DNM: Add unsafe_(g|s)et_backend_attribute

src/optimizer_interface.jl

@@ -1283,3 +1283,142 @@ function _get_start_values(
     end
     return
 end
+
+"""
+    unsafe_get_backend_attribute(
+        model::GenericModel,
+        attr::Union{MOI.AbstractModelAttribute,MOI.AbstractOptimizerAttribute},
+    )
+    unsafe_get_backend_attribute(
+        x::GenericVariableRef,
+        attr::MOI.AbstractVariableAttribute,
+    )
+    unsafe_get_backend_attribute(
+        c::ConstraintRef,
+        attr::MOI.AbstractConstraintAttribute,
+    )
+
+Get the attribute `attr` directly from the [`unsafe_backend`](@ref) of the
+associated model, skipping safety checks, such as whether the model was
+previously solved.
+
+## Unsafe behavior
+
+This method is unsafe because its behavior depends on the implementation of the
+backend solver.
+
+Where possible, use [`get_attribute`](@ref) instead.
+"""
+function unsafe_get_backend_attribute(
+    model::GenericModel,
+    attr::Union{MOI.AbstractModelAttribute,MOI.AbstractOptimizerAttribute},
+)
+    return _unsafe_get_backend_attribute(backend(model), attr)
+end
+
+function unsafe_get_backend_attribute(
+    x::GenericVariableRef,
+    attr::MOI.AbstractVariableAttribute,
+)
+    b = backend(owner_model(x))
+    return _unsafe_get_backend_attribute(b, attr, index(x))
+end
+
+function unsafe_get_backend_attribute(
+    c::ConstraintRef,
+    attr::MOI.AbstractConstraintAttribute,
+)
+    b = backend(owner_model(c))
+    return _unsafe_get_backend_attribute(b, attr, index(c))
+end
+
+function _unsafe_get_backend_attribute(model::MOI.ModelLike, args...)
+    return MOI.get(model, args...)
+end
+
+function _unsafe_get_backend_attribute(
+    model::MOI.Utilities.CachingOptimizer,
+    attr,
+    args...,
+)
+    if MOI.Utilities.state(model) == MOI.Utilities.EMPTY_OPTIMIZER
+        MOI.Utilities.attach_optimizer(model)
+    end
+    if MOI.Utilities.state(model) != MOI.Utilities.ATTACHED_OPTIMIZER
+        error("Cannot get backend attribute because no optimizer is attached")
+    end
+    return MOI.get(model, MOI.Utilities.AttributeFromOptimizer(attr), args...)
+end
+
+"""
+    unsafe_set_backend_attribute(
+        model::GenericModel,
+        attr::Union{MOI.AbstractModelAttribute,MOI.AbstractOptimizerAttribute},
+        value,
+    )
+    unsafe_set_backend_attribute(
+        x::GenericVariableRef,
+        attr::MOI.AbstractVariableAttribute,
+        value,
+    )
+    unsafe_set_backend_attribute(
+        c::ConstraintRef,
+        attr::MOI.AbstractConstraintAttribute,
+        value,
+    )
+
+Set the attribute `attr` of the [`unsafe_backend`](@ref) of the associated model
+to `value`, skipping safety checks, such as whether the model was previously
+solved.
+
+## Unsafe behavior
+
+This method is unsafe because its behavior depends on the implementation of the
+backend solver. In addition, the attribute is not cached, and so subsequent
+modifications to the model may silently discard the set value of the attribute.
+
+Where possible, use [`set_attribute`](@ref) instead.
+"""
+function unsafe_set_backend_attribute(
+    model::GenericModel,
+    attr::Union{MOI.AbstractModelAttribute,MOI.AbstractOptimizerAttribute},
+    value,
+)
+    return _unsafe_set_backend_attribute(backend(model), attr, value)
+end
+
+function unsafe_set_backend_attribute(
+    x::GenericVariableRef,
+    attr::MOI.AbstractVariableAttribute,
+    value,
+)
+    b = backend(owner_model(x))
+    return _unsafe_set_backend_attribute(b, attr, index(x), value)
+end
+
+function unsafe_set_backend_attribute(
+    c::ConstraintRef,
+    attr::MOI.AbstractConstraintAttribute,
+    value,
+)
+    b = backend(owner_model(c))
+    return _unsafe_set_backend_attribute(b, attr, index(c), value)
+end
+
+function _unsafe_set_backend_attribute(model::MOI.ModelLike, args...)
+    return MOI.set(model, args...)
+end
+
+function _unsafe_set_backend_attribute(
+    model::MOI.Utilities.CachingOptimizer,
+    attr,
+    args...,
+)
+    if MOI.Utilities.state(model) == MOI.Utilities.EMPTY_OPTIMIZER
+        MOI.Utilities.attach_optimizer(model)
+    end
+    if MOI.Utilities.state(model) != MOI.Utilities.ATTACHED_OPTIMIZER
+        error("Cannot set backend attribute because no optimizer is attached")
+    end
+    return MOI.set(model, MOI.Utilities.AttributeFromOptimizer(attr), args...)
+end

test/test_model.jl

@@ -1313,4 +1313,130 @@ function test_is_solved_and_feasible()
     return
 end
 
+struct ModelAttribute3684 <: MOI.AbstractModelAttribute end
+
+MOI.get(::MOI.Utilities.MockOptimizer, ::ModelAttribute3684) = "m3684"
+
+struct VariableAttribute3684 <: MOI.AbstractVariableAttribute end
+
+function MOI.get(
+    ::MOI.Utilities.MockOptimizer,
+    ::VariableAttribute3684,
+    x::MOI.VariableIndex,
+)
+    return "x3684-$(x.value)"
+end
+
+struct ConstraintAttribute3684 <: MOI.AbstractConstraintAttribute end
+
+function MOI.get(
+    ::MOI.Utilities.MockOptimizer,
+    ::ConstraintAttribute3684,
+    c::MOI.ConstraintIndex,
+)
+    return "c3684-$(c.value)"
+end
+
+function test_get_backend_attribute_caching_optimizer()
+    mock = MOIU.UniversalFallback(MOIU.Model{Float64}())
+    model = Model(() -> MOIU.MockOptimizer(mock))
+    @variable(model, x)
+    @constraint(model, c, x <= 1)
+    # ModelAttribute
+    attr = ModelAttribute3684()
+    @test get_attribute(model, attr) === nothing
+    @test unsafe_get_backend_attribute(model, attr) == "m3684"
+    @test get_attribute(model, MOI.Name()) == ""
+    @test unsafe_get_backend_attribute(model, MOI.Name()) == ""
+    unsafe_set_backend_attribute(model, MOI.Name(), "foo")
+    @test get_attribute(model, MOI.Name()) == ""
+    @test unsafe_get_backend_attribute(model, MOI.Name()) == "foo"
+    # VariableAttribute
+    attr = VariableAttribute3684()
+    @test get_attribute(x, attr) === nothing
+    @test startswith(unsafe_get_backend_attribute(x, attr), "x3684-")
+    @test get_attribute(x, MOI.VariableName()) == "x"
+    @test unsafe_get_backend_attribute(x, MOI.VariableName()) == "x"
+    unsafe_set_backend_attribute(x, MOI.VariableName(), "foo")
+    @test get_attribute(x, MOI.VariableName()) == "x"
+    @test unsafe_get_backend_attribute(x, MOI.VariableName()) == "foo"
+    # ConnstraintAttribute
+    attr = ConstraintAttribute3684()
+    @test get_attribute(c, attr) === nothing
+    @test startswith(unsafe_get_backend_attribute(c, attr), "c3684-")
+    @test get_attribute(c, MOI.ConstraintName()) == "c"
+    @test unsafe_get_backend_attribute(c, MOI.ConstraintName()) == "c"
+    unsafe_set_backend_attribute(c, MOI.ConstraintName(), "foo")
+    @test get_attribute(c, MOI.ConstraintName()) == "c"
+    @test unsafe_get_backend_attribute(c, MOI.ConstraintName()) == "foo"
+    return
+end
+
+function test_set_backend_attribute_caching_optimizer()
+    mock = MOIU.UniversalFallback(MOIU.Model{Float64}())
+    model = Model(() -> MOIU.MockOptimizer(mock))
+    # Call sett first, to check that we attach the CachingOptimizer
+    unsafe_set_backend_attribute(model, MOI.Name(), "foo")
+    @test get_attribute(model, MOI.Name()) == ""
+    @test unsafe_get_backend_attribute(model, MOI.Name()) == "foo"
+    return
+end
+
+function test_get_backend_attribute_direct()
+    mock = MOIU.UniversalFallback(MOIU.Model{Float64}())
+    model = direct_model(MOIU.MockOptimizer(mock))
+    @variable(model, x)
+    @constraint(model, c, x <= 1)
+    # ModelAttribute
+    attr = ModelAttribute3684()
+    @test get_attribute(model, attr) === "m3684"
+    @test unsafe_get_backend_attribute(model, attr) == "m3684"
+    @test get_attribute(model, MOI.Name()) == ""
+    @test unsafe_get_backend_attribute(model, MOI.Name()) == ""
+    unsafe_set_backend_attribute(model, MOI.Name(), "foo")
+    @test get_attribute(model, MOI.Name()) == "foo"
+    @test unsafe_get_backend_attribute(model, MOI.Name()) == "foo"
+    # VariableAttribute
+    attr = VariableAttribute3684()
+    @test startswith(get_attribute(x, attr), "x3684-")
+    @test startswith(unsafe_get_backend_attribute(x, attr), "x3684-")
+    @test get_attribute(x, MOI.VariableName()) == "x"
+    @test unsafe_get_backend_attribute(x, MOI.VariableName()) == "x"
+    unsafe_set_backend_attribute(x, MOI.VariableName(), "foo")
+    @test get_attribute(x, MOI.VariableName()) == "foo"
+    @test unsafe_get_backend_attribute(x, MOI.VariableName()) == "foo"
+    # ConnstraintAttribute
+    attr = ConstraintAttribute3684()
+    @test startswith(get_attribute(c, attr), "c3684-")
+    @test startswith(unsafe_get_backend_attribute(c, attr), "c3684-")
+    @test get_attribute(c, MOI.ConstraintName()) == "c"
+    @test unsafe_get_backend_attribute(c, MOI.ConstraintName()) == "c"
+    unsafe_set_backend_attribute(c, MOI.ConstraintName(), "foo")
+    @test get_attribute(c, MOI.ConstraintName()) == "foo"
+    @test unsafe_get_backend_attribute(c, MOI.ConstraintName()) == "foo"
+    return
+end
+
+function test_get_backend_attribute_no_optimizer()
+    model = Model()
+    @variable(model, x)
+    @constraint(model, c, x <= 1)
+    get_err = ErrorException(
+        "Cannot get backend attribute because no optimizer is attached",
+    )
+    set_err = ErrorException(
+        "Cannot set backend attribute because no optimizer is attached",
+    )
+    attr = ModelAttribute3684()
+    @test_throws get_err unsafe_get_backend_attribute(model, attr)
+    @test_throws set_err unsafe_set_backend_attribute(model, attr, "a")
+    attr = VariableAttribute3684()
+    @test_throws get_err unsafe_get_backend_attribute(x, attr)
+    @test_throws set_err unsafe_set_backend_attribute(x, attr, "a")
+    attr = ConstraintAttribute3684()
+    @test_throws get_err unsafe_get_backend_attribute(c, attr)
+    @test_throws set_err unsafe_set_backend_attribute(c, attr, "a")
+    return
+end
+
 end  # module TestModels