Render flamegraphs from the Cursive context

This will avoid updating the main view while another one overlaps it,
and there can be also some trickery due to they writes to the same
terminal.

This is for tfg, but not for flameshow (another implementation of
TUI flamegraphs).

src/interpreter/worker.rs

@@ -1,5 +1,6 @@
 use crate::{
-    interpreter::{clickhouse::TraceType, flamegraph, ContextArc},
+    interpreter::clickhouse::{Columns, TraceType},
+    interpreter::{flamegraph, ContextArc},
     view::{self, Navigation},
 };
 use anyhow::{anyhow, Result};
@@ -195,6 +196,24 @@ async fn start_tokio(context: ContextArc, receiver: ReceiverArc) {
     log::info!("Event worker finished");
 }
 
+async fn render_flamegraph(tui: bool, cb_sink: cursive::CbSink, block: Columns) -> Result<()> {
+    if tui {
+        cb_sink
+            .send(Box::new(move |siv: &mut cursive::Cursive| {
+                flamegraph::show(block)
+                    .or_else(|e| {
+                        siv.add_layer(views::Dialog::info(e.to_string()));
+                        return anyhow::Ok(());
+                    })
+                    .unwrap();
+            }))
+            .map_err(|_| anyhow!("Cannot send message to UI"))?;
+    } else {
+        flamegraph::open_in_speedscope(block).await?;
+    }
+    return Ok(());
+}
+
 async fn process_event(context: ContextArc, event: Event, need_clear: &mut bool) -> Result<()> {
     let cb_sink = context.lock().unwrap().cb_sink.clone();
     let clickhouse = context.lock().unwrap().clickhouse.clone();
@@ -262,37 +281,19 @@ async fn process_event(context: ContextArc, event: Event, need_clear: &mut bool)
         }
         Event::ShowServerFlameGraph(tui, trace_type) => {
             let flamegraph_block = clickhouse.get_flamegraph(trace_type, None, None).await?;
-
-            // NOTE: should we do this via cursive, to block the UI?
-            if tui {
-                flamegraph::show(flamegraph_block)?;
-            } else {
-                flamegraph::open_in_speedscope(flamegraph_block).await?;
-            }
+            render_flamegraph(tui, cb_sink, flamegraph_block).await?;
             *need_clear = true;
         }
         Event::ShowQueryFlameGraph(trace_type, tui, event_time_microseconds, query_ids) => {
             let flamegraph_block = clickhouse
                 .get_flamegraph(trace_type, Some(&query_ids), Some(event_time_microseconds))
                 .await?;
-
-            // NOTE: should we do this via cursive, to block the UI?
-            if tui {
-                flamegraph::show(flamegraph_block)?;
-            } else {
-                flamegraph::open_in_speedscope(flamegraph_block).await?;
-            }
+            render_flamegraph(tui, cb_sink, flamegraph_block).await?;
             *need_clear = true;
         }
         Event::ShowLiveQueryFlameGraph(tui, query_ids) => {
             let flamegraph_block = clickhouse.get_live_query_flamegraph(&query_ids).await?;
-
-            // NOTE: should we do this via cursive, to block the UI?
-            if tui {
-                flamegraph::show(flamegraph_block)?;
-            } else {
-                flamegraph::open_in_speedscope(flamegraph_block).await?;
-            }
+            render_flamegraph(tui, cb_sink, flamegraph_block).await?;
             *need_clear = true;
         }
         Event::ExplainPlanIndexes(database, query) => {