[LUCENE-9673] The level of IntBlockPool slice is always 1

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 9.0, 8.11
• Component/s: core/other
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: mashudong
• Created: 18/Jan/21 06:37
• Updated: 28/Aug/22 16:12
• Resolved: 28/Oct/21 14:25

Description

First slice is allocated by IntBlockPoo.newSlice(), and its level is 1,

 

private int newSlice(final int size) {
 if (intUpto > INT_BLOCK_SIZE-size) {
 nextBuffer();
 assert assertSliceBuffer(buffer);
 }
 
 final int upto = intUpto;
 intUpto += size;
 buffer[intUpto-1] = 1;
 return upto;
}

 

 

If one slice is not enough, IntBlockPoo.allocSlice() is called to allocate more slices,

as the following code shows, level is 1, newLevel is NEXT_LEVEL_ARRAY[0] which is also 1.

 

The result is the level of IntBlockPool slice is always 1, the first slice is  2 bytes long, and all subsequent slices are 4 bytes long.

 

private static final int[] NEXT_LEVEL_ARRAY = {1, 2, 3, 4, 5, 6, 7, 8, 9, 9};
private int allocSlice(final int[] slice, final int sliceOffset) {
 final int level = slice[sliceOffset];
 final int newLevel = NEXT_LEVEL_ARRAY[level - 1];
 final int newSize = LEVEL_SIZE_ARRAY[newLevel];
 // Maybe allocate another block
 if (intUpto > INT_BLOCK_SIZE - newSize) {
 nextBuffer();
 assert assertSliceBuffer(buffer);
 }
final int newUpto = intUpto;
 final int offset = newUpto + intOffset;
 intUpto += newSize;
 // Write forwarding address at end of last slice:
 slice[sliceOffset] = offset;
// Write new level:
 buffer[intUpto - 1] = newLevel;
return newUpto;
 }