perspective_client/
client.rs

1// ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
2// ┃ ██████ ██████ ██████       █      █      █      █      █ █▄  ▀███ █       ┃
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4// ┃ █▀▀▀▀▀ █▀▀▀▀▀ █▀██▀▀ ▄▄▄▄▄ █ ▄▄▄▄▄█ ▄▄▄▄▄█ ████████▌▐███ █████▄   █ ▄▄▄▄▄ ┃
5// ┃ █      ██████ █  ▀█▄       █ ██████      █      ███▌▐███ ███████▄ █       ┃
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7// ┃ Copyright (c) 2017, the Perspective Authors.                              ┃
8// ┃ ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌ ┃
9// ┃ This file is part of the Perspective library, distributed under the terms ┃
10// ┃ of the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). ┃
11// ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
12
13use std::collections::HashMap;
14use std::error::Error;
15use std::sync::atomic::AtomicU32;
16use std::sync::Arc;
17
18use async_lock::{Mutex, RwLock};
19use futures::future::{join_all, BoxFuture, LocalBoxFuture};
20use futures::Future;
21use nanoid::*;
22use prost::Message;
23use serde::{Deserialize, Serialize};
24
25use crate::proto::request::ClientReq;
26use crate::proto::response::ClientResp;
27use crate::proto::{
28    self, ColumnType, GetFeaturesReq, GetFeaturesResp, GetHostedTablesReq, GetHostedTablesResp,
29    HostedTable, MakeTableReq, Request, Response, ServerSystemInfoReq,
30};
31use crate::table::{Table, TableInitOptions, TableOptions};
32use crate::table_data::{TableData, UpdateData};
33use crate::utils::*;
34use crate::view::ViewWindow;
35
36/// Metadata about the engine runtime (such as total heap utilization).
37#[derive(Clone, Debug, Serialize, Deserialize)]
38pub struct SystemInfo {
39    pub heap_size: f64,
40}
41
42impl From<proto::ServerSystemInfoResp> for SystemInfo {
43    fn from(value: proto::ServerSystemInfoResp) -> Self {
44        SystemInfo {
45            heap_size: value.heap_size,
46        }
47    }
48}
49
50/// Metadata about what features are supported by the `Server` this `Client`
51/// is connected to.
52pub type Features = Arc<GetFeaturesResp>;
53
54impl GetFeaturesResp {
55    pub fn default_op(&self, col_type: ColumnType) -> Option<&str> {
56        self.filter_ops
57            .get(&(col_type as u32))?
58            .options
59            .first()
60            .map(|x| x.as_str())
61    }
62}
63
64type BoxFn<I, O> = Box<dyn Fn(I) -> O + Send + Sync + 'static>;
65type Box2Fn<I, J, O> = Box<dyn Fn(I, J) -> O + Send + Sync + 'static>;
66
67type Subscriptions<C> = Arc<RwLock<HashMap<u32, C>>>;
68type OnErrorCallback =
69    Box2Fn<Option<String>, Option<ReconnectCallback>, BoxFuture<'static, Result<(), ClientError>>>;
70type OnceCallback = Box<dyn FnOnce(Response) -> ClientResult<()> + Send + Sync + 'static>;
71type SendCallback = Arc<
72    dyn for<'a> Fn(&'a Request) -> BoxFuture<'a, Result<(), Box<dyn Error + Send + Sync>>>
73        + Send
74        + Sync
75        + 'static,
76>;
77
78pub trait ClientHandler: Clone + Send + Sync + 'static {
79    fn send_request<'a>(
80        &'a self,
81        msg: &'a [u8],
82    ) -> impl Future<Output = Result<(), Box<dyn Error + Send + Sync>>> + Send;
83}
84
85#[derive(Clone)]
86#[doc = include_str!("../../docs/client.md")]
87pub struct Client {
88    features: Arc<Mutex<Option<Features>>>,
89    send: SendCallback,
90    id_gen: Arc<AtomicU32>,
91    subscriptions_errors: Subscriptions<OnErrorCallback>,
92    subscriptions_once: Subscriptions<OnceCallback>,
93    subscriptions: Subscriptions<BoxFn<Response, BoxFuture<'static, Result<(), ClientError>>>>,
94}
95
96impl std::fmt::Debug for Client {
97    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
98        f.debug_struct("Client")
99            .field("id_gen", &self.id_gen)
100            .finish()
101    }
102}
103
104/// The type of the `reconnect` parameter passed to [`Client::handle_error`},
105/// and to the callback closure of [`Client::on_error`].
106///
107/// Calling this function from a [`Client::on_error`] closure should run the
108/// (implementation specific) client reconnect logic, e.g. rebindign a
109/// websocket.
110pub type ReconnectCallback =
111    Arc<dyn Fn() -> LocalBoxFuture<'static, Result<(), Box<dyn Error>>> + Send + Sync>;
112
113impl Client {
114    /// Create a new client instance with a closure that handles message
115    /// dispatch. See [`Client::new`] for details.
116    pub fn new_with_callback<T>(send_request: T) -> Self
117    where
118        T: for<'a> Fn(&'a [u8]) -> BoxFuture<'a, Result<(), Box<dyn Error + Send + Sync>>>
119            + 'static
120            + Sync
121            + Send,
122    {
123        let send_request = Arc::new(send_request);
124        let send: SendCallback = Arc::new(move |req| {
125            let mut bytes: Vec<u8> = Vec::new();
126            req.encode(&mut bytes).unwrap();
127            let send_request = send_request.clone();
128            Box::pin(async move { send_request(&bytes).await })
129        });
130
131        Client {
132            features: Arc::default(),
133            id_gen: Arc::new(AtomicU32::new(1)),
134            send,
135            subscriptions: Subscriptions::default(),
136            subscriptions_errors: Arc::default(),
137            subscriptions_once: Arc::default(),
138        }
139    }
140
141    /// Create a new [`Client`] instance with [`ClientHandler`].
142    pub fn new<T>(client_handler: T) -> Self
143    where
144        T: ClientHandler + 'static + Sync + Send,
145    {
146        Self::new_with_callback(move |req| {
147            let client_handler = client_handler.clone();
148            Box::pin(async move { client_handler.send_request(req).await })
149        })
150    }
151
152    /// Handle a message from the external message queue.
153    /// [`Client::handle_response`] is part of the low-level message-handling
154    /// API necessary to implement new transports for a [`Client`]
155    /// connection to a local-or-remote `perspective_server::Server`, and
156    /// doesn't generally need to be called directly by "users" of a
157    /// [`Client`] once connected.
158    pub async fn handle_response<'a>(&'a self, msg: &'a [u8]) -> ClientResult<bool> {
159        let msg = Response::decode(msg)?;
160        tracing::debug!("RECV {}", msg);
161        let mut wr = self.subscriptions_once.write().await;
162        if let Some(handler) = (*wr).remove(&msg.msg_id) {
163            drop(wr);
164            handler(msg)?;
165            return Ok(true);
166        } else if let Some(handler) = self.subscriptions.try_read().unwrap().get(&msg.msg_id) {
167            drop(wr);
168            handler(msg).await?;
169            return Ok(true);
170        }
171
172        tracing::warn!("Received unsolicited server message");
173        Ok(false)
174    }
175
176    pub async fn handle_error(
177        &self,
178        message: Option<String>,
179        reconnect: Option<ReconnectCallback>,
180    ) -> ClientResult<()> {
181        let subs = self.subscriptions_errors.read().await;
182        let tasks = join_all(
183            subs.values()
184                .map(|callback| callback(message.clone(), reconnect.clone())),
185        );
186        tasks.await.into_iter().collect::<Result<(), _>>()?;
187        Ok(())
188    }
189
190    pub async fn on_error(&self, on_error: OnErrorCallback) -> ClientResult<u32> {
191        let id = self.gen_id();
192        self.subscriptions_errors.write().await.insert(id, on_error);
193        Ok(id)
194    }
195
196    pub async fn init(&self) -> ClientResult<()> {
197        let msg = Request {
198            msg_id: self.gen_id(),
199            entity_id: "".to_owned(),
200            client_req: Some(ClientReq::GetFeaturesReq(GetFeaturesReq {})),
201        };
202
203        *self.features.lock().await = Some(Arc::new(match self.oneshot(&msg).await? {
204            ClientResp::GetFeaturesResp(features) => Ok(features),
205            resp => Err(resp),
206        }?));
207
208        Ok(())
209    }
210
211    /// Generate a message ID unique to this client.
212    pub(crate) fn gen_id(&self) -> u32 {
213        self.id_gen
214            .fetch_add(1, std::sync::atomic::Ordering::Acquire)
215    }
216
217    pub(crate) async fn unsubscribe(&self, update_id: u32) -> ClientResult<()> {
218        let callback = self
219            .subscriptions
220            .write()
221            .await
222            .remove(&update_id)
223            .ok_or(ClientError::Unknown("remove_update".to_string()))?;
224
225        drop(callback);
226        Ok(())
227    }
228
229    /// Register a callback which is expected to respond exactly once.
230    pub(crate) async fn subscribe_once(
231        &self,
232        msg: &Request,
233        on_update: Box<dyn FnOnce(Response) -> ClientResult<()> + Send + Sync + 'static>,
234    ) -> ClientResult<()> {
235        self.subscriptions_once
236            .write()
237            .await
238            .insert(msg.msg_id, on_update);
239
240        tracing::debug!("SEND {}", msg);
241        if let Err(e) = (self.send)(msg).await {
242            self.subscriptions_once.write().await.remove(&msg.msg_id);
243            Err(ClientError::Unknown(e.to_string()))
244        } else {
245            Ok(())
246        }
247    }
248
249    pub(crate) async fn subscribe(
250        &self,
251        msg: &Request,
252        on_update: BoxFn<Response, BoxFuture<'static, Result<(), ClientError>>>,
253    ) -> ClientResult<()> {
254        self.subscriptions
255            .write()
256            .await
257            .insert(msg.msg_id, on_update);
258        tracing::debug!("SEND {}", msg);
259        if let Err(e) = (self.send)(msg).await {
260            self.subscriptions.write().await.remove(&msg.msg_id);
261            Err(ClientError::Unknown(e.to_string()))
262        } else {
263            Ok(())
264        }
265    }
266
267    /// Send a `ClientReq` and await both the successful completion of the
268    /// `send`, _and_ the `ClientResp` which is returned.
269    pub(crate) async fn oneshot(&self, msg: &Request) -> ClientResult<ClientResp> {
270        let (sender, receiver) = futures::channel::oneshot::channel::<ClientResp>();
271        let on_update = Box::new(move |msg: Response| {
272            sender.send(msg.client_resp.unwrap()).map_err(|x| x.into())
273        });
274
275        self.subscribe_once(msg, on_update).await?;
276        receiver
277            .await
278            .map_err(|_| ClientError::Unknown("Internal error".to_owned()))
279    }
280
281    pub(crate) fn get_features(&self) -> ClientResult<Features> {
282        Ok(self
283            .features
284            .try_lock()
285            .ok_or(ClientError::NotInitialized)?
286            .as_ref()
287            .ok_or(ClientError::NotInitialized)?
288            .clone())
289    }
290
291    #[doc = include_str!("../../docs/client/table.md")]
292    pub async fn table(&self, input: TableData, options: TableInitOptions) -> ClientResult<Table> {
293        let entity_id = match options.name.clone() {
294            Some(x) => x.to_owned(),
295            None => nanoid!(),
296        };
297
298        if let TableData::View(view) = &input {
299            let window = ViewWindow::default();
300            let arrow = view.to_arrow(window).await?;
301            let mut table = self
302                .crate_table_inner(UpdateData::Arrow(arrow).into(), options.into(), entity_id)
303                .await?;
304
305            let callback = {
306                let table = table.clone();
307                move |update: crate::proto::ViewOnUpdateResp| {
308                    let table = table.clone();
309                    let update = update.delta.expect("Missing update");
310                    async move {
311                        table
312                            .update(
313                                UpdateData::Arrow(update.into()),
314                                crate::UpdateOptions::default(),
315                            )
316                            .await
317                            .unwrap_or_log();
318                    }
319                }
320            };
321
322            let on_update_token = view
323                .on_update(callback, crate::view::OnUpdateOptions {
324                    mode: Some(crate::view::OnUpdateMode::Row),
325                })
326                .await?;
327
328            table.view_update_token = Some(on_update_token);
329            Ok(table)
330        } else {
331            self.crate_table_inner(input, options.into(), entity_id)
332                .await
333        }
334    }
335
336    async fn crate_table_inner(
337        &self,
338        input: TableData,
339        options: TableOptions,
340        entity_id: String,
341    ) -> ClientResult<Table> {
342        let msg = Request {
343            msg_id: self.gen_id(),
344            entity_id: entity_id.clone(),
345            client_req: Some(ClientReq::MakeTableReq(MakeTableReq {
346                data: Some(input.into()),
347                options: Some(options.clone().try_into()?),
348            })),
349        };
350
351        let client = self.clone();
352        match self.oneshot(&msg).await? {
353            ClientResp::MakeTableResp(_) => Ok(Table::new(entity_id, client, options)),
354            resp => Err(resp.into()),
355        }
356    }
357
358    async fn get_table_infos(&self) -> ClientResult<Vec<HostedTable>> {
359        let msg = Request {
360            msg_id: self.gen_id(),
361            entity_id: "".to_owned(),
362            client_req: Some(ClientReq::GetHostedTablesReq(GetHostedTablesReq {})),
363        };
364
365        match self.oneshot(&msg).await? {
366            ClientResp::GetHostedTablesResp(GetHostedTablesResp { table_infos }) => Ok(table_infos),
367            resp => Err(resp.into()),
368        }
369    }
370
371    #[doc = include_str!("../../docs/client/open_table.md")]
372    pub async fn open_table(&self, entity_id: String) -> ClientResult<Table> {
373        let infos = self.get_table_infos().await?;
374
375        // TODO fix this - name is repeated 2x
376        if let Some(info) = infos.into_iter().find(|i| i.entity_id == entity_id) {
377            let options = TableOptions {
378                index: info.index,
379                limit: info.limit,
380            };
381
382            let client = self.clone();
383            Ok(Table::new(entity_id, client, options))
384        } else {
385            Err(ClientError::Unknown("Unknown table".to_owned()))
386        }
387    }
388
389    #[doc = include_str!("../../docs/client/get_hosted_table_names.md")]
390    pub async fn get_hosted_table_names(&self) -> ClientResult<Vec<String>> {
391        let msg = Request {
392            msg_id: self.gen_id(),
393            entity_id: "".to_owned(),
394            client_req: Some(ClientReq::GetHostedTablesReq(GetHostedTablesReq {})),
395        };
396
397        match self.oneshot(&msg).await? {
398            ClientResp::GetHostedTablesResp(GetHostedTablesResp { table_infos }) => {
399                Ok(table_infos.into_iter().map(|i| i.entity_id).collect())
400            },
401            resp => Err(resp.into()),
402        }
403    }
404
405    #[doc = include_str!("../../docs/client/system_info.md")]
406    pub async fn system_info(&self) -> ClientResult<SystemInfo> {
407        let msg = Request {
408            msg_id: self.gen_id(),
409            entity_id: "".to_string(),
410            client_req: Some(ClientReq::ServerSystemInfoReq(ServerSystemInfoReq {})),
411        };
412
413        match self.oneshot(&msg).await? {
414            ClientResp::ServerSystemInfoResp(resp) => Ok(resp.into()),
415            resp => Err(resp.into()),
416        }
417    }
418}
perspective_client/client.rs

perspective_client/
client.rs
