pw::ByteBuilder Class Reference

Overview

ByteBuilder facilitates building bytes in a fixed-size buffer. BytesBuilders never overflow. Status is tracked for each operation and an overall status is maintained, which reflects the most recent error.

A ByteBuilder does not own the buffer it writes to. It can be used to write bytes to any buffer. The ByteBuffer template class, defined below, allocates a buffer alongside a ByteBuilder.

Inheritance diagram for pw::ByteBuilder:

Classes
class	iterator

Public Types
using	element_type = const std::byte
using	value_type = std::byte
using	pointer = std::byte *
using	reference = std::byte &
using	iterator = iterator
using	const_iterator = iterator

Public Member Functions
constexpr	ByteBuilder (ByteSpan buffer)
	Creates an empty ByteBuilder.
	ByteBuilder (const ByteBuilder &)=delete
ByteBuilder &	operator= (const ByteBuilder &)=delete
const std::byte *	data () const
	Returns the contents of the bytes buffer.
Status	status () const
StatusWithSize	status_with_size () const
	Returns status() and size() as a StatusWithSize.
bool	ok () const
	True if status() is OkStatus().
bool	empty () const
	True if the bytes builder is empty.
size_t	size () const
	Returns the current length of the bytes.
size_t	max_size () const
	Returns the maximum length of the bytes.
void	clear ()
	Clears the bytes and resets its error state.
void	clear_status ()
	Sets the statuses to OkStatus();.
void	push_back (std::byte b)
void	pop_back ()
const_iterator	begin () const
	Root of bytebuffer wrapped in iterator type.
const_iterator	cbegin () const
const_iterator	end () const
	End of bytebuffer wrapped in iterator type.
const_iterator	cend () const
const std::byte &	front () const
	Front and Back C++ container functions.
const std::byte &	back () const
ByteBuilder &	append (size_t count, std::byte b)
	Appends the provided byte count times.
ByteBuilder &	append (const void *bytes, size_t count)
ByteBuilder &	append (ConstByteSpan bytes)
	Appends bytes from a byte span that calls the pointer/length version.
void	resize (size_t new_size)
ByteBuilder &	PutUint8 (uint8_t val)
	Put methods for inserting different 8-bit ints.
ByteBuilder &	PutInt8 (int8_t val)
ByteBuilder &	PutUint16 (uint16_t value, endian order=endian::little)
	Put methods for inserting different 16-bit ints.
ByteBuilder &	PutInt16 (int16_t value, endian order=endian::little)
ByteBuilder &	PutUint32 (uint32_t value, endian order=endian::little)
	Put methods for inserting different 32-bit ints.
ByteBuilder &	PutInt32 (int32_t value, endian order=endian::little)
ByteBuilder &	PutUint64 (uint64_t value, endian order=endian::little)
	Put methods for inserting different 64-bit ints.
ByteBuilder &	PutInt64 (int64_t value, endian order=endian::little)

Protected Member Functions
constexpr	ByteBuilder (const ByteSpan &buffer, const ByteBuilder &other)
	Functions to support ByteBuffer copies.
void	CopySizeAndStatus (const ByteBuilder &other)

Constructor & Destructor Documentation

ByteBuilder()

pw::ByteBuilder::ByteBuilder ( const ByteBuilder &  )

delete

Disallow copy/assign to avoid confusion about where the bytes is actually stored. ByteBuffers may be copied into one another.

Member Function Documentation

append()

ByteBuilder & pw::ByteBuilder::append	(	const void *	bytes,
		size_t	count
	)

Appends count bytes from 'bytes' to the end of the ByteBuilder. If count exceeds the remaining space in the ByteBuffer, no bytes will be appended and the status is set to RESOURCE_EXHAUSTED.

pop_back()

void pw::ByteBuilder::pop_back ( )

inline

Removes the last byte. Sets the status to OUT_OF_RANGE if the buffer is empty (in which case the unsigned overflow is intentional).

push_back()

void pw::ByteBuilder::push_back ( std::byte  b )

inline

Appends a single byte. Sets the status to RESOURCE_EXHAUSTED if the byte cannot be added because the buffer is full.

resize()

void pw::ByteBuilder::resize

(

size_t

new_size

)

Sets the ByteBuilder's size. This function only truncates; if new_size > size(), it sets status to OUT_OF_RANGE and does nothing.

status()

Status pw::ByteBuilder::status ( ) const

inline

Returns the ByteBuilder's status, which reflects the most recent error that occurred while updating the bytes. After an update fails, the status remains non-OK until it is cleared with clear() or clear_status().

Returns

• OK: No errors have occurred.
• RESOURCE_EXHAUSTED: Output to the ByteBuilder was truncated.
• INVALID_ARGUMENT: printf-style formatting failed.
• OUT_OF_RANGE: An operation outside the buffer was attempted.

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

• pw_bytes/public/pw_bytes/byte_builder.h