Processor for working with filesystem I/O. More...

#include <file_processor.h>

Inheritance diagram for ugcs::vsm::File_processor:

Classes
struct	Already_exists_exception_dummy_struct
	File already exists. More...

class	Native_controller
	Interface for native I/O controller which manages I/O operations for all native handles. More...

struct	Not_found_exception_dummy_struct
	File not found. More...

struct	Permission_denied_exception_dummy_struct
	Permission denied. More...

class	Stream
	Stream class which represents opened file. More...

Public Types
typedef std::shared_ptr < File_processor >	Ptr
	Pointer type.

typedef std::weak_ptr < File_processor >	Weak_ptr
	Pointer type.

typedef ugcs::vsm::Derived_exception < Exception, Not_found_exception_dummy_struct >	Not_found_exception
	Definition of a new exception type. More...

typedef ugcs::vsm::Derived_exception < Exception, Permission_denied_exception_dummy_struct >	Permission_denied_exception
	Definition of a new exception type. More...

typedef ugcs::vsm::Derived_exception < Exception, Already_exists_exception_dummy_struct >	Already_exists_exception
	Definition of a new exception type. More...

Public Types inherited from ugcs::vsm::Request_context< is_processor >
typedef std::shared_ptr < Request_context >	Ptr
	Pointer type.

typedef std::weak_ptr < Request_context >	Weak_ptr
	Pointer type.

Public Types inherited from ugcs::vsm::Request_container
enum	Type { Type::NONE = 0x0, Type::PROCESSOR = 0x1, Type::COMPLETION_CONTEXT = 0x2, Type::ANY = PROCESSOR \| COMPLETION_CONTEXT, Type::TEMPORAL = 0x4, Type::TEMP_COMPLETION_CONTEXT = COMPLETION_CONTEXT \| TEMPORAL }
	Container type. More...

typedef std::shared_ptr < Request_container >	Ptr
	Pointer type.

typedef std::weak_ptr < Request_container >	Weak_ptr
	Pointer type.

Public Member Functions
	VSM_DEFINE_EXCEPTION (Exception)
	Base class for all File_processor exceptions. More...

Stream::Ref	Open (const std::string &name, const std::string &mode, bool maintain_pos=true)
	Open file. More...

Public Member Functions inherited from ugcs::vsm::Request_context< is_processor >
virtual Type	Get_type () const override
	Get this container type. More...

Public Member Functions inherited from ugcs::vsm::Request_container
	Request_container (const std::string &name, Request_waiter::Ptr waiter=Request_waiter::Create())
	Create container with default associated waiter. More...

bool	Check_type (Type mask)
	Check if the container type conforms the specified characteristic mask. More...

void	Submit_request (Request::Ptr request)
	Submit request to this container for further processing or notification handlers invocation. More...

void	Submit_request_locked (Request::Ptr request, Request_waiter::Locker locker)
	The same as Submit_request, but with previously acquired lock of the associated waiter. More...

int	Process_requests (int requests_limit=0)
	Process all currently queued requests. More...

int	Process_requests (std::unique_lock< std::mutex > &lock, int requests_limit=0)
	Process all currently queued requests. More...

void	Set_waiter (Request_waiter::Ptr waiter)
	Set request waiter associated with this container. More...

Request_waiter::Ptr	Get_waiter () const
	Get request waiter associated with this container. More...

const std::string &	Get_name ()
	Get the name of the container. More...

void	Enable ()
	Enable the container. More...

void	Disable ()
	Disable the container. More...

bool	Is_enabled () const
	Check if the container is currently enabled. More...

Static Public Member Functions
template<typename... Args>
static Ptr	Create (Args &&...args)
	Create an instance. More...

template<typename... Args>
static Ptr	Get_instance (Args &&...args)
	Get global or create new processor instance. More...

static FILE *	Fopen_utf8 (const std::string &name, const std::string &mode)
	Platform independent method for opening a standard library file handle providing an UTF-8 encoded path and mode. More...

static bool	Rename_utf8 (const std::string &old_name, const std::string &new_name)
	Platform independent method for renaming a file providing UTF-8 encoded paths. More...

static bool	Remove_utf8 (const std::string &name)
	Platform independent method for removing a file providing UTF-8 encoded path.

static int	Access_utf8 (const std::string &name, int mode)
	Platform independent method for checking file access permission providing UTF-8 file name. More...

Static Public Member Functions inherited from ugcs::vsm::Request_context< is_processor >
template<typename... Args>
static Ptr	Create (Args &&...args)
	Create an instance. More...

Static Public Member Functions inherited from ugcs::vsm::Request_container
template<typename... Args>
static Ptr	Create (Args &&...args)
	Create an instance. More...

Protected Member Functions
void	Register_stream (File_processor::Stream::Ptr)
	Register opened stream in a processor. More...

Protected Member Functions inherited from ugcs::vsm::Request_container
void	Processing_loop ()
	Request processing loop implementation. More...

void	Set_disabled ()
	Disable the container and notify its waiter. More...

virtual void	On_wait_and_process ()
	Called when default processing loop want to wait for work and process it. More...

Friends
class	Stream

Additional Inherited Members
Protected Attributes inherited from ugcs::vsm::Request_container
Request_waiter::Ptr	waiter
	Waiter associated with this container. More...

std::list< Request::Ptr >	request_queue
	Queue of pending requests, i.e. More...

Detailed Description

Processor for working with filesystem I/O.

It is mostly intended for working with special files such as mapped devices in asynchronous mode. It is not so useful for regular files so the user code can use <cstdio> functions for them (unless it does not need asynchronous file operations). Keep in mind that this processor provides asynchronous I/O but not concurrent. All operations for each stream are serialized and never executed in parallel. In case the client code issues concurrent requests it should be aware that file position can be unpredictably updated unless it is explicitly specified.

Member Typedef Documentation

typedef ugcs::vsm::Derived_exception< Exception , Already_exists_exception_dummy_struct> ugcs::vsm::File_processor::Already_exists_exception

Definition of a new exception type.

typedef ugcs::vsm::Derived_exception< Exception , Not_found_exception_dummy_struct> ugcs::vsm::File_processor::Not_found_exception

Definition of a new exception type.

typedef ugcs::vsm::Derived_exception< Exception , Permission_denied_exception_dummy_struct> ugcs::vsm::File_processor::Permission_denied_exception

Definition of a new exception type.

Member Function Documentation

static int ugcs::vsm::File_processor::Access_utf8	(	const std::string &	name,
		int	mode
	)

static

Platform independent method for checking file access permission providing UTF-8 file name.

Parameters

name	UTF-8 encoded file name.
mode	Mode as in standard access() method.

Returns: As in standard access() method.

template<typename... Args>

static Ptr ugcs::vsm::File_processor::Create ( Args &&... args )

inlinestatic

Create an instance.

static FILE* ugcs::vsm::File_processor::Fopen_utf8	(	const std::string &	name,
		const std::string &	mode
	)

static

Platform independent method for opening a standard library file handle providing an UTF-8 encoded path and mode.

Parameters

name	UTF-8 encoded file path to open.
mode	UTF-8 encoded access mode, see standard fopen() method.

Returns: Valid file handle on success, or nullptr on failure.

template<typename... Args>

static Ptr ugcs::vsm::File_processor::Get_instance ( Args &&... args )

inlinestatic

Get global or create new processor instance.

Stream::Ref ugcs::vsm::File_processor::Open	(	const std::string &	name,
		const std::string &	mode,
		bool	maintain_pos = `true`
	)

Open file.

Parameters

name	File path.
mode	Opening mode similar to the corresponding argument for fopen() function. It supports "x" specifier and do not support "a" and "b" specifiers. All files are opened in binary mode. NOTE: In addition "rx" combination is supported and means create file in read-only mode if it does not exist.
maintain_pos	Indicates whether file position maintenance is required. It should be "false" for devices which do not support seeking. In this case file offset for all I/O operations will be set to zero. In case it is "true" the returned file stream will maintain current position accordingly to the number of bytes read or written.

Returns: Created file stream.

Exceptions

Invalid_param_exception	if mode string is not valid.
Not_found_exception	if the specified path does not exist when it must exist based on provided opening mode.
Permission_denied_exception	if there is insufficient permissions for file creation.
Already_exists_exception	if new file creation requested ('x' specified in opening mode) but the file already exists.
Exception	in case of any other error returned by platform.

void ugcs::vsm::File_processor::Register_stream ( File_processor::Stream::Ptr )

protected

Register opened stream in a processor.

static bool ugcs::vsm::File_processor::Rename_utf8	(	const std::string &	old_name,
		const std::string &	new_name
	)

static

Platform independent method for renaming a file providing UTF-8 encoded paths.

Parameters

old_name	UTF-8 encoded old file name.
new_name	UTF-8 encoded new file name;

Returns: true on success, false on failure.

ugcs::vsm::File_processor::VSM_DEFINE_EXCEPTION ( Exception )

Base class for all File_processor exceptions.

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

file_processor.h

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Typedef Documentation

Member Function Documentation