perf(eval): reduce memory syscall

7 files changed, 70 insertions, 112 deletions

diff --git a/src/eval/Element.zig b/src/eval/Element.zig
index 265ccf1..72b6d7d 100644
--- a/src/eval/Element.zig
+++ b/src/eval/Element.zig
@@ -5,6 +5,7 @@ pub const paragraph = @import("paragraph.zig");
 pub const Title = @import("Title.zig");
 pub const list = @import("list.zig");
 pub const Image = @import("Image.zig");
+pub const Root = @import("Root.zig");
 const blocks = @import("blocks.zig");
 pub const Code = blocks.Code;
 pub const Figure = blocks.Figure;
@@ -12,7 +13,6 @@ pub const Figure = blocks.Figure;
 const Element = @This();
 
 vtable: struct {
-    deinit: *const fn (*anyopaque, Allocator) void,
     html: *const fn (*anyopaque, Allocator) HTML.Error!HTML,
 },
 ptr: *anyopaque,
@@ -24,10 +24,6 @@ pub fn renderHTML(self: Element, alloc: Allocator) HTML.Error![]const u8 {
     return el.render(alloc);
 }
 
-pub fn deinit(self: Element, alloc: Allocator) void {
-    self.vtable.deinit(self.ptr, alloc);
-}
-
 pub fn html(self: Element, alloc: Allocator) HTML.Error!HTML {
     return self.vtable.html(self.ptr, alloc);
 }
@@ -44,18 +40,7 @@ pub const Empty = struct {
     }
 
     pub fn element(self: *Self) Element {
-        return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = Self.html } };
-    }
-
-    pub fn deinit(self: *Self, alloc: Allocator) void {
-        destroy(self, alloc);
-    }
-
-    fn destroy(context: *anyopaque, alloc: Allocator) void {
-        const self: *Self = @ptrCast(@alignCast(context));
-        for (self.content.items) |it| it.deinit(alloc);
-        self.content.deinit(alloc);
-        alloc.destroy(self);
+        return .{ .ptr = self, .vtable = .{ .html = Self.html } };
     }
 
     fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
@@ -79,16 +64,7 @@ pub const Literal = struct {
     }
 
     pub fn element(self: *Self) Element {
-        return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = Self.html } };
-    }
-
-    pub fn deinit(self: *Self, alloc: Allocator) void {
-        destroy(self, alloc);
-    }
-
-    fn destroy(context: *anyopaque, alloc: Allocator) void {
-        const self: *Self = @ptrCast(@alignCast(context));
-        alloc.destroy(self);
+        return .{ .ptr = self, .vtable = .{ .html = Self.html } };
     }
 
     fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
@@ -110,11 +86,7 @@ pub fn Simple(comptime tag: []const u8) type {
         }
 
         pub fn element(self: *Self) Element {
-            return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = Self.html } };
-        }
-
-        pub fn deinit(self: *Self, alloc: Allocator) void {
-            destroy(self, alloc);
+            return .{ .ptr = self, .vtable = .{ .html = Self.html } };
         }
 
         pub fn toTag(self: *Self, alloc: Allocator, comptime target: []const u8) !*Simple(target) {
@@ -135,13 +107,6 @@ pub fn Simple(comptime tag: []const u8) type {
             alloc.destroy(self);
         }
 
-        fn destroy(context: *anyopaque, alloc: Allocator) void {
-            var self: *Self = @ptrCast(@alignCast(context));
-            for (self.content.items) |it| it.deinit(alloc);
-            self.content.deinit(alloc);
-            alloc.destroy(self);
-        }
-
         fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
             const self: *Self = @ptrCast(@alignCast(context));
             var el = try HTML.Content.init(alloc, tag);
diff --git a/src/eval/Image.zig b/src/eval/Image.zig
index aa30585..53478b6 100644
--- a/src/eval/Image.zig
+++ b/src/eval/Image.zig
@@ -17,16 +17,7 @@ pub fn init(alloc: Allocator, src: []const u8) !*Self {
 }
 
 pub fn element(self: *Self) Element {
-    return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = html } };
-}
-
-pub fn deinit(self: *Self, alloc: Allocator) void {
-    destroy(self, alloc);
-}
-
-fn destroy(context: *anyopaque, alloc: Allocator) void {
-    const self: *Self = @ptrCast(@alignCast(context));
-    alloc.destroy(self);
+    return .{ .ptr = self, .vtable = .{ .html = html } };
 }
 
 fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
@@ -38,12 +29,13 @@ fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
 }
 
 test "html" {
-    const alloc = std.testing.allocator;
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    var alloc = arena.allocator();
     const expect = std.testing.expect;
     const eql = std.mem.eql;
 
     var img = try init(alloc, "foo");
-    defer img.deinit(alloc);
     const h = try img.element().renderHTML(alloc);
     defer alloc.free(h);
     try expect(eql(u8, h, "<img src=\"foo\">"));
diff --git a/src/eval/Root.zig b/src/eval/Root.zig
new file mode 100644
index 0000000..1834dd0
--- /dev/null
+++ b/src/eval/Root.zig
@@ -0,0 +1,53 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const Arena = std.heap.ArenaAllocator;
+const HTML = @import("html/Element.zig");
+const Element = @import("Element.zig");
+
+const Self = @This();
+
+content: std.ArrayList(Element),
+arena: Arena,
+
+pub fn init(parent: Allocator) !*Self {
+    var s = Self{
+        .content = undefined,
+        .arena = .init(parent),
+    };
+    var alloc = s.arena.allocator();
+    s.content = try .initCapacity(alloc, 2);
+    const v = try alloc.create(Self);
+    v.* = s;
+    return v;
+}
+
+pub fn deinit(self: *Self) void {
+    self.arena.deinit();
+}
+
+pub fn allocator(self: *Self) Allocator {
+    return self.arena.allocator();
+}
+
+pub fn append(self: *Self, el: Element) !void {
+    try self.content.append(self.allocator(), el);
+}
+
+pub fn element(self: *Self) Element {
+    return .{ .vtable = .{ .html = html }, .ptr = self };
+}
+
+pub fn renderHTML(self: *Self, alloc: Allocator) HTML.Error![]const u8 {
+    return try self.element().renderHTML(alloc);
+}
+
+fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
+    const self: *Self = @ptrCast(@alignCast(context));
+    const el = try HTML.Root.init(alloc);
+    errdefer el.deinit();
+    if (self.content.items.len == 0) return el.element();
+    for (self.content.items) |it| {
+        try el.append(try it.html(el.allocator()));
+    }
+    return el.element();
+}
diff --git a/src/eval/Title.zig b/src/eval/Title.zig
index 2e89953..ebb7fa2 100644
--- a/src/eval/Title.zig
+++ b/src/eval/Title.zig
@@ -15,17 +15,7 @@ pub fn init(alloc: Allocator, level: u3, content: Parent) !*Self {
 }
 
 pub fn element(self: *Self) Parent {
-    return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = html } };
-}
-
-pub fn deinit(self: *Self, alloc: Allocator) void {
-    self.element().deinit(alloc);
-}
-
-fn destroy(context: *anyopaque, alloc: Allocator) void {
-    var self: *Self = @ptrCast(@alignCast(context));
-    self.content.deinit(alloc);
-    alloc.destroy(self);
+    return .{ .ptr = self, .vtable = .{ .html = html } };
 }
 
 fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
diff --git a/src/eval/blocks.zig b/src/eval/blocks.zig
index 63a8f12..63c0291 100644
--- a/src/eval/blocks.zig
+++ b/src/eval/blocks.zig
@@ -16,18 +16,7 @@ pub const Code = struct {
     }
 
     pub fn element(self: *Self) Element {
-        return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = Self.html } };
-    }
-
-    pub fn deinit(self: *Self, alloc: Allocator) void {
-        destroy(self, alloc);
-    }
-
-    fn destroy(context: *anyopaque, alloc: Allocator) void {
-        var self: *Self = @ptrCast(@alignCast(context));
-        for (self.content.items) |it| it.deinit(alloc);
-        self.content.deinit(alloc);
-        alloc.destroy(self);
+        return .{ .ptr = self, .vtable = .{ .html = Self.html } };
     }
 
     fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
@@ -54,18 +43,7 @@ pub const Figure = struct {
     }
 
     pub fn element(self: *Self) Element {
-        return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = Self.html } };
-    }
-
-    pub fn deinit(self: *Self, alloc: Allocator) void {
-        destroy(self, alloc);
-    }
-
-    fn destroy(context: *anyopaque, alloc: Allocator) void {
-        const self: *Self = @ptrCast(@alignCast(context));
-        self.content.deinit(alloc);
-        if (self.caption) |cap| cap.deinit(alloc);
-        alloc.destroy(self);
+        return .{ .ptr = self, .vtable = .{ .html = Self.html } };
     }
 
     fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
diff --git a/src/eval/list.zig b/src/eval/list.zig
index 08f180a..06b7af7 100644
--- a/src/eval/list.zig
+++ b/src/eval/list.zig
@@ -18,21 +18,10 @@ fn List(comptime tag: []const u8) type {
         }
 
         pub fn element(self: *Self) Element {
-            return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = html } };
+            return .{ .ptr = self, .vtable = .{ .html = html } };
         }
 
-        pub fn deinit(self: *Self, alloc: Allocator) void {
-            destroy(self, alloc);
-        }
-
-        fn destroy(context: *anyopaque, alloc: Allocator) void {
-            var self: *Self = @ptrCast(@alignCast(context));
-            for (self.content.items) |it| it.deinit(alloc);
-            self.content.deinit(alloc);
-            alloc.destroy(self);
-        }
-
-        fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
+       fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
             const self: *Self = @ptrCast(@alignCast(context));
             var el = try HTML.Content.init(alloc, tag);
             for (self.content.items) |it| {
diff --git a/src/eval/paragraph.zig b/src/eval/paragraph.zig
index b076081..e57f995 100644
--- a/src/eval/paragraph.zig
+++ b/src/eval/paragraph.zig
@@ -26,17 +26,7 @@ pub const Link = struct {
     }
 
     pub fn element(self: *Self) Element {
-        return .{ .ptr = self, .vtable = .{ .deinit = destroy, .html = html } };
-    }
-
-    pub fn deinit(self: *Self, alloc: Allocator) void {
-        destroy(self, alloc);
-    }
-
-    fn destroy(context: *anyopaque, alloc: Allocator) void {
-        var self: *Self = @ptrCast(@alignCast(context));
-        self.content.deinit(alloc);
-        alloc.destroy(self);
+        return .{ .ptr = self, .vtable = .{ .html = html } };
     }
 
     fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
@@ -59,14 +49,15 @@ fn doTest(alloc: Allocator, el: Element, exp: []const u8) !void {
 }
 
 test "paragraph" {
-    const alloc = std.testing.allocator;
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    const alloc = arena.allocator();
 
     const lit = (try Element.Literal.init(alloc, "hello world")).element();
     try doTest(alloc, lit, "hello world");
 
     var p = try Block.init(alloc);
     try p.content.append(alloc, lit);
-    defer p.deinit(alloc);
     try doTest(alloc, p.element(), "<p>hello world</p>");
 
     const link = (try Link.init(alloc, (try Element.Literal.init(alloc, "foo")).element(), "example.org")).element();