32 lines
1.2 KiB
Text
32 lines
1.2 KiB
Text
# ludic.base/ecs_index_slot.ludic - where a value's list lives: a small value (a kind) is its own
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# slot; a large one (a chunk's packed cell) is given the next slot through a map, so a sparse
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# value costs one list and not every list up to it
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const IX_DENSE: int = 1024 # a value below this is its own slot; above, one is given it
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const IX_CAP: int = 16 # rows a value's list holds before it grows: a list grown in play is a new block
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@alloc_ok("once per distinct value: its list is made the first time the value is filed, and kept")
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function ix_list_new() -> words {
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let l = words(IX_CAP)
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List.clear(l)
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return l
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}
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# the slot value v's list is in, -1 when it has none (and `make` did not ask for one)
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function ix_slot(ix: IntIndex, v: int, make: bool) -> int {
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if v < 0 { return -1 }
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if v < IX_DENSE {
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if v >= len(ix.lists) {
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if not make { return -1 }
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while len(ix.lists) <= v { kept_push(ix.lists, ix_list_new()) }
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}
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return v
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}
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var s = imap_get(ix.sparse, v, -1)
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if s < 0 and make {
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while len(ix.lists) < IX_DENSE { kept_push(ix.lists, ix_list_new()) }
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s = len(ix.lists)
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kept_push(ix.lists, ix_list_new())
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imap_put(ix.sparse, v, s)
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}
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return s
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}
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