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jau::io::ByteInStream_File Class Referencefinal

File based byte input stream, including named file descriptor. More...

#include <byte_stream.hpp>

Inheritance diagram for jau::io::ByteInStream_File:
Collaboration diagram for jau::io::ByteInStream_File:

Public Member Functions

 ByteInStream_File (const ByteInStream_File &)=delete
 
 ByteInStream_File (const int dirfd, const std::string &path) noexcept
 Construct a stream based byte input stream from filesystem path and parent directory file descriptor. More...
 
 ByteInStream_File (const int fd) noexcept
 Construct a stream based byte input stream by duplicating given file descriptor. More...
 
 ByteInStream_File (const std::string &path) noexcept
 Construct a stream based byte input stream from filesystem path. More...
 
 ~ByteInStream_File () noexcept override
 
bool available (size_t n) noexcept override
 Return whether n bytes are available in the input stream, if has_content_size() or using an asynchronous source. More...
 
void close () noexcept override
 Close the stream if supported by the underlying mechanism. More...
 
uint64_t content_size () const noexcept override
 Returns the content_size if known. More...
 
int fd () const noexcept
 Returns the file descriptor if is_open(), otherwise -1 for no file descriptor. More...
 
bool has_content_size () const noexcept override
 Returns true if implementation is aware of content_size(), otherwise false. More...
 
std::string id () const noexcept override
 return the id of this data source More...
 
bool is_open () const noexcept override
 Checks if the stream has an associated file. More...
 
ByteInStream_Fileoperator= (const ByteInStream_File &)=delete
 
size_t peek (void *, size_t, size_t) noexcept override
 Read from the source but do not modify the internal offset. More...
 
size_t read (void *, size_t) noexcept override
 Read from the source. More...
 
uint64_t tellg () const noexcept override
 Returns the input position indicator, similar to std::basic_istream. More...
 
std::string to_string () const noexcept override
 
- Public Member Functions inherited from jau::io::ByteInStream
 ByteInStream () noexcept
 
 ByteInStream (const ByteInStream &)=delete
 
 ~ByteInStream () noexcept override=default
 
virtual bool available (size_t n) noexcept=0
 Return whether n bytes are available in the input stream, if has_content_size() or using an asynchronous source. More...
 
virtual void close () noexcept=0
 Close the stream if supported by the underlying mechanism. More...
 
virtual uint64_t content_size () const noexcept=0
 Returns the content_size if known. More...
 
size_t discard (size_t N) noexcept
 Discard the next N bytes of the data. More...
 
virtual bool has_content_size () const noexcept=0
 Returns true if implementation is aware of content_size(), otherwise false. More...
 
virtual std::string id () const noexcept
 return the id of this data source More...
 
virtual bool is_open () const noexcept=0
 Checks if the stream has an associated file. More...
 
ByteInStreamoperator= (const ByteInStream &)=delete
 
bool peek (uint8_t &out) noexcept
 Peek at one byte. More...
 
virtual size_t peek (void *out, size_t length, size_t peek_offset) noexcept=0
 Read from the source but do not modify the internal offset. More...
 
bool read (uint8_t &out) noexcept
 Read one byte. More...
 
virtual size_t read (void *out, size_t length) noexcept=0
 Read from the source. More...
 
virtual uint64_t tellg () const noexcept=0
 Returns the input position indicator, similar to std::basic_istream. More...
 
virtual std::string to_string () const noexcept=0
 
- Public Member Functions inherited from jau::io::iostate_func
 iostate_func () noexcept
 
 iostate_func (const iostate_func &o) noexcept=default
 
 iostate_func (iostate_func &&o) noexcept=default
 
virtual ~iostate_func () noexcept=default
 
bool bad () const noexcept
 Checks if a non-recoverable error has occurred. More...
 
virtual void clear (const iostate state=iostate::goodbit) noexcept
 Clears state flags by assignment to the given value. More...
 
bool eof () const noexcept
 Checks if end-of-file has been reached. More...
 
bool fail () const noexcept
 Checks if an error has occurred. More...
 
bool good () const noexcept
 Checks if no error nor eof() has occurred i.e. More...
 
 operator bool () const noexcept
 Checks if no error has occurred, synonym of !fail(). More...
 
bool operator! () const noexcept
 Checks if an error has occurred, synonym of fail(). More...
 
iostate_funcoperator= (const iostate_func &o) noexcept=default
 
iostate_funcoperator= (iostate_func &&o) noexcept=default
 
virtual iostate rdstate () const noexcept
 Returns the current state flags. More...
 
void setstate (const iostate state) noexcept
 Sets state flags, by keeping its previous bits. More...
 
bool timeout () const noexcept
 Checks if a timeout (non-recoverable) has occurred. More...
 

Additional Inherited Members

- Protected Member Functions inherited from jau::io::iostate_func
constexpr iostate rdstate_impl () const noexcept
 
constexpr void setstate_impl (iostate state) const noexcept
 

Detailed Description

File based byte input stream, including named file descriptor.

Implementation mimics std::ifstream via OS level file descriptor (FD) operations, giving more flexibility, allowing reusing existing FD and enabling openat() operations.

If source path denotes a named file descriptor, i.e. jau::fs::file_stats::is_fd() returns true, has_content_size() returns false and available() returns true as long the stream is open and EOS hasn't occurred.

Definition at line 385 of file byte_stream.hpp.

Constructor & Destructor Documentation

◆ ByteInStream_File() [1/4]

ByteInStream_File::ByteInStream_File ( const std::string &  path)
noexcept

Construct a stream based byte input stream from filesystem path.

In case the given path is a local file URI starting with file://, see jau::io::uri::is_local_file_protocol(), the leading file:// is cut off and the remainder being used.

Parameters
paththe path to the file, maybe a local file URI

Definition at line 310 of file byte_stream.cpp.

◆ ByteInStream_File() [2/4]

ByteInStream_File::ByteInStream_File ( const int  dirfd,
const std::string &  path 
)
noexcept

Construct a stream based byte input stream from filesystem path and parent directory file descriptor.

In case the given path is a local file URI starting with file://, see jau::io::uri::is_local_file_protocol(), the leading file:// is cut off and the remainder being used.

Parameters
dirfdparent directory file descriptor
paththe path to the file, maybe a local file URI

Definition at line 274 of file byte_stream.cpp.

◆ ByteInStream_File() [3/4]

ByteInStream_File::ByteInStream_File ( const int  fd)
noexcept

Construct a stream based byte input stream by duplicating given file descriptor.

In case the given path is a local file URI starting with file://, see jau::io::uri::is_local_file_protocol(), the leading file:// is cut off and the remainder being used.

Parameters
fdfile descriptor to duplicate leaving the given fd untouched

Definition at line 256 of file byte_stream.cpp.

◆ ByteInStream_File() [4/4]

jau::io::ByteInStream_File::ByteInStream_File ( const ByteInStream_File )
delete

◆ ~ByteInStream_File()

jau::io::ByteInStream_File::~ByteInStream_File ( )
inlineoverridenoexcept

Definition at line 449 of file byte_stream.hpp.

Member Function Documentation

◆ read()

size_t ByteInStream_File::read ( void *  out,
size_t  length 
)
overridevirtualnoexcept

Read from the source.

Moves the internal offset so that every call to read will return a new portion of the source.

Use available() to try to wait for a certain amount of bytes available.

This method shall only block until min(available, length) bytes are transfered.

See details of the implementing class.

Parameters
outthe byte array to write the result to
lengththe length of the byte array out
Returns
length in bytes that was actually read and put into out
See also
available()
ByteInStream Properties

Implements jau::io::ByteInStream.

Definition at line 180 of file byte_stream.cpp.

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◆ peek()

size_t ByteInStream_File::peek ( void *  out,
size_t  length,
size_t  peek_offset 
)
overridevirtualnoexcept

Read from the source but do not modify the internal offset.

Consecutive calls to peek() will return portions of the source starting at the same position.

Parameters
outthe byte array to write the output to
lengththe length of the byte array out
peek_offsetthe offset into the stream to read at
Returns
length in bytes that was actually read and put into out

Implements jau::io::ByteInStream.

Definition at line 211 of file byte_stream.cpp.

◆ available()

bool ByteInStream_File::available ( size_t  n)
overridevirtualnoexcept

Return whether n bytes are available in the input stream, if has_content_size() or using an asynchronous source.

If !has_content_size() and not being an asynchronous source, !end_of_data() is returned.

Method may be blocking when using an asynchronous source up until the requested bytes are available.

A subsequent call to read() shall return immediately with at least the requested numbers of bytes available, if has_content_size() or using an asynchronous source.

See details of the implementing class.

Parameters
nbyte count to wait for
Returns
true if n bytes are available, otherwise false
See also
has_content_size()
read()
ByteInStream Properties

Implements jau::io::ByteInStream.

Definition at line 252 of file byte_stream.cpp.

◆ is_open()

bool jau::io::ByteInStream_File::is_open ( ) const
inlineoverridevirtualnoexcept

Checks if the stream has an associated file.

Implements jau::io::ByteInStream.

Definition at line 401 of file byte_stream.hpp.

◆ id()

std::string jau::io::ByteInStream_File::id ( ) const
inlineoverridevirtualnoexcept

return the id of this data source

Returns
std::string representing the id of this data source

Reimplemented from jau::io::ByteInStream.

Definition at line 403 of file byte_stream.hpp.

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◆ fd()

int jau::io::ByteInStream_File::fd ( ) const
inlinenoexcept

Returns the file descriptor if is_open(), otherwise -1 for no file descriptor.

See also
is_open()

Definition at line 410 of file byte_stream.hpp.

◆ operator=()

ByteInStream_File & jau::io::ByteInStream_File::operator= ( const ByteInStream_File )
delete

◆ close()

void ByteInStream_File::close ( )
overridevirtualnoexcept

Close the stream if supported by the underlying mechanism.

Implements jau::io::ByteInStream.

Definition at line 313 of file byte_stream.cpp.

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◆ tellg()

uint64_t jau::io::ByteInStream_File::tellg ( ) const
inlineoverridevirtualnoexcept

Returns the input position indicator, similar to std::basic_istream.

Returns
number of bytes read so far.

Implements jau::io::ByteInStream.

Definition at line 451 of file byte_stream.hpp.

◆ has_content_size()

bool jau::io::ByteInStream_File::has_content_size ( ) const
inlineoverridevirtualnoexcept

Returns true if implementation is aware of content_size(), otherwise false.

See also
content_size()

Implements jau::io::ByteInStream.

Definition at line 453 of file byte_stream.hpp.

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◆ content_size()

uint64_t jau::io::ByteInStream_File::content_size ( ) const
inlineoverridevirtualnoexcept

Returns the content_size if known.

See also
has_content_size()

Implements jau::io::ByteInStream.

Definition at line 455 of file byte_stream.hpp.

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◆ to_string()

std::string ByteInStream_File::to_string ( ) const
overridevirtualnoexcept

Implements jau::io::ByteInStream.

Definition at line 321 of file byte_stream.cpp.

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