Java NavigableSet.first方法代碼示例

import java.util.NavigableSet; //導入方法依賴的package包/類
/**
 * Return a copy of the orders, limited by price
 *
 * @param limitPercent how many percent away from the best price the
 * threshold will be.
 * @param ascending when true, lowest prices are included (asks). When
 * false, highest prices are included (bids).
 * @return
 */
public Book getPriceLimitedOrders(double limitPercent, boolean ascending) {
    Book b = new Book();
    if (orders.isEmpty()) {
        return b;
    }

    // Get the best price and calculate threshold
    NavigableSet<Decimal> ns = ascending ? orders.navigableKeySet()
            : orders.descendingKeySet();
    Decimal bestPrice = ns.first();
    double limit = (ascending ? 1 : -1) * limitPercent;
    Decimal threshold = getPriceThreshold(bestPrice, limit);

    for (Decimal price : ns) {
        if ((ascending && price.isGreaterThan(threshold))
                || (!ascending && price.isSmallerThan(threshold))) {
            // Threshold reached
            break;
        }
        b.add(orders.get(price), false);
    }

    return b;
}
 

import java.util.NavigableSet; //導入方法依賴的package包/類
/**
 * Get the first order
 *
 * @param ascending when true - return order with the lowest price,
 * otherwise return order with the highest price
 * @return
 */
public Order getFirstOrder(boolean ascending) {
    if (orders.isEmpty()) {
        return null;
    }
    NavigableSet<Decimal> ns = ascending ? orders.navigableKeySet()
            : orders.descendingKeySet();
    Decimal bestPrice = ns.first();
    return getOrderForPrice(bestPrice);
}
 

import java.util.NavigableSet; //導入方法依賴的package包/類
ParentChildFilteredTermsEnum(TermsEnum tenum, NavigableSet<BytesRef> parentTypes) {
    super(tenum, true);
    this.parentTypes = parentTypes;
    this.seekTerm = parentTypes.isEmpty() ? null : parentTypes.first();
}
 

import java.util.NavigableSet; //導入方法依賴的package包/類
/**
 * Construct a QueryMatcher for a scan
 * @param scan
 * @param scanInfo The store's immutable scan info
 * @param columns
 * @param scanType Type of the scan
 * @param earliestPutTs Earliest put seen in any of the store files.
 * @param oldestUnexpiredTS the oldest timestamp we are interested in,
 *  based on TTL
 * @param regionCoprocessorHost 
 * @throws IOException 
 */
public ScanQueryMatcher(Scan scan, ScanInfo scanInfo, NavigableSet<byte[]> columns,
    ScanType scanType, long readPointToUse, long earliestPutTs, long oldestUnexpiredTS,
    long now, RegionCoprocessorHost regionCoprocessorHost) throws IOException {
  TimeRange timeRange = scan.getColumnFamilyTimeRange().get(scanInfo.getFamily());
  if (timeRange == null) {
    this.tr = scan.getTimeRange();
  } else {
    this.tr = timeRange;
  }
  this.rowComparator = scanInfo.getComparator();
  this.regionCoprocessorHost = regionCoprocessorHost;
  this.deletes =  instantiateDeleteTracker();
  this.stopRow = scan.getStopRow();
  this.startKey = KeyValueUtil.createFirstDeleteFamilyOnRow(scan.getStartRow(),
      scanInfo.getFamily());
  this.filter = scan.getFilter();
  this.earliestPutTs = earliestPutTs;
  this.oldestUnexpiredTS = oldestUnexpiredTS;
  this.now = now;

  this.maxReadPointToTrackVersions = readPointToUse;
  this.timeToPurgeDeletes = scanInfo.getTimeToPurgeDeletes();
  this.ttl = oldestUnexpiredTS;

  /* how to deal with deletes */
  this.isUserScan = scanType == ScanType.USER_SCAN;
  // keep deleted cells: if compaction or raw scan
  this.keepDeletedCells = scan.isRaw() ? KeepDeletedCells.TRUE :
    isUserScan ? KeepDeletedCells.FALSE : scanInfo.getKeepDeletedCells();
  // retain deletes: if minor compaction or raw scanisDone
  this.retainDeletesInOutput = scanType == ScanType.COMPACT_RETAIN_DELETES || scan.isRaw();
  // seePastDeleteMarker: user initiated scans
  this.seePastDeleteMarkers =
      scanInfo.getKeepDeletedCells() != KeepDeletedCells.FALSE && isUserScan;

  int maxVersions =
      scan.isRaw() ? scan.getMaxVersions() : Math.min(scan.getMaxVersions(),
        scanInfo.getMaxVersions());

  // Single branch to deal with two types of reads (columns vs all in family)
  if (columns == null || columns.size() == 0) {
    // there is always a null column in the wildcard column query.
    hasNullColumn = true;

    // use a specialized scan for wildcard column tracker.
    this.columns = new ScanWildcardColumnTracker(
        scanInfo.getMinVersions(), maxVersions, oldestUnexpiredTS);
  } else {
    // whether there is null column in the explicit column query
    hasNullColumn = (columns.first().length == 0);

    // We can share the ExplicitColumnTracker, diff is we reset
    // between rows, not between storefiles.
    this.columns = new ExplicitColumnTracker(columns, scanInfo.getMinVersions(), maxVersions,
        oldestUnexpiredTS);
  }
  this.isReversed = scan.isReversed();
}