1// Copyright (c) 2009-2010 Satoshi Nakamoto
2// Copyright (c) 2009-present 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_UTIL_FS_HELPERS_H
7#define BITCOIN_UTIL_FS_HELPERS_H
8
9#include <util/fs.h>
10
11#include <cstdint>
12#include <cstdio>
13#include <ios>
14#include <limits>
15#include <optional>
16#include <string>
17
18#ifdef __APPLE__
19enum class FSType {
20    EXFAT,
21    OTHER,
22    ERROR
23};
24
25/**
26 * Detect filesystem type for a given path.
27 * Currently identifies exFAT filesystems which cause issues on macOS.
28 *
29 * @param[in] path The directory path to check
30 * @return FSType enum indicating the filesystem type
31 */
32FSType GetFilesystemType(const fs::path& path);
33#endif
34
35/**
36 * Ensure file contents are fully committed to disk, using a platform-specific
37 * feature analogous to fsync().
38 */
39bool FileCommit(FILE* file);
40
41/**
42 * Sync directory contents. This is required on some environments to ensure that
43 * newly created files are committed to disk.
44 */
45void DirectoryCommit(const fs::path& dirname);
46
47bool TruncateFile(FILE* file, uint64_t length);
48
49/**
50 * 64-bit-clean file positioning.
51 *
52 * The wrapper is necessary for Windows, because `long` is only 32 bits there,
53 * even in 64-bit builds (LLP64).
54 */
55inline int FileSeek64(FILE* file, int64_t offset, int origin)
56{
57#if defined(WIN32)
58    return _fseeki64(file, offset, origin);
59#else
60    return std::fseek(file, offset, origin);
61#endif
62}
63
64/**
65 * 64-bit-clean file positioning.
66 *
67 * The wrapper is necessary for Windows, because `long` is only 32 bits there,
68 * even in 64-bit builds (LLP64).
69 */
70inline int64_t FileTell64(FILE* file)
71{
72#if defined(WIN32)
73    return _ftelli64(file);
74#else
75    return std::ftell(file);
76#endif
77}
78
79/**
80 * Try to raise the file descriptor limit to the requested number.
81 *
82 * @param[in] min_fd  The requested minimum number of file descriptors.
83 * @returns           The actual file descriptor limit. It may be lower or
84 *                    higher than min_fd. Returns std::numeric_limits<int>::max()
85 *                    if the OS imposes no limit (RLIM_INFINITY).
86 *
87 */
88int RaiseFileDescriptorLimit(int min_fd);
89
90void AllocateFileRange(FILE* file, uint64_t offset, unsigned int length);
91
92/**
93 * Rename src to dest.
94 * @return true if the rename was successful.
95 */
96[[nodiscard]] bool RenameOver(fs::path src, fs::path dest);
97
98namespace util {
99enum class LockResult {
100    Success,
101    ErrorWrite,
102    ErrorLock,
103};
104[[nodiscard]] LockResult LockDirectory(const fs::path& directory, const fs::path& lockfile_name, bool probe_only = false);
105} // namespace util
106void UnlockDirectory(const fs::path& directory, const fs::path& lockfile_name);
107bool CheckDiskSpace(const fs::path& dir, uint64_t additional_bytes = 0);
108
109/** Get the size of a file by scanning it.
110 *
111 * @param[in] path The file path
112 * @param[in] max Stop seeking beyond this limit
113 * @return The file size or max
114 */
115std::streampos GetFileSize(const char* path, std::streamsize max = std::numeric_limits<std::streamsize>::max());
116
117/** Release all directory locks. This is used for unit testing only, at runtime
118 * the global destructor will take care of the locks.
119 */
120void ReleaseDirectoryLocks();
121
122bool TryCreateDirectories(const fs::path& p);
123fs::path GetDefaultDataDir();
124
125/** Convert fs::perms to symbolic string of the form 'rwxrwxrwx'
126 *
127 * @param[in] p the perms to be converted
128 * @return Symbolic permissions string
129 */
130std::string PermsToSymbolicString(fs::perms p);
131/** Interpret a custom permissions level string as fs::perms
132 *
133 * @param[in] s Permission level string
134 * @return Permissions as fs::perms
135 */
136std::optional<fs::perms> InterpretPermString(const std::string& s);
137
138/** Check if a directory is writable by creating a temporary file on it.
139 *
140 * @param[in] dir_path Path of the directory to test
141 * @return true if a temporary file could be created and removed, false otherwise.
142 * @throw std::runtime_error if dir_path is not a directory.
143 */
144bool IsDirWritable(const fs::path& dir_path);
145
146#ifdef WIN32
147fs::path GetSpecialFolderPath(int nFolder, bool fCreate = true);
148#endif
149
150#endif // BITCOIN_UTIL_FS_HELPERS_H
151