validation: Extract basic block file logic into FlatFileSeq class.

CMakeLists.txt

@@ -186,6 +186,7 @@ set(SERVER_SOURCES
         ./src/chain.cpp
         ./src/checkpoints.cpp
         ./src/consensus/tx_verify.cpp
+        ./src/flatfile.cpp
         ./src/httprpc.cpp
         ./src/httpserver.cpp
         ./src/indirectmap.h

src/Makefile.am

@@ -190,6 +190,7 @@ BITCOIN_CORE_H = \
   pairresult.h \
   addressbook.h \
   wallet/db.h \
+  flatfile.h \
   fs.h \
   hash.h \
   httprpc.h \
@@ -326,6 +327,7 @@ libbitcoin_server_a_SOURCES = \
   checkpoints.cpp \
   consensus/params.cpp \
   consensus/tx_verify.cpp \
+  flatfile.cpp \
   consensus/zerocoin_verify.cpp \
   evo/deterministicmns.cpp \
   evo/evodb.cpp \

src/flatfile.cpp

@@ -0,0 +1,48 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <stdexcept>
+
+#include "flatfile.h"
+#include "logging.h"
+#include "tinyformat.h"
+#include "util.h"
+
+FlatFileSeq::FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size) :
+    m_dir(std::move(dir)),
+    m_prefix(prefix),
+    m_chunk_size(chunk_size)
+{
+    if (chunk_size == 0) {
+        throw std::invalid_argument("chunk_size must be positive");
+    }
+}
+
+fs::path FlatFileSeq::FileName(const CDiskBlockPos& pos) const
+{
+    return m_dir / strprintf("%s%05u.dat", m_prefix, pos.nFile);
+}
+
+FILE* FlatFileSeq::Open(const CDiskBlockPos& pos, bool fReadOnly)
+{
+    if (pos.IsNull())
+        return nullptr;
+    fs::path path = FileName(pos);
+    fs::create_directories(path.parent_path());
+    FILE* file = fsbridge::fopen(path, fReadOnly ? "rb": "rb+");
+    if (!file && !fReadOnly)
+        file = fsbridge::fopen(path, "wb+");
+    if (!file) {
+        LogPrintf("Unable to open file %s\n", path.string());
+        return nullptr;
+    }
+    if (pos.nPos) {
+        if (fseek(file, pos.nPos, SEEK_SET)) {
+            LogPrintf("Unable to seek to position %u of %s\n", pos.nPos, path.string());
+            fclose(file);
+            return nullptr;
+        }
+    }
+    return file;
+}

src/flatfile.h

@@ -0,0 +1,39 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_FLATFILE_H
+#define BITCOIN_FLATFILE_H
+
+#include "chain.h"
+#include "fs.h"
+
+/**
+ * FlatFileSeq represents a sequence of numbered files storing raw data. This class facilitates
+ * access to and efficient management of these files.
+ */
+class FlatFileSeq
+{
+private:
+    const fs::path m_dir;
+    const char* const m_prefix;
+    const size_t m_chunk_size;
+
+public:
+    /**
+     * Constructor
+     *
+     * @param dir The base directory that all files live in.
+     * @param prefix A short prefix given to all file names.
+     * @param chunk_size Disk space is pre-allocated in multiples of this amount.
+     */
+    FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size);
+
+    /** Get the name of the file at the given position. */
+    fs::path FileName(const CDiskBlockPos& pos) const;
+
+    /** Open a handle to the file at the given position. */
+    FILE* Open(const CDiskBlockPos& pos, bool fReadOnly = false);
+};
+
+#endif // BITCOIN_FLATFILE_H

src/init.cpp

@@ -689,7 +689,7 @@ void ThreadImport(const std::vector<fs::path>& vImportFiles)
         int nFile = 0;
         while (true) {
             CDiskBlockPos pos(nFile, 0);
-            if (!fs::exists(GetBlockPosFilename(pos, "blk")))
+            if (!fs::exists(GetBlockPosFilename(pos)))
                 break; // No block files left to reindex
             FILE* file = OpenBlockFile(pos, true);
             if (!file)

src/validation.cpp

@@ -24,6 +24,7 @@
 #include "consensus/zerocoin_verify.h"
 #include "evo/deterministicmns.h"
 #include "evo/specialtx.h"
+#include "flatfile.h"
 #include "fs.h"
 #include "guiinterface.h"
 #include "init.h"
@@ -34,13 +35,9 @@
 #include "masternode-payments.h"
 #include "masternode-sync.h"
 #include "masternodeman.h"
-#include "messagesigner.h"
-#include "netmessagemaker.h"
-#include "net_processing.h"
 #include "policy/policy.h"
 #include "pow.h"
 #include "reverse_iterate.h"
-#include "sapling/sapling_validation.h"
 #include "script/sigcache.h"
 #include "spork.h"
 #include "sporkdb.h"
@@ -224,6 +221,8 @@ enum FlushStateMode {
 
 // See definition for documentation
 bool static FlushStateToDisk(CValidationState &state, FlushStateMode mode);
+static FlatFileSeq BlockFileSeq();
+static FlatFileSeq UndoFileSeq();
 
 bool CheckFinalTx(const CTransactionRef& tx, int flags)
 {
@@ -3496,6 +3495,16 @@ FILE* OpenDiskFile(const CDiskBlockPos& pos, const char* prefix, bool fReadOnly)
     return file;
 }
 
+static FlatFileSeq BlockFileSeq()
+{
+    return FlatFileSeq(GetBlocksDir(), "blk", BLOCKFILE_CHUNK_SIZE);
+}
+
+static FlatFileSeq UndoFileSeq()
+{
+    return FlatFileSeq(GetBlocksDir(), "rev", UNDOFILE_CHUNK_SIZE);
+}
+
 FILE* OpenBlockFile(const CDiskBlockPos& pos, bool fReadOnly)
 {
     return OpenDiskFile(pos, "blk", fReadOnly);
@@ -3506,9 +3515,9 @@ FILE* OpenUndoFile(const CDiskBlockPos& pos, bool fReadOnly)
     return OpenDiskFile(pos, "rev", fReadOnly);
 }
 
-fs::path GetBlockPosFilename(const CDiskBlockPos& pos, const char* prefix)
+fs::path GetBlockPosFilename(const CDiskBlockPos &pos)
 {
-    return GetBlocksDir() / strprintf("%s%05u.dat", prefix, pos.nFile);
+    return BlockFileSeq().FileName(pos);
 }
 
 CBlockIndex* InsertBlockIndex(uint256 hash)

src/validation.h

@@ -178,7 +178,7 @@ FILE* OpenBlockFile(const CDiskBlockPos& pos, bool fReadOnly = false);
 /** Open an undo file (rev?????.dat) */
 FILE* OpenUndoFile(const CDiskBlockPos& pos, bool fReadOnly = false);
 /** Translation to a filesystem path */
-fs::path GetBlockPosFilename(const CDiskBlockPos& pos, const char* prefix);
+fs::path GetBlockPosFilename(const CDiskBlockPos &pos);
 /** Import blocks from an external file */
 bool LoadExternalBlockFile(FILE* fileIn, CDiskBlockPos* dbp = NULL);
 /** Ensures we have a genesis block in the block tree, possibly writing one to disk. */