Abstract EraseBlockData out of RewindBlockIndex

Note that the former 'else' branch in RewindBlockIndex is now dealt with more naturally inside the EraseBlockData call (by checking whether the parent needs to be re-added as candidate after deleting a child).
ninaris · Feb 24, 2019 · 9d6dcc5 · 9d6dcc5
1 parent f3f9c1d
commit 9d6dcc5
Showing 1 changed file with 40 additions and 27 deletions.
diff --git a/src/validation.cpp b/src/validation.cpp
@@ -206,8 +206,10 @@ class CChainState {
     CBlockIndex* FindMostWorkChain() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const CDiskBlockPos& pos, const Consensus::Params& consensusParams) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
-
     bool RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs, const CChainParams& params) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+
+    //! Mark a block as not having block data
+    void EraseBlockData(CBlockIndex* index) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 } g_chainstate;
 
 /**
@@ -4168,6 +4170,42 @@ bool ReplayBlocks(const CChainParams& params, CCoinsView* view) {
     return g_chainstate.ReplayBlocks(params, view);
 }
 
+//! Helper for CChainState::RewindBlockIndex
+void CChainState::EraseBlockData(CBlockIndex* index)
+{
+    AssertLockHeld(cs_main);
+    assert(!chainActive.Contains(index)); // Make sure this block isn't active
+
+    // Reduce validity
+    index->nStatus = std::min<unsigned int>(index->nStatus & BLOCK_VALID_MASK, BLOCK_VALID_TREE) | (index->nStatus & ~BLOCK_VALID_MASK);
+    // Remove have-data flags.
+    index->nStatus &= ~(BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO);
+    // Remove storage location.
+    index->nFile = 0;
+    index->nDataPos = 0;
+    index->nUndoPos = 0;
+    // Remove various other things
+    index->nTx = 0;
+    index->nChainTx = 0;
+    index->nSequenceId = 0;
+    // Make sure it gets written.
+    setDirtyBlockIndex.insert(index);
+    // Update indexes
+    setBlockIndexCandidates.erase(index);
+    std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> ret = mapBlocksUnlinked.equal_range(index->pprev);
+    while (ret.first != ret.second) {
+        if (ret.first->second == index) {
+            mapBlocksUnlinked.erase(ret.first++);
+        } else {
+            ++ret.first;
+        }
+    }
+    // Mark parent as eligible for main chain again
+    if (index->pprev && index->pprev->IsValid(BLOCK_VALID_TRANSACTIONS) && index->pprev->HaveTxsDownloaded()) {
+        setBlockIndexCandidates.insert(index->pprev);
+    }
+}
+
 bool CChainState::RewindBlockIndex(const CChainParams& params)
 {
     LOCK(cs_main);
@@ -4219,32 +4257,7 @@ bool CChainState::RewindBlockIndex(const CChainParams& params)
         // rewind all the way.  Blocks remaining on chainActive at this point
         // must not have their validity reduced.
         if (IsWitnessEnabled(pindexIter->pprev, params.GetConsensus()) && !(pindexIter->nStatus & BLOCK_OPT_WITNESS) && !chainActive.Contains(pindexIter)) {
-            // Reduce validity
-            pindexIter->nStatus = std::min<unsigned int>(pindexIter->nStatus & BLOCK_VALID_MASK, BLOCK_VALID_TREE) | (pindexIter->nStatus & ~BLOCK_VALID_MASK);
-            // Remove have-data flags.
-            pindexIter->nStatus &= ~(BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO);
-            // Remove storage location.
-            pindexIter->nFile = 0;
-            pindexIter->nDataPos = 0;
-            pindexIter->nUndoPos = 0;
-            // Remove various other things
-            pindexIter->nTx = 0;
-            pindexIter->nChainTx = 0;
-            pindexIter->nSequenceId = 0;
-            // Make sure it gets written.
-            setDirtyBlockIndex.insert(pindexIter);
-            // Update indexes
-            setBlockIndexCandidates.erase(pindexIter);
-            std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> ret = mapBlocksUnlinked.equal_range(pindexIter->pprev);
-            while (ret.first != ret.second) {
-                if (ret.first->second == pindexIter) {
-                    mapBlocksUnlinked.erase(ret.first++);
-                } else {
-                    ++ret.first;
-                }
-            }
-        } else if (pindexIter->IsValid(BLOCK_VALID_TRANSACTIONS) && pindexIter->HaveTxsDownloaded()) {
-            setBlockIndexCandidates.insert(pindexIter);
+            EraseBlockData(pindexIter);
         }
     }