BKD Tree

Mismatch 返回a、b两个字节数组 * 第一个不相同字节的索引 * 完全一致则返回-1， * 返回较短的数组的长度.

NewRadixSelector Sole constructor.

NewReader Caller must pre-seek the provided IndexInput to the index location that BKDWriter.finish returned.

ReadInts Read count integers into docIDs.

ReadIntsVisitor Read count integers and feed the result directly to org.apache.lucene.index.PointValues.IntersectVisitor.visit(int).

Subtract Result = a - b, where a >= b, else IllegalArgumentException is thrown.

DEFAULT_MAX_MB_SORT_IN_HEAP Default maximum heap to use, before spilling to (slower) disk.

DEFAULT_MAX_POINTS_IN_LEAF_NODE Default maximum number of point in each leaf block.

size of the histogram.

MAX_DIMS Maximum number of index dimensions (2 * max index dimensions).

MAX_INDEX_DIMS Maximum number of index dimensions.

size of the online buffer: 8 KB.

SPLITS_BEFORE_EXACT_BOUNDS Number of splits before we compute the exact bounding box of an inner node.

Config Basic parameters for indexing points on the BKD tree.

HeapPointReader Utility class to read buffered points from in-heap arrays.

HeapPointValue Reusable implementation for a point value on-heap.

HeapPointWriter Utility class to write new points into in-heap arrays.

IndexTree Used to walk the off-heap index.

IntersectState Used to track all state for a single call to intersect.

OfflinePointValue Reusable implementation for a point value offline.

OfflinePointWriter Writes points to disk in a fixed-with format.

PathSlice Sliced reference to points in an PointWriter.

RadixSelector Offline Radix selector for BKD tree.

Reader Handles intersection of an multi-dimensional shape in byte[] space with a block KD-tree previously written with BKDWriter.

VerifyPointsVisitor Walks the entire N-dimensional points space, verifying that all points fall within the last cell's boundaries.

Writer Recursively builds a block KD-tree to assign all incoming points in N-dim space to smaller and smaller N-dim rectangles (cells) until the number of points in a given rectangle is <= config.maxPointsInLeafNode.

LeafNodes flat representation of a kd-tree.

PointReader One pass iterator through all points previously written with a PointWriter, abstracting away whether points are read from (offline) disk or simple arrays in heap.

PointValue Represents a dimensional point value written in the BKD tree.

PointWriter Appends many points, and then at the end provides a PointReader to iterate those points.