| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * Licensed 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 from |
| * |
| * 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 edu.uci.ics.hyracks.storage.am.lsm.btree.impls; |
| |
| import java.util.Iterator; |
| import java.util.ListIterator; |
| |
| import edu.uci.ics.hyracks.api.exceptions.HyracksDataException; |
| import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder; |
| import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleReference; |
| import edu.uci.ics.hyracks.dataflow.common.util.TupleUtils; |
| import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame; |
| import edu.uci.ics.hyracks.storage.am.btree.impls.BTree; |
| import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor; |
| import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate; |
| import edu.uci.ics.hyracks.storage.am.common.api.ICursorInitialState; |
| import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor; |
| import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor; |
| import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback; |
| import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate; |
| import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor; |
| import edu.uci.ics.hyracks.storage.am.common.api.IndexException; |
| import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback; |
| import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent; |
| import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext; |
| import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexSearchCursor; |
| |
| public class LSMBTreeRangeSearchCursor extends LSMIndexSearchCursor { |
| private final ArrayTupleReference copyTuple; |
| private final RangePredicate reusablePred; |
| |
| private ISearchOperationCallback searchCallback; |
| private RangePredicate predicate; |
| private IIndexAccessor memBTreeAccessor; |
| private ArrayTupleBuilder tupleBuilder; |
| private boolean proceed = true; |
| |
| public LSMBTreeRangeSearchCursor(ILSMIndexOperationContext opCtx) { |
| super(opCtx); |
| this.copyTuple = new ArrayTupleReference(); |
| this.reusablePred = new RangePredicate(null, null, true, true, null, null); |
| } |
| |
| @Override |
| public void reset() throws HyracksDataException, IndexException { |
| super.reset(); |
| proceed = true; |
| } |
| |
| @Override |
| public void next() throws HyracksDataException { |
| outputElement = outputPriorityQueue.poll(); |
| needPush = true; |
| proceed = false; |
| } |
| |
| protected void checkPriorityQueue() throws HyracksDataException, IndexException { |
| while (!outputPriorityQueue.isEmpty() || needPush == true) { |
| if (!outputPriorityQueue.isEmpty()) { |
| PriorityQueueElement checkElement = outputPriorityQueue.peek(); |
| if (proceed && !searchCallback.proceed(checkElement.getTuple())) { |
| if (includeMemComponent) { |
| PriorityQueueElement inMemElement = null; |
| boolean inMemElementFound = false; |
| // scan the PQ for the in-memory component's element |
| Iterator<PriorityQueueElement> it = outputPriorityQueue.iterator(); |
| while (it.hasNext()) { |
| inMemElement = it.next(); |
| if (inMemElement.getCursorIndex() == 0) { |
| inMemElementFound = true; |
| it.remove(); |
| break; |
| } |
| } |
| if (inMemElementFound) { |
| // copy the in-mem tuple |
| if (tupleBuilder == null) { |
| tupleBuilder = new ArrayTupleBuilder(cmp.getKeyFieldCount()); |
| } |
| TupleUtils.copyTuple(tupleBuilder, inMemElement.getTuple(), cmp.getKeyFieldCount()); |
| copyTuple.reset(tupleBuilder.getFieldEndOffsets(), tupleBuilder.getByteArray()); |
| |
| // unlatch/unpin |
| rangeCursors[0].reset(); |
| |
| // reconcile |
| if (checkElement.getCursorIndex() == 0) { |
| searchCallback.reconcile(copyTuple); |
| } else { |
| searchCallback.reconcile(checkElement.getTuple()); |
| searchCallback.complete(checkElement.getTuple()); |
| } |
| // retraverse |
| reusablePred.setLowKey(copyTuple, true); |
| memBTreeAccessor.search(rangeCursors[0], reusablePred); |
| boolean isNotExhaustedCursor = pushIntoPriorityQueue(inMemElement); |
| |
| if (checkElement.getCursorIndex() == 0) { |
| if (!isNotExhaustedCursor || cmp.compare(copyTuple, inMemElement.getTuple()) != 0) { |
| searchCallback.complete(copyTuple); |
| searchCallback.cancel(copyTuple); |
| continue; |
| } |
| searchCallback.complete(copyTuple); |
| } |
| } else { |
| // the in-memory cursor is exhausted |
| searchCallback.reconcile(checkElement.getTuple()); |
| } |
| } else { |
| searchCallback.reconcile(checkElement.getTuple()); |
| } |
| } |
| // If there is no previous tuple or the previous tuple can be ignored |
| if (outputElement == null) { |
| if (isDeleted(checkElement)) { |
| // If the key has been deleted then pop it and set needPush to true. |
| // We cannot push immediately because the tuple may be |
| // modified if hasNext() is called |
| outputElement = outputPriorityQueue.poll(); |
| searchCallback.cancel(checkElement.getTuple()); |
| needPush = true; |
| proceed = false; |
| } else { |
| break; |
| } |
| } else { |
| // Compare the previous tuple and the head tuple in the PQ |
| if (compare(cmp, outputElement.getTuple(), checkElement.getTuple()) == 0) { |
| // If the previous tuple and the head tuple are |
| // identical |
| // then pop the head tuple and push the next tuple from |
| // the tree of head tuple |
| |
| // the head element of PQ is useless now |
| PriorityQueueElement e = outputPriorityQueue.poll(); |
| pushIntoPriorityQueue(e); |
| } else { |
| // If the previous tuple and the head tuple are different |
| // the info of previous tuple is useless |
| if (needPush == true) { |
| pushIntoPriorityQueue(outputElement); |
| needPush = false; |
| } |
| proceed = true; |
| outputElement = null; |
| } |
| } |
| } else { |
| // the priority queue is empty and needPush |
| pushIntoPriorityQueue(outputElement); |
| needPush = false; |
| outputElement = null; |
| proceed = true; |
| } |
| } |
| } |
| |
| @Override |
| public void open(ICursorInitialState initialState, ISearchPredicate searchPred) throws HyracksDataException, |
| IndexException { |
| LSMBTreeCursorInitialState lsmInitialState = (LSMBTreeCursorInitialState) initialState; |
| cmp = lsmInitialState.getOriginalKeyComparator(); |
| includeMemComponent = lsmInitialState.getIncludeMemComponent(); |
| operationalComponents = lsmInitialState.getOperationalComponents(); |
| lsmHarness = lsmInitialState.getLSMHarness(); |
| searchCallback = lsmInitialState.getSearchOperationCallback(); |
| memBTreeAccessor = lsmInitialState.getMemBTreeAccessor(); |
| predicate = (RangePredicate) lsmInitialState.getSearchPredicate(); |
| reusablePred.setLowKeyComparator(cmp); |
| reusablePred.setHighKey(predicate.getHighKey(), predicate.isHighKeyInclusive()); |
| reusablePred.setHighKeyComparator(predicate.getHighKeyComparator()); |
| |
| int numBTrees = lsmInitialState.getNumBTrees(); |
| rangeCursors = new IIndexCursor[numBTrees]; |
| for (int i = 0; i < numBTrees; i++) { |
| IBTreeLeafFrame leafFrame = (IBTreeLeafFrame) lsmInitialState.getLeafFrameFactory().createFrame(); |
| rangeCursors[i] = new BTreeRangeSearchCursor(leafFrame, false); |
| } |
| setPriorityQueueComparator(); |
| |
| int cursorIx = 0; |
| ListIterator<ILSMComponent> btreesIter = operationalComponents.listIterator(); |
| if (includeMemComponent) { |
| // Open cursor of in-memory BTree at index 0. |
| memBTreeAccessor.search(rangeCursors[cursorIx], searchPred); |
| // Skip 0 because it is the in-memory BTree. |
| ++cursorIx; |
| btreesIter.next(); |
| } |
| |
| // Open cursors of on-disk BTrees. |
| int numDiskComponents = includeMemComponent ? numBTrees - 1 : numBTrees; |
| ITreeIndexAccessor[] diskBTreeAccessors = new ITreeIndexAccessor[numDiskComponents]; |
| int diskBTreeIx = 0; |
| while (btreesIter.hasNext()) { |
| BTree diskBTree = (BTree) ((LSMBTreeImmutableComponent) btreesIter.next()).getBTree(); |
| diskBTreeAccessors[diskBTreeIx] = diskBTree.createAccessor(NoOpOperationCallback.INSTANCE, |
| NoOpOperationCallback.INSTANCE); |
| diskBTreeAccessors[diskBTreeIx].search(rangeCursors[cursorIx], searchPred); |
| cursorIx++; |
| diskBTreeIx++; |
| } |
| initPriorityQueue(); |
| proceed = true; |
| } |
| } |
