graph: add Limit method
This exposes the next node ID that would be allocated. This is a prerequisite
for allowing the dense data structures to be sized independently from `Graph`.
PiperOrigin-RevId: 543356285
Change-Id: I0b658ab14df8a20f8893e91481881c8cb4bced5c
diff --git a/graph.h b/graph.h
index 458fa25..bd73b0c 100644
--- a/graph.h
+++ b/graph.h
@@ -331,7 +331,7 @@
// key set limited to allocated Ids.
class DenseIdSet {
public:
- explicit DenseIdSet(size_t size) : ids_(size, false) {}
+ explicit DenseIdSet(Id limit) : ids_(limit.ix_, false) {}
bool Insert(Id id) {
const auto ix = id.ix_;
if (ix >= ids_.size()) {
@@ -360,9 +360,9 @@
// but with constant time operations and key set limited to allocated Ids.
class DenseIdMapping {
public:
- explicit DenseIdMapping(size_t size) {
- ids_.reserve(size);
- for (size_t ix = 0; ix < size; ++ix) {
+ explicit DenseIdMapping(Id limit) {
+ ids_.reserve(limit.ix_);
+ for (size_t ix = 0; ix < limit.ix_; ++ix) {
ids_.emplace_back(ix);
}
}
@@ -380,11 +380,15 @@
};
DenseIdSet MakeDenseIdSet() const {
- return DenseIdSet(indirection_.size());
+ return DenseIdSet(Limit());
}
DenseIdMapping MakeDenseIdMapping() const {
- return DenseIdMapping(indirection_.size());
+ return DenseIdMapping(Limit());
+ }
+
+ Id Limit() const {
+ return Id(indirection_.size());
}
bool Is(Id id) const {
@@ -392,9 +396,9 @@
}
Id Allocate() {
- const auto ix = indirection_.size();
+ const auto id = Limit();
indirection_.emplace_back(Which::ABSENT, 0);
- return Id(ix);
+ return id;
}
template <typename Node, typename... Args>
