[Do not merge] Basis record/restore

src/Algorithm/basic/solvelpform.jl

@@ -43,6 +43,7 @@ function get_units_usage(
         push!(units_usage, (form, MasterColumnsUnit, READ_ONLY))
         push!(units_usage, (form, MasterBranchConstrsUnit, READ_ONLY))
         push!(units_usage, (form, MasterCutsUnit, READ_ONLY))
+        push!(units_usage, (form, MasterBasisUnit, READ_ONLY))
     end
     return units_usage
 end

src/Algorithm/colgen.jl

@@ -107,6 +107,7 @@ function get_units_usage(algo::ColumnGeneration, reform::Reformulation)
     units_usage = Tuple{AbstractModel,UnitType,UnitPermission}[] 
     master = getmaster(reform)
     push!(units_usage, (master, MasterColumnsUnit, READ_AND_WRITE))
+    push!(units_usage, (master, MasterBasisUnit, READ_AND_WRITE))
     #push!(units_usage, (master, PartialSolutionUnit, READ_ONLY))
     if stabilization_is_used(algo)
         push!(units_usage, (master, ColGenStabilizationUnit, READ_AND_WRITE))

src/Algorithm/conquer.jl

@@ -264,7 +264,6 @@ end
 function run_heuristics!(ctx::ColCutGenContext, heuristics, env, reform, node_state)
     for heuristic in heuristics
         # TODO: check time limit of Coluna
-
         if ip_gap_closed(node_state, atol = ctx.params.opt_atol, rtol = ctx.params.opt_rtol)
             return false
         end
@@ -345,7 +344,6 @@ end
 
 function run_colcutgen_conquer!(ctx::ColCutGenContext, env, reform, input)
     node = get_node(input)
-    restore_from_records!(get_units_to_restore(input), TreeSearch.get_records(node))
     node_state = TreeSearch.get_opt_state(node)
 
     time_limit_reached!(node_state, env) && return
@@ -387,6 +385,8 @@ end
 function run!(algo::ColCutGenConquer, env::Env, reform::Reformulation, input::AbstractConquerInput)
     !run_conquer(input) && return
     ctx = new_context(type_of_context(algo), algo, reform, input)
+    node = get_node(input)
+    restore_from_records!(get_units_to_restore(input), TreeSearch.get_records(node))
     run_colcutgen_conquer!(ctx, env, reform, input)
     return
 end

src/Algorithm/formstorages.jl

@@ -234,6 +234,42 @@ function ClB.restore_from_record!(
 end
 
 
+####
+####
+struct MasterBasisUnit <: AbstractRecordUnit end
+
+struct MasterBasisRecord <: AbstractRecord
+    basis::Union{Nothing,MathProg.Basis}
+end
+
+struct MasterBasisKey <: AbstractStorageUnitKey end
+
+key_from_storage_unit_type(::Type{MasterBasisUnit}) = MasterBasisKey()
+record_type_from_key(::MasterBasisKey) = MasterBasisRecord
+
+ClB.storage_unit(::Type{MasterBasisUnit}, _) = MasterBasisUnit()
+
+function ClB.record(::Type{MasterBasisRecord}, id::Int, form::Formulation, unit::MasterBasisUnit)
+    optimizer = getoptimizer(form, 1)
+    basis = MathProg.get_basis(form, optimizer)
+    return MasterBasisRecord(basis)
+end
+
+ClB.record_type(::Type{MasterBasisUnit}) = MasterBasisRecord
+ClB.storage_unit_type(::Type{MasterBasisRecord}) = MasterBasisUnit
+
+apply_set_basis!(form, optimizer::MoiOptimizer, basis) = MathProg.set_basis!(form, optimizer, basis)
+apply_set_basis!(form, _, basis) = nothing
+
+function ClB.restore_from_record!(
+    form::Formulation, ::MasterBasisUnit, state::MasterBasisRecord
+)
+    optimizer = getoptimizer(form, 1)
+    if !isnothing(state.basis)
+        apply_set_basis!(form, optimizer, state.basis)
+    end
+    return
+end
 
 ##### UNCOVERED CODE BELOW #####
 

src/Benders/Benders.jl

@@ -19,8 +19,6 @@ struct UnboundedError <: Exception end
 "Returns the separation subproblems."
 @mustimplement "BendersProbInfo" get_benders_subprobs(context) = nothing
 
-
-
 """
     optimize_master_problem!(master, context, env) -> MasterResult
 

src/MathProg/MOIinterface.jl

@@ -338,6 +338,60 @@ function get_dual_solutions(form::F, optimizer::MoiOptimizer) where {F <: Formul
     return solutions
 end
 
+
+struct Basis
+    vars::Dict{VarId,MOI.BasisStatusCode}
+    constrs::Dict{ConstrId,MOI.BasisStatusCode}
+end
+
+function get_basis(form::F, optimizer::MoiOptimizer) where {F <: Formulation}
+    inner = getinner(optimizer)
+    nb_primal_sols = MOI.get(inner, MOI.ResultCount())
+    if nb_primal_sols <= 0 || MOI.get(inner, MOI.PrimalStatus(1)) != MOI.FEASIBLE_POINT
+        return nothing
+    end
+
+    vars = Dict{VarId,MOI.BasisStatusCode}()
+    for (varid, var) in getvars(form)
+        iscuractive(form, varid) && isexplicit(form, varid) || continue
+        moi_index = getindex(getmoirecord(var))
+        if moi_index.value != -1
+            vars[varid] = MOI.get(inner, MOI.VariableBasisStatus(), moi_index)
+        end
+    end
+
+    constrs = Dict{ConstrId,MOI.BasisStatusCode}()
+    for (constrid, constr) in getconstrs(form)
+        iscuractive(form, constrid) && isexplicit(form, constrid) || continue
+        moi_index = getindex(getmoirecord(constr))
+        if moi_index.value != -1
+            constrs[constrid] = MOI.get(inner, MOI.ConstraintBasisStatus(), moi_index)
+        end
+    end
+    return Basis(vars, constrs)
+end
+
+function set_basis!(form::F, optimizer::MoiOptimizer, basis::Basis) where {F <: Formulation}
+    inner = getinner(optimizer)
+    for (varid, var) in getvars(form)
+        iscuractive(form, varid) && isexplicit(form, varid) || continue
+        moi_index = getindex(getmoirecord(var))
+        var_basis = get(basis.vars, varid, nothing)
+        if !isnothing(var_basis)
+            MOI.set(inner, MOI.VariableBasisStatus(), moi_index, var_basis)
+        end
+    end
+    for (constrid, constr) in getconstrs(form)
+        iscuractive(form, constrid) && isexplicit(form, constrid) || continue
+        moi_index = getindex(getmoirecord(constr))
+        constr_basis = get(basis.constrs, constrid, nothing)
+        if !isnothing(constr_basis)
+            MOI.set(inner, MOI.ConstraintBasisStatus(), moi_index, constr_basis)
+        end
+    end
+    return
+end
+
 function get_dual_infeasibility_certificate(form::F, optimizer::MoiOptimizer) where {F <: Formulation}
     inner = getinner(optimizer)
     nb_certificates = MOI.get(inner, MOI.ResultCount())