record overhead. In addition to entryID, key length and key bytes, the
|
* record overhead includes the indexID + INS/DEL bit
|
*/
|
private static final int REC_OVERHEAD = INT_SIZE + 1;
|
|
/** Buffer records are either insert records or delete records. */
|
private static final byte DEL = 0, INS = 1;
|
|
/** The size of a buffer. */
|
private final int size;
|
/** Byte array holding the actual buffer data. */
|
private final byte buffer[];
|
|
/**
|
* Used to break a tie (keys equal) when the buffers are being merged
|
* for writing to the index scratch file.
|
*/
|
private long bufferID;
|
|
/** OffSet where next key is written. */
|
private int keyOffset;
|
/** OffSet where next value record is written. */
|
private int recordOffset;
|
/** Amount of bytes left in the buffer. */
|
private int bytesLeft;
|
/** Number of keys in the buffer. */
|
private int keys;
|
/** Used to iterate over the buffer when writing to a scratch file. */
|
private int position;
|
|
/**
|
* Used to make sure that an instance of this class is put on the
|
* correct scratch file writer work queue for processing.
|
*/
|
private Importer.IndexKey indexKey;
|
|
/** Initial capacity of re-usable buffer used in key compares. */
|
private static final int CAP = 32;
|
|
/**
|
* This buffer is reused during key compares. It's main purpose is to keep
|
* memory footprint as small as possible.
|
*/
|
private ByteBuffer keyBuffer = ByteBuffer.allocate(CAP);
|
|
/**
|
* Set to {@code true} if the buffer should not be recycled. Used when the
|
* importer/rebuild index process is doing phase one cleanup and flushing
|
* buffers not completed.
|
*/
|
private boolean discarded;
|
|
|
/**
|
* Create an instance of a IndexBuffer using the specified size.
|
*
|
* @param size The size of the underlying byte array.
|
*/
|
public IndexOutputBuffer(int size) {
|
this.size = size;
|
this.buffer = new byte[size];
|
this.bytesLeft = size;
|
this.recordOffset = size - 1;
|
}
|
|
|
/**
|
* Reset an IndexBuffer so it can be re-cycled.
|
*/
|
public void reset() {
|
bytesLeft = size;
|
keyOffset = 0;
|
recordOffset = size - 1;
|
keys = 0;
|
position = 0;
|
indexKey = null;
|
}
|
|
/**
|
* Creates a new poison buffer. Poison buffers are used to stop the processing of import tasks.
|
*
|
* @return a new poison buffer
|
*/
|
public static IndexOutputBuffer poison()
|
{
|
return new IndexOutputBuffer(0);
|
}
|
|
/**
|
* Set the ID of a buffer to the specified value.
|
*
|
* @param bufferID The value to set the buffer ID to.
|
*/
|
public void setBufferID(long bufferID)
|
{
|
this.bufferID = bufferID;
|
}
|
|
/**
|
* Return the ID of a buffer.
|
*
|
* @return The value of a buffer's ID.
|
*/
|
private long getBufferID()
|
{
|
return this.bufferID;
|
}
|
|
/**
|
* Determines if a buffer is a poison buffer. A poison buffer is used to
|
* shutdown work queues when import/rebuild index phase one is completed.
|
* A poison buffer has a 0 size.
|
*
|
* @return {@code true} if a buffer is a poison buffer, or {@code false}
|
* otherwise.
|
*/
|
public boolean isPoison()
|
{
|
return size == 0;
|
}
|
|
/**
|
* Determines if buffer should be re-cycled by calling {@link #reset()}.
|
*
|
* @return {@code true} if buffer should be recycled, or {@code false} if it
|
* should not.
|
*/
|
public boolean isDiscarded()
|
{
|
return discarded;
|
}
|
|
/**
|
* Sets the discarded flag to {@code true}.
|
*/
|
public void discard()
|
{
|
discarded = true;
|
}
|
|
/**
|
* Returns {@code true} if there is enough space available to write the
|
* specified byte array in the buffer. It returns {@code false} otherwise.
|
*
|
* @param kBytes The byte array to check space against.
|
* @param entryID The entryID value to check space against.
|
* @return {@code true} if there is space to write the byte array in a
|
* buffer, or {@code false} otherwise.
|
*/
|
public boolean isSpaceAvailable(byte[] kBytes, long entryID) {
|
return getRequiredSize(kBytes.length, entryID) < bytesLeft;
|
}
|
|
/**
|
* Return a buffer's current position value.
|
*
|
* @return The buffer's current position value.
|
*/
|
public int getPosition()
|
{
|
return position;
|
}
|
|
/**
|
* Set a buffer's position value to the specified position.
|
*
|
* @param position The value to set the position to.
|
*/
|
public void setPosition(int position)
|
{
|
this.position = position;
|
}
|
|
/**
|
* Sort the buffer.
|
*/
|
public void sort() {
|
sort(0, keys);
|
}
|
|
/**
|
* Add the specified key byte array and EntryID to the buffer.
|
*
|
* @param keyBytes The key byte array.
|
* @param entryID The EntryID.
|
* @param indexID The index ID the record belongs.
|
* @param insert <CODE>True</CODE> if key is an insert, false otherwise.
|
*/
|
public void add(byte[] keyBytes, EntryID entryID, int indexID, boolean insert) {
|
// write the record data, but leave the space to write the record size just
|
// before it
|
recordOffset = addRecord(keyBytes, entryID.longValue(), indexID, insert);
|
// then write the returned record size
|
keyOffset += writeIntBytes(buffer, keyOffset, recordOffset);
|
bytesLeft = recordOffset - keyOffset;
|
keys++;
|
}
|
|
|
/**
|
* Writes the full record minus the record size itself.
|
*/
|
private int addRecord(byte[] key, long entryID, int indexID, boolean insert)
|
{
|
int retOffset = recordOffset - getRecordSize(key.length, entryID);
|
int offSet = retOffset;
|
|
// write the INS/DEL bit
|
buffer[offSet++] = insert ? INS : DEL;
|
// write the indexID
|
offSet += writeIntBytes(buffer, offSet, indexID);
|
// write the entryID
|
offSet = PackedInteger.writeLong(buffer, offSet, entryID);
|
// write the key length
|
offSet = PackedInteger.writeInt(buffer, offSet, key.length);
|
// write the key bytes
|
System.arraycopy(key, 0, buffer, offSet, key.length);
|
return retOffset;
|
}
|
|
|
/**
|
* Computes the full size of the record.
|
*
|
* @param keyLen The length of the key of index
|
* @param entryID The entry id
|
* @return The size that such record would take in the IndexOutputBuffer
|
*/
|
public static int getRequiredSize(int keyLen, long entryID)
|
{
|
// Adds up the key length + key bytes + entryID + indexID + the INS/DEL bit
|
// and finally the space needed to store the record size
|
return getRecordSize(keyLen, entryID) + INT_SIZE;
|
}
|
|
private static int getRecordSize(int keyLen, long entryID)
|
{
|
// Adds up the key length + key bytes + ...
|
return PackedInteger.getWriteIntLength(keyLen) + keyLen +
|
// ... entryID + (indexID + INS/DEL bit).
|
PackedInteger.getWriteLongLength(entryID) + REC_OVERHEAD;
|
}
|
|
/**
|
* Write record at specified position to the specified output stream.
|
* Used when when writing the index scratch files.
|
*
|
* @param stream The stream to write the record at the index to.
|
* @param position The position of the record to write.
|
*/
|
public void writeEntryID(ByteArrayOutputStream stream, int position)
|
{
|
int offSet = getOffset(position);
|
int len = PackedInteger.getReadLongLength(buffer, offSet + REC_OVERHEAD);
|
stream.write(buffer, offSet + REC_OVERHEAD, len);
|
}
|
|
|
/**
|
* Return {@code true} if the record specified by the position is an insert
|
* record, or {@code false} if it a delete record.
|
*
|
* @param position The position of the record.
|
* @return {@code true} if the record is an insert record, or {@code false}
|
* if it is a delete record.
|
*/
|
public boolean isInsertRecord(int position)
|
{
|
int recOffset = getOffset(position);
|
return buffer[recOffset] == INS;
|
}
|
|
/**
|
* Return the size of the key part of the record.
|
*
|
* @return The size of the key part of the record.
|
*/
|
public int getKeySize()
|
{
|
int offSet = getOffset(position) + REC_OVERHEAD;
|
offSet += PackedInteger.getReadLongLength(buffer, offSet);
|
return PackedInteger.readInt(buffer, offSet);
|
}
|
|
/**
|
* Return the key value part of a record indicated by the current buffer
|
* position.
|
*
|
* @return byte array containing the key value.
|
*/
|
public byte[] getKey()
|
{
|
return getKey(position);
|
}
|
|
/** Used to minimized memory usage when comparing keys. */
|
private ByteBuffer getKeyBuf(int position)
|
{
|
keyBuffer.clear();
|
int offSet = getOffset(position) + REC_OVERHEAD;
|
offSet += PackedInteger.getReadLongLength(buffer, offSet);
|
int keyLen = PackedInteger.readInt(buffer, offSet);
|
offSet += PackedInteger.getReadIntLength(buffer, offSet);
|
//Re-allocate if the key is bigger than the capacity.
|
if(keyLen > keyBuffer.capacity())
|
{
|
keyBuffer = ByteBuffer.allocate(keyLen);
|
}
|
keyBuffer.put(buffer, offSet, keyLen);
|
keyBuffer.flip();
|
return keyBuffer;
|
}
|
|
|
/**
|
* Return the key value part of a record specified by the index.
|
*
|
* @param position position to return.
|
* @return byte array containing the key value.
|
*/
|
private byte[] getKey(int position)
|
{
|
int offSet = getOffset(position) + REC_OVERHEAD;
|
offSet += PackedInteger.getReadLongLength(buffer, offSet);
|
int keyLen = PackedInteger.readInt(buffer, offSet);
|
offSet += PackedInteger.getReadIntLength(buffer, offSet);
|
byte[] key = new byte[keyLen];
|
System.arraycopy(buffer, offSet, key, 0, keyLen);
|
return key;
|
}
|
|
private int getOffset(int position)
|
{
|
return getIntegerValue(position * INT_SIZE);
|
}
|
|
/**
|
* Return index id associated with the current position's record.
|
*
|
* @return The index id.
|
*/
|
public int getIndexID()
|
{
|
return getIndexID(position);
|
}
|
|
private int getIndexID(int position)
|
{
|
return getIndexIDFromOffset(getOffset(position));
|
}
|
|
private int getIndexIDFromOffset(int offset)
|
{
|
return getIntegerValue(offset + 1);
|
}
|
|
private boolean is(CompareOp op, int xPosition, int yPosition)
|
{
|
int xoffSet = getOffset(xPosition);
|
int xIndexID = getIndexIDFromOffset(xoffSet);
|
xoffSet += REC_OVERHEAD;
|
xoffSet += PackedInteger.getReadLongLength(buffer, xoffSet);
|
int xKeyLen = PackedInteger.readInt(buffer, xoffSet);
|
int xKey = PackedInteger.getReadIntLength(buffer, xoffSet) + xoffSet;
|
|
int yoffSet = getOffset(yPosition);
|
int yIndexID = getIndexIDFromOffset(yoffSet);
|
yoffSet += REC_OVERHEAD;
|
yoffSet += PackedInteger.getReadLongLength(buffer, yoffSet);
|
int yKeyLen = PackedInteger.readInt(buffer, yoffSet);
|
int yKey = PackedInteger.getReadIntLength(buffer, yoffSet) + yoffSet;
|
|
int cmp = indexComparator.compare(buffer, xKey, xKeyLen, xIndexID, yKey, yKeyLen, yIndexID);
|
return evaluateReturnCode(cmp, op);
|
}
|
|
private boolean is(CompareOp op, int xPosition, byte[] yKey, int yIndexID)
|
{
|
int xoffSet = getOffset(xPosition);
|
int xIndexID = getIndexIDFromOffset(xoffSet);
|
xoffSet += REC_OVERHEAD;
|
xoffSet += PackedInteger.getReadLongLength(buffer, xoffSet);
|
int xKeyLen = PackedInteger.readInt(buffer, xoffSet);
|
int xKey = PackedInteger.getReadIntLength(buffer, xoffSet) + xoffSet;
|
|
int cmp = indexComparator.compare(buffer, xKey, xKeyLen, xIndexID, yKey, yKey.length, yIndexID);
|
return evaluateReturnCode(cmp, op);
|
}
|
|
/**
|
* Compare the byte array at the current position with the specified one and
|
* using the specified index id. It will return {@code true} if the byte
|
* array at the current position is equal to the specified byte array as
|
* determined by the comparator and the index ID is is equal. It will
|
* return {@code false} otherwise.
|
*
|
* @param b The byte array to compare.
|
* @param bIndexID The index key.
|
* @return <CODE>True</CODE> if the byte arrays are equal.
|
*/
|
public boolean compare(byte[]b, int bIndexID)
|
{
|
int offset = getOffset(position);
|
int indexID = getIndexIDFromOffset(offset);
|
offset += REC_OVERHEAD;
|
offset += PackedInteger.getReadLongLength(buffer, offset);
|
int keyLen = PackedInteger.readInt(buffer, offset);
|
int key = PackedInteger.getReadIntLength(buffer, offset) + offset;
|
return indexComparator.compare(buffer, key, keyLen, b, b.length) == 0
|
&& indexID == bIndexID;
|
}
|
|
|
/**
|
* Compare current IndexBuffer to the specified index buffer using both the
|
* comparator and index ID of both buffers.
|
*
|
* The key at the value of position in both buffers are used in the compare.
|
*
|
* @param b The IndexBuffer to compare to.
|
* @return 0 if the buffers are equal, -1 if the current buffer is less
|
* than the specified buffer, or 1 if it is greater.
|
*/
|
@Override
|
public int compareTo(IndexOutputBuffer b)
|
{
|
final ByteBuffer keyBuf = b.getKeyBuf(b.position);
|
int offset = getOffset(position);
|
int indexID = getIndexIDFromOffset(offset);
|
offset += REC_OVERHEAD;
|
offset += PackedInteger.getReadLongLength(buffer, offset);
|
int keyLen = PackedInteger.readInt(buffer, offset);
|
int key = PackedInteger.getReadIntLength(buffer, offset) + offset;
|
|
final int cmp = indexComparator.compare(buffer, key, keyLen, keyBuf.array(), keyBuf.limit());
|
if (cmp != 0)
|
{
|
return cmp;
|
}
|
|
final int bIndexID = b.getIndexID();
|
if (indexID == bIndexID)
|
{
|
// This is tested in a tree set remove when a buffer is removed from the tree set.
|
return compare(this.bufferID, b.getBufferID());
|
}
|
else if (indexID < bIndexID)
|
{
|
return -1;
|
}
|
else
|
{
|
return 1;
|
}
|
}
|
|
private int compare(long l1, long l2)
|
{
|
if (l1 == l2)
|
{
|
return 0;
|
}
|
else if (l1 < l2)
|
{
|
return -1;
|
}
|
else
|
{
|
return 1;
|
}
|
}
|
|
|
/**
|
* Write a record to specified output stream using the record pointed to by
|
* the current position and the specified byte stream of ids.
|
*
|
* @param dataStream The data output stream to write to.
|
*
|
* @throws IOException If an I/O error occurs writing the record.
|
*/
|
public void writeKey(DataOutputStream dataStream) throws IOException
|
{
|
int offSet = getOffset(position) + REC_OVERHEAD;
|
offSet += PackedInteger.getReadLongLength(buffer, offSet);
|
int keyLen = PackedInteger.readInt(buffer, offSet);
|
offSet += PackedInteger.getReadIntLength(buffer, offSet);
|
dataStream.write(buffer, offSet, keyLen);
|
}
|
|
/**
|
* Compare the byte array at the current position with the byte array at the
|
* specified index.
|
*
|
* @param i The index pointing to the byte array to compare.
|
* @return {@code true} if the byte arrays are equal, or {@code false} otherwise
|
*/
|
public boolean compare(int i)
|
{
|
return is(CompareOp.EQ, i, position);
|
}
|
|
/**
|
* Return the current number of keys.
|
*
|
* @return The number of keys currently in an index buffer.
|
*/
|
public int getNumberKeys()
|
{
|
return keys;
|
}
|
|
/**
|
* Return {@code true} if the buffer has more data to process, or
|
* {@code false} otherwise. Used when iterating over the buffer writing the
|
* scratch index file.
|
*
|
* @return {@code true} if a buffer has more data to process, or
|
* {@code false} otherwise.
|
*/
|
public boolean hasMoreData()
|
{
|
return position + 1 < keys;
|
}
|
|
/**
|
* Advance the position pointer to the next record in the buffer. Used when
|
* iterating over the buffer examining keys.
|
*/
|
public void nextRecord()
|
{
|
position++;
|
}
|
|
private int writeIntBytes(byte[] buffer, int offset, int val)
|
{
|
for (int i = offset + INT_SIZE - 1; i >= offset; i--) {
|
buffer[i] = (byte) (val & 0xff);
|
val >>>= 8;
|
}
|
return INT_SIZE;
|
}
|
|
private int getIntegerValue(int index)
|
{
|
int answer = 0;
|
for (int i = 0; i < INT_SIZE; i++) {
|
byte b = buffer[index + i];
|
answer <<= 8;
|
answer |= (b & 0xff);
|
}
|
return answer;
|
}
|
|
private int med3(int a, int b, int c)
|
{
|
return is(CompareOp.LT, a, b) ?
|
(is(CompareOp.LT,b,c) ? b : is(CompareOp.LT,a,c) ? c : a) :
|
(is(CompareOp.GT,b,c) ? b : is(CompareOp.GT,a,c) ? c : a);
|
}
|
|
private void sort(int off, int len)
|
{
|
if (len < 7) {
|
for (int i=off; i<len+off; i++)
|
{
|
for (int j=i; j>off && is(CompareOp.GT, j-1, j); j--)
|
{
|
swap(j, j-1);
|
}
|
}
|
return;
|
}
|
|
int m = off + (len >> 1);
|
if (len > 7) {
|
int l = off;
|
int n = off + len - 1;
|
if (len > 40) {
|
int s = len/8;
|
l = med3(l, l+s, l+2*s);
|
m = med3(m-s, m, m+s);
|
n = med3(n-2*s, n-s, n);
|
}
|
m = med3(l, m, n);
|
}
|
|
byte[] mKey = getKey(m);
|
int mIndexID = getIndexID(m);
|
|
int a = off, b = a, c = off + len - 1, d = c;
|
while(true)
|
{
|
while (b <= c && is(CompareOp.LE, b, mKey, mIndexID))
|
{
|
if (is(CompareOp.EQ, b, mKey, mIndexID))
|
{
|
swap(a++, b);
|
}
|
b++;
|
}
|
while (c >= b && is(CompareOp.GE, c, mKey, mIndexID))
|
{
|
if (is(CompareOp.EQ, c, mKey, mIndexID))
|
{
|
swap(c, d--);
|
}
|
c--;
|
}
|
if (b > c)
|
{
|
break;
|
}
|
swap(b++, c--);
|
}
|
|
// Swap partition elements back to middle
|
int s, n = off + len;
|
s = Math.min(a-off, b-a );
|
vectorSwap(off, b-s, s);
|
s = Math.min(d-c, n-d-1);
|
vectorSwap(b, n-s, s);
|
|
s = b - a;
|
// Recursively sort non-partition-elements
|
if (s > 1)
|
{
|
sort(off, s);
|
}
|
s = d - c;
|
if (s > 1)
|
{
|
sort(n-s, s);
|
}
|
}
|
|
private void swap(int a, int b)
|
{
|
int aOffset = a * INT_SIZE;
|
int bOffset = b * INT_SIZE;
|
int bVal = getIntegerValue(bOffset);
|
System.arraycopy(buffer, aOffset, buffer, bOffset, INT_SIZE);
|
writeIntBytes(buffer, aOffset, bVal);
|
}
|
|
private void vectorSwap(int a, int b, int n)
|
{
|
for (int i=0; i<n; i++, a++, b++)
|
{
|
swap(a, b);
|
}
|
}
|
|
private boolean evaluateReturnCode(int rc, CompareOp op)
|
{
|
switch(op) {
|
case LT:
|
return rc < 0;
|
case GT:
|
return rc > 0;
|
case LE:
|
return rc <= 0;
|
case GE:
|
return rc >= 0;
|
case EQ:
|
return rc == 0;
|
default:
|
return false;
|
}
|
}
|
|
|
/**
|
* Interface that defines two methods used to compare keys used in this
|
* class. The Comparator interface cannot be used in this class, so this
|
* special one is used that knows about the special properties of this class.
|
*
|
* @param <T> object to use in the compare
|
*/
|
public static interface ComparatorBuffer<T> {
|
|
|
/**
|
* Compare two offsets in an object, usually a byte array.
|
*
|
* @param o The object.
|
* @param offset The first offset.
|
* @param length The first length.
|
* @param indexID The first index id.
|
* @param otherOffset The second offset.
|
* @param otherLength The second length.
|
* @param otherIndexID The second index id.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second.
|
*/
|
int compare(T o, int offset, int length, int indexID, int otherOffset,
|
int otherLength, int otherIndexID);
|
|
|
/**
|
* Compare an offset in an object with the specified object.
|
*
|
* @param o The first object.
|
* @param offset The first offset.
|
* @param length The first length.
|
* @param indexID The first index id.
|
* @param other The second object.
|
* @param otherLength The length of the second object.
|
* @param otherIndexID The second index id.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second
|
* object.
|
*/
|
int compare(T o, int offset, int length, int indexID, T other,
|
int otherLength, int otherIndexID);
|
|
|
/**
|
* Compare an offset in an object with the specified object.
|
*
|
* @param o The first object.
|
* @param offset The first offset.
|
* @param length The first length.
|
* @param other The second object.
|
* @param otherLen The length of the second object.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second
|
* object.
|
*/
|
int compare(T o, int offset, int length, T other,
|
int otherLen);
|
|
}
|
|
|
/**
|
* Implementation of ComparatorBuffer interface. Used to compare keys when
|
* they are non-DN indexes.
|
*/
|
public static class IndexComparator implements IndexOutputBuffer.ComparatorBuffer<byte[]>
|
{
|
|
/**
|
* Compare two offsets in an byte array using the index compare
|
* algorithm. The specified index ID is used in the comparison if the
|
* byte arrays are equal.
|
*
|
* @param b The byte array.
|
* @param offset The first offset.
|
* @param length The first length.
|
* @param indexID The first index id.
|
* @param otherOffset The second offset.
|
* @param otherLength The second length.
|
* @param otherIndexID The second index id.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second.
|
*/
|
@Override
|
public int compare(byte[] b, int offset, int length, int indexID,
|
int otherOffset, int otherLength, int otherIndexID)
|
{
|
for(int i = 0; i < length && i < otherLength; i++)
|
{
|
if(b[offset + i] > b[otherOffset + i])
|
{
|
return 1;
|
}
|
else if (b[offset + i] < b[otherOffset + i])
|
{
|
return -1;
|
}
|
}
|
return compareLengthThenIndexID(length, indexID, otherLength, otherIndexID);
|
}
|
|
/**
|
* Compare an offset in an byte array with the specified byte array,
|
* using the DN compare algorithm. The specified index ID is used in the
|
* comparison if the byte arrays are equal.
|
*
|
* @param b The byte array.
|
* @param offset The first offset.
|
* @param length The first length.
|
* @param indexID The first index id.
|
* @param other The second byte array to compare to.
|
* @param otherLength The second byte array's length.
|
* @param otherIndexID The second index id.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second
|
* byte array.
|
*/
|
@Override
|
public int compare(byte[] b, int offset, int length, int indexID,
|
byte[] other, int otherLength, int otherIndexID)
|
{
|
for(int i = 0; i < length && i < otherLength; i++)
|
{
|
if(b[offset + i] > other[i])
|
{
|
return 1;
|
}
|
else if (b[offset + i] < other[i])
|
{
|
return -1;
|
}
|
}
|
return compareLengthThenIndexID(length, indexID, otherLength, otherIndexID);
|
}
|
|
/**
|
* The arrays are equal, make sure they are in the same index
|
* since multiple suffixes might have the same key.
|
*/
|
private int compareLengthThenIndexID(int length, int indexID, int otherLength, int otherIndexID)
|
{
|
if (length == otherLength)
|
{
|
return compare(indexID, otherIndexID);
|
}
|
else if (length > otherLength)
|
{
|
return 1;
|
}
|
else
|
{
|
return -1;
|
}
|
}
|
|
/**
|
* Compare an offset in an byte array with the specified byte array,
|
* using the DN compare algorithm.
|
*
|
* @param b The byte array.
|
* @param offset The first offset.
|
* @param length The first length.
|
* @param other The second byte array to compare to.
|
* @param otherLength The second byte array's length.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second
|
* byte array.
|
*/
|
@Override
|
public int compare(byte[] b, int offset, int length, byte[] other,
|
int otherLength)
|
{
|
for(int i = 0; i < length && i < otherLength; i++)
|
{
|
if(b[offset + i] > other[i])
|
{
|
return 1;
|
}
|
else if (b[offset + i] < other[i])
|
{
|
return -1;
|
}
|
}
|
return compare(length, otherLength);
|
}
|
|
private int compare(int i1, int i2)
|
{
|
if (i1 == i2)
|
{
|
return 0;
|
}
|
else if (i1 > i2)
|
{
|
return 1;
|
}
|
else
|
{
|
return -1;
|
}
|
}
|
}
|
|
|
/**
|
* Set the index key associated with an index buffer.
|
*
|
* @param indexKey The index key.
|
*/
|
public void setIndexKey(Importer.IndexKey indexKey)
|
{
|
this.indexKey = indexKey;
|
}
|
|
|
/**
|
* Return the index key of an index buffer.
|
* @return The index buffer's index key.
|
*/
|
public Importer.IndexKey getIndexKey()
|
{
|
return indexKey;
|
}
|
}
|
