ugcs::vsm::File_processor::Stream Class Reference

Stream class which represents opened file. More...

#include <file_processor.h>

Inheritance diagram for ugcs::vsm::File_processor::Stream:

Classes
class	Mode
	Mode for file opening. More...
class	Native_handle
	Interface for platform native file handle. More...

Public Types
enum	Lock_result { Lock_result::OK, Lock_result::BLOCKED, Lock_result::ERROR }
	Lock operation result. More...
typedef std::shared_ptr< Stream >	Ptr
	Pointer type.
typedef std::weak_ptr< Stream >	Weak_ptr
	Pointer type.
typedef Reference_guard < Stream::Ptr >	Ref
	Reference type. More...
typedef Callback_proxy< void, Io_result >	Lock_handler
	Default prototype for lock operation completion handler. More...
Public Types inherited from ugcs::vsm::Io_stream
enum	State { State::CLOSED, State::OPENING, State::OPENING_PASSIVE, State::OPENED }
	Stream states. More...
enum	Type {   FILE, SERIAL, ANDROID_SERIAL, TCP,   UDP, UDP_MULTICAST, CAN, UNDEFINED }
	Stream types. More...
typedef std::shared_ptr < Io_stream >	Ptr
	Pointer type.
typedef std::weak_ptr< Io_stream >	Weak_ptr
	Pointer type.
typedef Reference_guard < Io_stream::Ptr >	Ref
	Guard object. More...
typedef int64_t	Offset
	Offset for read/write operations. More...
typedef Callback_proxy< void, Io_result >	Write_handler
	Default prototype for write operation completion handler. More...
typedef Callback_proxy< void, Io_buffer::Ptr, Io_result >	Read_handler
	Default prototype for read operation completion handler. More...
typedef Callback_proxy< void >	Close_handler
	Default prototype for close operation completion handler. More...

Public Member Functions
	Stream (File_processor::Ptr processor, const std::string &path, Mode mode, bool maintain_pos, Native_handle::Unique_ptr &&native_handle)
	Construct file stream. More...
Offset	Get_current_pos () const
	Get current position in the stream. More...
Offset	Seek (Offset pos, bool is_relative=false)
	Set new current position for the stream. More...
Operation_waiter	Lock (Lock_handler completion_handler, Request_completion_context::Ptr comp_ctx=Request_temp_completion_context::Create(), bool lock=true)
	Put an exclusive lock on file. More...
Operation_waiter	Unlock (Lock_handler completion_handler=Make_dummy_callback< void, Io_result >(), Request_completion_context::Ptr comp_ctx=Request_temp_completion_context::Create())
	Remove lock from file. More...
Public Member Functions inherited from ugcs::vsm::Io_stream
void	Add_ref ()
	Add reference to the stream. More...
void	Release_ref ()
	Release reference for the stream. More...
Operation_waiter	Write (Io_buffer::Ptr buffer, Offset offset, Write_handler completion_handler=Make_dummy_callback< void, Io_result >(), Request_completion_context::Ptr comp_ctx=Request_temp_completion_context::Create())
	Initiate write operation. More...
Operation_waiter	Write (Io_buffer::Ptr buffer, Write_handler completion_handler=Make_dummy_callback< void, Io_result >(), Request_completion_context::Ptr comp_ctx=Request_temp_completion_context::Create())
	Initiate write operation. More...
Operation_waiter	Read (size_t max_to_read, size_t min_to_read, Offset offset, Read_handler completion_handler=Make_dummy_callback< void, Io_buffer::Ptr, Io_result >(), Request_completion_context::Ptr comp_ctx=Request_temp_completion_context::Create())
	Initiate read operation. More...
Operation_waiter	Read (size_t max_to_read, size_t min_to_read=1, Read_handler completion_handler=Make_dummy_callback< void, Io_buffer::Ptr, Io_result >(), Request_completion_context::Ptr comp_ctx=Request_temp_completion_context::Create())
	Initiate read operation. More...
Operation_waiter	Close (Close_handler completion_handler=Make_dummy_callback< void >(), Request_completion_context::Ptr comp_ctx=Request_temp_completion_context::Create())
	Initiate stream close operation. More...
	Io_stream (const Io_stream &)=delete
	There is no sense in copying the stream. More...
	Io_stream (Type type)
	Constructor.
State	Get_state () const
	Get current state of the stream. More...
bool	Is_closed () const
	Checks if stream is closed or not. More...
std::string	Get_name () const
	Get human readable stream name. More...
Type	Get_type () const

Static Public Member Functions
template<typename... Args>
static Ptr	Create (Args &&...args)
	Create an instance. More...
Static Public Member Functions inherited from ugcs::vsm::Io_stream
template<typename... Args>
static Ptr	Create (Args &&...args)
	Create an instance. More...
static const char *	Io_result_as_char (const Io_result res)
	Convert Io_result value to character string. More...

Friends
class	File_processor
class	Native_handle

Additional Inherited Members
Static Public Attributes inherited from ugcs::vsm::Io_stream
static const Offset	OFFSET_NONE
	Offset special value which indicates that the offset value is not specified.
static const Offset	OFFSET_END
	Offset special value which indicates that the offset value corresponds to the stream end (e.g. More...
Protected Member Functions inherited from ugcs::vsm::Io_stream
void	Set_name (const std::string &)
	Set the stream name. More...
Protected Attributes inherited from ugcs::vsm::Io_stream
Type	stream_type
State	state = State::CLOSED
	Current state of the stream. More...
std::atomic_int	ref_count = { 0 }
	Reference counter. More...

Detailed Description

Stream class which represents opened file.

Member Typedef Documentation

typedef Callback_proxy<void, Io_result> ugcs::vsm::File_processor::Stream::Lock_handler

Default prototype for lock operation completion handler.

typedef Reference_guard<Stream::Ptr> ugcs::vsm::File_processor::Stream::Ref

Reference type.

Member Enumeration Documentation

enum ugcs::vsm::File_processor::Stream::Lock_result

strong

Lock operation result.

Enumerator
OK	Lock acquired.
BLOCKED	Lock owned by other stream.
ERROR	Error while locking.

Constructor & Destructor Documentation

ugcs::vsm::File_processor::Stream::Stream	(	File_processor::Ptr	processor,
		const std::string &	path,
		Mode	mode,
		bool	maintain_pos,
		Native_handle::Unique_ptr &&	native_handle
	)

Construct file stream.

Parameters

processor	Associated processor instance.
path	File path.
mode	Parsed file opening mode.
maintain_pos	Indicates whether file position maintenance is required. See File_processor::Open.
native_handle	Native handle to be used for stream operations.

Member Function Documentation

template<typename... Args>

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

inlinestatic

Create an instance.

Offset ugcs::vsm::File_processor::Stream::Get_current_pos ( ) const

inline

Get current position in the stream.

This method has meaning only file position is maintained by the stream.

Returns

Current position in the stream.

Operation_waiter ugcs::vsm::File_processor::Stream::Lock	(	Lock_handler	completion_handler,
		Request_completion_context::Ptr	comp_ctx = Request_temp_completion_context::Create(),
		bool	lock = true
	)

Put an exclusive lock on file.

On Windows it's mandatory lock on first byte of file implemented via LockFileEx() call. On Linux it's advisory lock implemented via flock() call. File can be unlocked via Unlock() call or via Close().

NOTE: No double lock supported: Stream can be locked again only after successful Unlock() operation. I.e. subsequent Lock on the same stream will fail until Unlock() is called and unlock completion is delivered.

Parameters

completion_handler	User specified completion handler.
comp_ctx	User specified completion context.
lock	true: lock operation, false: unlock operation.

Returns

Operation_waiter which can be used to wait, or set timeout or cancel for pending lock operation.

Offset ugcs::vsm::File_processor::Stream::Seek	(	Offset	pos,
		bool	is_relative = false
	)

Set new current position for the stream.

In case the stream does not maintain the current position, this operation does nothing. Be aware that seeking result is undefined if read or write operation is in progress.

Parameters

pos	New current position value.
is_relative	Indicates that position is set relatively to the current position value.

Returns

New absolute current position value.

Exceptions

Invalid_param_exception

if the resulted position is invalid (e.g. negative).

Operation_waiter ugcs::vsm::File_processor::Stream::Unlock ( Lock_handler  completion_handler = Make_dummy_callback<void, Io_result>(), Request_completion_context::Ptr  comp_ctx = Request_temp_completion_context::Create()  )

inline

Remove lock from file.

On Windows it unlocks on first byte of file implemented via UnlockFile() call. On Linux it is implemented via flock() call.

Parameters

completion_handler	User specified completion handler.
comp_ctx	User specified completion context.

Returns

Operation_waiter which can be used to wait for pending unlock operation to complete.

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

• file_processor.h