blob: 0c26439afcde742363031ea137d2475490a661e7 [file] [log] [blame]
// Copyright 2018 Brian Smith.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
pub trait Accumulator {
fn write_byte(&mut self, value: u8);
fn write_bytes(&mut self, value: &[u8]);
}
pub(super) struct LengthMeasurement {
len: usize,
}
impl Into<usize> for LengthMeasurement {
fn into(self) -> usize { self.len }
}
impl LengthMeasurement {
pub fn zero() -> Self { Self { len: 0 } }
}
impl Accumulator for LengthMeasurement {
fn write_byte(&mut self, _value: u8) { self.len += 1; }
fn write_bytes(&mut self, value: &[u8]) { self.len += value.len(); }
}
pub(super) struct Writer {
bytes: Vec<u8>,
requested_capacity: usize,
}
impl Writer {
pub(super) fn with_capacity(capacity: LengthMeasurement) -> Self {
Self {
bytes: Vec::with_capacity(capacity.len),
requested_capacity: capacity.len,
}
}
}
impl Into<Box<[u8]>> for Writer {
fn into(self) -> Box<[u8]> {
assert_eq!(self.requested_capacity, self.bytes.len());
self.bytes.into_boxed_slice()
}
}
impl Accumulator for Writer {
fn write_byte(&mut self, value: u8) { self.bytes.push(value); }
fn write_bytes(&mut self, value: &[u8]) { self.bytes.extend(value); }
}
pub fn write_copy(accumulator: &mut Accumulator, to_copy: untrusted::Input) {
accumulator.write_bytes(to_copy.as_slice_less_safe())
}