pack-priv final Class SizeClasses

LOG2_SIZE_CLASS_GROUP: Log of size class count for each size doubling. LOG2_MAX_LOOKUP_SIZE: Log of max size class in the lookup table. sizeClasses: Complete table of [index, log2Group, log2Delta, nDelta, isMultiPageSize, isSubPage, log2DeltaLookup] tuples. index: Size class index. log2Group: Log of group base size (no deltas added). log2Delta: Log of delta to previous size class. nDelta: Delta multiplier. isMultiPageSize: 'yes' if a multiple of the page size, 'no' otherwise. isSubPage: 'yes' if a subpage size class, 'no' otherwise. log2DeltaLookup: Same as log2Delta if a lookup table size class, 'no' otherwise.

nSubpages: Number of subpages size classes. nSizes: Number of size classes. nPSizes: Number of size classes that are multiples of pageSize. smallMaxSizeIdx: Maximum small size class index. lookupMaxClass: Maximum size class included in lookup table. log2NormalMinClass: Log of minimum normal size class.

The first size class and spacing are 1 << LOG2_QUANTUM. Each group has 1 << LOG2_SIZE_CLASS_GROUP of size classes. size = 1 << log2Group + nDelta * (1 << log2Delta) The first size class has an unusual encoding, because the size has to be split between group and delta*nDelta. If pageShift = 13, sizeClasses looks like this: (index, log2Group, log2Delta, nDelta, isMultiPageSize, isSubPage, log2DeltaLookup)

( 0, 4, 4, 0, no, yes, 4) ( 1, 4, 4, 1, no, yes, 4) ( 2, 4, 4, 2, no, yes, 4) ( 3, 4, 4, 3, no, yes, 4)

( 4, 6, 4, 1, no, yes, 4) ( 5, 6, 4, 2, no, yes, 4) ( 6, 6, 4, 3, no, yes, 4) ( 7, 6, 4, 4, no, yes, 4)

( 8, 7, 5, 1, no, yes, 5) ( 9, 7, 5, 2, no, yes, 5) ( 10, 7, 5, 3, no, yes, 5) ( 11, 7, 5, 4, no, yes, 5) ... ... ( 72, 23, 21, 1, yes, no, no) ( 73, 23, 21, 2, yes, no, no) ( 74, 23, 21, 3, yes, no, no) ( 75, 23, 21, 4, yes, no, no)

( 76, 24, 22, 1, yes, no, no)