use std::any::TypeId;
use std::rc::Rc;
use std::sync::Arc;
use globalcache::ValueSize;
use datasize::DataSize;
use crate::object::{Object};
use crate::error::{Result, PdfError};
pub trait AnyObject {
fn type_name(&self) -> &'static str;
fn type_id(&self) -> TypeId;
fn size(&self) -> usize;
}
impl<T> AnyObject for T
where T: Object + 'static + DataSize
{
fn type_name(&self) -> &'static str {
std::any::type_name::<T>()
}
fn type_id(&self) -> TypeId {
TypeId::of::<T>()
}
fn size(&self) -> usize {
datasize::data_size(self)
}
}
#[derive(Clone)]
pub struct Any(Rc<dyn AnyObject>);
impl Any {
pub fn downcast<T>(self) -> Result<Rc<T>>
where T: AnyObject + 'static
{
if TypeId::of::<T>() == self.0.type_id() {
unsafe {
let raw: *const dyn AnyObject = Rc::into_raw(self.0);
Ok(Rc::from_raw(raw as *const T))
}
} else {
Err(type_mismatch::<T>(self.0.type_name()))
}
}
pub fn new<T>(rc: Rc<T>) -> Any
where T: AnyObject + 'static
{
Any(rc as _)
}
pub fn type_name(&self) -> &'static str {
self.0.type_name()
}
}
impl<T: AnyObject + 'static> From<Rc<T>> for Any {
fn from(t: Rc<T>) -> Self {
Any::new(t)
}
}
#[derive(Clone)]
pub struct AnySync(Arc<dyn AnyObject+Sync+Send>);
impl AnySync {
pub fn downcast<T>(self) -> Result<Arc<T>>
where T: AnyObject + Sync + Send + 'static
{
if TypeId::of::<T>() == self.0.type_id() {
unsafe {
let raw: *const (dyn AnyObject+Sync+Send) = Arc::into_raw(self.0);
Ok(Arc::from_raw(raw as *const T))
}
} else {
Err(type_mismatch::<T>(self.0.type_name()))
}
}
pub fn new<T>(arc: Arc<T>) -> AnySync
where T: AnyObject + Sync + Send + 'static
{
AnySync(arc as _)
}
pub fn type_name(&self) -> &'static str {
self.0.type_name()
}
}
impl<T: AnyObject + Sync + Send + 'static> From<Arc<T>> for AnySync {
fn from(t: Arc<T>) -> Self {
AnySync::new(t)
}
}
impl ValueSize for AnySync {
fn size(&self) -> usize {
self.0.size()
}
}
fn type_mismatch<T: AnyObject + 'static>(name: &str) -> PdfError {
PdfError::Other { msg: format!("expected {}, found {}", std::any::type_name::<T>(), name) }
}