Bitcoin Core  26.99.0
P2P Digital Currency
flatfile.h
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1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2020 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 
6 #ifndef BITCOIN_FLATFILE_H
7 #define BITCOIN_FLATFILE_H
8 
9 #include <string>
10 
11 #include <serialize.h>
12 #include <util/fs.h>
13 
15 {
16  int nFile{-1};
17  unsigned int nPos{0};
18 
20 
22 
23  FlatFilePos(int nFileIn, unsigned int nPosIn) :
24  nFile(nFileIn),
25  nPos(nPosIn)
26  {}
27 
28  friend bool operator==(const FlatFilePos &a, const FlatFilePos &b) {
29  return (a.nFile == b.nFile && a.nPos == b.nPos);
30  }
31 
32  friend bool operator!=(const FlatFilePos &a, const FlatFilePos &b) {
33  return !(a == b);
34  }
35 
36  bool IsNull() const { return (nFile == -1); }
37 
38  std::string ToString() const;
39 };
40 
46 {
47 private:
48  const fs::path m_dir;
49  const char* const m_prefix;
50  const size_t m_chunk_size;
51 
52 public:
60  FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size);
61 
63  fs::path FileName(const FlatFilePos& pos) const;
64 
66  FILE* Open(const FlatFilePos& pos, bool read_only = false);
67 
77  size_t Allocate(const FlatFilePos& pos, size_t add_size, bool& out_of_space);
78 
86  bool Flush(const FlatFilePos& pos, bool finalize = false);
87 };
88 
89 #endif // BITCOIN_FLATFILE_H
FlatFileSeq represents a sequence of numbered files storing raw data.
Definition: flatfile.h:46
fs::path FileName(const FlatFilePos &pos) const
Get the name of the file at the given position.
Definition: flatfile.cpp:28
const fs::path m_dir
Definition: flatfile.h:48
const size_t m_chunk_size
Definition: flatfile.h:50
size_t Allocate(const FlatFilePos &pos, size_t add_size, bool &out_of_space)
Allocate additional space in a file after the given starting position.
Definition: flatfile.cpp:55
bool Flush(const FlatFilePos &pos, bool finalize=false)
Commit a file to disk, and optionally truncate off extra pre-allocated bytes if final.
Definition: flatfile.cpp:81
const char *const m_prefix
Definition: flatfile.h:49
FlatFileSeq(fs::path dir, const char *prefix, size_t chunk_size)
Constructor.
Definition: flatfile.cpp:13
FILE * Open(const FlatFilePos &pos, bool read_only=false)
Open a handle to the file at the given position.
Definition: flatfile.cpp:33
Path class wrapper to block calls to the fs::path(std::string) implicit constructor and the fs::path:...
Definition: fs.h:33
const char * prefix
Definition: rest.cpp:1005
#define VARINT(obj)
Definition: serialize.h:513
#define VARINT_MODE(obj, mode)
Definition: serialize.h:512
@ NONNEGATIVE_SIGNED
#define READWRITE(...)
Definition: serialize.h:159
int nFile
Definition: flatfile.h:16
friend bool operator==(const FlatFilePos &a, const FlatFilePos &b)
Definition: flatfile.h:28
FlatFilePos(int nFileIn, unsigned int nPosIn)
Definition: flatfile.h:23
friend bool operator!=(const FlatFilePos &a, const FlatFilePos &b)
Definition: flatfile.h:32
std::string ToString() const
Definition: flatfile.cpp:23
unsigned int nPos
Definition: flatfile.h:17
SERIALIZE_METHODS(FlatFilePos, obj)
Definition: flatfile.h:19
FlatFilePos()
Definition: flatfile.h:21
bool IsNull() const
Definition: flatfile.h:36