Refactor and simplify src/utils.jl (#238)

src/Xpress.jl

@@ -26,8 +26,6 @@ const libxprs = joinpath(
 )
 
 include("Lib/Lib.jl")
-
-include("utils.jl")
 include("helper.jl")
 include("api.jl")
 include("xprs_callbacks.jl")

src/helper.jl

@@ -67,6 +67,91 @@ Base.cconvert(::Type{Ptr{Cvoid}}, prob::XpressProblem) = prob
 
 Base.unsafe_convert(::Type{Ptr{Cvoid}}, prob::XpressProblem) = prob.ptr
 
+function _invoke(f::Function, pos::Int, ::Type{Int}, args...)
+    out = Ref{Cint}(0)
+    args = collect(args)
+    insert!(args, pos, out)
+    if (r = f(args...)) != 0
+        throw(XpressError(r, "Unable to invoke $f"))
+    end
+    return out[]
+end
+
+function _invoke(f::Function, pos::Int, ::Type{Float64}, args...)
+    out = Ref{Float64}(0.0)
+    args = collect(args)
+    insert!(args, pos, out)
+    if (r = f(args...)) != 0
+        throw(XpressError(r, "Unable to invoke $f"))
+    end
+    return out[]
+end
+
+function _invoke(f::Function, pos::Int, ::Type{String}, args...)
+    buffer = Array{Cchar}(undef, 1024)
+    GC.@preserve buffer begin
+        out = Cstring(pointer(buffer))
+        args = collect(Any, args)
+        insert!(args, pos, out)
+        if (r = f(args...)) != 0
+            throw(XpressError(r, "Unable to invoke $f"))
+        end
+        return unsafe_string(out)
+    end
+end
+
+macro _invoke(expr)
+    @assert Meta.isexpr(expr, :(::)) "macro argument must have return type declaration"
+    f, return_type = expr.args
+    @assert Meta.isexpr(f, :call) "macro argument must have a function call"
+    invoke_expr = Expr(:call, _invoke, f.args[1], 0, return_type)
+    for i in 2:length(f.args)
+        if f.args[i] == :_
+            invoke_expr.args[3] = i - 1
+        else
+            push!(invoke_expr.args, esc(f.args[i]))
+        end
+    end
+    return invoke_expr
+end
+
+"""
+    @checked f(prob)
+
+Lets you invoke a lower level `Lib` function and check that Xpress does not
+error.
+
+Use this macro to minimize repetition and increase readability.
+
+The first argument must be a object that can be cast into an Xpress pointer,
+e.g., `Ptr{XpressProblem}`.
+
+This is passed to `get_xpress_error_message(xprs_ptr)` to get the error message.
+
+## Example
+
+```julia
+@checked Lib.XPRSsetprobname(prob, name)
+```
+"""
+macro checked(expr)
+    @assert expr.head == :call "Can only use @checked on function calls"
+    @assert (expr.args[1].head == :(.)) && (expr.args[1].args[1] == :Lib) "Can only use @checked on Lib.\$function"
+    @assert length(expr.args) >= 2 "Lib.\$function must be contain atleast one argument and the first argument must be of type XpressProblem"
+    prob = expr.args[2]
+    return quote
+        val = $(esc(expr))::Cint
+        if val != 0
+            e = get_xpress_error_message($(esc(prob)))
+            throw(XpressError(val, "Xpress internal error:\n\n$e.\n"))
+        end
+    end
+end
+
+function get_xpress_error_message(prob)
+    return lstrip(@_invoke(Lib.XPRSgetlasterror(prob, _)::String), ['?'])
+end
+
 function getattribute(prob::XpressProblem, name::String)
     p_id, p_type = Ref{Cint}(), Ref{Cint}()
     Lib.XPRSgetattribinfo(prob, name, p_id, p_type)
@@ -128,11 +213,6 @@ get_banner() = @_invoke Lib.XPRSgetbanner(_)::String
 
 get_version() = VersionNumber(@_invoke Lib.XPRSgetversion(_)::String)
 
-function get_xpress_error_message(prob::XpressProblem)
-    last_error = @_invoke Lib.XPRSgetlasterror(prob, _)::String
-    return lstrip(last_error, ['?'])
-end
-
 """
     show(io::IO, prob::XpressProblem)
 

test/runtests.jl

@@ -12,13 +12,3 @@ println("Optimizer version: $(Xpress.get_version())")
 @testset "$f" for f in filter!(f -> startswith(f, "test_"), readdir(@__DIR__))
     include(f)
 end
-
-@testset "Xpress tests" begin
-    prob = Xpress.XpressProblem()
-    @test Xpress.getcontrol(prob, "HEURTHREADS") == 0
-    r = Xpress.Lib.XPRSreadprob(prob, "", "")
-    if Xpress.get_version() >= v"41.0.0"
-        msg = "Xpress internal error:\n\n85 Error: File not found: .\n"
-        @test_throws Xpress.XpressError(85, msg) Xpress._check(prob, r)
-    end
-end

test/test_helper.jl

@@ -8,6 +8,8 @@ module TestHelper
 using Xpress
 using Test
 
+import Xpress.Lib as Lib
+
 function runtests()
     for name in names(@__MODULE__; all = true)
         if startswith("$(name)", "test_")
@@ -83,6 +85,40 @@ function test_XpressProblem_show()
     return
 end
 
+function test_checked()
+    if Xpress.get_version() < v"41.0.0"
+        return
+    end
+    prob = Xpress.XpressProblem()
+    msg = "Xpress internal error:\n\n85 Error: File not found: .\n"
+    @test_throws(
+        Xpress.XpressError(85, msg),
+        Xpress.@checked(Lib.XPRSreadprob(prob, "", "")),
+    )
+    return
+end
+
+function test_invoke_errors()
+    prob = C_NULL
+    @test_throws(
+        Xpress.XpressError,
+        Xpress.@_invoke(
+            Lib.XPRSgetintattrib(prob, Lib.XPRS_ORIGINALCOLS, _)::Int,
+        ),
+    )
+    @test_throws(
+        Xpress.XpressError,
+        Xpress.@_invoke(
+            Lib.XPRSgetdblattrib(prob, Lib.XPRS_OBJSENSE, _)::Float64,
+        ),
+    )
+    @test_throws(
+        Xpress.XpressError,
+        Xpress.@_invoke(Lib.XPRSgetlasterror(prob, _)::String)
+    )
+    return
+end
+
 end  # TestHelper
 
 TestHelper.runtests()