How to use

BTreeIndex

in

com.oberasoftware.jasdb.core.index.btreeplus

@Override
public void close() throws JasDBStorageException {
  openIndex();
  fullLock.lock();
  resourceLockManager.exclusiveLock();
  try {
    if(channel != null) {
      closeIndexResources();
    }
  } finally {
    resourceLockManager.exclusiveUnlock(true);
    fullLock.unlock();
  }
}

@Override
public void openIndex() throws JasDBStorageException {
  if(closed) {
    throw new JasDBStorageException("Index is closed");
  } else if(rootBlock == null) {
    fullLock.lock();
    try {
      initializeIndex();
    } finally {
      fullLock.unlock();
    }
  }
}

private Index createInStore(String bagName, KeyInfo keyInfo) throws JasDBStorageException {
  if(!indexes.containsKey(bagName)) {
    loadIndexes(bagName);
  }
  Map<String, Index> bagIndexes = this.indexes.get(bagName);
  if(bagIndexes != null && !bagIndexes.containsKey(keyInfo.getKeyName())) {
    File indexFile = createIndexFile(bagName, keyInfo.getKeyName(), false);
    try {
      Index index = new BTreeIndex(indexFile, keyInfo);
      configureIndex(IndexTypes.BTREE, index);
      IndexDefinition definition = new IndexDefinition(keyInfo.getKeyName(), keyInfo.keyAsHeader(), keyInfo.valueAsHeader(), index.getIndexType());
      metadataStore.addBagIndex(instanceId, bagName, definition);
      bagIndexes.put(keyInfo.getKeyName(), index);
      return index;
    } catch(ConfigurationException e) {
      throw new JasDBStorageException("Unable to create index, configuration error", e);
    }
  } else if(bagIndexes != null){
    return bagIndexes.get(keyInfo.getKeyName());
  } else {
    return null;
  }
}

@Override
public MemoryAware getMemoryManager() throws JasDBStorageException {
  openIndex();
  return persister;
}

@Override
public void rebuildIndex(Iterator<IndexableItem> indexableItems) throws JasDBStorageException {
  fullLock.lock();
  resourceLockManager.exclusiveLock();
  try {
    resetIndex();
    state = IndexState.REBUILDING;
    IndexRebuildUtil.bulkInsertIndex(this, keyInfo, indexableItems);
    flushIndex();
    state = IndexState.OK;
  } finally {
    resourceLockManager.exclusiveUnlock();
    fullLock.unlock();
  }
}

@Override
public IndexSearchResultIteratorCollection searchIndex(SearchCondition searchCondition, SearchLimit searchLimit) throws JasDBStorageException {
  openIndex();
  SearchOperation searchOperation;
  SearchCondition condition = searchCondition;
  if(searchCondition instanceof RangeCondition) {
    searchOperation = rangeSearchOperation;
  } else if(searchCondition instanceof NotEqualsCondition) {
    searchOperation = notEqualsSearchOperation;
  } else if(searchCondition instanceof EqualsCondition){
    condition = handleEqualsToRange((EqualsCondition) searchCondition);
    if(condition == searchCondition) {
      searchOperation = equalsSearchOperation;
    } else {
      searchOperation = rangeSearchOperation;
    }
  } else {
    throw new JasDBStorageException("Search Condition is not supported by Btree");
  }
  StatRecord searchRecord = StatisticsMonitor.createRecord("btree:search");
  resourceLockManager.sharedLock();
  try {
    return searchOperation.search(condition, searchLimit);
  } finally {
    resourceLockManager.sharedUnlock();
    searchRecord.stop();
  }
}

@Override
public void updateKey(Key oldKey, Key newKey) throws JasDBStorageException {
  openIndex();
  StatRecord updateIndex = StatisticsMonitor.createRecord("btree:update");
  resourceLockManager.sharedLock();
  lockManager.startLockChain();
  lockManager.acquireLock(LockIntentType.UPDATE, rootBlock);
  try {
    LeaveBlock leaveBlock = rootBlock.findLeaveBlock(LockIntentType.UPDATE, oldKey);
    doLeaveBlockUpdate(leaveBlock, newKey);
  } finally {
    lockManager.releaseLockChain();
    resourceLockManager.sharedUnlock();
    updateIndex.stop();
  }
}

@Override
public void removeFromIndex(Key key) throws JasDBStorageException {
  openIndex();
  resourceLockManager.sharedLock();
  lockManager.startLockChain();
  lockManager.acquireLock(LockIntentType.LEAVELOCK_OPTIMISTIC, rootBlock);
  try {
    LeaveBlock leaveBlock = rootBlock.findLeaveBlock(LockIntentType.LEAVELOCK_OPTIMISTIC, key);
    if(leaveBlock.size() == persister.getMinKeys()) {
      lockManager.releaseLockChain();
      lockManager.startLockChain();
      lockManager.acquireLock(LockIntentType.WRITE_EXCLUSIVE, rootBlock);
      leaveBlock = rootBlock.findLeaveBlock(LockIntentType.WRITE_EXCLUSIVE, key);
      doLeaveBlockRemove(leaveBlock, key);
    } else {
      doLeaveBlockRemove(leaveBlock, key);
    }
  } finally {
    lockManager.releaseLockChain();
    resourceLockManager.sharedUnlock();
  }
}

@Override
public void insertIntoIndex(Key key) throws JasDBStorageException {
  openIndex();
  StatRecord btreeInsertRecord = StatisticsMonitor.createRecord("btree:insert");
  resourceLockManager.sharedLock();
  lockManager.startLockChain();
  lockManager.acquireLock(LockIntentType.LEAVELOCK_OPTIMISTIC, rootBlock);
  try {
    LeaveBlock leaveBlock = rootBlock.findLeaveBlock(LockIntentType.LEAVELOCK_OPTIMISTIC, key);
    if(leaveBlock.size() == persister.getMaxKeys()) {
      lockManager.releaseLockChain();
      lockManager.startLockChain();
      lockManager.acquireLock(LockIntentType.WRITE_EXCLUSIVE, rootBlock);
      leaveBlock = rootBlock.findLeaveBlock(LockIntentType.WRITE_EXCLUSIVE, key);
      doLeaveBlockInsert(leaveBlock, key);
    } else {
      //no overflow, we can just write into the leave
      doLeaveBlockInsert(leaveBlock, key);
    }
  } finally {
    lockManager.releaseLockChain();
    resourceLockManager.sharedUnlock();
    btreeInsertRecord.stop();
  }
}

private void resetIndex() throws JasDBStorageException {
  //we close so the old index can be removed and reopened with a new fresh file
  if(!closed) {
    closeIndexResources();
  }
  if(!indexLocation.exists() || indexLocation.delete()) {
    closed = false;
    rootBlock = null;
  } else {
    throw new JasDBStorageException("Unable to reset index, old index could not be removed");
  }
}

private Index loadIndex(String bagName, IndexDefinition indexDefinition) throws JasDBStorageException {
  try {
    KeyInfo keyInfo = new KeyInfoImpl(indexDefinition.getHeaderDescriptor(), indexDefinition.getValueDescriptor());
    File indexFile = createIndexFile(bagName, indexDefinition.getIndexName(), false);
    switch(IndexTypes.getTypeFor(indexDefinition.getIndexType())) {
      case BTREE:
        LOG.debug("Loaded BTree Index for key: {}", indexDefinition.getIndexName());
        Index btreeIndex = new BTreeIndex(indexFile, keyInfo);
        return configureIndex(IndexTypes.BTREE, btreeIndex);
      default:
        throw new JasDBStorageException("Reading from this index type: " + indexDefinition.getIndexName() +
            " is not supported");
    }
  } catch(ConfigurationException e) {
    throw new JasDBStorageException("Unable to load index, invalid configuration", e);
  }
}

protected BlockPersister getPersister() throws JasDBStorageException {
  openIndex();
  return persister;
}

@Override
public void removeIndex() throws JasDBStorageException {
  fullLock.lock();
  resourceLockManager.exclusiveLock();
  try {
    if(channel != null) {
      closeIndexResources();
    }
    if(!indexLocation.delete()) {
      indexLocation.deleteOnExit();
    }
  } finally {
    resourceLockManager.exclusiveUnlock(true);
    fullLock.lock();
  }
}

@Override
public void openWriter() throws JasDBStorageException {
  this.keyInfo = new KeyInfoImpl(new SimpleIndexField("__ID", new UUIDKeyType()), new SimpleIndexField("RECORD_POINTER", new LongKeyType()));
  this.index = new BTreeIndex(indexLocation, keyInfo);
  this.writer.openWriter();
  this.index.openIndex();
}

RootBlock getRootBlock() throws JasDBStorageException {
  openIndex();
  return rootBlock;
}

@Override
public void openWriter() throws JasDBStorageException {
  this.keyInfo = new KeyInfoImpl(new SimpleIndexField("__ID", new UUIDKeyType()), new SimpleIndexField("data", new DataKeyType()));
  try {
    this.index = new BTreeIndex(recordStorageLocation, keyInfo);
    this.index.openIndex();
  } catch(OverlappingFileLockException e) {
    throw new RecordStoreInUseException("Record datastore: " + recordStorageLocation + " is already in use, cannot be opened");
  }
}

protected LockManager getLockManager() throws JasDBStorageException {
  openIndex();
  return lockManager;
}

@Override
public IndexIterator getIndexIterator() throws JasDBStorageException {
  openIndex();
  return new FullIndexIterator(rootBlock, lockManager, persister);
}

@Override
public void flushIndex() throws JasDBStorageException {
  openIndex();
  persister.flush();
}

@Override
public IndexScanReport scan(ScanIntent intent, Iterator<IndexableItem> indexableItems) throws JasDBStorageException {
  try {
    openIndex();
    fullLock.lock();
    try {
      if(intent == ScanIntent.RESCAN || intent == ScanIntent.DETECT_INCOMPLETE || scanReport == null) {
        scanReport = IndexScanner.doIndexScan(this, keyInfo, indexableItems, intent != ScanIntent.DETECT_INCOMPLETE);
      }
      return scanReport;
    } finally {
      fullLock.unlock();
    }
  } catch(JasDBStorageException e) {
    scanReport = new IndexScanReportImpl(IndexState.INVALID, System.currentTimeMillis(), 0);
    return scanReport;
  }
}