perf: compress idle terminal scrollback (#3556)

1 files changed, 50 insertions, 0 deletions

diff --git a/src/pane/terminal.rs b/src/pane/terminal.rs
index 154a9539..ecc12ed5 100644
--- a/src/pane/terminal.rs
+++ b/src/pane/terminal.rs
@@ -176,6 +176,13 @@ pub(crate) struct TerminalReadSnapshot {
     pub truncated: bool,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum TerminalCompressionStep {
+    Busy,
+    ActivityChanged(u64),
+    Compressed(crate::ghostty::TerminalCompressionResult),
+}
+
 pub(crate) struct GhosttyPaneTerminal {
     pub core: Mutex<GhosttyPaneCore>,
     key_encoder: Mutex<crate::ghostty::KeyEncoder>,
@@ -479,6 +486,18 @@ impl PaneTerminal {
         self.ghostty.detection_text()
     }
 
+    pub(crate) fn try_compression_activity(&self) -> Result<Option<u64>, crate::ghostty::Error> {
+        self.ghostty.try_compression_activity()
+    }
+
+    pub(crate) fn try_compress_incremental_if_activity(
+        &self,
+        expected_activity: u64,
+    ) -> Result<TerminalCompressionStep, crate::ghostty::Error> {
+        self.ghostty
+            .try_compress_incremental_if_activity(expected_activity)
+    }
+
     pub(crate) fn recent_text_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
         self.ghostty.recent_text_snapshot(lines)
     }
@@ -2074,6 +2093,37 @@ impl GhosttyPaneTerminal {
             .unwrap_or_default()
     }
 
+    fn try_lock_core(&self) -> Option<std::sync::MutexGuard<'_, GhosttyPaneCore>> {
+        match self.core.try_lock() {
+            Ok(core) => Some(core),
+            Err(std::sync::TryLockError::WouldBlock) => None,
+            Err(std::sync::TryLockError::Poisoned(poisoned)) => Some(poisoned.into_inner()),
+        }
+    }
+
+    pub(crate) fn try_compression_activity(&self) -> Result<Option<u64>, crate::ghostty::Error> {
+        let Some(core) = self.try_lock_core() else {
+            return Ok(None);
+        };
+        core.terminal.compression_activity().map(Some)
+    }
+
+    pub(crate) fn try_compress_incremental_if_activity(
+        &self,
+        expected_activity: u64,
+    ) -> Result<TerminalCompressionStep, crate::ghostty::Error> {
+        let Some(mut core) = self.try_lock_core() else {
+            return Ok(TerminalCompressionStep::Busy);
+        };
+        let activity = core.terminal.compression_activity()?;
+        if activity != expected_activity {
+            return Ok(TerminalCompressionStep::ActivityChanged(activity));
+        }
+        core.terminal
+            .compress_incremental()
+            .map(TerminalCompressionStep::Compressed)
+    }
+
     #[cfg(test)]
     pub fn recent_text(&self, lines: usize) -> String {
         self.recent_text_snapshot(lines).text