Feature: Configurable scroll buffer (#936)

* Configurable scroll buffer

* Fix unit test failures

* Add scroll_buffer_size description in the default config file

* Fix config file

2 files changed, 10 insertions, 0 deletions

diff --git a/zellij-utils/src/consts.rs b/zellij-utils/src/consts.rs
index 416153f20..494d12a20 100644
--- a/zellij-utils/src/consts.rs
+++ b/zellij-utils/src/consts.rs
@@ -5,6 +5,7 @@ use crate::shared::set_permissions;
 use directories_next::ProjectDirs;
 use lazy_static::lazy_static;
 use nix::unistd::Uid;
+use once_cell::sync::OnceCell;
 use std::path::PathBuf;
 use std::{env, fs};
 
@@ -12,6 +13,8 @@ pub const ZELLIJ_CONFIG_FILE_ENV: &str = "ZELLIJ_CONFIG_FILE";
 pub const ZELLIJ_CONFIG_DIR_ENV: &str = "ZELLIJ_CONFIG_DIR";
 pub const ZELLIJ_LAYOUT_DIR_ENV: &str = "ZELLIJ_LAYOUT_DIR";
 pub const VERSION: &str = env!("CARGO_PKG_VERSION");
+pub const DEFAULT_SCROLL_BUFFER_SIZE: usize = 10_000;
+pub static SCROLL_BUFFER_SIZE: OnceCell<usize> = OnceCell::new();
 
 pub const SYSTEM_DEFAULT_CONFIG_DIR: &str = "/etc/zellij";
 pub const SYSTEM_DEFAULT_DATA_DIR_PREFIX: &str = system_default_data_dir();
diff --git a/zellij-utils/src/input/options.rs b/zellij-utils/src/input/options.rs
index e0a38946b..dcaad306a 100644
--- a/zellij-utils/src/input/options.rs
+++ b/zellij-utils/src/input/options.rs
@@ -72,6 +72,8 @@ pub struct Options {
     /// Set behaviour on force close (quit or detach)
     #[structopt(long)]
     pub on_force_close: Option<OnForceClose>,
+    #[structopt(long)]
+    pub scroll_buffer_size: Option<usize>,
 }
 
 impl Options {
@@ -96,6 +98,7 @@ impl Options {
         let layout_dir = other.layout_dir.or_else(|| self.layout_dir.clone());
         let theme = other.theme.or_else(|| self.theme.clone());
         let on_force_close = other.on_force_close.or(self.on_force_close);
+        let scroll_buffer_size = other.scroll_buffer_size.or(self.scroll_buffer_size);
 
         Options {
             simplified_ui,
@@ -107,6 +110,7 @@ impl Options {
             pane_frames,
             mirror_session,
             on_force_close,
+            scroll_buffer_size,
         }
     }
 
@@ -135,6 +139,7 @@ impl Options {
         let layout_dir = other.layout_dir.or_else(|| self.layout_dir.clone());
         let theme = other.theme.or_else(|| self.theme.clone());
         let on_force_close = other.on_force_close.or(self.on_force_close);
+        let scroll_buffer_size = other.scroll_buffer_size.or(self.scroll_buffer_size);
 
         Options {
             simplified_ui,
@@ -146,6 +151,7 @@ impl Options {
             pane_frames,
             mirror_session,
             on_force_close,
+            scroll_buffer_size,
         }
     }
 
@@ -193,6 +199,7 @@ impl From<CliOptions> for Options {
             pane_frames: opts.pane_frames,
             mirror_session: opts.mirror_session,
             on_force_close: opts.on_force_close,
+            scroll_buffer_size: opts.scroll_buffer_size,
         }
     }
 }