Java TreeSet.floor方法代碼示例

import java.util.TreeSet; //導入方法依賴的package包/類
/**
 * Returns the cache {@link CacheSpan} corresponding to the provided lookup {@link CacheSpan}.
 * <p>
 * If the lookup position is contained by an existing entry in the cache, then the returned
 * {@link CacheSpan} defines the file in which the data is stored. If the lookup position is not
 * contained by an existing entry, then the returned {@link CacheSpan} defines the maximum extents
 * of the hole in the cache.
 *
 * @param lookupSpan A lookup {@link CacheSpan} specifying a key and position.
 * @return The corresponding cache {@link CacheSpan}.
 */
private CacheSpan getSpan(CacheSpan lookupSpan) {
  String key = lookupSpan.key;
  long offset = lookupSpan.position;
  TreeSet<CacheSpan> entries = cachedSpans.get(key);
  if (entries == null) {
    return CacheSpan.createOpenHole(key, lookupSpan.position);
  }
  CacheSpan floorSpan = entries.floor(lookupSpan);
  if (floorSpan != null &&
      floorSpan.position <= offset && offset < floorSpan.position + floorSpan.length) {
    // The lookup position is contained within floorSpan.
    if (floorSpan.file.exists()) {
      return floorSpan;
    } else {
      // The file has been deleted from under us. It's likely that other files will have been
      // deleted too, so scan the whole in-memory representation.
      removeStaleSpans();
      return getSpan(lookupSpan);
    }
  }
  CacheSpan ceilEntry = entries.ceiling(lookupSpan);
  return ceilEntry == null ? CacheSpan.createOpenHole(key, lookupSpan.position) :
      CacheSpan.createClosedHole(key, lookupSpan.position,
          ceilEntry.position - lookupSpan.position);
}
 

import java.util.TreeSet; //導入方法依賴的package包/類
/**
 * For each character in each running line, add it to a list assigned to the appropriate header
 * column e.g. all the characters between
 */
public static Map<String, List<ChartCharacter>> groupRunningLineCharactersByColumn(
        TreeSet<RunningLineColumnIndex> runningLineColumnIndices,
        List<ChartCharacter> runningLine) {
    Map<String, List<ChartCharacter>> runningLineCharactersByColumn = new LinkedHashMap<>();

    for (ChartCharacter pdfCharacter : runningLine) {
        // get the location of the character for this particular running line row
        RunningLineColumnIndex columnIndex =
                new RunningLineColumnIndex(pdfCharacter.getxDirAdj());

        // find the header column it belongs to by locating the column with the next-lowest
        // xDirAdj value to the columnIndex
        RunningLineColumnIndex floor = runningLineColumnIndices.floor(columnIndex);

        // for each header column, store the characters that apply to it
        String columnHeader = floor.getColumnHeader();
        List<ChartCharacter> chartCharacters = runningLineCharactersByColumn.get(columnHeader);
        if (chartCharacters == null) {
            chartCharacters = new ArrayList<>();
        }
        chartCharacters.add(pdfCharacter);
        runningLineCharactersByColumn.put(columnHeader, chartCharacters);
    }

    return runningLineCharactersByColumn;
}
 

import java.util.TreeSet; //導入方法依賴的package包/類
@Override
public synchronized boolean isCached(String key, long position, long length) {
  TreeSet<CacheSpan> entries = cachedSpans.get(key);
  if (entries == null) {
    return false;
  }
  CacheSpan lookupSpan = CacheSpan.createLookup(key, position);
  CacheSpan floorSpan = entries.floor(lookupSpan);
  if (floorSpan == null || floorSpan.position + floorSpan.length <= position) {
    // We don't have a span covering the start of the queried region.
    return false;
  }
  long queryEndPosition = position + length;
  long currentEndPosition = floorSpan.position + floorSpan.length;
  if (currentEndPosition >= queryEndPosition) {
    // floorSpan covers the queried region.
    return true;
  }
  Iterator<CacheSpan> iterator = entries.tailSet(floorSpan, false).iterator();
  while (iterator.hasNext()) {
    CacheSpan next = iterator.next();
    if (next.position > currentEndPosition) {
      // There's a hole in the cache within the queried region.
      return false;
    }
    // We expect currentEndPosition to always equal (next.position + next.length), but
    // perform a max check anyway to guard against the existence of overlapping spans.
    currentEndPosition = Math.max(currentEndPosition, next.position + next.length);
    if (currentEndPosition >= queryEndPosition) {
      // We've found spans covering the queried region.
      return true;
    }
  }
  // We ran out of spans before covering the queried region.
  return false;
}
 

import java.util.TreeSet; //導入方法依賴的package包/類
/**
 * floor returns preceding element
 */
public void testFloor() {
    TreeSet q = set5();
    Object e1 = q.floor(three);
    assertEquals(three, e1);

    Object e2 = q.floor(six);
    assertEquals(five, e2);

    Object e3 = q.floor(one);
    assertEquals(one, e3);

    Object e4 = q.floor(zero);
    assertNull(e4);
}