Files
daqbuffer/crates/streams/src/json_stream.rs
2024-07-24 12:06:30 +02:00

104 lines
2.9 KiB
Rust

use crate::cbor_stream::SitemtyDynEventsStream;
use err::Error;
use futures_util::Stream;
use futures_util::StreamExt;
use items_0::streamitem::RangeCompletableItem;
use items_0::streamitem::StreamItem;
use items_0::Events;
use items_0::WithLen;
use netpod::log::*;
use std::pin::Pin;
use std::time::Duration;
pub struct JsonBytes(String);
impl JsonBytes {
pub fn new<S: Into<String>>(s: S) -> Self {
Self(s.into())
}
pub fn into_inner(self) -> String {
self.0
}
pub fn len(&self) -> u32 {
self.0.len() as _
}
}
impl WithLen for JsonBytes {
fn len(&self) -> usize {
self.len() as usize
}
}
impl From<JsonBytes> for String {
fn from(value: JsonBytes) -> Self {
value.0
}
}
pub type JsonStream = Pin<Box<dyn Stream<Item = Result<JsonBytes, Error>> + Send>>;
pub fn events_stream_to_json_stream(stream: SitemtyDynEventsStream) -> impl Stream<Item = Result<JsonBytes, Error>> {
let interval = tokio::time::interval(Duration::from_millis(4000));
let stream = tokio_stream::StreamExt::timeout_repeating(stream, interval).map(|x| match x {
Ok(x) => map_events(x),
Err(_) => make_keepalive(),
});
let prepend = {
let item = make_keepalive();
futures_util::stream::iter([item])
};
prepend.chain(stream)
}
fn map_events(x: Result<StreamItem<RangeCompletableItem<Box<dyn Events>>>, Error>) -> Result<JsonBytes, Error> {
match x {
Ok(x) => match x {
StreamItem::DataItem(x) => match x {
RangeCompletableItem::Data(evs) => {
let s = evs.to_json_string();
let item = JsonBytes::new(s);
Ok(item)
}
RangeCompletableItem::RangeComplete => {
let item = serde_json::json!({
"rangeFinal": true,
});
let s = serde_json::to_string(&item)?;
let item = JsonBytes::new(s);
Ok(item)
}
},
StreamItem::Log(item) => {
info!("{item:?}");
let item = JsonBytes::new(String::new());
Ok(item)
}
StreamItem::Stats(item) => {
info!("{item:?}");
let item = JsonBytes::new(String::new());
Ok(item)
}
},
Err(e) => {
let item = serde_json::json!({
"error": e.to_string(),
});
let s = serde_json::to_string(&item)?;
let item = JsonBytes::new(s);
Ok(item)
}
}
}
fn make_keepalive() -> Result<JsonBytes, Error> {
let item = serde_json::json!({
"type": "keepalive",
});
let s = serde_json::to_string(&item).unwrap();
let item = Ok(JsonBytes::new(s));
item
}