factor out into common crate

items_2/src/streams.rs

@@ -1,94 +1 @@
-use crate::WithLen;
-use err::Error;
-use serde::Serialize;
-use std::any::Any;
-use std::fmt;
 
-pub trait CollectorType: Send + Unpin + WithLen {
-    type Input: Collectable;
-    type Output: crate::collect::Collected + ToJsonResult + Serialize;
-
-    fn ingest(&mut self, src: &mut Self::Input);
-    fn set_range_complete(&mut self);
-    fn set_timed_out(&mut self);
-
-    // TODO use this crate's Error instead:
-    fn result(&mut self) -> Result<Self::Output, Error>;
-}
-
-pub trait Collector: Send + Unpin + WithLen {
-    fn ingest(&mut self, src: &mut dyn Collectable);
-    fn set_range_complete(&mut self);
-    fn set_timed_out(&mut self);
-    fn result(&mut self) -> Result<Box<dyn ToJsonResult>, Error>;
-}
-
-pub trait CollectableType {
-    type Collector: CollectorType<Input = Self>;
-    fn new_collector() -> Self::Collector;
-}
-
-pub trait Collectable: Any {
-    fn new_collector(&self) -> Box<dyn Collector>;
-    fn as_any_mut(&mut self) -> &mut dyn Any;
-}
-
-impl<T: CollectorType + 'static> Collector for T {
-    fn ingest(&mut self, src: &mut dyn Collectable) {
-        let src: &mut <T as CollectorType>::Input = src.as_any_mut().downcast_mut().expect("can not downcast");
-        T::ingest(self, src)
-    }
-
-    fn set_range_complete(&mut self) {
-        T::set_range_complete(self)
-    }
-
-    fn set_timed_out(&mut self) {
-        T::set_timed_out(self)
-    }
-
-    fn result(&mut self) -> Result<Box<dyn ToJsonResult>, Error> {
-        let ret = T::result(self)?;
-        Ok(Box::new(ret) as _)
-    }
-}
-
-impl<T: CollectableType + 'static> Collectable for T {
-    fn new_collector(&self) -> Box<dyn Collector> {
-        Box::new(T::new_collector()) as _
-    }
-
-    fn as_any_mut(&mut self) -> &mut dyn Any {
-        // TODO interesting: why exactly does returning `&mut self` not work here?
-        self
-    }
-}
-
-// TODO check usage of this trait
-pub trait ToJsonBytes {
-    fn to_json_bytes(&self) -> Result<Vec<u8>, Error>;
-}
-
-// TODO check usage of this trait
-pub trait ToJsonResult: erased_serde::Serialize + fmt::Debug + Send {
-    fn to_json_result(&self) -> Result<Box<dyn ToJsonBytes>, Error>;
-    fn as_any(&self) -> &dyn Any;
-}
-
-erased_serde::serialize_trait_object!(ToJsonResult);
-
-impl ToJsonResult for serde_json::Value {
-    fn to_json_result(&self) -> Result<Box<dyn ToJsonBytes>, Error> {
-        Ok(Box::new(self.clone()))
-    }
-
-    fn as_any(&self) -> &dyn Any {
-        self
-    }
-}
-
-impl ToJsonBytes for serde_json::Value {
-    fn to_json_bytes(&self) -> Result<Vec<u8>, Error> {
-        Ok(serde_json::to_vec(self)?)
-    }
-}