vlink::FastStream Class Reference

High-performance std::ostream with an embedded resizable string buffer. More...

#include <fast_stream.h>

Inheritance diagram for vlink::FastStream:

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Public Member Functions
	FastStream () noexcept
	Constructs a FastStream with a default initial buffer capacity.
	~FastStream () noexcept override
	Destructor. Releases the internal string buffer.
void	reset () noexcept
	Clears all buffered content and resets the stream error state.
void	append_to (std::string &target) const noexcept
	Appends the current buffered content to an existing std::string.
std::string_view	take_view () noexcept
	Returns a std::string_view of the current buffer contents.
size_t	size () const noexcept
	Returns the current number of bytes stored in the buffer.
size_t	capacity () const noexcept
	Returns the current allocated capacity of the internal buffer in bytes.
void	shrink_to_fit () noexcept
	Releases any excess capacity allocated by the internal buffer.
FastStream &	write_raw (const char *data, size_t len) noexcept
	Writes raw bytes directly into the buffer, bypassing std::ostream formatting.

Detailed Description

High-performance std::ostream with an embedded resizable string buffer.

Used internally by Logger to accumulate a single log message and hand it off to the sink as a std::string_view without an extra copy. All std::ostream formatting (hex, precision, fill, etc.) is supported.

Constructor & Destructor Documentation

FastStream()

vlink::FastStream::FastStream ( )

noexcept

Constructs a FastStream with a default initial buffer capacity.

The default capacity is 256 bytes. The buffer grows automatically when the message length exceeds the current capacity.

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~FastStream()

vlink::FastStream::~FastStream ( )

overridenoexcept

Destructor. Releases the internal string buffer.

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Member Function Documentation

append_to()

void vlink::FastStream::append_to ( std::string & target ) const

noexcept

Appends the current buffered content to an existing std::string.

The internal buffer is not reset after this call. Use this method when the content needs to be collected into an external string incrementally.

Parameters

target

The string to which buffered content is appended.

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capacity()

size_t vlink::FastStream::capacity ( ) const

nodiscardnoexcept

Returns the current allocated capacity of the internal buffer in bytes.

Returns

Capacity in bytes.

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reset()

void vlink::FastStream::reset ( )

noexcept

Clears all buffered content and resets the stream error state.

After reset() the stream is ready to receive a new message. The allocated memory of the underlying buffer is retained (no deallocation).

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shrink_to_fit()

void vlink::FastStream::shrink_to_fit ( )

noexcept

Releases any excess capacity allocated by the internal buffer.

Useful after a particularly large log message to reclaim memory back to a sensible minimum (kMinCapacity = 64 bytes).

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size()

size_t vlink::FastStream::size ( ) const

nodiscardnoexcept

Returns the current number of bytes stored in the buffer.

Returns

Number of bytes written since the last reset().

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take_view()

std::string_view vlink::FastStream::take_view ( )

noexcept

Returns a std::string_view of the current buffer contents.

The stream is not reset by this call. The returned view remains valid only until the next write to the stream or an explicit reset(). This is the primary zero-copy hand-off mechanism used by the Logger.

Warning

Do not store the returned view beyond the lifetime of the next stream operation. Treating it as a persistent string leads to undefined behaviour.

Returns

A std::string_view over the internal buffer content.

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write_raw()

FastStream & vlink::FastStream::write_raw ( const char * data, size_t len )

noexcept

Writes raw bytes directly into the buffer, bypassing std::ostream formatting.

This is faster than std::ostream::write for pre-formatted C-strings because it avoids locale and format-flag overhead.

Parameters

data	Pointer to the bytes to write. Must not be null if len > 0.
len	Number of bytes to write.

Returns

A reference to *this to support chaining.

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

• include/vlink/base/fast_stream.h