Merge bitcoin/bitcoin#28458: refactor: Remove unused GetType() from CBufferedFile and CAutoFile

fa19c914f7fe7be127c0fb330b41ff7c091f40aa scripted-diff: Rename CBufferedFile to BufferedFile (MarcoFalke)
fa2f2413b87f5fc1e5c92bf510beebdcd0091714 Remove unused GetType() from CBufferedFile and CAutoFile (MarcoFalke)
5c2b3cd4b856f1bb536daaf7f576b1b1b42293ca dbwrapper: Use DataStream for batch operations (TheCharlatan)

Pull request description:

  This refactor is required for https://github.com/bitcoin/bitcoin/pull/28052 and https://github.com/bitcoin/bitcoin/pull/28451

  Thus, split it out.

ACKs for top commit:
  ajtowns:
    utACK fa19c914f7fe7be127c0fb330b41ff7c091f40aa
  TheCharlatan:
    ACK fa19c914f7fe7be127c0fb330b41ff7c091f40aa

Tree-SHA512: d9c232324702512e45fd73ec3e3170f1e8a8c8f9c49cb613a6b693a9f83358914155527ace2517a2cd626a0cedcada56ef70a2a7812edafb1888fd6765eebba2

10 files changed, 31 insertions, 38 deletions

diff --git a/src/bench/streams_findbyte.cpp b/src/bench/streams_findbyte.cpp
index 77f5940926..22b8f1b356 100644
--- a/src/bench/streams_findbyte.cpp
+++ b/src/bench/streams_findbyte.cpp
@@ -16,7 +16,7 @@ static void FindByte(benchmark::Bench& bench)
     data[file_size-1] = 1;
     fwrite(&data, sizeof(uint8_t), file_size, file);
     rewind(file);
-    CBufferedFile bf(file, /*nBufSize=*/file_size + 1, /*nRewindIn=*/file_size, 0, 0);
+    BufferedFile bf{file, /*nBufSize=*/file_size + 1, /*nRewindIn=*/file_size, 0};
 
     bench.run([&] {
         bf.SetPos(0);
diff --git a/src/dbwrapper.cpp b/src/dbwrapper.cpp
index c95937ba75..775496e21b 100644
--- a/src/dbwrapper.cpp
+++ b/src/dbwrapper.cpp
@@ -4,7 +4,6 @@
 
 #include <dbwrapper.h>
 
-#include <clientversion.h>
 #include <logging.h>
 #include <random.h>
 #include <serialize.h>
@@ -156,9 +155,9 @@ struct CDBBatch::WriteBatchImpl {
     leveldb::WriteBatch batch;
 };
 
-CDBBatch::CDBBatch(const CDBWrapper& _parent) : parent(_parent),
-                                                m_impl_batch{std::make_unique<CDBBatch::WriteBatchImpl>()},
-                                                ssValue(SER_DISK, CLIENT_VERSION){};
+CDBBatch::CDBBatch(const CDBWrapper& _parent)
+    : parent{_parent},
+      m_impl_batch{std::make_unique<CDBBatch::WriteBatchImpl>()} {};
 
 CDBBatch::~CDBBatch() = default;
 
@@ -168,7 +167,7 @@ void CDBBatch::Clear()
     size_estimate = 0;
 }
 
-void CDBBatch::WriteImpl(Span<const std::byte> key, CDataStream& ssValue)
+void CDBBatch::WriteImpl(Span<const std::byte> key, DataStream& ssValue)
 {
     leveldb::Slice slKey(CharCast(key.data()), key.size());
     ssValue.Xor(dbwrapper_private::GetObfuscateKey(parent));
diff --git a/src/dbwrapper.h b/src/dbwrapper.h
index 2f7448e878..63c2f99d2a 100644
--- a/src/dbwrapper.h
+++ b/src/dbwrapper.h
@@ -80,11 +80,11 @@ private:
     const std::unique_ptr<WriteBatchImpl> m_impl_batch;
 
     DataStream ssKey{};
-    CDataStream ssValue;
+    DataStream ssValue{};
 
     size_t size_estimate{0};
 
-    void WriteImpl(Span<const std::byte> key, CDataStream& ssValue);
+    void WriteImpl(Span<const std::byte> key, DataStream& ssValue);
     void EraseImpl(Span<const std::byte> key);
 
 public:
diff --git a/src/index/txindex.cpp b/src/index/txindex.cpp
index 3c9ec84e24..6b38e19d81 100644
--- a/src/index/txindex.cpp
+++ b/src/index/txindex.cpp
@@ -79,7 +79,7 @@ bool TxIndex::FindTx(const uint256& tx_hash, uint256& block_hash, CTransactionRe
         return false;
     }
 
-    CAutoFile file(m_chainstate->m_blockman.OpenBlockFile(postx, true), SER_DISK, CLIENT_VERSION);
+    CAutoFile file{m_chainstate->m_blockman.OpenBlockFile(postx, true), CLIENT_VERSION};
     if (file.IsNull()) {
         return error("%s: OpenBlockFile failed", __func__);
     }
diff --git a/src/kernel/mempool_persist.cpp b/src/kernel/mempool_persist.cpp
index 6be07da222..ff655c5ffa 100644
--- a/src/kernel/mempool_persist.cpp
+++ b/src/kernel/mempool_persist.cpp
@@ -41,7 +41,7 @@ bool LoadMempool(CTxMemPool& pool, const fs::path& load_path, Chainstate& active
     if (load_path.empty()) return false;
 
     FILE* filestr{opts.mockable_fopen_function(load_path, "rb")};
-    CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
+    CAutoFile file{filestr, CLIENT_VERSION};
     if (file.IsNull()) {
         LogPrintf("Failed to open mempool file from disk. Continuing anyway.\n");
         return false;
@@ -157,7 +157,7 @@ bool DumpMempool(const CTxMemPool& pool, const fs::path& dump_path, FopenFn mock
             return false;
         }
 
-        CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
+        CAutoFile file{filestr, CLIENT_VERSION};
 
         uint64_t version = MEMPOOL_DUMP_VERSION;
         file << version;
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 70f11be586..f43c5cbec5 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -822,7 +822,7 @@ bool BlockManager::FindUndoPos(BlockValidationState& state, int nFile, FlatFileP
 bool BlockManager::WriteBlockToDisk(const CBlock& block, FlatFilePos& pos) const
 {
     // Open history file to append
-    CAutoFile fileout(OpenBlockFile(pos), SER_DISK, CLIENT_VERSION);
+    CAutoFile fileout{OpenBlockFile(pos), CLIENT_VERSION};
     if (fileout.IsNull()) {
         return error("WriteBlockToDisk: OpenBlockFile failed");
     }
@@ -878,7 +878,7 @@ bool BlockManager::ReadBlockFromDisk(CBlock& block, const FlatFilePos& pos) cons
     block.SetNull();
 
     // Open history file to read
-    CAutoFile filein(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION);
+    CAutoFile filein{OpenBlockFile(pos, true), CLIENT_VERSION};
     if (filein.IsNull()) {
         return error("ReadBlockFromDisk: OpenBlockFile failed for %s", pos.ToString());
     }
diff --git a/src/streams.h b/src/streams.h
index 5ff952be76..f9a817c9b6 100644
--- a/src/streams.h
+++ b/src/streams.h
@@ -550,12 +550,10 @@ public:
 class CAutoFile : public AutoFile
 {
 private:
-    const int nType;
     const int nVersion;
 
 public:
-    explicit CAutoFile(std::FILE* file, int type, int version, std::vector<std::byte> data_xor = {}) : AutoFile{file, std::move(data_xor)}, nType{type}, nVersion{version} {}
-    int GetType() const          { return nType; }
+    explicit CAutoFile(std::FILE* file, int version, std::vector<std::byte> data_xor = {}) : AutoFile{file, std::move(data_xor)}, nVersion{version} {}
     int GetVersion() const       { return nVersion; }
 
     template<typename T>
@@ -579,10 +577,9 @@ public:
  *  Will automatically close the file when it goes out of scope if not null.
  *  If you need to close the file early, use file.fclose() instead of fclose(file).
  */
-class CBufferedFile
+class BufferedFile
 {
 private:
-    const int nType;
     const int nVersion;
 
     FILE *src;            //!< source file
@@ -603,7 +600,7 @@ private:
             return false;
         size_t nBytes = fread((void*)&vchBuf[pos], 1, readNow, src);
         if (nBytes == 0) {
-            throw std::ios_base::failure(feof(src) ? "CBufferedFile::Fill: end of file" : "CBufferedFile::Fill: fread failed");
+            throw std::ios_base::failure(feof(src) ? "BufferedFile::Fill: end of file" : "BufferedFile::Fill: fread failed");
         }
         nSrcPos += nBytes;
         return true;
@@ -632,25 +629,24 @@ private:
     }
 
 public:
-    CBufferedFile(FILE* fileIn, uint64_t nBufSize, uint64_t nRewindIn, int nTypeIn, int nVersionIn)
-        : nType(nTypeIn), nVersion(nVersionIn), nReadLimit(std::numeric_limits<uint64_t>::max()), nRewind(nRewindIn), vchBuf(nBufSize, std::byte{0})
+    BufferedFile(FILE* fileIn, uint64_t nBufSize, uint64_t nRewindIn, int nVersionIn)
+        : nVersion{nVersionIn}, nReadLimit{std::numeric_limits<uint64_t>::max()}, nRewind{nRewindIn}, vchBuf(nBufSize, std::byte{0})
     {
         if (nRewindIn >= nBufSize)
             throw std::ios_base::failure("Rewind limit must be less than buffer size");
         src = fileIn;
     }
 
-    ~CBufferedFile()
+    ~BufferedFile()
     {
         fclose();
     }
 
     // Disallow copies
-    CBufferedFile(const CBufferedFile&) = delete;
-    CBufferedFile& operator=(const CBufferedFile&) = delete;
+    BufferedFile(const BufferedFile&) = delete;
+    BufferedFile& operator=(const BufferedFile&) = delete;
 
     int GetVersion() const { return nVersion; }
-    int GetType() const { return nType; }
 
     void fclose()
     {
@@ -715,7 +711,7 @@ public:
     }
 
     template<typename T>
-    CBufferedFile& operator>>(T&& obj) {
+    BufferedFile& operator>>(T&& obj) {
         ::Unserialize(*this, obj);
         return (*this);
     }
diff --git a/src/test/fuzz/buffered_file.cpp b/src/test/fuzz/buffered_file.cpp
index 2f7ce60c7f..1116274e3d 100644
--- a/src/test/fuzz/buffered_file.cpp
+++ b/src/test/fuzz/buffered_file.cpp
@@ -18,10 +18,10 @@ FUZZ_TARGET(buffered_file)
 {
     FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
     FuzzedFileProvider fuzzed_file_provider = ConsumeFile(fuzzed_data_provider);
-    std::optional<CBufferedFile> opt_buffered_file;
+    std::optional<BufferedFile> opt_buffered_file;
     FILE* fuzzed_file = fuzzed_file_provider.open();
     try {
-        opt_buffered_file.emplace(fuzzed_file, fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096), fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096), fuzzed_data_provider.ConsumeIntegral<int>(), fuzzed_data_provider.ConsumeIntegral<int>());
+        opt_buffered_file.emplace(fuzzed_file, fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096), fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096), fuzzed_data_provider.ConsumeIntegral<int>());
     } catch (const std::ios_base::failure&) {
         if (fuzzed_file != nullptr) {
             fclose(fuzzed_file);
@@ -62,7 +62,6 @@ FUZZ_TARGET(buffered_file)
                 });
         }
         opt_buffered_file->GetPos();
-        opt_buffered_file->GetType();
         opt_buffered_file->GetVersion();
     }
 }
diff --git a/src/test/streams_tests.cpp b/src/test/streams_tests.cpp
index 589a2fd766..99740ee779 100644
--- a/src/test/streams_tests.cpp
+++ b/src/test/streams_tests.cpp
@@ -260,7 +260,7 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
     // The buffer size (second arg) must be greater than the rewind
     // amount (third arg).
     try {
-        CBufferedFile bfbad(file, 25, 25, 222, 333);
+        BufferedFile bfbad{file, 25, 25, 333};
         BOOST_CHECK(false);
     } catch (const std::exception& e) {
         BOOST_CHECK(strstr(e.what(),
@@ -268,11 +268,10 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
     }
 
     // The buffer is 25 bytes, allow rewinding 10 bytes.
-    CBufferedFile bf(file, 25, 10, 222, 333);
+    BufferedFile bf{file, 25, 10, 333};
     BOOST_CHECK(!bf.eof());
 
-    // These two members have no functional effect.
-    BOOST_CHECK_EQUAL(bf.GetType(), 222);
+    // This member has no functional effect.
     BOOST_CHECK_EQUAL(bf.GetVersion(), 333);
 
     uint8_t i;
@@ -357,7 +356,7 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
         BOOST_CHECK(false);
     } catch (const std::exception& e) {
         BOOST_CHECK(strstr(e.what(),
-                        "CBufferedFile::Fill: end of file") != nullptr);
+                        "BufferedFile::Fill: end of file") != nullptr);
     }
     // Attempting to read beyond the end sets the EOF indicator.
     BOOST_CHECK(bf.eof());
@@ -392,7 +391,7 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file_skip)
     rewind(file);
 
     // The buffer is 25 bytes, allow rewinding 10 bytes.
-    CBufferedFile bf(file, 25, 10, 222, 333);
+    BufferedFile bf{file, 25, 10, 333};
 
     uint8_t i;
     // This is like bf >> (7-byte-variable), in that it will cause data
@@ -446,7 +445,7 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file_rand)
 
         size_t bufSize = InsecureRandRange(300) + 1;
         size_t rewindSize = InsecureRandRange(bufSize);
-        CBufferedFile bf(file, bufSize, rewindSize, 222, 333);
+        BufferedFile bf{file, bufSize, rewindSize, 333};
         size_t currentPos = 0;
         size_t maxPos = 0;
         for (int step = 0; step < 100; ++step) {
diff --git a/src/validation.cpp b/src/validation.cpp
index 6e0addc877..894ead23f4 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -4588,8 +4588,8 @@ void ChainstateManager::LoadExternalBlockFile(
 
     int nLoaded = 0;
     try {
-        // This takes over fileIn and calls fclose() on it in the CBufferedFile destructor
-        CBufferedFile blkdat(fileIn, 2*MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE+8, SER_DISK, CLIENT_VERSION);
+        // This takes over fileIn and calls fclose() on it in the BufferedFile destructor
+        BufferedFile blkdat{fileIn, 2 * MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE + 8, CLIENT_VERSION};
         // nRewind indicates where to resume scanning in case something goes wrong,
         // such as a block fails to deserialize.
         uint64_t nRewind = blkdat.GetPos();