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use sanakirja::{Alignment, Representable};
use std;
pub const MAX_LENGTH: usize = 255;
#[repr(packed)]
pub struct SmallString {
pub len: u8,
pub str: [u8; MAX_LENGTH],
}
#[derive(Clone, Copy)]
pub struct SmallStr<'a>(*const u8, std::marker::PhantomData<&'a ()>);
impl Clone for SmallString {
fn clone(&self) -> Self {
Self::from_str(self.as_str())
}
}
impl std::fmt::Debug for SmallString {
fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
self.as_small_str().fmt(fmt)
}
}
impl<'a> PartialEq for SmallStr<'a> {
fn eq(&self, x: &SmallStr) -> bool {
self.as_str().eq(x.as_str())
}
}
impl<'a> Eq for SmallStr<'a> {}
impl PartialEq for SmallString {
fn eq(&self, x: &SmallString) -> bool {
self.as_str().eq(x.as_str())
}
}
impl Eq for SmallString {}
impl<'a> std::hash::Hash for SmallStr<'a> {
fn hash<H: std::hash::Hasher>(&self, x: &mut H) {
self.as_str().hash(x)
}
}
impl std::hash::Hash for SmallString {
fn hash<H: std::hash::Hasher>(&self, x: &mut H) {
self.as_str().hash(x)
}
}
impl<'a> PartialOrd for SmallStr<'a> {
fn partial_cmp(&self, x: &SmallStr) -> Option<std::cmp::Ordering> {
self.as_str().partial_cmp(x.as_str())
}
}
impl<'a> Ord for SmallStr<'a> {
fn cmp(&self, x: &SmallStr) -> std::cmp::Ordering {
self.as_str().cmp(x.as_str())
}
}
impl<'a> std::fmt::Debug for SmallStr<'a> {
fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
self.as_str().fmt(fmt)
}
}
impl SmallString {
pub fn len(&self) -> usize {
self.len as usize
}
pub fn is_empty(&self) -> bool {
self.len() == 0
}
pub fn from_str(s: &str) -> Self {
let mut b = SmallString {
len: s.len() as u8,
str: [0; MAX_LENGTH],
};
b.clone_from_str(s);
b
}
pub fn clone_from_str(&mut self, s: &str) {
self.len = s.len() as u8;
(&mut self.str[..s.len()]).copy_from_slice(s.as_bytes());
}
pub fn clear(&mut self) {
self.len = 0;
}
pub fn push_str(&mut self, s: &str) {
let l = self.len as usize;
assert!(l + s.len() <= 0xff);
(&mut self.str[l..l + s.len()]).copy_from_slice(s.as_bytes());
self.len += s.len() as u8;
}
pub fn as_small_str(&self) -> SmallStr {
SmallStr(
self as *const SmallString as *const u8,
std::marker::PhantomData,
)
}
pub fn as_str(&self) -> &str {
self.as_small_str().as_str()
}
}
impl<'a> SmallStr<'a> {
pub fn is_empty(&self) -> bool {
self.len() == 0
}
pub fn len(&self) -> usize {
unsafe { (*self.0) as usize }
}
pub fn as_str(&self) -> &'a str {
unsafe {
std::str::from_utf8_unchecked(std::slice::from_raw_parts(
self.0.offset(1),
*self.0 as usize,
))
}
}
pub fn to_unsafe(&self) -> UnsafeSmallStr {
UnsafeSmallStr(self.0)
}
pub unsafe fn from_unsafe(u: UnsafeSmallStr) -> Self {
SmallStr(u.0, std::marker::PhantomData)
}
pub fn to_owned(&self) -> SmallString {
SmallString::from_str(self.as_str())
}
}
#[derive(Clone, Copy)]
pub struct UnsafeSmallStr(*const u8);
impl std::fmt::Debug for UnsafeSmallStr {
fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
unsafe { SmallStr::from_unsafe(*self).fmt(fmt) }
}
}
impl Representable for UnsafeSmallStr {
fn alignment() -> Alignment {
Alignment::B1
}
fn onpage_size(&self) -> u16 {
unsafe {
let len = (*self.0) as u16;
1 + len
}
}
unsafe fn write_value(&self, p: *mut u8) {
trace!("write_value {:?}", p);
std::ptr::copy(self.0, p, self.onpage_size() as usize)
}
unsafe fn read_value(p: *const u8) -> Self {
trace!("read_value {:?}", p);
UnsafeSmallStr(p)
}
unsafe fn cmp_value<T>(&self, _: &T, x: Self) -> std::cmp::Ordering {
let a = SmallStr::from_unsafe(UnsafeSmallStr(self.0));
let b = SmallStr::from_unsafe(x);
a.as_str().cmp(b.as_str())
}
type PageOffsets = std::iter::Empty<u64>;
fn page_offsets(&self) -> Self::PageOffsets {
std::iter::empty()
}
}