From b6b1f02565331cd653758e1bdd295febd3baaf7c Mon Sep 17 00:00:00 2001
From: CJ van den Berg <cj@vdbonline.com>
Date: Mon, 8 Dec 2025 14:32:01 +0100
Subject: [PATCH] fix: switch to a shared GraphemeCache and increase it's size
 to 512kb

---
 src/renderer/vaxis/GraphemeCache.zig | 23 +++++++++++++++++++++++
 src/renderer/vaxis/Layer.zig         |  3 +++
 src/renderer/vaxis/Plane.zig         | 16 +++-------------
 src/renderer/vaxis/renderer.zig      |  3 +++
 4 files changed, 32 insertions(+), 13 deletions(-)
 create mode 100644 src/renderer/vaxis/GraphemeCache.zig

diff --git a/src/renderer/vaxis/GraphemeCache.zig b/src/renderer/vaxis/GraphemeCache.zig
new file mode 100644
index 0000000..b47e9b6
--- /dev/null
+++ b/src/renderer/vaxis/GraphemeCache.zig
@@ -0,0 +1,23 @@
+storage: *Storage,
+
+pub const GraphemeCache = @This();
+
+pub inline fn put(self: *@This(), bytes: []const u8) []u8 {
+    return self.storage.put(bytes);
+}
+
+pub const Storage = struct {
+    buf: [1024 * 512]u8 = undefined,
+    idx: usize = 0,
+
+    pub fn put(self: *@This(), bytes: []const u8) []u8 {
+        if (self.idx + bytes.len > self.buf.len) self.idx = 0;
+        defer self.idx += bytes.len;
+        @memcpy(self.buf[self.idx .. self.idx + bytes.len], bytes);
+        return self.buf[self.idx .. self.idx + bytes.len];
+    }
+
+    pub fn cache(self: *@This()) GraphemeCache {
+        return .{ .storage = self };
+    }
+};
diff --git a/src/renderer/vaxis/Layer.zig b/src/renderer/vaxis/Layer.zig
index 50831c8..042af43 100644
--- a/src/renderer/vaxis/Layer.zig
+++ b/src/renderer/vaxis/Layer.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 const vaxis = @import("vaxis");
 
 pub const Plane = @import("Plane.zig");
+const GraphemeCache = @import("GraphemeCache.zig");
 
 const Layer = @This();
 
@@ -9,6 +10,7 @@ view: View,
 y_off: i32 = 0,
 x_off: i32 = 0,
 plane_: Plane,
+cache_storage: GraphemeCache.Storage = .{},
 
 const View = struct {
     allocator: std.mem.Allocator,
@@ -57,6 +59,7 @@ pub fn init(allocator: std.mem.Allocator, opts: Options) std.mem.Allocator.Error
     const name = "layer";
     self.plane_ = .{
         .window = self.window(),
+        .cache = self.cache_storage.cache(),
         .name_buf = undefined,
         .name_len = name.len,
     };
diff --git a/src/renderer/vaxis/Plane.zig b/src/renderer/vaxis/Plane.zig
index 50fcf1e..8ff6943 100644
--- a/src/renderer/vaxis/Plane.zig
+++ b/src/renderer/vaxis/Plane.zig
@@ -8,6 +8,7 @@ const vaxis = @import("vaxis");
 const Buffer = @import("Buffer");
 const color = @import("color");
 const RGB = @import("color").RGB;
+const GraphemeCache = @import("GraphemeCache.zig");
 
 const Plane = @This();
 
@@ -18,7 +19,7 @@ row: i32 = 0,
 col: i32 = 0,
 name_buf: [name_buf_len]u8,
 name_len: usize,
-cache: GraphemeCache = .{},
+cache: GraphemeCache,
 style: vaxis.Cell.Style = .{},
 style_base: vaxis.Cell.Style = .{},
 scrolling: bool = false,
@@ -49,6 +50,7 @@ pub fn init(nopts: *const Options, parent_: Plane) !Plane {
     const len = @min(nopts.name.len, name_buf_len);
     var plane: Plane = .{
         .window = parent_.window.child(opts),
+        .cache = parent_.cache,
         .name_buf = undefined,
         .name_len = len,
         .scrolling = nopts.flags == .VSCROLL,
@@ -500,18 +502,6 @@ pub fn metrics(self: *const Plane, tab_width: usize) Buffer.Metrics {
     };
 }
 
-const GraphemeCache = struct {
-    buf: [1024 * 32]u8 = undefined,
-    idx: usize = 0,
-
-    pub fn put(self: *GraphemeCache, bytes: []const u8) []u8 {
-        if (self.idx + bytes.len > self.buf.len) self.idx = 0;
-        defer self.idx += bytes.len;
-        @memcpy(self.buf[self.idx .. self.idx + bytes.len], bytes);
-        return self.buf[self.idx .. self.idx + bytes.len];
-    }
-};
-
 fn to_cell_color(col: ThemeColor) vaxis.Cell.Color {
     return .{ .rgb = RGB.to_u8s(RGB.from_u24(col.color)) };
 }
diff --git a/src/renderer/vaxis/renderer.zig b/src/renderer/vaxis/renderer.zig
index 5f6376c..78524c2 100644
--- a/src/renderer/vaxis/renderer.zig
+++ b/src/renderer/vaxis/renderer.zig
@@ -16,6 +16,7 @@ pub const CursorShape = vaxis.Cell.CursorShape;
 
 pub const style = @import("style.zig").StyleBits;
 pub const styles = @import("style.zig");
+const GraphemeCache = @import("GraphemeCache.zig");
 
 const Self = @This();
 pub const log_name = "vaxis";
@@ -25,6 +26,7 @@ allocator: std.mem.Allocator,
 tty: vaxis.Tty,
 vx: vaxis.Vaxis,
 tty_buffer: []u8,
+cache_storage: GraphemeCache.Storage = .{},
 
 no_alternate: bool,
 event_buffer: std.Io.Writer.Allocating,
@@ -240,6 +242,7 @@ pub fn stdplane(self: *Self) Plane {
     const name = "root";
     var plane: Plane = .{
         .window = self.vx.window(),
+        .cache = self.cache_storage.cache(),
         .name_buf = undefined,
         .name_len = name.len,
     };