validation: Refactor OpenDiskFile into method on FlatFileSeq.

Author: jimpo

src/flatfile.cpp

@@ -5,6 +5,7 @@
 #include <stdexcept>
 
 #include <flatfile.h>
+#include <logging.h>
 #include <tinyformat.h>
 
 FlatFileSeq::FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size) :
@@ -21,3 +22,26 @@ 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

@@ -31,6 +31,9 @@ class FlatFileSeq
 
     /** 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/validation.cpp

@@ -3769,29 +3769,6 @@ static void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfte
            nLastBlockWeCanPrune, count);
 }
 
-static FILE* OpenDiskFile(const CDiskBlockPos &pos, const char *prefix, bool fReadOnly)
-{
-    if (pos.IsNull())
-        return nullptr;
-    fs::path path = GetBlockPosFilename(pos, prefix);
-    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;
-}
-
 static FlatFileSeq BlockFileSeq()
 {
     return FlatFileSeq(GetBlocksDir(), "blk", BLOCKFILE_CHUNK_SIZE);
@@ -3803,12 +3780,12 @@ static FlatFileSeq UndoFileSeq()
 }
 
 FILE* OpenBlockFile(const CDiskBlockPos &pos, bool fReadOnly) {
-    return OpenDiskFile(pos, "blk", fReadOnly);
+    return BlockFileSeq().Open(pos, fReadOnly);
 }
 
 /** Open an undo file (rev?????.dat) */
 static FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly) {
-    return OpenDiskFile(pos, "rev", fReadOnly);
+    return UndoFileSeq().Open(pos, fReadOnly);
 }
 
 fs::path GetBlockPosFilename(const CDiskBlockPos &pos)