[LUCENE-4098] Efficient bulk operations for packed integer arrays

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 4.0-ALPHA, 6.0
• Component/s: core/other
• Lucene Fields: New, Patch Available
• Assignee: Michael McCandless
• Reporter: Adrien Grand
• Created: 31/May/12 21:30
• Updated: 28/Aug/22 16:18
• Resolved: 02/Jun/12 22:36

Description

There are some places in Lucene code that

{iterate over,set}

ranges of values of a packed integer array. Because bit-packing implementations (Packed*) tend be slower than direct implementations, this can take a lot of time.

For example, under some scenarii, GrowableWriter can take most of its (averaged) set time in resizing operations.

However, some bit-packing schemes, such as the one that is used by Packed64SingleBlock*, allow to implement efficient bulk operations such as get/set/fill. Implementing these bulk operations in {{PackedInts.

{Reader,Mutable}

}} and using them across other components instead of their single-value counterpart could help improve performance.