Switch BlockMap to use an unordered_set under the hood

src/bench/rpc_blockchain.cpp

@@ -21,8 +21,7 @@ static void BlockToJsonVerbose(benchmark::Bench& bench)
     stream >> block;
 
     CBlockIndex blockindex;
-    const uint256 blockHash = block.GetHash();
-    blockindex.phashBlock = &blockHash;
+    blockindex.m_hash_block = block.GetHash();
     blockindex.nBits = 403014710;
 
     bench.run([&] {

src/chain.h

@@ -137,8 +137,8 @@ enum BlockStatus: uint32_t {
 class CBlockIndex
 {
 public:
-    //! pointer to the hash of the block, if any. Memory is owned by this CBlockIndex
-    const uint256* phashBlock{nullptr};
+    //! hash of the block. m_hash_block.IsNull() if there is not yet a hash
+    uint256 m_hash_block;
 
     //! pointer to the index of the predecessor of this block
     CBlockIndex* pprev{nullptr};
@@ -230,9 +230,9 @@ class CBlockIndex
         return block;
     }
 
-    uint256 GetBlockHash() const
+    const uint256& GetBlockHash() const
     {
-        return *phashBlock;
+        return m_hash_block;
     }
 
     /**

src/rpc/blockchain.cpp

@@ -1347,10 +1347,10 @@ static UniValue getchaintips(const JSONRPCRequest& request)
     std::set<const CBlockIndex*> setOrphans;
     std::set<const CBlockIndex*> setPrevs;
 
-    for (const std::pair<const uint256, CBlockIndex*>& item : chainman.BlockIndex()) {
-        if (!chainman.ActiveChain().Contains(item.second)) {
-            setOrphans.insert(item.second);
-            setPrevs.insert(item.second->pprev);
+    for (CBlockIndex* pindex : chainman.BlockIndex()) {
+        if (!chainman.ActiveChain().Contains(pindex)) {
+            setOrphans.insert(pindex);
+            setPrevs.insert(pindex->pprev);
         }
     }
 
@@ -1368,7 +1368,7 @@ static UniValue getchaintips(const JSONRPCRequest& request)
     for (const CBlockIndex* block : setTips) {
         UniValue obj(UniValue::VOBJ);
         obj.pushKV("height", block->nHeight);
-        obj.pushKV("hash", block->phashBlock->GetHex());
+        obj.pushKV("hash", block->m_hash_block.GetHex());
 
         const int branchLen = block->nHeight - chainman.ActiveChain().FindFork(block)->nHeight;
         obj.pushKV("branchlen", branchLen);

src/test/fuzz/chain.cpp

@@ -19,8 +19,6 @@ void test_one_input(const std::vector<uint8_t>& buffer)
         return;
     }
 
-    const uint256 zero{};
-    disk_block_index->phashBlock = &zero;
     (void)disk_block_index->GetBlockHash();
     (void)disk_block_index->GetBlockPos();
     (void)disk_block_index->GetBlockTime();
@@ -59,7 +57,6 @@ void test_one_input(const std::vector<uint8_t>& buffer)
     }
 
     CBlockIndex block_index{block_header};
-    block_index.phashBlock = &zero;
     (void)block_index.GetBlockHash();
     (void)block_index.ToString();
 }

src/test/miner_tests.cpp

@@ -377,7 +377,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     while (::ChainActive().Tip()->nHeight < 209999) {
         CBlockIndex* prev = ::ChainActive().Tip();
         CBlockIndex* next = new CBlockIndex();
-        next->phashBlock = new uint256(InsecureRand256());
+        next->m_hash_block = uint256(InsecureRand256());
         ::ChainstateActive().CoinsTip().SetBestBlock(next->GetBlockHash());
         next->pprev = prev;
         next->nHeight = prev->nHeight + 1;
@@ -389,7 +389,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     while (::ChainActive().Tip()->nHeight < 210000) {
         CBlockIndex* prev = ::ChainActive().Tip();
         CBlockIndex* next = new CBlockIndex();
-        next->phashBlock = new uint256(InsecureRand256());
+        next->m_hash_block = uint256(InsecureRand256());
         ::ChainstateActive().CoinsTip().SetBestBlock(next->GetBlockHash());
         next->pprev = prev;
         next->nHeight = prev->nHeight + 1;
@@ -421,7 +421,6 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
         CBlockIndex* del = ::ChainActive().Tip();
         ::ChainActive().SetTip(del->pprev);
         ::ChainstateActive().CoinsTip().SetBestBlock(del->pprev->GetBlockHash());
-        delete del->phashBlock;
         delete del;
     }
 

src/test/skiplist_tests.cpp

@@ -51,7 +51,7 @@ BOOST_AUTO_TEST_CASE(getlocator_test)
         vHashMain[i] = ArithToUint256(i); // Set the hash equal to the height, so we can quickly check the distances.
         vBlocksMain[i].nHeight = i;
         vBlocksMain[i].pprev = i ? &vBlocksMain[i - 1] : nullptr;
-        vBlocksMain[i].phashBlock = &vHashMain[i];
+        vBlocksMain[i].m_hash_block = vHashMain[i];
         vBlocksMain[i].BuildSkip();
         BOOST_CHECK_EQUAL((int)UintToArith256(vBlocksMain[i].GetBlockHash()).GetLow64(), vBlocksMain[i].nHeight);
         BOOST_CHECK(vBlocksMain[i].pprev == nullptr || vBlocksMain[i].nHeight == vBlocksMain[i].pprev->nHeight + 1);
@@ -64,7 +64,7 @@ BOOST_AUTO_TEST_CASE(getlocator_test)
         vHashSide[i] = ArithToUint256(i + 50000 + (arith_uint256(1) << 128)); // Add 1<<128 to the hashes, so GetLow64() still returns the height.
         vBlocksSide[i].nHeight = i + 50000;
         vBlocksSide[i].pprev = i ? &vBlocksSide[i - 1] : (vBlocksMain.data()+49999);
-        vBlocksSide[i].phashBlock = &vHashSide[i];
+        vBlocksSide[i].m_hash_block = vHashSide[i];
         vBlocksSide[i].BuildSkip();
         BOOST_CHECK_EQUAL((int)UintToArith256(vBlocksSide[i].GetBlockHash()).GetLow64(), vBlocksSide[i].nHeight);
         BOOST_CHECK(vBlocksSide[i].pprev == nullptr || vBlocksSide[i].nHeight == vBlocksSide[i].pprev->nHeight + 1);
@@ -106,7 +106,7 @@ BOOST_AUTO_TEST_CASE(findearliestatleast_test)
         vHashMain[i] = ArithToUint256(i); // Set the hash equal to the height
         vBlocksMain[i].nHeight = i;
         vBlocksMain[i].pprev = i ? &vBlocksMain[i - 1] : nullptr;
-        vBlocksMain[i].phashBlock = &vHashMain[i];
+        vBlocksMain[i].m_hash_block = vHashMain[i];
         vBlocksMain[i].BuildSkip();
         if (i < 10) {
             vBlocksMain[i].nTime = i;