handle okay

src/chunking.rs

@@ -6,6 +6,7 @@ use std::{
 	Context,
     },
     pin::Pin,
+    marker::PhantomData,
 };
 use tokio::{
     io::{
@@ -173,3 +174,86 @@ mod tests
 	assert_eq!(&output[..], "Hello world\nHow are you");
     }
 }
+
+/// A stream that chunks its input.
+#[pin_project]
+pub struct ChunkingStream<S, T, Into=Vec<T>>
+{
+    #[pin] stream: Fuse<S>,
+    buf: Vec<T>,
+    cap: usize,
+    _output: PhantomData<Into>,
+
+    push_now: bool,
+}
+
+
+impl<S, T, Into>  ChunkingStream<S,T, Into>
+where S: Stream<Item=T>,
+      Into: From<Vec<T>>
+{
+    pub fn new(stream: S, sz: usize) -> Self
+    {
+	Self {
+	    stream: stream.fuse(),
+	    buf: Vec::with_capacity(sz),
+	    cap: sz,
+	    _output: PhantomData,
+	    push_now: false,
+	}
+    }
+    pub fn into_inner(self) -> S
+    {
+	self.stream.into_inner()
+    }
+    pub fn cap(&self) -> usize
+    {
+	self.cap
+    }
+    pub fn buffer(&self) -> &[T]
+    {
+	&self.buf[..]
+    }
+
+    /// Force the next read to send the buffer even if it's not full.
+    ///
+    /// # Note
+    /// The buffer still won't send if it's empty.
+    pub fn push_now(&mut self)
+    {
+	self.push_now= true;
+    }
+}
+
+impl<S, T, Into> Stream for ChunkingStream<S,T, Into>
+where S: Stream<Item=T>,
+      Into: From<Vec<T>>
+{
+    type Item = Into;
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+	while !(self.push_now && !self.buf.is_empty()) && self.buf.len() < self.cap {
+	    // Buffer isn't full, keep filling
+	    let this = self.as_mut().project();
+
+	    match this.stream.poll_next(cx) {
+		Poll::Ready(None) => {
+		    // Stream is over
+		    break;
+		},
+		Poll::Ready(Some(item)) => {
+		    this.buf.push(item);
+		},
+		_ => return Poll::Pending,
+	    }
+	}
+	// Buffer is full or we reach end of stream
+	Poll::Ready(if self.buf.len() == 0 {
+	    None
+	} else {
+	    let this = self.project();
+	    *this.push_now = false;
+	    let output = std::mem::replace(this.buf, Vec::with_capacity(*this.cap));
+	    Some(output.into())
+	})
+    }
+}

src/ext.rs

@@ -1,4 +1,5 @@
 //! Extensions
+use super::*;
 use std::{
     iter,
     ops::{
@@ -162,3 +163,21 @@ impl<T> DerefMut for AssertNotSend<T>
 	&mut self.0
     }
 }
+
+pub trait ChunkStreamExt<T>: Sized
+{
+    fn chunk_into<I: From<Vec<T>>>(self, sz: usize) -> chunking::ChunkingStream<Self,T,I>;
+    fn chunk(self, sz: usize) -> chunking::ChunkingStream<Self, T>
+    {
+	self.chunk_into(sz)
+    }
+}
+
+impl<S, T> ChunkStreamExt<T> for S
+where S: Stream<Item=T>
+{
+    fn chunk_into<I: From<Vec<T>>>(self, sz: usize) -> chunking::ChunkingStream<Self,T,I>
+    {
+	chunking::ChunkingStream::new(self, sz)
+    }
+}

src/feed.rs

@@ -2,8 +2,10 @@
 use super::*;
 #[cfg(any(feature="feed-sentance", feature="split-sentance"))]
 use sanitise::Sentance;
+use std::iter;
 
-pub const DEFAULT_FEED_BOUNDS: std::ops::RangeFrom<usize> = 2..; //TODO: Add to config somehow
+
+pub const DEFAULT_FEED_BOUNDS: std::ops::RangeFrom<usize> = 2..;
 
 /// Feed `what` into `chain`, at least `bounds` tokens.
 ///
@@ -73,12 +75,12 @@ pub async fn full(who: &IpAddr, state: State, body: impl Unpin + Stream<Item = R
     if_debug! {
 	let timer = std::time::Instant::now();
     }
-    let bounds = &state.config_cache().feed_bounds;
+    //let bounds = &state.config_cache().feed_bounds;
     macro_rules! feed {
-	($chain:expr, $buffer:ident) => {
+	($buffer:expr) => {
 	    {
 		let buffer = $buffer;
-		feed($chain, &buffer, bounds)
+		state.chain_write(buffer.map(ToOwned::to_owned)).await.map_err(|_| FillBodyError)?;
 	    }
 	}
     }
@@ -101,15 +103,11 @@ pub async fn full(who: &IpAddr, state: State, body: impl Unpin + Stream<Item = R
 	    let buffer = std::str::from_utf8(&buffer[..]).map_err(|_| FillBodyError)?;
 	    let buffer = state.inbound_filter().filter_cow(buffer);
 	    info!("{} -> {:?}", who, buffer);
-	    let mut chain = state.chain().write().await;
 	    cfg_if! {
 		if #[cfg(feature="split-newlines")] {
-		    for buffer in buffer.split('\n').filter(|line| !line.trim().is_empty()) {
+		    feed!(buffer.split('\n').filter(|line| !line.trim().is_empty())) 
-			feed!(&mut chain, buffer);
-		    }
 		} else {
-		    feed!(&mut chain, buffer);
+		    feed!(iter::once(buffer));
-
 		}
 	    }
 	} else {
@@ -124,10 +122,10 @@ pub async fn full(who: &IpAddr, state: State, body: impl Unpin + Stream<Item = R
 		let line = state.inbound_filter().filter_cow(&line);
 		let line = line.trim();
 		if !line.is_empty() {
-		    #[cfg(not(feature="hog-buffer"))] 
+		    //#[cfg(not(feature="hog-buffer"))] 
-		    let mut chain = state.chain().write().await; // Acquire mutex once per line? Is this right?
+		    //let mut chain = state.chain().write().await; // Acquire mutex once per line? Is this right?
 		    
-		    feed!(&mut chain, line);
+		    feed!(iter::once(line));
 		    info!("{} -> {:?}", who, line);
 		}
 		written+=line.len();

src/gen.rs

@@ -1,34 +1,46 @@
 //! Generating the strings
 use super::*;
+use tokio::sync::mpsc::error::SendError;
+use futures::StreamExt;
 
-#[derive(Debug)]
+#[derive(Debug, Default)]
-pub struct GenBodyError(pub String);
+pub struct GenBodyError(Option<String>);
 
 impl error::Error for GenBodyError{}
 impl fmt::Display for GenBodyError
 {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
     {
-	write!(f, "failed to write {:?} to body", self.0)
+	if let Some(z) = &self.0 {
+	    write!(f, "failed to write read string {:?} to body", z)
+	} else {
+	    write!(f, "failed to read string from chain. it might be empty.")
+	}
     }
 }
 
 
 pub async fn body(state: State, num: Option<usize>, mut output: mpsc::Sender<String>) -> Result<(), GenBodyError>
 {
-    let chain = state.chain().read().await;
+    let mut chain = state.chain_read();
-    if !chain.is_empty() {
     let filter = state.outbound_filter();
     match num {
 	Some(num) if num < state.config().max_gen_size => {
-		//This could DoS `full_body` and writes, potentially.
+	    let mut chain = chain.take(num);
-		for string in chain.str_iter_for(num) {
+	    while let Some(string) = chain.next().await {
-		    output.send(filter.filter_owned(string)).await.map_err(|e| GenBodyError(e.0))?;
+		output.send(filter.filter_owned(string)).await?;
 	    }
 	},
-	    _ => output.send(filter.filter_owned(chain.generate_str())).await.map_err(|e| GenBodyError(e.0))?,
+	_ => output.send(filter.filter_owned(chain.next().await.ok_or_else(GenBodyError::default)?)).await?,
-	}
     }
     Ok(())
 }
 
+
+impl From<SendError<String>> for GenBodyError
+{
+    #[inline] fn from(from: SendError<String>) -> Self
+    {
+	Self(Some(from.0))
+    }
+}

src/handle.rs

@@ -0,0 +1,285 @@
+//! Chain handler.
+use super::*;
+use std::{
+    marker::Send,
+    sync::Weak,
+    num::NonZeroUsize,
+    task::{Poll, Context,},
+    pin::Pin,
+};
+use tokio::{
+    sync::{
+	RwLock,
+	RwLockReadGuard,
+	mpsc::{
+	    self,
+	    error::SendError,
+	},
+    },
+    task::JoinHandle,
+    time::{
+	self,
+	Duration,
+    },
+};
+use futures::StreamExt;
+
+/// Settings for chain handler
+#[derive(Debug, Clone, PartialEq)]
+pub struct Settings
+{
+    pub backlog: usize,
+    pub capacity: usize,
+    pub timeout: Duration,
+    pub throttle: Option<Duration>,
+    pub bounds: range::DynRange<usize>,
+}
+
+impl Settings
+{
+    /// Should we keep this string.
+    #[inline] fn matches(&self, s: &str) -> bool
+    {
+	true
+    }
+}
+
+impl Default for Settings
+{
+    #[inline]
+    fn default() -> Self
+    {
+	Self {
+	    backlog: 32,
+	    capacity: 4,
+	    timeout: Duration::from_secs(5),
+	    throttle: Some(Duration::from_millis(200)),
+	    bounds: feed::DEFAULT_FEED_BOUNDS.into(),
+	}
+    }
+}
+
+
+#[derive(Debug)]
+struct HostInner<T>
+{
+    input: mpsc::Receiver<Vec<T>>,
+}
+
+#[derive(Debug)]
+struct Handle<T: Send+ chain::Chainable>
+{
+    chain: RwLock<chain::Chain<T>>,
+    input: mpsc::Sender<Vec<T>>,
+    opt: Settings,
+
+    /// Data used only for the worker task.
+    host: msg::Once<HostInner<T>>,
+}
+
+#[derive(Clone, Debug)]
+pub struct ChainHandle<T: Send + chain::Chainable>(Arc<Box<Handle<T>>>);
+
+impl<T: Send+ chain::Chainable> ChainHandle<T>
+{
+    #[inline] pub fn new(chain: chain::Chain<T>) -> Self
+    {
+	Self::with_settings(chain, Default::default())
+    }
+    pub fn with_settings(chain: chain::Chain<T>, opt: Settings) -> Self
+    {
+	let (itx, irx) = mpsc::channel(opt.backlog);
+	Self(Arc::new(Box::new(Handle{
+	    chain: RwLock::new(chain),
+	    input: itx,
+	    opt,
+	    
+	    host: msg::Once::new(HostInner{
+		input: irx,
+	    })
+	})))
+    }
+
+    /// Acquire the chain read lock
+    async fn chain(&self) -> RwLockReadGuard<'_, chain::Chain<T>>
+    {
+	self.0.chain.read().await
+    }
+
+    /// A reference to the chain
+    pub fn chain_ref(&self) -> &RwLock<chain::Chain<T>>
+    {
+	&self.0.chain
+    }
+
+    /// Create a stream that reads generated values forever.
+    pub fn read(&self) -> ChainStream<T>
+    {
+	ChainStream{
+	    chain: Arc::downgrade(&self.0),
+	    buffer: Vec::with_capacity(self.0.opt.backlog),
+	}
+    }
+
+    /// Send this buffer to the chain
+    pub async fn write(&self, buf: Vec<T>) -> Result<(), SendError<Vec<T>>>
+    {
+	self.0.input.clone().send(buf).await
+    }
+}
+
+impl ChainHandle<String>
+{
+    #[deprecated = "use read() pls"]
+    pub async fn generate_body(&self, state: &state::State, num: Option<usize>, mut output: mpsc::Sender<String>) -> Result<(), SendError<String>>
+    {
+	let chain = self.chain().await;
+	if !chain.is_empty() {
+	    let filter = state.outbound_filter();
+	    match num {
+		Some(num) if num < state.config().max_gen_size => {
+		    //This could DoS writes, potentially.
+		    for string in chain.str_iter_for(num) {
+			output.send(filter.filter_owned(string)).await?;
+		    }
+		},
+		_ => output.send(filter.filter_owned(chain.generate_str())).await?,
+	    }
+	}
+	Ok(())
+    }
+}
+
+/// Host this handle on the current task.
+///
+/// # Panics
+/// If `from` has already been hosted.
+pub async fn host(from: ChainHandle<String>)
+{
+    let opt = from.0.opt.clone();
+    let data = from.0.host.unwrap().await;
+
+    let (mut tx, child) = {
+	// The `real` input channel.
+	let from = from.clone();
+	let opt = opt.clone();
+	let (tx, rx) = mpsc::channel::<Vec<Vec<_>>>(opt.backlog);
+	(tx, tokio::spawn(async move {
+	    let mut rx = if let Some(thr) = opt.throttle {
+		time::throttle(thr, rx).boxed()
+	    } else {
+		rx.boxed()
+	    };
+	    trace!("child: Begin waiting on parent");
+	    while let Some(item) = rx.next().await {
+		let mut lock = from.0.chain.write().await;
+		for item in item.into_iter()
+		{
+		    use std::ops::DerefMut;
+		    for item in item.into_iter() {
+			feed::feed(lock.deref_mut(), item, &from.0.opt.bounds);
+		    }
+		}
+	    }
+	    trace!("child: exiting");
+	}))
+    };
+
+    trace!("Begin polling on child");
+    tokio::select!{
+	v = child => {
+	    match v  {
+		#[cold] Ok(_) => {warn!("Child exited before we have? This should probably never happen.")},//Should never happen.
+		Err(e) => {error!("Child exited abnormally. Aborting: {}", e)}, //Child panic or cancel.
+	    }
+	},
+	_ = async move {
+	    let mut rx = data.input.chunk(opt.capacity); //we don't even need this tbh
+	    
+	    while Arc::strong_count(&from.0) > 2 {
+		tokio::select!{
+		    _ = time::delay_for(opt.timeout) => {
+			rx.push_now();
+		    }
+		    Some(buffer) = rx.next() => {
+			if let Err(err) = tx.send(buffer).await {
+			    // Receive closed?
+			    //
+			    // This probably shouldn't happen, as we `select!` for it up there and child never calls `close()` on `rx`.
+			    // In any case, it means we should abort.
+			    error!("Failed to send buffer: {}", err);
+			    break;
+			}
+		    }
+		}
+	    }
+	} => {
+	    // Normal exit
+	    trace!("Normal exit")
+	},
+    }
+    // No more handles except child, no more possible inputs.
+    trace!("Returning");
+}
+
+/// Spawn a new chain handler for this chain.
+pub fn spawn(from: chain::Chain<String>, opt: Settings) -> (JoinHandle<()>, ChainHandle<String>)
+{
+    let handle = ChainHandle::with_settings(from, opt);
+    (tokio::spawn(host(handle.clone())), handle)
+}
+
+#[derive(Debug)]
+pub struct ChainStream<T: Send + chain::Chainable>
+{
+    chain: Weak<Box<Handle<T>>>,
+    buffer: Vec<T>,
+}
+
+impl ChainStream<String>
+{
+    async fn try_pull(&mut self, n: usize) -> Option<NonZeroUsize>
+    {
+	if n == 0 {
+	    return None;
+	}
+	if let Some(read) = self.chain.upgrade() {
+	    let chain = read.chain.read().await;
+	    if chain.is_empty() {
+		return None;
+	    }
+	    
+	    let n = if n == 1 {
+		self.buffer.push(chain.generate_str());
+		1
+	    } else {
+		self.buffer.extend(chain.str_iter_for(n));
+		n //for now
+	    };
+	    Some(unsafe{NonZeroUsize::new_unchecked(n)})
+	} else {
+	    None
+	}
+    }
+}
+
+impl Stream for ChainStream<String>
+{
+    type Item = String;
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+	use futures::Future;
+	let this = self.get_mut();
+	
+	if this.buffer.len() == 0 {
+	    let pull = this.try_pull(this.buffer.capacity());
+	    tokio::pin!(pull);
+	    match pull.poll(cx) {
+		Poll::Ready(Some(_)) => {},
+		Poll::Pending => return Poll::Pending,
+		_ => return Poll::Ready(None),
+	    };
+	}
+	debug_assert!(this.buffer.len()>0);
+	Poll::Ready(Some(this.buffer.remove(0)))
+    }
+}

src/main.rs

@@ -78,6 +78,7 @@ use state::State;
 mod save;
 mod forwarded_list;
 use forwarded_list::XForwardedFor;
+mod handle;
 
 mod feed;
 mod gen;
@@ -134,7 +135,7 @@ async fn main() {
     debug!("Using config {:?}", config);
     trace!("With config cached: {:?}", ccache);
     
-    let chain = Arc::new(RwLock::new(match save::load(&config.file).await {
+    let (chain_handle, chain) = handle::spawn(match save::load(&config.file).await {
 	Ok(chain) => {
 	    info!("Loaded chain from {:?}", config.file);
 	    chain
@@ -144,7 +145,7 @@ async fn main() {
 	    trace!("Error: {}", e);
 	    Chain::new()
 	},
-    }));
+    }, Default::default()/*TODO*/);
     {
 	let mut tasks = Vec::<BoxFuture<'static, ()>>::new();
 	let (state, chain) = {
@@ -152,7 +153,7 @@ async fn main() {
 	    
 	    let state = State::new(config,
 				   ccache,
-				   Arc::clone(&chain),
+				   chain,
 				   Arc::clone(&save_when));
 	    let state2 = state.clone();
 	    let saver = tokio::spawn(save::host(Box::new(state.clone())));

src/msg.rs

@@ -3,6 +3,7 @@ use super::*;
 use tokio::{
     sync::{
 	watch,
+	Mutex,
     },
 };
 use std::{
@@ -12,7 +13,9 @@ use std::{
     error,
 };
 use futures::{
-    future::Future,
+    future::{
+	Future,
+    },
 };
 
 #[derive(Debug)]
@@ -160,3 +163,48 @@ impl Future for Initialiser
 	uhh.poll(cx)
     }
 }
+
+/// A value that can be consumed once.
+#[derive(Debug)]
+pub struct Once<T>(Mutex<Option<T>>);
+
+impl<T> Once<T>
+{
+    /// Create a new instance
+    pub fn new(from: T) -> Self
+    {
+	Self(Mutex::new(Some(from)))
+    }
+    /// Consume into the instance from behind a potentially shared reference.
+    pub async fn consume_shared(self: Arc<Self>) -> Option<T>
+    {
+	match Arc::try_unwrap(self) {
+	    Ok(x) => x.0.into_inner(),
+	    Err(x) => x.0.lock().await.take(),
+	}
+    }
+
+    /// Consume from a shared reference and panic if the value has already been consumed.
+    pub async fn unwrap_shared(self: Arc<Self>) -> T
+    {
+	self.consume_shared().await.unwrap()
+    }
+
+    /// Consume into the instance.
+    pub async fn consume(&self) -> Option<T>
+    {
+	self.0.lock().await.take()
+    }
+
+    /// Consume and panic if the value has already been consumed.
+    pub async fn unwrap(&self) -> T
+    {
+	self.consume().await.unwrap()
+    }
+
+    /// Consume into the inner value
+    pub fn into_inner(self) -> Option<T>
+    {
+	self.0.into_inner()
+    }
+}

src/sanitise/filter.rs

@@ -272,6 +272,6 @@ mod tests
 	let string = "abcdef  ghi  jk1\nhian";
 
 	assert_eq!(filter.filter_str(&string).to_string(), filter.filter_cow(&string).to_string());
-	assert_eq!(filter.filter_cow(&string).to_string(), filter.filter(string.chars()).collect::<String>());
+	assert_eq!(filter.filter_cow(&string).to_string(), filter.filter_iter(string.chars()).collect::<String>());
     }
 }

src/sanitise/sentance.rs

@@ -25,7 +25,7 @@ macro_rules! new {
     };
 }
 
-const DEFAULT_BOUNDARIES: &[char] = &['\n', '.', ':', '!', '?'];
+const DEFAULT_BOUNDARIES: &[char] = &['\n', '.', ':', '!', '?', '~'];
 
 lazy_static! {
     static ref BOUNDARIES: smallmap::Map<char, ()> = {

src/sanitise/word.rs

@@ -25,7 +25,7 @@ macro_rules! new {
     };
 }
 
-const DEFAULT_BOUNDARIES: &[char] = &['!', '.', ','];
+const DEFAULT_BOUNDARIES: &[char] = &['!', '.', ',', '*'];
 
 lazy_static! {
     static ref BOUNDARIES: smallmap::Map<char, ()> = {

src/save.rs

@@ -43,7 +43,7 @@ type Decompressor<T> = BzDecoder<T>;
 
 pub async fn save_now(state: &State) -> io::Result<()>
 {
-    let chain = state.chain().read().await;
+    let chain = state.chain_ref().read().await;
     use std::ops::Deref;
     let to = &state.config().file;
     save_now_to(chain.deref(),to).await
@@ -82,7 +82,7 @@ pub async fn host(mut state: Box<State>)
 	debug!("Begin save handler");
 	while Arc::strong_count(state.when()) > 1 {
 	    {
-		let chain = state.chain().read().await;
+		let chain = state.chain_ref().read().await;
 		use std::ops::Deref;
 		if let Err(e) = save_now_to(chain.deref(), &to).await {
 		    error!("Failed to save chain: {}", e);

src/sentance.rs

@@ -1,17 +1,19 @@
 //! /sentance/
 use super::*;
+use futures::StreamExt;
 
 pub async fn body(state: State, num: Option<usize>, mut output: mpsc::Sender<String>) -> Result<(), gen::GenBodyError>
 {
     let string = {
-	let chain = state.chain().read().await;
+	let mut chain = state.chain_read();
-	if chain.is_empty() {
-	    return Ok(());
-	}
 
 	match num  {
-	    None => chain.generate_str(),
+	    None => chain.next().await.ok_or_else(gen::GenBodyError::default)?,
-	    Some(num) => (0..num).map(|_| chain.generate_str()).join("\n"),
+	    Some(num) if num < state.config().max_gen_size => {//(0..num).map(|_| chain.generate_str()).join("\n"),
+		let chain = chain.take(num);
+		chain.collect::<Vec<_>>().await.join("\n")//TODO: Stream version of JoinStrExt
+	    },
+	    _ => return Err(Default::default()),
 	}
     };
 
@@ -20,14 +22,14 @@ pub async fn body(state: State, num: Option<usize>, mut output: mpsc::Sender<Str
     if let Some(num) = num {
 	for sen in sanitise::Sentance::new_iter(&string).take(num)
 	{
-	    output.send(filter.filter_owned(sen.to_owned())).await.map_err(|e| gen::GenBodyError(e.0))?;
+	    output.send(filter.filter_owned(sen.to_owned())).await?;
 	}
     } else {
 	output.send(filter.filter_owned(match sanitise::Sentance::new_iter(&string) 
 				      .max_by_key(|x| x.len()) {
 					  Some(x) => x,
 					  #[cold] None => return Ok(()),  
-				      }.to_owned())).await.map_err(|e| gen::GenBodyError(e.0))?;
+				      }.to_owned())).await?;
     }
     Ok(())
 }

src/signals.rs

@@ -36,7 +36,7 @@ pub async fn handle(mut state: State)
 		    match save::load(&state.config().file).await {
 			Ok(new) => {
 			    {
-				let mut chain = state.chain().write().await;
+				let mut chain = state.chain_ref().write().await;
 				*chain = new;
 			    }
 			    trace!("Replaced with read chain");

src/state.rs

@@ -3,6 +3,7 @@ use super::*;
 use tokio::{
     sync::{
 	watch,
+	mpsc::error::SendError,
     },
 };
 use config::Config;
@@ -25,7 +26,7 @@ impl fmt::Display for ShutdownError
 pub struct State
 {
     config: Arc<Box<(Config, config::Cache)>>, //to avoid cloning config
-    chain: Arc<RwLock<Chain<String>>>,
+    chain: handle::ChainHandle<String>,
     save: Arc<Notify>,
     begin: Initialiser,
 
@@ -78,7 +79,7 @@ impl State
 	&self.config_cache().outbound_filter
     }
     
-    pub fn new(config: Config, cache: config::Cache, chain: Arc<RwLock<Chain<String>>>, save: Arc<Notify>) -> Self
+    pub fn new(config: Config, cache: config::Cache, chain: handle::ChainHandle<String>, save: Arc<Notify>) -> Self
     {
 	let (shutdown, shutdown_recv) = watch::channel(false);
 	Self {
@@ -106,9 +107,23 @@ impl State
 	self.save.notify();
     }
 
-    pub fn chain(&self) -> &RwLock<Chain<String>>
+    /*pub fn chain(&self) -> &RwLock<Chain<String>>
     {
 	&self.chain.as_ref()
+}*/
+    pub fn chain_ref(&self) -> &RwLock<Chain<String>>
+    {
+	&self.chain.chain_ref()
+    }
+
+    pub fn chain_read(&self) -> handle::ChainStream<String>
+    {
+	self.chain.read()
+    }
+
+    pub async fn chain_write(&self, buffer: impl IntoIterator<Item = String>) -> Result<(), SendError<Vec<String>>>
+    {
+	self.chain.write(buffer.into_iter().collect()).await
     }
 
     pub fn when(&self) -> &Arc<Notify>