/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Feb 12, 2007
*/
package com.bigdata.btree.proc;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import com.bigdata.btree.Errors;
import com.bigdata.btree.IIndex;
import com.bigdata.btree.raba.IRaba;
import com.bigdata.btree.raba.codec.IRabaCoder;
import com.bigdata.util.BytesUtil;
/**
* Batch removal of one or more tuples, optionally returning their existing
* values, the #of tuples that were deleted, or a mask indicating which tuples
* were deleted (polymorphic return type).
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public class BatchRemove extends AbstractKeyArrayIndexProcedure<Object> implements
IParallelizableIndexProcedure<Object> {
/**
*
*/
private static final long serialVersionUID = -5332443478547654844L;
private boolean assertFound;
private ReturnWhatEnum returnWhat;
/**
* True iff the procedure will verify that each supplied key was in fact
* found in the index.
*/
public boolean getAssertFound() {
return assertFound;
}
/**
* True iff the old values stored under the keys will be returned by
* {@link #apply(IIndex)}.
*/
public boolean getReturnOldValues() {
return returnWhat == ReturnWhatEnum.OldValues;
}
@Override
public final boolean isReadOnly() {
return false;
}
/**
* What to return.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan
* Thompson</a>
*/
private static enum ReturnWhatEnum {
/**
* Return the #of tuples that were deleted.
*/
MutationCount(0),
/**
* Return the old value for each tuple.
*/
OldValues(1),
/**
* Return a {@link ResultBitBuffer}, which is basically a bit mask
* indicating which of the caller's tuples were deleted.
*/
BitMask(2);
private final int w;
private ReturnWhatEnum(final int w) {
this.w = w;
}
public int getValue() {
return w;
}
public static ReturnWhatEnum valueOf(final int w) {
switch (w) {
case 0:
return MutationCount;
case 1:
return OldValues;
case 2:
return BitMask;
default:
throw new IllegalArgumentException();
}
}
};
/**
* Factory for {@link BatchRemove} procedures.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public static class BatchRemoveConstructor extends
AbstractKeyArrayIndexProcedureConstructor<BatchRemove> {
/**
* Singleton requests the return of the values that were removed from
* the index by the operation.
*/
public static final BatchRemoveConstructor RETURN_OLD_VALUES = new BatchRemoveConstructor(
false/* assertFound */, ReturnWhatEnum.OldValues);
/**
* Singleton does NOT request the return of the values that were removed
* from the index by the operation. Instead, only the #of deleted tuples
* is return (the mutationCount).
*/
public static final BatchRemoveConstructor RETURN_MUTATION_COUNT = new BatchRemoveConstructor(
false/* assertFound */, ReturnWhatEnum.MutationCount);
/**
* Singleton requests the return of a {@link ResultBitBuffer} providing
* a bit mask of the tuples which were removed from the index by this
* operation (that is, those tuples which were pre-existing in the index
* in a non-deleted state).
*/
public static final BatchRemoveConstructor RETURN_BIT_MASK = new BatchRemoveConstructor(
false/* assertFound */, ReturnWhatEnum.BitMask);
/**
* Singleton does NOT request the return of the values that were removed
* from the index by the operation but asserts that each key was in fact
* present in the index.
*/
public static final BatchRemoveConstructor ASSERT_FOUND_RETURN_NO_VALUES = new BatchRemoveConstructor(
true/* assertFound */, ReturnWhatEnum.BitMask);
private final boolean assertFound;
private final ReturnWhatEnum returnWhat;
/**
* Values ARE NOT sent.
*/
@Override
public final boolean sendValues() {
return false;
}
private BatchRemoveConstructor(final boolean assertFound,
final ReturnWhatEnum returnWhat) {
this.assertFound = assertFound;
this.returnWhat = returnWhat;
}
@Override
public BatchRemove newInstance(final IRabaCoder keySer, final IRabaCoder valSer,
final int fromIndex, final int toIndex, final byte[][] keys, final byte[][] vals) {
if (vals != null)
throw new IllegalArgumentException(Errors.ERR_VALS_NOT_NULL);
return new BatchRemove(keySer, valSer, fromIndex, toIndex, keys,
assertFound, returnWhat);
}
}
/**
* De-serialization ctor.
*
*/
public BatchRemove() {
}
/**
* Batch remove operation.
*
* @param keys
* A series of keys paired to values. Each key is an variable
* length unsigned byte[]. The keys MUST be presented in sorted
* order.
* @param returnOldValues
* When <code>true</code> the old values for those keys will be
* returned by {@link #apply(IIndex)}.
*
* @see BatchRemoveConstructor
*/
protected BatchRemove(final IRabaCoder keySer, final IRabaCoder valSer,
final int fromIndex, final int toIndex, final byte[][] keys, final boolean assertFound,
final ReturnWhatEnum returnWhat) {
super(keySer, valSer, fromIndex, toIndex, keys, null/* vals */);
this.assertFound = assertFound;
this.returnWhat = returnWhat;
if (returnWhat == null)
throw new IllegalArgumentException();
}
/**
* Applies the operation.
*
* @param ndx
*
* @return The old values as a {@link ResultBuffer} iff they were requested.
*
* @throws AssertionError
* if {@link #getAssertFound()} is <code>true</code> and a
* given key was not found in the index.
*/
@Override
public Object applyOnce(final IIndex ndx, final IRaba keys, final IRaba vals) {
final int n = keys.size();
final boolean returnOldValues = getReturnOldValues();
final byte[][] ret = returnOldValues ? new byte[n][] : null;
final boolean[] modified = returnWhat == ReturnWhatEnum.BitMask ? new boolean[n]
: null;
int i = 0, mutationCount = 0;
while (i < n) {
final byte[] key = keys.get(i);
if (!returnOldValues && ndx.contains(key)) {
// Track a mutation counter.
mutationCount++;
if (modified != null) {
modified[i] = true;
}
}
final byte[] oldval = ndx.remove(key);
if(assertFound) {
if (oldval == null) {
throw new AssertionError("No entry: "
+ BytesUtil.toString(key));
}
}
if (returnOldValues) {
ret[i] = oldval;
}
i++;
}
switch (returnWhat) {
case MutationCount:
return Long.valueOf(mutationCount);
case OldValues:
return new ResultBuffer(n, ret, ndx.getIndexMetadata()
.getTupleSerializer().getLeafValuesCoder());
case BitMask:
return new ResultBitBuffer(n, modified, mutationCount);
default:
throw new AssertionError();
}
}
/**
* Returns an appropriate aggregator depending on {@link #returnWhat}.
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
protected IResultHandler<Object,Object> newAggregator() {
switch (returnWhat) {
case MutationCount:
return (IResultHandler) new LongAggregator();
case OldValues:
return (IResultHandler) new ResultBufferHandler(getKeys().size(), getValuesCoder());
case BitMask:
return (IResultHandler) new ResultBitBufferHandler(getKeys().size());
default:
throw new AssertionError();
}
}
@Override
protected void readMetadata(final ObjectInput in) throws IOException,
ClassNotFoundException {
super.readMetadata(in);
assertFound = in.readBoolean();
returnWhat = ReturnWhatEnum.valueOf(in.readByte());
}
@Override
protected void writeMetadata(final ObjectOutput out) throws IOException {
super.writeMetadata(out);
out.writeBoolean(assertFound);
out.writeByte((byte) returnWhat.getValue());
}
}