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//! [![github]](https://github.com/dtolnay/bufsize) [![crates-io]](https://crates.io/crates/bufsize) [![docs-rs]](https://docs.rs/bufsize)
//!
//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs
#![doc(html_root_url = "https://docs.rs/bufsize/1.0.7")]
#![allow(
clippy::let_underscore_untyped,
clippy::must_use_candidate,
clippy::needless_doctest_main,
clippy::new_without_default
)]
use bytes::buf::{Buf, BufMut, UninitSlice};
/// Implementation of [`BufMut`] to count the size of a resulting buffer.
///
/// This effectively requires the data to be serialized twice, but in many use
/// cases inlining allows most of the effort of generating actual data to be
/// elided.
///
/// # Example
///
/// ```
/// use bufsize::SizeCounter;
/// use bytes::BufMut;
///
/// pub struct DataStructure;
///
/// impl DataStructure {
/// pub fn serialize<B: BufMut>(&self, buf: &mut B) {
/// let name = "DataStructure";
/// buf.put_u8(name.len() as u8);
/// buf.put_slice(name.as_bytes());
/// buf.put_u32_le(9999);
/// buf.put_f32_le(1.0);
/// }
/// }
///
/// fn main() {
/// let mut sizecount = SizeCounter::new();
/// DataStructure.serialize(&mut sizecount);
///
/// let mut buffer = Vec::with_capacity(sizecount.size());
/// DataStructure.serialize(&mut buffer);
///
/// assert_eq!(sizecount.size(), buffer.len());
/// }
/// ```
#[derive(Debug)]
pub struct SizeCounter {
count: usize,
}
impl SizeCounter {
pub fn new() -> Self {
SizeCounter { count: 0 }
}
pub fn size(&self) -> usize {
self.count
}
}
unsafe impl BufMut for SizeCounter {
#[inline]
fn remaining_mut(&self) -> usize {
usize::max_value()
}
#[inline]
unsafe fn advance_mut(&mut self, cnt: usize) {
let _ = cnt;
}
fn chunk_mut(&mut self) -> &mut UninitSlice {
unimplemented!("SizeCounter doesn't really have a buffer")
}
#[inline]
fn has_remaining_mut(&self) -> bool {
true
}
fn put<T: Buf>(&mut self, src: T)
where
Self: Sized,
{
self.count += src.remaining();
}
#[inline]
fn put_slice(&mut self, src: &[u8]) {
self.count += src.len();
}
#[inline]
fn put_u8(&mut self, n: u8) {
let _ = n;
self.count += 1;
}
#[inline]
fn put_i8(&mut self, n: i8) {
let _ = n;
self.count += 1;
}
#[inline]
fn put_u16(&mut self, n: u16) {
let _ = n;
self.count += 2;
}
#[inline]
fn put_u16_le(&mut self, n: u16) {
let _ = n;
self.count += 2;
}
#[inline]
fn put_i16(&mut self, n: i16) {
let _ = n;
self.count += 2;
}
#[inline]
fn put_i16_le(&mut self, n: i16) {
let _ = n;
self.count += 2;
}
#[inline]
fn put_u32(&mut self, n: u32) {
let _ = n;
self.count += 4;
}
#[inline]
fn put_u32_le(&mut self, n: u32) {
let _ = n;
self.count += 4;
}
#[inline]
fn put_i32(&mut self, n: i32) {
let _ = n;
self.count += 4;
}
#[inline]
fn put_i32_le(&mut self, n: i32) {
let _ = n;
self.count += 4;
}
#[inline]
fn put_u64(&mut self, n: u64) {
let _ = n;
self.count += 8;
}
#[inline]
fn put_u64_le(&mut self, n: u64) {
let _ = n;
self.count += 8;
}
#[inline]
fn put_i64(&mut self, n: i64) {
let _ = n;
self.count += 8;
}
#[inline]
fn put_i64_le(&mut self, n: i64) {
let _ = n;
self.count += 8;
}
#[inline]
fn put_u128(&mut self, n: u128) {
let _ = n;
self.count += 16;
}
#[inline]
fn put_u128_le(&mut self, n: u128) {
let _ = n;
self.count += 16;
}
#[inline]
fn put_i128(&mut self, n: i128) {
let _ = n;
self.count += 16;
}
#[inline]
fn put_i128_le(&mut self, n: i128) {
let _ = n;
self.count += 16;
}
#[inline]
fn put_uint(&mut self, n: u64, nbytes: usize) {
let _ = n;
self.count += nbytes;
}
#[inline]
fn put_uint_le(&mut self, n: u64, nbytes: usize) {
let _ = n;
self.count += nbytes;
}
#[inline]
fn put_int(&mut self, n: i64, nbytes: usize) {
let _ = n;
self.count += nbytes;
}
#[inline]
fn put_int_le(&mut self, n: i64, nbytes: usize) {
let _ = n;
self.count += nbytes;
}
#[inline]
fn put_f32(&mut self, n: f32) {
let _ = n;
self.count += 4;
}
#[inline]
fn put_f32_le(&mut self, n: f32) {
let _ = n;
self.count += 4;
}
#[inline]
fn put_f64(&mut self, n: f64) {
let _ = n;
self.count += 8;
}
#[inline]
fn put_f64_le(&mut self, n: f64) {
let _ = n;
self.count += 8;
}
}