validation: Move PruneOneBlockFile to BlockManager

[META] This is a pure refactor commit.

Move PruneBlockFile to BlockManager because:
1. PruneOneBlockFile only acts on BlockManager
2. Eliminates the need for callers (FindFilesToPrune{,Manual}) to have a
   reference to the larger ChainstateManager, just a reference to
   BlockManager is enough. See following commits.

src/validation.cpp

@@ -3912,12 +3912,12 @@ uint64_t CalculateCurrentUsage()
     return retval;
 }
 
-void ChainstateManager::PruneOneBlockFile(const int fileNumber)
+void BlockManager::PruneOneBlockFile(const int fileNumber)
 {
     AssertLockHeld(cs_main);
     LOCK(cs_LastBlockFile);
 
-    for (const auto& entry : m_blockman.m_block_index) {
+    for (const auto& entry : m_block_index) {
         CBlockIndex* pindex = entry.second;
         if (pindex->nFile == fileNumber) {
             pindex->nStatus &= ~BLOCK_HAVE_DATA;
@@ -3931,12 +3931,12 @@ void ChainstateManager::PruneOneBlockFile(const int fileNumber)
             // to be downloaded again in order to consider its chain, at which
             // point it would be considered as a candidate for
             // m_blocks_unlinked or setBlockIndexCandidates.
-            auto range = m_blockman.m_blocks_unlinked.equal_range(pindex->pprev);
+            auto range = m_blocks_unlinked.equal_range(pindex->pprev);
             while (range.first != range.second) {
                 std::multimap<CBlockIndex *, CBlockIndex *>::iterator _it = range.first;
                 range.first++;
                 if (_it->second == pindex) {
-                    m_blockman.m_blocks_unlinked.erase(_it);
+                    m_blocks_unlinked.erase(_it);
                 }
             }
         }
@@ -3972,7 +3972,7 @@ static void FindFilesToPruneManual(ChainstateManager& chainman, std::set<int>& s
     for (int fileNumber = 0; fileNumber < nLastBlockFile; fileNumber++) {
         if (vinfoBlockFile[fileNumber].nSize == 0 || vinfoBlockFile[fileNumber].nHeightLast > nLastBlockWeCanPrune)
             continue;
-        chainman.PruneOneBlockFile(fileNumber);
+        chainman.m_blockman.PruneOneBlockFile(fileNumber);
         setFilesToPrune.insert(fileNumber);
         count++;
     }
@@ -4047,7 +4047,7 @@ static void FindFilesToPrune(ChainstateManager& chainman, std::set<int>& setFile
             if (vinfoBlockFile[fileNumber].nHeightLast > nLastBlockWeCanPrune)
                 continue;
 
-            chainman.PruneOneBlockFile(fileNumber);
+            chainman.m_blockman.PruneOneBlockFile(fileNumber);
             // Queue up the files for removal
             setFilesToPrune.insert(fileNumber);
             nCurrentUsage -= nBytesToPrune;

src/validation.h

@@ -407,6 +407,9 @@ public:
     /** Create a new block index entry for a given block hash */
     CBlockIndex* InsertBlockIndex(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
+    //! Mark one block file as pruned (modify associated database entries)
+    void PruneOneBlockFile(const int fileNumber) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+
     /**
      * If a block header hasn't already been seen, call CheckBlockHeader on it, ensure
      * that it doesn't descend from an invalid block, and then add it to m_block_index.
@@ -903,9 +906,6 @@ public:
      */
     bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, BlockValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex = nullptr) LOCKS_EXCLUDED(cs_main);
 
-    //! Mark one block file as pruned (modify associated database entries)
-    void PruneOneBlockFile(const int fileNumber) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
-
     //! Load the block tree and coins database from disk, initializing state if we're running with -reindex
     bool LoadBlockIndex(const CChainParams& chainparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 

src/wallet/test/wallet_tests.cpp

@@ -126,7 +126,7 @@ BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup)
     // Prune the older block file.
     {
         LOCK(cs_main);
-        Assert(m_node.chainman)->PruneOneBlockFile(oldTip->GetBlockPos().nFile);
+        Assert(m_node.chainman)->m_blockman.PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     }
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});
 
@@ -152,7 +152,7 @@ BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup)
     // Prune the remaining block file.
     {
         LOCK(cs_main);
-        Assert(m_node.chainman)->PruneOneBlockFile(newTip->GetBlockPos().nFile);
+        Assert(m_node.chainman)->m_blockman.PruneOneBlockFile(newTip->GetBlockPos().nFile);
     }
     UnlinkPrunedFiles({newTip->GetBlockPos().nFile});
 
@@ -189,7 +189,7 @@ BOOST_FIXTURE_TEST_CASE(importmulti_rescan, TestChain100Setup)
     // Prune the older block file.
     {
         LOCK(cs_main);
-        Assert(m_node.chainman)->PruneOneBlockFile(oldTip->GetBlockPos().nFile);
+        Assert(m_node.chainman)->m_blockman.PruneOneBlockFile(oldTip->GetBlockPos().nFile);
     }
     UnlinkPrunedFiles({oldTip->GetBlockPos().nFile});