core: configurable scrollback limit

TODO.md

@@ -25,5 +25,3 @@ paged-terminal branch:
 
 - tests and logic for overflowing page capacities:
   * graphemes
-  * styles
-- configurable scrollback size

src/config/Config.zig

@@ -427,6 +427,27 @@ command: ?[]const u8 = null,
 /// command.
 @"abnormal-command-exit-runtime": u32 = 250,
 
+/// The size of the scrollback buffer in bytes. This also includes the active
+/// screen. No matter what this is set to, enough memory will always be
+/// allocated for the visible screen and anything leftover is the limit for
+/// the scrollback.
+///
+/// When this limit is reached, the oldest lines are removed from the
+/// scrollback.
+///
+/// Scrollback currently exists completely in memory. This means that the
+/// larger this value, the larger potential memory usage. Scrollback is
+/// allocated lazily up to this limit, so if you set this to a very large
+/// value, it will not immediately consume a lot of memory.
+///
+/// This size is per terminal surface, not for the entire application.
+///
+/// It is not currently possible to set an unlimited scrollback buffer.
+/// This is a future planned feature.
+///
+/// This can be changed at runtime but will only affect new terminal surfaces.
+@"scrollback-limit": u32 = 10_000,
+
 /// Match a regular expression against the terminal text and associate clicking
 /// it with an action. This can be used to match URLs, file paths, etc. Actions
 /// can be opening using the system opener (i.e. `open` or `xdg-open`) or

src/renderer/cursor.zig

@@ -63,7 +63,7 @@ pub fn cursorStyle(
 test "cursor: default uses configured style" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var term = try terminal.Terminal.init(alloc, 10, 10);
+    var term = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 10 });
     defer term.deinit(alloc);
 
     term.screen.cursor.cursor_style = .bar;
@@ -84,7 +84,7 @@ test "cursor: default uses configured style" {
 test "cursor: blinking disabled" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var term = try terminal.Terminal.init(alloc, 10, 10);
+    var term = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 10 });
     defer term.deinit(alloc);
 
     term.screen.cursor.cursor_style = .bar;
@@ -105,7 +105,7 @@ test "cursor: blinking disabled" {
 test "cursor: explictly not visible" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var term = try terminal.Terminal.init(alloc, 10, 10);
+    var term = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 10 });
     defer term.deinit(alloc);
 
     term.screen.cursor.cursor_style = .bar;
@@ -127,7 +127,7 @@ test "cursor: explictly not visible" {
 test "cursor: always block with preedit" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var term = try terminal.Terminal.init(alloc, 10, 10);
+    var term = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 10 });
     defer term.deinit(alloc);
 
     var state: State = .{

src/terminal/kitty/graphics_storage.zig

@@ -645,7 +645,7 @@ fn trackPin(
 test "storage: add placement with zero placement id" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 100, 100);
+    var t = try terminal.Terminal.init(alloc, .{ .cols = 100, .rows = 100 });
     defer t.deinit(alloc);
     t.width_px = 100;
     t.height_px = 100;
@@ -674,7 +674,7 @@ test "storage: add placement with zero placement id" {
 test "storage: delete all placements and images" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 3, 3);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 3, .cols = 3 });
     defer t.deinit(alloc);
     const tracked = t.screen.pages.countTrackedPins();
 
@@ -697,7 +697,7 @@ test "storage: delete all placements and images" {
 test "storage: delete all placements and images preserves limit" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 3, 3);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 3, .cols = 3 });
     defer t.deinit(alloc);
     const tracked = t.screen.pages.countTrackedPins();
 
@@ -722,7 +722,7 @@ test "storage: delete all placements and images preserves limit" {
 test "storage: delete all placements" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 3, 3);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 3, .cols = 3 });
     defer t.deinit(alloc);
     const tracked = t.screen.pages.countTrackedPins();
 
@@ -745,7 +745,7 @@ test "storage: delete all placements" {
 test "storage: delete all placements by image id" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 3, 3);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 3, .cols = 3 });
     defer t.deinit(alloc);
     const tracked = t.screen.pages.countTrackedPins();
 
@@ -768,7 +768,7 @@ test "storage: delete all placements by image id" {
 test "storage: delete all placements by image id and unused images" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 3, 3);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 3, .cols = 3 });
     defer t.deinit(alloc);
     const tracked = t.screen.pages.countTrackedPins();
 
@@ -791,7 +791,7 @@ test "storage: delete all placements by image id and unused images" {
 test "storage: delete placement by specific id" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 3, 3);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 3, .cols = 3 });
     defer t.deinit(alloc);
     const tracked = t.screen.pages.countTrackedPins();
 
@@ -819,7 +819,7 @@ test "storage: delete placement by specific id" {
 test "storage: delete intersecting cursor" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 100, 100);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 100, .cols = 100 });
     defer t.deinit(alloc);
     t.width_px = 100;
     t.height_px = 100;
@@ -851,7 +851,7 @@ test "storage: delete intersecting cursor" {
 test "storage: delete intersecting cursor plus unused" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 100, 100);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 100, .cols = 100 });
     defer t.deinit(alloc);
     t.width_px = 100;
     t.height_px = 100;
@@ -883,7 +883,7 @@ test "storage: delete intersecting cursor plus unused" {
 test "storage: delete intersecting cursor hits multiple" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 100, 100);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 100, .cols = 100 });
     defer t.deinit(alloc);
     t.width_px = 100;
     t.height_px = 100;
@@ -909,7 +909,7 @@ test "storage: delete intersecting cursor hits multiple" {
 test "storage: delete by column" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 100, 100);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 100, .cols = 100 });
     defer t.deinit(alloc);
     t.width_px = 100;
     t.height_px = 100;
@@ -942,7 +942,7 @@ test "storage: delete by column" {
 test "storage: delete by row" {
     const testing = std.testing;
     const alloc = testing.allocator;
-    var t = try terminal.Terminal.init(alloc, 100, 100);
+    var t = try terminal.Terminal.init(alloc, .{ .rows = 100, .cols = 100 });
     defer t.deinit(alloc);
     t.width_px = 100;
     t.height_px = 100;

src/termio/Exec.zig

@@ -128,11 +128,11 @@ pub const DerivedConfig = struct {
 /// process.
 pub fn init(alloc: Allocator, opts: termio.Options) !Exec {
     // Create our terminal
-    var term = try terminal.Terminal.init(
-        alloc,
-        opts.grid_size.columns,
-        opts.grid_size.rows,
-    );
+    var term = try terminal.Terminal.init(alloc, .{
+        .cols = opts.grid_size.columns,
+        .rows = opts.grid_size.rows,
+        .max_scrollback = opts.full_config.@"scrollback-limit",
+    });
     errdefer term.deinit(alloc);
     term.default_palette = opts.config.palette;
     term.color_palette.colors = opts.config.palette;