txgraph: Add DoWork function (feature)

This can be called when the caller has time to spend now, and wants future operations
to be fast.

src/test/fuzz/txgraph.cpp

@@ -526,6 +526,10 @@ FUZZ_TARGET(txgraph)
                 // these here without making more calls to real, which could affect its internal
                 // state. A full comparison is done at the end.
                 break;
+            } else if (command-- == 0) {
+                // DoWork.
+                real->DoWork();
+                break;
             }
         }
     }

src/txgraph.cpp

@@ -428,6 +428,8 @@ public:
     void ApplyDependencies(int level) noexcept;
     /** Make a specified Cluster have quality ACCEPTABLE or OPTIMAL. */
     void MakeAcceptable(Cluster& cluster) noexcept;
+    /** Make all Clusters at the specified level have quality ACCEPTABLE or OPTIMAL. */
+    void MakeAllAcceptable(int level) noexcept;
 
     // Implementations for the public TxGraph interface.
 
@@ -436,6 +438,8 @@ public:
     void AddDependency(const Ref& parent, const Ref& child) noexcept final;
     void SetTransactionFee(const Ref&, int64_t fee) noexcept final;
 
+    void DoWork() noexcept final;
+
     void StartStaging() noexcept final;
     void CommitStaging() noexcept final;
     void AbortStaging() noexcept final;
@@ -1370,6 +1374,17 @@ void TxGraphImpl::MakeAcceptable(Cluster& cluster) noexcept
     }
 }
 
+void TxGraphImpl::MakeAllAcceptable(int level) noexcept
+{
+    ApplyDependencies(level);
+    auto& clusterset = GetClusterSet(level);
+    if (clusterset.m_oversized == true) return;
+    auto& queue = clusterset.m_clusters[int(QualityLevel::NEEDS_RELINEARIZE)];
+    while (!queue.empty()) {
+        MakeAcceptable(*queue.back().get());
+    }
+}
+
 Cluster::Cluster(TxGraphImpl& graph, const FeePerWeight& feerate, GraphIndex graph_index) noexcept
 {
     // Create a new transaction in the DepGraph, and remember its position in m_mapping.
@@ -1942,6 +1957,13 @@ void TxGraphImpl::SanityCheck() const
     }
 }
 
+void TxGraphImpl::DoWork() noexcept
+{
+    for (int level = 0; level <= GetTopLevel(); ++level) {
+        MakeAllAcceptable(level);
+    }
+}
+
 } // namespace
 
 TxGraph::Ref::~Ref()

src/txgraph.h

@@ -91,6 +91,11 @@ public:
      *  effect. */
     virtual void SetTransactionFee(const Ref& arg, int64_t fee) noexcept = 0;
 
+    /** TxGraph is internally lazy, and will not compute many things until they are needed.
+     *  Calling DoWork will compute everything now, so that future operations are fast. This can be
+     *  invoked while oversized. */
+    virtual void DoWork() noexcept = 0;
+
     /** Create a staging graph (which cannot exist already). This acts as if a full copy of
      *  the transaction graph is made, upon which further modifications are made. This copy can
      *  be inspected, and then either discarded, or the main graph can be replaced by it by