Use integer IDs for components and supplemental attributes instead of UUIDs

src/InfrastructureSystems.jl

@@ -105,13 +105,10 @@ Required interface functions for subtypes:
 
 Optional interface functions:
 
-  - get_uuid()
+  - [`get_id`](@ref)
+  - [`supports_time_series`](@ref)
 
-Subtypes may contain time series. Which requires
-
-  - `supports_time_series(::SupplementalAttribute)`
-
-All subtypes must include an instance of ComponentUUIDs in order to track
+All subtypes must include an instance of [`ComponentIDs`](@ref) in order to track
 components attached to each attribute.
 """
 abstract type SupplementalAttribute <: InfrastructureSystemsType end
@@ -182,7 +179,7 @@ include("static_time_series.jl")
 include("time_series_parameters.jl")
 include("containers.jl")
 include("component_container.jl")
-include("component_uuids.jl")
+include("component_ids.jl")
 include("geographic_supplemental_attribute.jl")
 include("generated/includes.jl")
 include("time_series_parser.jl")

src/component.jl

@@ -1,20 +1,29 @@
 """
-Assign a new UUID to the component.
+Assign a new integer ID to the component, drawn from the system counter, and update any
+references to its old ID in the time series metadata store, supplemental attribute
+associations, and subsystem membership sets.
 """
-function assign_new_uuid_internal!(component::InfrastructureSystemsComponent)
-    old_uuid = get_uuid(component)
-    new_uuid = make_uuid()
+function assign_new_id_internal!(data, component::InfrastructureSystemsComponent)
+    old_id = get_id(component)
+    new_id = get_next_component_id!(data)
     mgr = get_time_series_manager(component)
     if !isnothing(mgr)
-        replace_component_uuid!(mgr.metadata_store, old_uuid, new_uuid)
+        replace_component_id!(mgr.metadata_store, old_id, new_id)
     end
 
     associations = _get_supplemental_attribute_associations(component)
     if !isnothing(associations)
-        replace_component_uuid!(associations, old_uuid, new_uuid)
+        replace_component_id!(associations, old_id, new_id)
     end
 
-    set_uuid!(get_internal(component), new_uuid)
+    for ids in values(data.subsystems)
+        if old_id in ids
+            pop!(ids, old_id)
+            push!(ids, new_id)
+        end
+    end
+
+    set_id!(get_internal(component), new_id)
     return
 end
 
@@ -47,8 +56,8 @@ end
 function clear_supplemental_attributes!(component::InfrastructureSystemsComponent)
     mgr = _get_supplemental_attributes_manager(component)
     isnothing(mgr) && return
-    for uuid in list_associated_supplemental_attribute_uuids(mgr.associations, component)
-        attribute = get_supplemental_attribute(mgr, uuid)
+    for id in list_associated_supplemental_attribute_ids(mgr.associations, component)
+        attribute = get_supplemental_attribute(mgr, id)
         remove_supplemental_attribute!(mgr, component, attribute)
     end
     @debug "Cleared attributes in $(summary(component))."
@@ -85,7 +94,7 @@ function _get_supplemental_attributes(
     isnothing(mgr) && return supplemental_attribute_type[]
     return supplemental_attribute_type[
         get_supplemental_attribute(mgr, x) for
-        x in list_associated_supplemental_attribute_uuids(
+        x in list_associated_supplemental_attribute_ids(
             mgr.associations,
             component,
             supplemental_attribute_type,
@@ -116,12 +125,12 @@ function _get_supplemental_attributes(
     mgr = _get_supplemental_attributes_manager(component)
     isnothing(mgr) && return [supplemental_attribute_type]
     attrs = Vector{supplemental_attribute_type}()
-    for uuid in list_associated_supplemental_attribute_uuids(
+    for id in list_associated_supplemental_attribute_ids(
         mgr.associations,
         component,
         supplemental_attribute_type,
     )
-        attribute = get_supplemental_attribute(mgr, uuid)
+        attribute = get_supplemental_attribute(mgr, id)
         if filter_func(attribute)
             push!(attrs, attribute)
         end
@@ -132,12 +141,12 @@ end
 
 function get_supplemental_attribute(
     component::InfrastructureSystemsComponent,
-    uuid::Base.UUID,
+    id::Int,
 )
     mgr = _get_supplemental_attributes_manager(component)
     isnothing(mgr) &&
         error("$(summary(component)) does not have supplemental attributes")
-    return get_supplemental_attribute(mgr, uuid)
+    return get_supplemental_attribute(mgr, id)
 end
 
 function _get_supplemental_attributes_manager(component::InfrastructureSystemsComponent)

src/component_ids.jl

@@ -0,0 +1,39 @@
+# This is an abstraction of a Set in order to enable de-serialization of supplemental
+# attributes.
+
+"""
+Set-like storage of component integer ids attached to a [`SupplementalAttribute`](@ref).
+
+Supplemental attribute subtypes include a `ComponentIDs` field so associations can be
+tracked and serialized without storing full component references.
+"""
+struct ComponentIDs <: InfrastructureSystemsType
+    ids::Set{Int}
+
+    function ComponentIDs(ids = Set{Int}())
+        new(ids)
+    end
+end
+
+Base.copy(x::ComponentIDs) = copy(x.ids)
+Base.delete!(x::ComponentIDs, id) = delete!(x.ids, id)
+Base.empty!(x::ComponentIDs) = empty!(x.ids)
+Base.filter!(f, x::ComponentIDs) = filter!(f, x.ids)
+Base.in(x, y::ComponentIDs) = in(x, y.ids)
+Base.isempty(x::ComponentIDs) = isempty(x.ids)
+Base.iterate(x::ComponentIDs, args...) = iterate(x.ids, args...)
+Base.length(x::ComponentIDs) = length(x.ids)
+Base.pop!(x::ComponentIDs) = pop!(x.ids)
+Base.pop!(x::ComponentIDs, y) = pop!(x.ids, y)
+Base.pop!(x::ComponentIDs, y, default) = pop!(x.ids, y, default)
+Base.push!(x::ComponentIDs, y) = push!(x.ids, y)
+Base.setdiff!(x::ComponentIDs, y::ComponentIDs) = setdiff!(x.ids, y.ids)
+Base.sizehint!(x::ComponentIDs, newsz) = sizehint!(x.ids, newsz)
+
+function deserialize(::Type{ComponentIDs}, data::Dict)
+    ids = Set{Int}()
+    for id in data["ids"]
+        push!(ids, Int(id))
+    end
+    return ComponentIDs(ids)
+end

src/components.jl

@@ -315,18 +315,18 @@ See also: [`iterate_components`](@ref)
 function get_components(
     ::Type{T},
     components::Components;
-    component_uuids::Union{Nothing, Set{Base.UUID}} = nothing,
+    component_ids::Union{Nothing, Set{Int}} = nothing,
 ) where {T <: InfrastructureSystemsComponent}
-    return iterate_instances(T, components.data, component_uuids)
+    return iterate_instances(T, components.data, component_ids)
 end
 
 function get_components(
     filter_func::Function,
     ::Type{T},
     components::Components;
-    component_uuids::Union{Nothing, Set{Base.UUID}} = nothing,
+    component_ids::Union{Nothing, Set{Int}} = nothing,
 ) where {T <: InfrastructureSystemsComponent}
-    return iterate_instances(filter_func, T, components.data, component_uuids)
+    return iterate_instances(filter_func, T, components.data, component_ids)
 end
 
 """

src/internal.jl

@@ -28,31 +28,46 @@ deserialize(T::Type{<:SystemUnitsSettings}, val::Dict) = deserialize_struct(T, v
 end
 
 """
-Internal storage common to InfrastructureSystems types.
+Sentinel value for the integer `id` of a component or supplemental attribute that has not
+yet been attached to a [`SystemData`](@ref). Assigned IDs start at 1.
+"""
+const UNASSIGNED_ID = 0
+
+"""
+Internal storage common to [`InfrastructureSystemsType`](@ref)s.
+
+Components and supplemental attributes are identified by an integer `id` assigned by the
+owning [`SystemData`](@ref) when they are attached (see [`get_id`](@ref)); it is
+[`UNASSIGNED_ID`](@ref) until then. The `uuid` is retained for time series, whose content
+and metadata are still identified by UUID. Each instance also holds optional
+[`SharedSystemReferences`](@ref) when attached to a system, optional unit metadata, and an
+optional user extension dictionary accessed through [`get_ext`](@ref).
 """
 mutable struct InfrastructureSystemsInternal <: InfrastructureSystemsType
+    id::Int
     uuid::Base.UUID
     shared_system_references::Union{Nothing, SharedSystemReferences}
     units_info::Union{Nothing, SystemUnitsSettings}
     ext::Union{Nothing, Dict{String, Any}}
 end
 
 """
-Creates InfrastructureSystemsInternal with a new UUID.
+Creates InfrastructureSystemsInternal with a new UUID and an unassigned integer ID.
 """
 InfrastructureSystemsInternal(;
+    id = UNASSIGNED_ID,
     uuid = make_uuid(),
     shared_system_references = nothing,
     units_info = nothing,
     ext = nothing,
 ) =
-    InfrastructureSystemsInternal(uuid, shared_system_references, units_info, ext)
+    InfrastructureSystemsInternal(id, uuid, shared_system_references, units_info, ext)
 
 """
 Creates InfrastructureSystemsInternal with an existing UUID.
 """
 InfrastructureSystemsInternal(u::Base.UUID) =
-    InfrastructureSystemsInternal(u, nothing, nothing, nothing)
+    InfrastructureSystemsInternal(UNASSIGNED_ID, u, nothing, nothing, nothing)
 
 """
 Return a user-modifiable dictionary to store extra information.
@@ -76,6 +91,9 @@ end
 get_uuid(internal::InfrastructureSystemsInternal) = internal.uuid
 set_uuid!(internal::InfrastructureSystemsInternal, uuid) = internal.uuid = uuid
 
+get_id(internal::InfrastructureSystemsInternal) = internal.id
+set_id!(internal::InfrastructureSystemsInternal, id::Int) = internal.id = id
+
 function set_shared_system_references!(
     internal::InfrastructureSystemsInternal,
     refs::Union{Nothing, SharedSystemReferences},
@@ -94,6 +112,22 @@ function get_uuid(obj::InfrastructureSystemsType)
     return get_internal(obj).uuid
 end
 
+"""
+Get the integer id of a component or supplemental attribute. Returns [`UNASSIGNED_ID`](@ref)
+if the object has not been attached to a [`SystemData`](@ref).
+"""
+function get_id(obj::InfrastructureSystemsType)
+    return get_internal(obj).id
+end
+
+"""
+Set the integer ID of a component or supplemental attribute.
+"""
+function set_id!(obj::InfrastructureSystemsType, id::Int)
+    set_id!(get_internal(obj), id)
+    return
+end
+
 """
 Assign a new UUID.
 """
@@ -139,7 +173,7 @@ function compare_values(
 )
     match = true
     for name in fieldnames(InfrastructureSystemsInternal)
-        if name in exclude || (name == :uuid && !compare_uuids) ||
+        if name in exclude || (name in (:uuid, :id) && !compare_uuids) ||
            name == :shared_system_references
             continue
         end

src/iterators.jl

@@ -4,19 +4,19 @@ function iterate_instances(
     filter_func::Function,
     ::Type{T},
     data::_ContainerTypes,
-    uuids::Set{Base.UUID},
+    ids::Set{Int},
 ) where {T <: InfrastructureSystemsType}
-    func_uuids = x -> get_uuid(x) in uuids
-    _filter_func = x -> filter_func(x) && func_uuids(x)
+    func_ids = x -> get_id(x) in ids
+    _filter_func = x -> filter_func(x) && func_ids(x)
     return iterate_instances(_filter_func, T, data, nothing)
 end
 
 function iterate_instances(
     ::Type{T},
     data::_ContainerTypes,
-    uuids::Set{Base.UUID},
+    ids::Set{Int},
 ) where {T <: InfrastructureSystemsType}
-    filter_func = x -> get_uuid(x) in uuids
+    filter_func = x -> get_id(x) in ids
     return iterate_instances(filter_func, T, data, nothing)
 end