Base: Add count argument to Base.summarysize
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topolarity
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Jul 2, 2025
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| size::Int = (ss.count ? 1 : (7 * Core.sizeof(Int) + 6 * Core.sizeof(Int32))) | ||
| size += (ss.count ? 1 : (4 * nfields(obj) + ifelse(Sys.WORD_SIZE == 64, 4, 0))) |
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I don't know where these magic numbers were pulled from, so I'm not sure if this is 1 object or 2 (or 3?)
I'll need to reverse engineer before merging.
topolarity
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Jul 2, 2025
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It would be good to specify in the docstring whether count returns the number of heap allocations or the number of Julia objects. Does a 1000-element Memory of integers count as one or 1000? |
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Frequently the number of allocations can be more important for performance than the amount of memory allocated. This adds a small utility to `summarysize` to allow counting the number of unique reachable objects, which can be useful to understand, e.g., if you are performing many small allocations or how many of the allocations in a function ended up reachable from the result.
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topolarity
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Jul 2, 2025
| end | ||
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| nth_pointer_isdefined(obj, i::Int) = ccall(:jl_nth_pointer_isdefined, Cint, (Any, Csize_t), obj, i-1) != 0 | ||
| get_nth_pointer(obj, i::Int) = ccall(:jl_get_nth_pointer, Any, (Any, Csize_t), obj, i-1) | ||
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| """ | ||
| Base.summarysize(obj; exclude=Union{...}, chargeall=Union{...})::Int | ||
| Base.summarysize(obj; count = false, exclude=Union{...}, chargeall=Union{...})::Int |
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This might be clearer as:
Suggested change
| Base.summarysize(obj; count = false, exclude=Union{...}, chargeall=Union{...})::Int | |
| Base.summarysize(obj; count::Symbol = :size, exclude=Union{...}, chargeall=Union{...})::Int |
so the new functionality would be summarysize(x; count=:allocations)
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In many cases, number of allocations is more important than memory allocated (w.r.t. performance).
This adds a small utility to
summarysizeto allow counting the number of unique reachable objects, which can be useful to understand, e.g., if you are performing many small allocations or how many of the allocations in a function ended up reachable from the result.