Add internal interfaces for prune locks

Including desc member of PruneLockInfo for a human-readable description

src/interfaces/chain.h

@@ -34,6 +34,7 @@ struct CBlockLocator;
 struct FeeCalculation;
 namespace node {
 struct NodeContext;
+struct PruneLockInfo;
 } // namespace node
 
 namespace interfaces {
@@ -148,6 +149,10 @@ public:
     //! pruned), and contains transactions.
     virtual bool haveBlockOnDisk(int height) = 0;
 
+    virtual bool pruneLockExists(const std::string& name) const = 0;
+    virtual void updatePruneLock(const std::string& name, const node::PruneLockInfo& lock_info) = 0;
+    virtual void deletePruneLock(const std::string& name) = 0;
+
     //! Get locator for the current chain tip.
     virtual CBlockLocator getTipLocator() = 0;
 

src/node/blockstorage.cpp

@@ -403,11 +403,21 @@ void BlockManager::FindFilesToPrune(
              min_block_to_prune, last_block_can_prune, count);
 }
 
+bool BlockManager::PruneLockExists(const std::string& name) const {
+    return m_prune_locks.count(name);
+}
+
 void BlockManager::UpdatePruneLock(const std::string& name, const PruneLockInfo& lock_info) {
     AssertLockHeld(::cs_main);
     m_prune_locks[name] = lock_info;
 }
 
+void BlockManager::DeletePruneLock(const std::string& name)
+{
+    AssertLockHeld(::cs_main);
+    m_prune_locks.erase(name);
+}
+
 CBlockIndex* BlockManager::InsertBlockIndex(const uint256& hash)
 {
     AssertLockHeld(cs_main);

src/node/blockstorage.h

@@ -92,6 +92,7 @@ struct CBlockIndexHeightOnlyComparator {
 };
 
 struct PruneLockInfo {
+    std::string desc; //! Arbitrary human-readable description of the lock purpose
     int height_first{std::numeric_limits<int>::max()}; //! Height of earliest block that should be kept and not pruned
     int height_last{std::numeric_limits<int>::max()}; //! Height of latest block that should be kept and not pruned
 };
@@ -409,8 +410,10 @@ public:
     //! Check whether the block associated with this index entry is pruned or not.
     bool IsBlockPruned(const CBlockIndex& block) const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
+    bool PruneLockExists(const std::string& name) const SHARED_LOCKS_REQUIRED(::cs_main);
     //! Create or update a prune lock identified by its name
     void UpdatePruneLock(const std::string& name, const PruneLockInfo& lock_info) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
+    void DeletePruneLock(const std::string& name) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /** Open a block file (blk?????.dat) */
     AutoFile OpenBlockFile(const FlatFilePos& pos, bool fReadOnly = false) const;

src/node/interfaces.cpp

@@ -554,6 +554,24 @@ public:
         const CBlockIndex* block{chainman().ActiveChain()[height]};
         return block && ((block->nStatus & BLOCK_HAVE_DATA) != 0) && block->nTx > 0;
     }
+    bool pruneLockExists(const std::string& name) const override
+    {
+        LOCK(cs_main);
+        auto& blockman = m_node.chainman->m_blockman;
+        return blockman.PruneLockExists(name);
+    }
+    void updatePruneLock(const std::string& name, const node::PruneLockInfo& lock_info) override
+    {
+        LOCK(cs_main);
+        auto& blockman = m_node.chainman->m_blockman;
+        blockman.UpdatePruneLock(name, lock_info);
+    }
+    void deletePruneLock(const std::string& name) override
+    {
+        LOCK(cs_main);
+        auto& blockman = m_node.chainman->m_blockman;
+        blockman.DeletePruneLock(name);
+    }
     CBlockLocator getTipLocator() override
     {
         LOCK(::cs_main);