use bitflags::_core::fmt::Formatter;
use parking_lot::{MappedRwLockReadGuard, RwLock, RwLockReadGuard};
use std::fmt;
use std::fmt::Display;
use std::ops::{Index, IndexMut, Range};
lazy_static! {
static ref BUFFER: RwLock<StringLiteralBuffer> =
RwLock::new(StringLiteralBuffer(String::with_capacity(8192)));
}
#[derive(Clone, Default, Debug)]
pub struct StringLiteralBuffer(pub String);
impl StringLiteralBuffer {
pub fn get_str(&self, range: StringLiteral) -> &str {
&self.0[range.as_usize_range()]
}
pub fn get_str_mut(&mut self, range: StringLiteral) -> &mut str {
&mut self.0[range.as_usize_range()]
}
pub fn add_str_literal(&mut self, string: &str) -> Result<StringLiteral, ()> {
if string.len() > u16::MAX as usize {
Err(())
} else {
let start = self.0.len();
self.0.push_str(string);
Ok((start..self.0.len()).into())
}
}
}
impl Index<StringLiteral> for StringLiteralBuffer {
type Output = str;
fn index(&self, range: StringLiteral) -> &Self::Output {
self.get_str(range)
}
}
impl IndexMut<StringLiteral> for StringLiteralBuffer {
fn index_mut(&mut self, range: StringLiteral) -> &mut Self::Output {
self.get_str_mut(range)
}
}
#[derive(Copy, Clone, Debug)]
pub struct StringLiteral {
pub start: u16,
pub end: u16,
}
impl StringLiteral {
pub fn new(src: &str) -> Result<Self, ()> {
BUFFER.write().add_str_literal(src)
}
pub fn as_usize_range(self) -> Range<usize> {
(self.start as usize)..(self.end as usize)
}
pub fn as_raw_range(self) -> Range<u16> {
self.start..self.end
}
pub fn as_str<'lt>(self) -> MappedRwLockReadGuard<'lt, str> {
RwLockReadGuard::map(BUFFER.read(), |buff| &buff[self])
}
pub const fn empty() -> Self {
Self { start: 0, end: 0 }
}
}
impl From<Range<u16>> for StringLiteral {
fn from(range: Range<u16>) -> Self {
Self {
start: range.start,
end: range.end,
}
}
}
impl From<Range<usize>> for StringLiteral {
fn from(range: Range<usize>) -> Self {
Self {
start: range.start as u16,
end: range.end as u16,
}
}
}
impl Into<Range<u16>> for StringLiteral {
fn into(self) -> Range<u16> {
self.start..self.end
}
}
impl Into<Range<usize>> for StringLiteral {
fn into(self) -> Range<usize> {
self.as_usize_range()
}
}
impl PartialEq for StringLiteral {
fn eq(&self, other: &Self) -> bool {
let buffer = BUFFER.read();
buffer[*self] == buffer[*other]
}
}
impl Eq for StringLiteral {}
impl Display for StringLiteral {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
f.write_str(&BUFFER.read()[*self])
}
}