Massive load time for Julia 1.3+

[colinxs]

First off, awesome package! I've really enjoyed it so far. Unfortunately I came across an issue with load time while trying out Julia 1.3.

In the following example:

f = tempname() * ".jlso"
JLSO.save(f, :x=>rand(1000), :y=>rand(1000)) 
x = JLSO.load(f)

The first call to JLSO.load(f) takes 1-2 minutes with Julia 1.3 (rc2, rc3, and rc4.1) on multiple machines, but only a few seconds with Julia 1.2. This is true for any level of compression or serializer. The difference appears to only be from compile time, as subsequent loads for other files are fast.

[oxinabox]

Julia 1.3 has not been released yet, because of these kinds of issues.

[rofinn]

Looks like this might be fixed on 1.3-rc5 JuliaLang/julia#33615

[colinxs]

Looks like RC5 fixed it! In a fresh session:

julia> f = tempname() * ".jlso";
julia> JLSO.save(f, :x=>rand(1000), :y=>rand(1000));
julia> @time JLSO.load(f);
  2.822424 seconds (16.27 M allocations: 781.691 MiB, 9.60% gc time)

[colinxs]

I forgot to add: the slowdown came from _upgrade_env(pkgs::Dict) in deprecations.jl, and unfortunately there's still a relatively high penalty from it. Without it:

julia> @time JLSO.load(f);
1.372000 seconds (4.57 M allocations: 234.462 MiB, 2.11% gc time)

[rofinn]

Is that also still a 1-time cost or is it twice as expensive every time you call JLSO.load?