fs_helpers.cpp File Reference

#include <bitcoin-build-config.h>
#include <util/fs_helpers.h>
#include <random.h>
#include <sync.h>
#include <tinyformat.h>
#include <util/byte_units.h>
#include <util/fs.h>
#include <util/log.h>
#include <util/syserror.h>
#include <cerrno>
#include <fstream>
#include <map>
#include <memory>
#include <optional>
#include <stdexcept>
#include <string>
#include <system_error>
#include <utility>
#include <fcntl.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <unistd.h>

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Namespaces
namespace	util

Functions
static std::map< std::string, std::unique_ptr< fsbridge::FileLock > > dir_locks	GUARDED_BY (cs_dir_locks)
	A map that contains all the currently held directory locks. More...
LockResult	util::LockDirectory (const fs::path &directory, const fs::path &lockfile_name, bool probe_only)
void	UnlockDirectory (const fs::path &directory, const fs::path &lockfile_name)
void	ReleaseDirectoryLocks ()
	Release all directory locks. More...
bool	CheckDiskSpace (const fs::path &dir, uint64_t additional_bytes)
std::streampos	GetFileSize (const char *path, std::streamsize max)
	Get the size of a file by scanning it. More...
bool	FileCommit (FILE *file)
	Ensure file contents are fully committed to disk, using a platform-specific feature analogous to fsync(). More...
void	DirectoryCommit (const fs::path &dirname)
	Sync directory contents. More...
bool	TruncateFile (FILE *file, unsigned int length)
int	RaiseFileDescriptorLimit (int nMinFD)
	this function tries to raise the file descriptor limit to the requested number. More...
void	AllocateFileRange (FILE *file, unsigned int offset, unsigned int length)
	this function tries to make a particular range of a file allocated (corresponding to disk space) it is advisory, and the range specified in the arguments will never contain live data More...
bool	RenameOver (fs::path src, fs::path dest)
	Rename src to dest. More...
bool	TryCreateDirectories (const fs::path &p)
	Ignores exceptions thrown by create_directories if the requested directory exists. More...
std::string	PermsToSymbolicString (fs::perms p)
	Convert fs::perms to symbolic string of the form 'rwxrwxrwx'. More...
std::optional< fs::perms >	InterpretPermString (const std::string &s)
	Interpret a custom permissions level string as fs::perms. More...
bool	IsDirWritable (const fs::path &dir_path)
	Check if a directory is writable by creating a temporary file on it. More...

Variables
static GlobalMutex	cs_dir_locks
	Mutex to protect dir_locks. More...

Function Documentation

AllocateFileRange()

void AllocateFileRange	(	FILE *	file,
		unsigned int	offset,
		unsigned int	length
	)

this function tries to make a particular range of a file allocated (corresponding to disk space) it is advisory, and the range specified in the arguments will never contain live data

Definition at line 185 of file fs_helpers.cpp.

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CheckDiskSpace()

bool CheckDiskSpace	(	const fs::path &	dir,
		uint64_t	additional_bytes
	)

Definition at line 91 of file fs_helpers.cpp.

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DirectoryCommit()

void DirectoryCommit

(

const fs::path &

dirname

)

Sync directory contents.

This is required on some environments to ensure that newly created files are committed to disk.

Definition at line 137 of file fs_helpers.cpp.

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FileCommit()

bool FileCommit

(

FILE *

file

)

Ensure file contents are fully committed to disk, using a platform-specific feature analogous to fsync().

Definition at line 106 of file fs_helpers.cpp.

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GetFileSize()

std::streampos GetFileSize	(	const char *	path,
		std::streamsize	max = std::numeric_limits< std::streamsize >::max()
	)

Get the size of a file by scanning it.

Parameters

[in]	path	The file path
[in]	max	Stop seeking beyond this limit

Returns

The file size or max

Definition at line 99 of file fs_helpers.cpp.

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GUARDED_BY()

static std::map< std::string, std::unique_ptr< fsbridge::FileLock > > dir_locks GUARDED_BY ( cs_dir_locks  )

static

A map that contains all the currently held directory locks.

After successful locking, these will be held here until the global destructor cleans them up and thus automatically unlocks them, or ReleaseDirectoryLocks is called.

InterpretPermString()

std::optional< fs::perms > InterpretPermString

(

const std::string &

s

)

Interpret a custom permissions level string as fs::perms.

Parameters

[in]

s

Permission level string

Returns

Permissions as fs::perms

Definition at line 295 of file fs_helpers.cpp.

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IsDirWritable()

bool IsDirWritable

(

const fs::path &

dir_path

)

Check if a directory is writable by creating a temporary file on it.

Parameters

[in]

dir_path

Path of the directory to test

Returns

true if a temporary file could be created and removed, false otherwise.

Exceptions

std::runtime_error

if dir_path is not a directory.

Definition at line 311 of file fs_helpers.cpp.

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PermsToSymbolicString()

std::string PermsToSymbolicString

(

fs::perms

p

)

Convert fs::perms to symbolic string of the form 'rwxrwxrwx'.

Parameters

[in]

p

the perms to be converted

Returns

Symbolic permissions string

Definition at line 272 of file fs_helpers.cpp.

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RaiseFileDescriptorLimit()

int RaiseFileDescriptorLimit

(

int

nMinFD

)

this function tries to raise the file descriptor limit to the requested number.

It returns the actual file descriptor limit (which may be more or less than nMinFD)

Definition at line 161 of file fs_helpers.cpp.

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ReleaseDirectoryLocks()

void ReleaseDirectoryLocks

(

)

Release all directory locks.

This is used for unit testing only, at runtime the global destructor will take care of the locks.

Definition at line 85 of file fs_helpers.cpp.

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RenameOver()

bool RenameOver	(	fs::path	src,
		fs::path	dest
	)

Rename src to dest.

Returns

true if the rename was successful.

Definition at line 247 of file fs_helpers.cpp.

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TruncateFile()

bool TruncateFile	(	FILE *	file,
		unsigned int	length
	)

Definition at line 148 of file fs_helpers.cpp.

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TryCreateDirectories()

bool TryCreateDirectories

(

const fs::path &

p

)

Ignores exceptions thrown by create_directories if the requested directory exists.

Specifically handles case where path p exists, but it wasn't possible for the user to write to the parent directory.

Definition at line 259 of file fs_helpers.cpp.

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UnlockDirectory()

void UnlockDirectory	(	const fs::path &	directory,
		const fs::path &	lockfile_name
	)

Definition at line 79 of file fs_helpers.cpp.

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Variable Documentation

cs_dir_locks

GlobalMutex cs_dir_locks

static

Mutex to protect dir_locks.

Definition at line 43 of file fs_helpers.cpp.