foobar2000_io::file

#include <filesystem.h>

Inheritance diagram for foobar2000_io::file:

Public Types
enum	t_seek_mode { seek_from_beginning = 0, seek_from_current = 1, seek_from_eof = 2 }
Public Types inherited from service_base
typedef service_base	t_interface

Public Member Functions
virtual bool	can_seek ()=0
void	ensure_local ()
void	ensure_seekable ()
	FB2K_MAKE_SERVICE_INTERFACE (file, service_base)
virtual bool	get_content_type (pfc::string_base &p_out)=0
virtual t_filesize	get_position (abort_callback &p_abort)=0
t_filesize	get_remaining (abort_callback &p_abort)
virtual t_filesize	get_size (abort_callback &p_abort)=0
t_filesize	get_size_ex (abort_callback &p_abort)
t_filestats	get_stats (abort_callback &p_abort)
virtual t_filetimestamp	get_timestamp (abort_callback &p_abort)
bool	is_eof (abort_callback &p_abort)
virtual bool	is_in_memory ()
virtual bool	is_remote ()=0
virtual void	on_idle (abort_callback &p_abort)
void	probe_remaining (t_filesize bytes, abort_callback &p_abort)
virtual void	reopen (abort_callback &p_abort)=0
virtual void	resize (t_filesize p_size, abort_callback &p_abort)=0
virtual void	seek (t_filesize p_position, abort_callback &p_abort)=0
virtual void	seek_ex (t_sfilesize p_position, t_seek_mode p_mode, abort_callback &p_abort)
void	seek_probe (t_filesize p_position, abort_callback &p_abort)
void	set_eof (abort_callback &p_abort)
t_filesize	skip (t_filesize p_bytes, abort_callback &p_abort)
t_filesize	skip_seek (t_filesize p_bytes, abort_callback &p_abort)
void	truncate (t_filesize p_position, abort_callback &p_abort)
Public Member Functions inherited from service_base
template<typename outPtr_t >
bool	cast (outPtr_t &outPtr)
virtual int	service_add_ref ()=0 throw ()
virtual bool	service_query (service_ptr_t< service_base > &p_out, const GUID &p_guid)
template<class T >
bool	service_query_t (service_ptr_t< T > &p_out)
virtual int	service_release ()=0 throw ()
Public Member Functions inherited from foobar2000_io::stream_reader
virtual t_size	read (void *p_buffer, t_size p_bytes, abort_callback &p_abort)=0
template<typename T >
void	read_bendian_t (T &p_object, abort_callback &p_abort)
template<typename T >
void	read_lendian_t (T &p_object, abort_callback &p_abort)
virtual void	read_object (void *p_buffer, t_size p_bytes, abort_callback &p_abort)
template<typename T >
void	read_object_t (T &p_object, abort_callback &p_abort)
void	read_string (pfc::string_base &p_out, abort_callback &p_abort)
pfc::string	read_string (abort_callback &p_abort)
void	read_string_ex (pfc::string_base &p_out, t_size p_bytes, abort_callback &p_abort)
pfc::string	read_string_ex (t_size p_len, abort_callback &p_abort)
void	read_string_nullterm (pfc::string_base &out, abort_callback &abort)
void	read_string_raw (pfc::string_base &p_out, abort_callback &p_abort)
template<typename t_outArray >
void	read_till_eof (t_outArray &out, abort_callback &abort)
virtual void	skip_object (t_filesize p_bytes, abort_callback &p_abort)
t_filesize	skip_till_eof (abort_callback &abort)
Public Member Functions inherited from foobar2000_io::stream_writer
virtual void	write (const void *p_buffer, t_size p_bytes, abort_callback &p_abort)=0
template<typename T >
void	write_bendian_t (const T &p_object, abort_callback &p_abort)
template<typename T >
void	write_lendian_t (const T &p_object, abort_callback &p_abort)
void	write_object (const void *p_buffer, t_size p_bytes, abort_callback &p_abort)
template<typename T >
void	write_object_t (const T &p_object, abort_callback &p_abort)
void	write_string (const char *p_string, abort_callback &p_abort)
void	write_string (const char *p_string, t_size p_len, abort_callback &p_abort)
template<typename T >
void	write_string (const T &val, abort_callback &p_abort)
void	write_string_nullterm (const char *p_string, abort_callback &p_abort)
void	write_string_raw (const char *p_string, abort_callback &p_abort)

Static Public Member Functions
static t_filesize	g_transfer (stream_reader *src, stream_writer *dst, t_filesize bytes, abort_callback &p_abort)
static t_filesize	g_transfer (service_ptr_t< file > p_src, service_ptr_t< file > p_dst, t_filesize p_bytes, abort_callback &p_abort)
static void	g_transfer_file (const service_ptr_t< file > &p_from, const service_ptr_t< file > &p_to, abort_callback &p_abort)
static void	g_transfer_object (stream_reader *src, stream_writer *dst, t_filesize bytes, abort_callback &p_abort)
static void	g_transfer_object (service_ptr_t< file > p_src, service_ptr_t< file > p_dst, t_filesize p_bytes, abort_callback &p_abort)

Additional Inherited Members
Protected Member Functions inherited from service_base
	service_base ()
	~service_base ()
Protected Member Functions inherited from foobar2000_io::stream_reader
	stream_reader ()
	~stream_reader ()
Protected Member Functions inherited from foobar2000_io::stream_writer
	stream_writer ()
	~stream_writer ()

Detailed Description

A class providing abstraction for an open file object, with reading/writing/seeking methods. See also: stream_reader, stream_writer (which it inherits read/write methods from).
Error handling: all methods may throw exception_io or one of derivatives on failure; exception_aborted when abort_callback is signaled.

Definition at line 208 of file filesystem.h.

Member Enumeration Documentation

enum foobar2000_io::file::t_seek_mode

Seeking mode constants. Note: these are purposedly defined to same values as standard C SEEK_* constants.

Enumerator
seek_from_beginning	Seek relative to beginning of file (same as seeking to absolute offset).
seek_from_current	Seek relative to current position.
seek_from_eof	Seek relative to end of file.

Definition at line 212 of file filesystem.h.

                         {
            seek_from_beginning = 0,
            seek_from_current = 1,
            seek_from_eof = 2,
        };

Member Function Documentation

virtual bool foobar2000_io::file::can_seek ( )

pure virtual

Returns whether the file is seekable or not. If can_seek() returns false, all seek() or seek_ex() calls will fail; reopen() is still usable on nonseekable streams.

void file::ensure_local

(

)

Helper; throws exception_io_object_is_remote if the file is remote.

Definition at line 839 of file filesystem.cpp.

                        {
    if (is_remote()) throw exception_io_object_is_remote();
}

void file::ensure_seekable

(

)

Helper; throws exception_io_object_not_seekable if file is not seekable.

Definition at line 843 of file filesystem.cpp.

                           {
    if (!can_seek()) throw exception_io_object_not_seekable();
}

foobar2000_io::file::FB2K_MAKE_SERVICE_INTERFACE	(	file	,
		service_base
	)

static t_filesize foobar2000_io::file::g_transfer ( stream_reader *  src, stream_writer *  dst, t_filesize  bytes, abort_callback &  p_abort  )

static

Helper; transfers specified number of bytes between streams.

Returns

number of bytes actually transferred. May be less than requested if e.g. EOF is reached.

t_filesize file::g_transfer ( service_ptr_t< file >  p_src, service_ptr_t< file >  p_dst, t_filesize  p_bytes, abort_callback &  p_abort  )

static

Helper; improved performance over g_transfer on streams (avoids disk fragmentation when transferring large blocks).

Definition at line 868 of file filesystem.cpp.

                                                                                                                           {
    return g_transfer(pfc::implicit_cast<stream_reader*>(p_src.get_ptr()),pfc::implicit_cast<stream_writer*>(p_dst.get_ptr()),p_bytes,p_abort);
}

void file::g_transfer_file ( const service_ptr_t< file > &  p_from, const service_ptr_t< file > &  p_to, abort_callback &  p_abort  )

static

Helper; transfers entire file content from one file to another, erasing previous content.

Definition at line 625 of file filesystem.cpp.

                                                                                                                       {
    t_filesize length = p_from->get_size(p_abort);
    p_from->reopen( p_abort );
//  p_from->seek(0,p_abort);
    p_to->seek(0,p_abort);
    p_to->set_eof(p_abort);
    if (length == filesize_invalid) {
        g_transfer(p_from, p_to, ~0, p_abort);
    } else if (length > 0) {
        g_transfer_object(p_from,p_to,length,p_abort);
    }
}

static void foobar2000_io::file::g_transfer_object ( stream_reader *  src, stream_writer *  dst, t_filesize  bytes, abort_callback &  p_abort  )

static

Helper; transfers specified number of bytes between streams. Throws exception if requested number of bytes could not be read (EOF).

void file::g_transfer_object ( service_ptr_t< file >  p_src, service_ptr_t< file >  p_dst, t_filesize  p_bytes, abort_callback &  p_abort  )

static

Helper; improved performance over g_transfer_file on streams (avoids disk fragmentation when transferring large blocks).

Definition at line 872 of file filesystem.cpp.

                                                                                                                            {
    if (p_bytes > 1024) /* don't bother on small objects */ 
    {
        t_filesize srcFileSize = p_src->get_size(p_abort); // detect truncation
        if (srcFileSize != ~0) {
            t_filesize remaining = srcFileSize - p_src->get_position(p_abort);
            if (p_bytes > remaining) throw exception_io_data_truncation();
        }

        t_filesize oldsize = p_dst->get_size(p_abort); // pre-resize the target file
        if (oldsize != filesize_invalid) {
            t_filesize newpos = p_dst->get_position(p_abort) + p_bytes;
            if (newpos > oldsize) p_dst->resize(newpos ,p_abort);
        }

    }
    g_transfer_object(pfc::implicit_cast<stream_reader*>(p_src.get_ptr()),pfc::implicit_cast<stream_writer*>(p_dst.get_ptr()),p_bytes,p_abort);
}

virtual bool foobar2000_io::file::get_content_type ( pfc::string_base &  p_out )

pure virtual

Retrieves mime type of the file.

Parameters

p_out

Receives content type string on success.

virtual t_filesize foobar2000_io::file::get_position ( abort_callback &  p_abort )

pure virtual

Retrieves read/write cursor position in the file. In case of non-seekable stream, this should return number of bytes read so far since open/reopen call.

Parameters

p_abort

abort_callback object signaling user aborting the operation.

Returns

Read/write cursor position

t_filesize file::get_remaining

(

abort_callback &

p_abort

)

Helper; retrieves amount of bytes between read/write cursor position and end of file. Fails when length can't be determined.

Definition at line 852 of file filesystem.cpp.

                                                       {
    t_filesize length = get_size_ex(p_abort);
    t_filesize position = get_position(p_abort);
    pfc::dynamic_assert(position <= length);
    return length - position;
}

virtual t_filesize foobar2000_io::file::get_size ( abort_callback &  p_abort )

pure virtual

Retrieves size of the file.

Parameters

p_abort

abort_callback object signaling user aborting the operation.

Returns

File size on success; filesize_invalid if unknown (nonseekable stream etc).

t_filesize file::get_size_ex

(

abort_callback &

p_abort

)

Helper; retrieves size of the file. If size is not available (get_size() returns filesize_invalid), throws exception_io_no_length.

Definition at line 833 of file filesystem.cpp.

                                                     {
    t_filesize temp = get_size(p_abort);
    if (temp == filesize_invalid) throw exception_io_no_length();
    return temp;
}

t_filestats file::get_stats

(

abort_callback &

p_abort

)

Retrieves file stats structure. Uses get_size() and get_timestamp().

Definition at line 594 of file filesystem.cpp.

{
    t_filestats temp;
    temp.m_size = get_size(p_abort);
    temp.m_timestamp = get_timestamp(p_abort);
    return temp;
}

virtual t_filetimestamp foobar2000_io::file::get_timestamp ( abort_callback &  p_abort )

inlinevirtual

Retrieves last modification time of the file.

Parameters

p_abort

abort_callback object signaling user aborting the operation.

Returns

Last modification time o fthe file; filetimestamp_invalid if N/A.

Definition at line 267 of file filesystem.h.

{return filetimestamp_invalid;}

bool file::is_eof

(

abort_callback &

p_abort

)

Returns whether read/write cursor position is at the end of file.

Definition at line 675 of file filesystem.cpp.

                                          {
    t_filesize position,size;
    position = get_position(p_abort);
    size = get_size(p_abort);
    if (size == filesize_invalid) return false;
    return position >= size;
}

virtual bool foobar2000_io::file::is_in_memory ( )

inlinevirtual

Hint, returns whether the file is already fully buffered into memory.

Definition at line 258 of file filesystem.h.

{return false;}

virtual bool foobar2000_io::file::is_remote ( )

pure virtual

Indicates whether the file is a remote resource and non-sequential access may be slowed down by lag. This is typically returns to true on non-seekable sources but may also return true on seekable sources indicating that seeking is supported but will be relatively slow.

virtual void foobar2000_io::file::on_idle ( abort_callback &  p_abort )

inlinevirtual

Optional, called by owner thread before sleeping.

Parameters

p_abort

abort_callback object signaling user aborting the operation.

Definition at line 262 of file filesystem.h.

{}

void file::probe_remaining	(	t_filesize	bytes,
		abort_callback &	p_abort
	)

Security helper; fails early with exception_io_data_truncation if it is not possible to read this amount of bytes from this file at this position.

Definition at line 859 of file filesystem.cpp.

                                                                     {
    t_filesize length = get_size(p_abort);
    if (length != ~0) {
        t_filesize remaining = length - get_position(p_abort);
        if (remaining < bytes) throw exception_io_data_truncation();
    }
}

virtual void foobar2000_io::file::reopen ( abort_callback &  p_abort )

pure virtual

Resets non-seekable stream, or seeks to zero on seekable file.

Parameters

p_abort

abort_callback object signaling user aborting the operation.

virtual void foobar2000_io::file::resize ( t_filesize  p_size, abort_callback &  p_abort  )

pure virtual

Resizes file to the specified size in bytes.

Parameters

p_abort

abort_callback object signaling user aborting the operation.

virtual void foobar2000_io::file::seek ( t_filesize  p_position, abort_callback &  p_abort  )

pure virtual

Sets read/write cursor position to the specified offset. Throws exception_io_seek_out_of_range if the specified offset is outside the valid range.

Parameters

p_position	position to seek to.
p_abort	abort_callback object signaling user aborting the operation.

void file::seek_ex ( t_sfilesize  p_position, file::t_seek_mode  p_mode, abort_callback &  p_abort  )

virtual

Sets read/write cursor position to the specified offset; extended form allowing seeking relative to current position or to end of file.

Parameters

p_position	Position to seek to; interpretation of this value depends on p_mode parameter.
p_mode	Seeking mode; see t_seek_mode enum values for further description.
p_abort	abort_callback object signaling user aborting the operation.

Definition at line 24 of file filesystem.cpp.

                                                                                          {
    switch(p_mode) {
    case seek_from_beginning:
        seek(p_position,p_abort);
        break;
    case seek_from_current:
        seek(p_position + get_position(p_abort),p_abort);
        break;
    case seek_from_eof:
        seek(p_position + get_size_ex(p_abort),p_abort);
        break;
    default:
        throw exception_io_data();
    }
}

void file::seek_probe	(	t_filesize	p_position,
		abort_callback &	p_abort
	)

Same as seek() but throws exception_io_data instead of exception_io_seek_out_of_range.

Definition at line 20 of file filesystem.cpp.

                                                                     {
    try { seek(p_position, p_abort); } catch(exception_io_seek_out_of_range) {throw exception_io_data();}
}

void foobar2000_io::file::set_eof ( abort_callback &  p_abort )

inline

Truncates the file at current read/write cursor position.

Definition at line 286 of file filesystem.h.

{resize(get_position(p_abort),p_abort);}

t_filesize file::skip ( t_filesize  p_bytes, abort_callback &  p_abort  )

virtual

Attempts to skip specified number of bytes in the stream.

Parameters

p_bytes	Number of bytes to skip.
p_abort	abort_callback object signaling user aborting the operation.

Returns

Number of bytes actually skipped, May be less than requested when EOF was reached.

Reimplemented from foobar2000_io::stream_reader.

Definition at line 925 of file filesystem.cpp.

                                                                 {
    if (p_bytes > 1024 && can_seek()) {
        const t_filesize size = get_size(p_abort);
        if (size != filesize_invalid) {
            const t_filesize position = get_position(p_abort);
            const t_filesize toskip = pfc::min_t( p_bytes, size - position );
            seek(position + toskip,p_abort);
            return toskip;
        }
    }
    return stream_reader::skip(p_bytes,p_abort);
}

t_filesize file::skip_seek	(	t_filesize	p_bytes,
		abort_callback &	p_abort
	)

Definition at line 912 of file filesystem.cpp.

                                                                      {
    const t_filesize size = get_size(p_abort);
    if (size != filesize_invalid) {
        const t_filesize position = get_position(p_abort);
        const t_filesize toskip = pfc::min_t( p_bytes, size - position );
        seek(position + toskip,p_abort);
        return toskip;
    } else {
        this->seek_ex( p_bytes, seek_from_current, p_abort );
        return p_bytes;
    }
}

void file::truncate	(	t_filesize	p_position,
		abort_callback &	p_abort
	)

Truncates file to specified size (while preserving read/write cursor position if possible); uses set_eof().

Definition at line 741 of file filesystem.cpp.

                                                                {
    if (p_position < get_size(p_abort)) resize(p_position,p_abort);
}

---

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

• foobar2000/SDK/filesystem.h
• foobar2000/SDK/filesystem.cpp