scripted-diff: shorten BLOCK_SERIALIZATION_HEADER_SIZE constant

Renames the constant to be less verbose and better reflect its purpose:
it represents the size of the storage header that precedes serialized block data on disk,
not to be confused with a block's own header.

-BEGIN VERIFY SCRIPT-
git grep -q "STORAGE_HEADER_BYTES" $(git ls-files) && echo "Error: Target name STORAGE_HEADER_BYTES already exists in the codebase" && exit 1
sed -i 's/BLOCK_SERIALIZATION_HEADER_SIZE/STORAGE_HEADER_BYTES/g' $(git grep -l 'BLOCK_SERIALIZATION_HEADER_SIZE')
-END VERIFY SCRIPT-

Author: l0rinc

src/node/blockstorage.cpp

@@ -949,7 +949,7 @@ bool BlockManager::WriteBlockUndo(const CBlockUndo& blockundo, BlockValidationSt
 
             // Write index header
             fileout << GetParams().MessageStart() << blockundo_size;
-            pos.nPos += BLOCK_SERIALIZATION_HEADER_SIZE;
+            pos.nPos += STORAGE_HEADER_BYTES;
             {
                 // Calculate checksum
                 HashWriter hasher{};
@@ -1087,7 +1087,7 @@ bool BlockManager::ReadRawBlock(std::vector<uint8_t>& block, const FlatFilePos&
 FlatFilePos BlockManager::WriteBlock(const CBlock& block, int nHeight)
 {
     const unsigned int block_size{static_cast<unsigned int>(GetSerializeSize(TX_WITH_WITNESS(block)))};
-    FlatFilePos pos{FindNextBlockPos(block_size + BLOCK_SERIALIZATION_HEADER_SIZE, nHeight, block.GetBlockTime())};
+    FlatFilePos pos{FindNextBlockPos(block_size + STORAGE_HEADER_BYTES, nHeight, block.GetBlockTime())};
     if (pos.IsNull()) {
         LogError("FindNextBlockPos failed");
         return FlatFilePos();
@@ -1101,7 +1101,7 @@ FlatFilePos BlockManager::WriteBlock(const CBlock& block, int nHeight)
 
     // Write index header
     fileout << GetParams().MessageStart() << block_size;
-    pos.nPos += BLOCK_SERIALIZATION_HEADER_SIZE;
+    pos.nPos += STORAGE_HEADER_BYTES;
     // Write block
     fileout << TX_WITH_WITNESS(block);
     return pos;

src/node/blockstorage.h

@@ -75,10 +75,10 @@ static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
 static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
 
 /** Size of header written by WriteBlock before a serialized CBlock (8 bytes) */
-static constexpr size_t BLOCK_SERIALIZATION_HEADER_SIZE{std::tuple_size_v<MessageStartChars> + sizeof(unsigned int)};
+static constexpr size_t STORAGE_HEADER_BYTES{std::tuple_size_v<MessageStartChars> + sizeof(unsigned int)};
 
 /** Total overhead when writing undo data: header (8 bytes) plus checksum (32 bytes) */
-static constexpr size_t UNDO_DATA_DISK_OVERHEAD{BLOCK_SERIALIZATION_HEADER_SIZE + uint256::size()};
+static constexpr size_t UNDO_DATA_DISK_OVERHEAD{STORAGE_HEADER_BYTES + uint256::size()};
 
 // Because validation code takes pointers to the map's CBlockIndex objects, if
 // we ever switch to another associative container, we need to either use a
@@ -164,7 +164,7 @@ class BlockManager
      * blockfile info, and checks if there is enough disk space to save the block.
      *
      * The nAddSize argument passed to this function should include not just the size of the serialized CBlock, but also the size of
-     * separator fields (BLOCK_SERIALIZATION_HEADER_SIZE).
+     * separator fields (STORAGE_HEADER_BYTES).
      */
     [[nodiscard]] FlatFilePos FindNextBlockPos(unsigned int nAddSize, unsigned int nHeight, uint64_t nTime);
     [[nodiscard]] bool FlushChainstateBlockFile(int tip_height);

src/test/blockmanager_tests.cpp

@@ -17,7 +17,7 @@
 #include <test/util/logging.h>
 #include <test/util/setup_common.h>
 
-using node::BLOCK_SERIALIZATION_HEADER_SIZE;
+using node::STORAGE_HEADER_BYTES;
 using node::BlockManager;
 using node::KernelNotifications;
 using node::MAX_BLOCKFILE_SIZE;
@@ -40,12 +40,12 @@ BOOST_AUTO_TEST_CASE(blockmanager_find_block_pos)
     };
     BlockManager blockman{*Assert(m_node.shutdown_signal), blockman_opts};
     // simulate adding a genesis block normally
-    BOOST_CHECK_EQUAL(blockman.WriteBlock(params->GenesisBlock(), 0).nPos, BLOCK_SERIALIZATION_HEADER_SIZE);
+    BOOST_CHECK_EQUAL(blockman.WriteBlock(params->GenesisBlock(), 0).nPos, STORAGE_HEADER_BYTES);
     // simulate what happens during reindex
     // simulate a well-formed genesis block being found at offset 8 in the blk00000.dat file
     // the block is found at offset 8 because there is an 8 byte serialization header
     // consisting of 4 magic bytes + 4 length bytes before each block in a well-formed blk file.
-    const FlatFilePos pos{0, BLOCK_SERIALIZATION_HEADER_SIZE};
+    const FlatFilePos pos{0, STORAGE_HEADER_BYTES};
     blockman.UpdateBlockInfo(params->GenesisBlock(), 0, pos);
     // now simulate what happens after reindex for the first new block processed
     // the actual block contents don't matter, just that it's a block.
@@ -54,7 +54,7 @@ BOOST_AUTO_TEST_CASE(blockmanager_find_block_pos)
     // 8 bytes (for serialization header) + 285 (for serialized genesis block) = 293
     // add another 8 bytes for the second block's serialization header and we get 293 + 8 = 301
     FlatFilePos actual{blockman.WriteBlock(params->GenesisBlock(), 1)};
-    BOOST_CHECK_EQUAL(actual.nPos, BLOCK_SERIALIZATION_HEADER_SIZE + ::GetSerializeSize(TX_WITH_WITNESS(params->GenesisBlock())) + BLOCK_SERIALIZATION_HEADER_SIZE);
+    BOOST_CHECK_EQUAL(actual.nPos, STORAGE_HEADER_BYTES + ::GetSerializeSize(TX_WITH_WITNESS(params->GenesisBlock())) + STORAGE_HEADER_BYTES);
 }
 
 BOOST_FIXTURE_TEST_CASE(blockmanager_scan_unlink_already_pruned_files, TestChain100Setup)
@@ -172,7 +172,7 @@ BOOST_AUTO_TEST_CASE(blockmanager_flush_block_file)
     FlatFilePos pos2{blockman.WriteBlock(block2, /*nHeight=*/2)};
 
     // Two blocks in the file
-    BOOST_CHECK_EQUAL(blockman.CalculateCurrentUsage(), (TEST_BLOCK_SIZE + BLOCK_SERIALIZATION_HEADER_SIZE) * 2);
+    BOOST_CHECK_EQUAL(blockman.CalculateCurrentUsage(), (TEST_BLOCK_SIZE + STORAGE_HEADER_BYTES) * 2);
 
     // First two blocks are written as expected
     // Errors are expected because block data is junk, thrown AFTER successful read
@@ -199,7 +199,7 @@ BOOST_AUTO_TEST_CASE(blockmanager_flush_block_file)
     // Metadata is updated...
     BOOST_CHECK_EQUAL(block_data->nBlocks, 3);
     // ...but there are still only two blocks in the file
-    BOOST_CHECK_EQUAL(blockman.CalculateCurrentUsage(), (TEST_BLOCK_SIZE + BLOCK_SERIALIZATION_HEADER_SIZE) * 2);
+    BOOST_CHECK_EQUAL(blockman.CalculateCurrentUsage(), (TEST_BLOCK_SIZE + STORAGE_HEADER_BYTES) * 2);
 
     // Block 2 was not overwritten:
     blockman.ReadBlock(read_block, pos2);