Struct SizeSink 

pub struct SizeSink { /* private fields */ }

A byte-counting write sink that measures a proof’s serialized size without materializing it: it keeps only a running length, discarding every chunk the moment its bytes are counted, and once the total would exceed cap it refuses further writes (returning core::fmt::Error, which the streaming emitters map to EmitError::SizeCapExceeded). This lets us report our own proof size on the benchmarks page in O(1) memory, and guarantees a pathological (super-linear) proof aborts early rather than exhausting RAM — the streaming, capped counterpart to emit_*(...).len().

Implementations

impl SizeSink

pub fn new(cap: u64) -> Self

A sink that counts up to cap bytes before it starts refusing writes.

pub fn bytes(&self) -> u64

Bytes streamed through so far (the serialized proof size when emission ran to completion).

pub fn overflowed(&self) -> bool

Whether the cap was hit — the measured proof is at least cap bytes, exact size unknown.

Trait Implementations

impl Write for SizeSink

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.