Load hulpke/extraperfect as lazy artifact (#2432)

Artifacts.toml

@@ -0,0 +1,16 @@
+[gap_extraperfect]
+git-tree-sha1 = "084fa12573e5089ceb3299f9d341f244b415da52"
+lazy = true
+
+    [[gap_extraperfect.download]]
+    sha256 = "e565303927682f54cba20a69b8d23673b9b9d4d2a2bc88751f58ed5d3365e29f"
+    url = "https://github.com/oscar-system/GAP.jl/releases/download/archive-tag/extraperfect.tar.gz"
+    # Created from https://github.com/hulpke/extraperfect using
+    # #!/bin/sh
+    # export SOURCE_DATE_EPOCH=$(git log -1 --pretty=%ct)
+    # rm -rf extraperfect
+    # mkdir extraperfect
+    # gzip -9 -n -c perf27.grp > extraperfect/perf27.grp.gz
+    # gzip -9 -n -c perf33.grp > extraperfect/perf33.grp.gz
+    # gtar --mtime="$(git log -1 --pretty=%cI)" --owner=0 --group=0 --numeric-owner -cvf extraperfect.tar extraperfect
+    # gzip -n -c extraperfect.tar > extraperfect.tar.gz

Project.toml

@@ -10,6 +10,7 @@ DocStringExtensions = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"
 GAP = "c863536a-3901-11e9-33e7-d5cd0df7b904"
 Hecke = "3e1990a7-5d81-5526-99ce-9ba3ff248f21"
 JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
+LazyArtifacts = "4af54fe1-eca0-43a8-85a7-787d91b784e3"
 Nemo = "2edaba10-b0f1-5616-af89-8c11ac63239a"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 Polymake = "d720cf60-89b5-51f5-aff5-213f193123e7"

gap/OscarInterface/gap/OscarInterface.gi

@@ -1,3 +1,18 @@
+BindGlobal("ReplaceGapFunc", function(name, func)
+  local orig_name;
+  # Store a copy of the original value, but only if that copy does not yet
+  # exist. This ensures we don't overwrite it during a call to `Reread`.
+  orig_name := Concatenation("_ORIG_", name);
+  if not IsBoundGlobal(orig_name) then
+    BindGlobal(orig_name, ValueGlobal(name));
+  fi;
+  MakeReadWriteGlobal(name);
+  UnbindGlobal(name);
+  BindGlobal(name, func);
+end);
+
+############################################################################
+
 InstallOtherMethod( ImagesRepresentative,
     [ IsActionHomomorphism and HasJuliaData, IsMultiplicativeElementWithInverse ],
 function( hom, elm )

gap/OscarInterface/gap/alnuth.gi

@@ -3,19 +3,6 @@
 #
 LoadPackage("alnuth"); # HACK
 
-BindGlobal("ReplaceGapFunc", function(name, func)
-  local orig_name;
-  # Store a copy of the original value, but only if that copy does not yet
-  # exist. This ensures we don't overwrite it during a call to `Reread`.
-  orig_name := Concatenation("_ORIG_", name);
-  if not IsBoundGlobal(orig_name) then
-    BindGlobal(orig_name, ValueGlobal(name));
-  fi;
-  MakeReadWriteGlobal(name);
-  UnbindGlobal(name);
-  BindGlobal(name, func);
-end);
-
 # store isomorphism between GAP and OSCAR univariate polynomial ring over the
 # rationals as we need it a lot
 BindGlobal("_PolyRingIso", Oscar.iso_gap_oscar(PolynomialRing(Rationals)));

src/GAP/GAP.jl

@@ -1,7 +1,7 @@
 include("wrappers.jl")
 include("customize.jl")
+include("utils.jl")
 include("gap_to_oscar.jl")
 include("oscar_to_gap.jl")
 include("iso_gap_oscar.jl")
 include("iso_oscar_gap.jl")
-

src/GAP/utils.jl

@@ -0,0 +1,11 @@
+function _write_gap_file(relpath::String, content::String)
+  gaproot = GAP.Setup.gaproot()
+  path = joinpath(gaproot, relpath)
+  mkpath(dirname(path))
+  # write to a temporary file and move later to avoid race conditions
+  tmpfile = tempname(dirname(path); cleanup=false)
+  open(tmpfile, "w") do file
+    write(file, content)
+  end
+  Base.Filesystem.rename(tmpfile, path)
+end

src/Groups/libraries/libraries.jl

@@ -65,6 +65,8 @@ function __init_group_libraries()
   _atlas_group_filter_attrs[character] = (Oscar.GroupClassFunction, GAP.Globals.Character, nothing)
   _atlas_group_filter_attrs[characteristic] = (_IntOrIntVec, GAP.Globals.Characteristic, nothing)
   _atlas_group_filter_attrs[dim] = (_IntOrIntVec, GAP.Globals.Dimension, nothing)
+
+  __init_extraperfect()
 end
 
 # return the output of the function f and the corresponding GAP function

src/Groups/libraries/perfectgroups.jl

@@ -179,3 +179,19 @@ function number_perfect_groups(n::IntegerUnion)
 end
 
 # TODO: add all_perfect_groups() iterator
+
+function __init_extraperfect()
+  for i in [27, 33]
+    _write_gap_file(
+      "grp/perf$(i).grp",
+      "Read(JuliaToGAP(IsString, Oscar._path_extraperfect($(i))));\n",
+    )
+  end
+end
+
+function _path_extraperfect(i::Int)
+  return joinpath(
+    artifact"gap_extraperfect/extraperfect",
+    "perf$(i).grp.gz",
+  )
+end

src/Oscar.jl

@@ -20,6 +20,7 @@ OSCAR is licensed under the GPL v3+ (see LICENSE.md).
 module Oscar
 
 using Preferences
+using LazyArtifacts
 
 include("imports.jl")
 

test/Groups/libraries.jl

@@ -108,6 +108,9 @@ end
    @test number_perfect_groups(ZZRingElem(60)^3) == 1
    @test_throws ArgumentError number_perfect_groups(0) # invalid argument
    @test_throws ArgumentError number_perfect_groups(ZZRingElem(60)^10)  # result not known
+
+   # lazy artifact loading (needs network access, see https://github.com/oscar-system/Oscar.jl/issues/2480)
+   #@test perfect_group(1376256, 1) isa PermGroup
 end
 
 @testset "Small groups" begin