Overview

Wraps a stream to ensure only a limited number of bytes can be written.

Write attempts which would exceed the current limit will return OUT_OF_RANGE.

Inheritance diagram for pw::stream::LimitedStreamWriter:

Public Member Functions
	LimitedStreamWriter (Writer &writer, size_t limit=kUnlimited)

size_t	limit () const
	Returns the current limit of this writer.

void	set_limit (size_t limit)

size_t	bytes_written () const
	Returns the number of bytes written to the stream.

Public Member Functions inherited from pw::stream::Stream
constexpr bool	readable () const

constexpr bool	writable () const

constexpr bool	seekable () const

constexpr bool	seekable (Whence origin) const
	True if the stream supports seeking from the specified origin.

Result< ByteSpan >	Read (ByteSpan dest)

Result< ByteSpan >	Read (void *dest, size_t size_bytes)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Result< ByteSpan >	ReadExact (ByteSpan const buffer)

Status	Write (ConstByteSpan data)

Status	Write (const void *data, size_t size_bytes)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Status	Write (const std::byte b)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Status	Seek (ptrdiff_t offset, Whence origin=kBeginning)

size_t	Tell ()

size_t	ConservativeReadLimit () const

size_t	ConservativeWriteLimit () const

Private Member Functions
Status	DoWrite (ConstByteSpan data) override
	Virtual Write() function implemented by derived classes.

size_t	ConservativeLimit (LimitType limit_type) const override

Additional Inherited Members
Public Types inherited from pw::stream::Stream
enum	Whence : uint8_t { kBeginning = 0b001 , kCurrent = 0b010 , kEnd = 0b100 }
	Positions from which to seek. More...

Static Public Attributes inherited from pw::stream::Stream
static constexpr size_t	kUnlimited = std::numeric_limits<size_t>::max()
	Value returned from read/write limit if unlimited.

static constexpr size_t	kUnknownPosition = std::numeric_limits<size_t>::max()
	Returned by Tell() if getting the position is not supported.

Protected Types inherited from pw::stream::Stream
enum class	LimitType : bool { kRead , kWrite }

Constructor & Destructor Documentation

pw::stream::LimitedStreamWriter::LimitedStreamWriter	(	Writer &	writer,
		size_t	limit = `kUnlimited`
	)

inline

Constructs a LimitedStreamWriter which wraps another stream.

Parameters

[in]	writer	The stream to wrap.
[in]	limit	The maximum number of bytes which can be written. Defaults to `kUnlimited`.

size_t pw::stream::LimitedStreamWriter::ConservativeLimit ( LimitType limit_type ) const

inlineoverrideprivatevirtual

Virtual function optionally implemented by derived classes that is used for ConservativeReadLimit() and ConservativeWriteLimit().

The default implementation returns kUnlimited or 0 depending on whether the stream is readable/writable.

Reimplemented from pw::stream::Stream.

Status pw::stream::LimitedStreamWriter::DoWrite ( ConstByteSpan data )

inlineoverrideprivatevirtual

Virtual Write() function implemented by derived classes.

void pw::stream::LimitedStreamWriter::set_limit ( size_t limit )

inline

Changes the current limit of this writer.

NOTE: If the limit is set to a value <= bytes_written(), no additional data can be written.

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