joedb::Abstract_Interpreted_File Class Reference

This class allows accessing a file in joedbi text format. More...

#include <joedb/journal/Interpreted_File.h>

Inheritance diagram for joedb::Abstract_Interpreted_File:

Collaboration diagram for joedb::Abstract_Interpreted_File:

Public Member Functions
	Abstract_Interpreted_File (Abstract_File &file)
int64_t	get_size () const override
	Get the size of the file, or -1 if it is unknown.
size_t	pread (char *data, size_t size, int64_t offset) const override
	Read a range of bytes.
void	pwrite (const char *buffer, size_t size, int64_t offset) override
	Write a range of bytes. Extend file size if necessary.
void	sync () override
	Write data durably (including file-size change)
void	shared_lock (int64_t start, int64_t size) override
	Lock a range of bytes for reading (prevents writes, not reads)
void	exclusive_lock (int64_t start, int64_t size) override
	Lock a range of bytes for writing (prevents both writes and reads)
void	unlock (int64_t start, int64_t size) noexcept override
	Remove a lock. The range should match the range of a corresponding lock.
Public Member Functions inherited from joedb::Abstract_File
	Abstract_File (Open_Mode mode)
bool	is_shared () const noexcept
bool	is_readonly () const noexcept
Open_Mode	get_mode () const noexcept
virtual void	datasync ()
	Write data durably (no file-size change)
void	exclusive_lock_tail ()
void	unlock_tail () noexcept
void	exclusive_lock_head ()
void	shared_lock_head ()
void	unlock_head () noexcept
std::string	read_blob (Blob blob) const
virtual void	copy_to (Abstract_File &destination, int64_t start, int64_t size) const
virtual bool	equal_to (const Abstract_File &destination, int64_t from, int64_t until) const
void	copy_to (Abstract_File &destination) const
virtual	~Abstract_File ()=default

Additional Inherited Members
Static Public Member Functions inherited from joedb::Abstract_File
static void	reading_past_end_of_file ()
Protected Member Functions inherited from joedb::Abstract_File
void	make_readonly ()
void	make_writable ()
Static Protected Attributes inherited from joedb::Abstract_File
static constexpr int64_t	last_position = (1ULL << 63) - 1

Detailed Description

It works by keeping a binary version of the file in memory, and keeping it in sync with the text file. An empty new line is written at each checkpoint. Opening the text file fails if it does not end with an empty new line.

Definition at line 24 of file Interpreted_File.h.

Constructor & Destructor Documentation

Abstract_Interpreted_File()

joedb::Abstract_Interpreted_File::Abstract_Interpreted_File

(

Abstract_File &

file

)

Definition at line 25 of file Interpreted_File.cpp.

Member Function Documentation

exclusive_lock()

void joedb::Abstract_Interpreted_File::exclusive_lock ( int64_t  start, int64_t  size  )

overridevirtual

Reimplemented from joedb::Abstract_File.

Definition at line 95 of file Interpreted_File.cpp.

get_size()

int64_t joedb::Abstract_Interpreted_File::get_size ( ) const

overridevirtual

Reimplemented from joedb::Abstract_File.

Definition at line 42 of file Interpreted_File.cpp.

pread()

size_t joedb::Abstract_Interpreted_File::pread ( char *  data, size_t  size, int64_t  offset  ) const

overridevirtual

For very large reads, the returned value may be less than size, even if the end of the file is not reached. It is assumed that small reads (such as the 41 bytes of the joedb header) will not be truncated. 0 is returned if the end of the file is reached.

Reimplemented from joedb::Abstract_File.

Definition at line 49 of file Interpreted_File.cpp.

pwrite()

void joedb::Abstract_Interpreted_File::pwrite ( const char *  data, size_t  size, int64_t  offset  )

overridevirtual

Reimplemented from joedb::Abstract_File.

Definition at line 61 of file Interpreted_File.cpp.

shared_lock()

void joedb::Abstract_Interpreted_File::shared_lock ( int64_t  start, int64_t  size  )

overridevirtual

Reimplemented from joedb::Abstract_File.

Definition at line 87 of file Interpreted_File.cpp.

sync()

void joedb::Abstract_Interpreted_File::sync ( )

overridevirtual

Reimplemented from joedb::Abstract_File.

Definition at line 80 of file Interpreted_File.cpp.

unlock()

void joedb::Abstract_Interpreted_File::unlock ( int64_t  start, int64_t  size  )

overridevirtualnoexcept

Reimplemented from joedb::Abstract_File.

Definition at line 103 of file Interpreted_File.cpp.

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The documentation for this class was generated from the following files:

• /home/rcoulom/repos/joedb/src/joedb/journal/Interpreted_File.h
• /home/rcoulom/repos/joedb/src/joedb/journal/Interpreted_File.cpp