From bd659c5b4f67252061d48c866bb7210daa941e27 Mon Sep 17 00:00:00 2001
From: xfy <i@rua.plus>
Date: Wed, 17 Jun 2026 09:40:19 +0800
Subject: [PATCH] perf: add HTML/CSS minification for SSR responses and
 highlight CSS

- Add lol_html-based HTML whitespace minifier (utils/html_minify.rs)
  that collapses whitespace and strips comments while preserving
  <pre>, <code>, <textarea>, <script>, <style> content
- Add Axum middleware (middleware/minify_html.rs) that minifies
  text/html responses with per-URL moka cache (256 entries, 300s TTL)
- Wire middleware into the server router in main.rs
- Add CSS minifier to generate_highlight_css build step
- Apply minify_html to rendered markdown output and TOC
- Add http-body-util dependency for body collection in middleware
---
 Cargo.lock                        |  1 +
 Cargo.toml                        |  2 +
 src/api/markdown.rs               |  4 +-
 src/bin/generate_highlight_css.rs | 52 +++++++++++++++-
 src/main.rs                       |  7 +++
 src/middleware/minify_html.rs     | 98 +++++++++++++++++++++++++++++++
 src/middleware/mod.rs             |  2 +
 src/utils/html_minify.rs          | 75 +++++++++++++++++++++++
 src/utils/mod.rs                  |  3 +
 9 files changed, 240 insertions(+), 4 deletions(-)
 create mode 100644 src/middleware/minify_html.rs
 create mode 100644 src/middleware/mod.rs
 create mode 100644 src/utils/html_minify.rs

diff --git a/Cargo.lock b/Cargo.lock
index 5252a6a..26d0e94 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5312,6 +5312,7 @@ dependencies = [
  "governor",
  "hex",
  "http",
+ "http-body-util",
  "image",
  "js-sys",
  "lol_html",
diff --git a/Cargo.toml b/Cargo.toml
index c9e1989..2e337f2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,6 +21,7 @@ tower-http = { version = "0.6", optional = true }
 rand = { version = "0.8", features = ["getrandom"], optional = true }
 http = { version = "1", optional = true }
 axum = { version = "0.8", optional = true, features = ["multipart"] }
+http-body-util = { version = "0.1", optional = true }
 serde_json = "1.0"
 sha2 = { version = "0.10", optional = true }
 hex = { version = "0.4", optional = true }
@@ -72,6 +73,7 @@ server = [
     "dep:tracing",
     "dep:tracing-subscriber",
     "dep:tower-http",
+    "dep:http-body-util",
     "dep:lol_html",
     "dep:syntect",
     "dep:axum",
diff --git a/src/api/markdown.rs b/src/api/markdown.rs
index b26320a..3a0324d 100644
--- a/src/api/markdown.rs
+++ b/src/api/markdown.rs
@@ -190,8 +190,8 @@ pub fn render_markdown_enhanced(md: &str) -> RenderedContent {
     }
 
     RenderedContent {
-        html: clean_html(&html),
-        toc_html,
+        html: crate::utils::html_minify::minify_html(&clean_html(&html)),
+        toc_html: crate::utils::html_minify::minify_html(&toc_html),
     }
 }
 
diff --git a/src/bin/generate_highlight_css.rs b/src/bin/generate_highlight_css.rs
index f7580f7..cfb65be 100644
--- a/src/bin/generate_highlight_css.rs
+++ b/src/bin/generate_highlight_css.rs
@@ -43,12 +43,15 @@ fn main() {
     let mocha_rewritten = rewrite_rules(&mocha_clean, ".md-content pre code", ".dark ");
 
     let mut output = String::new();
-    output.push_str("/* Auto-generated by generate_highlight_css — DO NOT EDIT */\n\n");
+    output.push_str("/* Auto-generated by generate_highlight_css — DO NOT EDIT */\n");
     output.push_str("/* Catppuccin Latte (light) */\n");
     output.push_str(&latte_rewritten);
-    output.push_str("\n/* Catppuccin Mocha (dark) */\n");
+    output.push_str("/* Catppuccin Mocha (dark) */\n");
     output.push_str(&mocha_rewritten);
 
+    // 压缩最终 CSS：去掉注释、空白和换行
+    let output = minify_css(&output);
+
     // 确保 public/ 目录存在并写入生成的 CSS
     std::fs::create_dir_all("public").expect("Failed to create public/");
     std::fs::write("public/highlight.css", output).expect("Failed to write public/highlight.css");
@@ -91,6 +94,51 @@ fn strip_comments(css: &str) -> String {
 /// - `css`: syntect 生成的原始 CSS；
 /// - `base`: 作用域基础选择器，这里固定为 `.md-content pre code`；
 /// - `prefix`: 主题前缀，浅色主题传空字符串，深色主题传 `.dark `。
+/// 压缩 CSS：移除注释、合并空白、删除选择器/属性周围的无用空格。
+fn minify_css(css: &str) -> String {
+    let mut out = String::with_capacity(css.len());
+    let chars: Vec<char> = css.chars().collect();
+    let mut i = 0;
+    let mut last_significant: Option<char> = None;
+    let mut pending_space = false;
+
+    while i < chars.len() {
+        // 跳过 /* ... */ 注释
+        if i + 1 < chars.len() && chars[i] == '/' && chars[i + 1] == '*' {
+            i += 2;
+            while i + 1 < chars.len() && !(chars[i] == '*' && chars[i + 1] == '/') {
+                i += 1;
+            }
+            i += 2;
+            continue;
+        }
+
+        let ch = chars[i];
+        if ch.is_whitespace() {
+            if last_significant.is_some() {
+                pending_space = true;
+            }
+            i += 1;
+            continue;
+        }
+
+        // 在特定分隔符前后不需要空格
+        let no_space_before = "{ } : ; ,".contains(ch);
+        let no_space_after = last_significant.map_or(false, |c| "{ } : ; ,".contains(c));
+
+        if pending_space && !no_space_after && !no_space_before {
+            out.push(' ');
+        }
+        pending_space = false;
+
+        out.push(ch);
+        last_significant = Some(ch);
+        i += 1;
+    }
+
+    out.trim().to_string()
+}
+
 fn rewrite_rules(css: &str, base: &str, prefix: &str) -> String {
     let mut out = String::new();
     let mut pos = 0;
diff --git a/src/main.rs b/src/main.rs
index 69521e7..ee966d0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -20,6 +20,8 @@ mod db;
 #[cfg(feature = "server")]
 mod highlight;
 mod hooks;
+#[cfg(feature = "server")]
+mod middleware;
 mod models;
 mod pages;
 mod router;
@@ -101,6 +103,11 @@ fn main() {
             // 合并三条路由：自定义 API、静态资源、Dioxus 主应用
             let router = api_routes.merge(static_routes).merge(dioxus_app);
 
+            // 对 SSR 返回的 HTML 做空白压缩（保留 <pre>/<code> 等标签内格式）
+            let router = router.layer(axum::middleware::from_fn(
+                crate::middleware::minify_html::layer,
+            ));
+
             Ok(router)
         });
     }
diff --git a/src/middleware/minify_html.rs b/src/middleware/minify_html.rs
new file mode 100644
index 0000000..de2f639
--- /dev/null
+++ b/src/middleware/minify_html.rs
@@ -0,0 +1,98 @@
+//! SSR HTML 空白压缩中间件。
+//!
+//! 对 Dioxus fullstack 返回的 `text/html` 响应做轻量 minify。
+//! 为了避免 SSR 增量渲染缓存命中后仍然重复 minify，中间件内部维护了一个按 URL
+//! 缓存的内存缓存（容量有限、TTL 较短），minify 后的结果会直接复用。
+
+#[cfg(feature = "server")]
+use axum::{
+    body::Body,
+    extract::Request,
+    http::{header, StatusCode},
+    middleware::Next,
+    response::Response,
+};
+use http_body_util::BodyExt;
+use moka::future::Cache;
+use std::time::Duration;
+
+/// 按 URL 缓存 minify 结果，避免 SSR 缓存命中后重复计算。
+static MINIFY_CACHE: std::sync::LazyLock<Cache<String, String>> =
+    std::sync::LazyLock::new(|| {
+        Cache::builder()
+            .max_capacity(256)
+            .time_to_live(Duration::from_secs(300))
+            .build()
+    });
+
+/// Axum 中间件入口。
+pub async fn layer(request: Request, next: Next) -> Response {
+    let uri = request.uri().clone();
+    let response = next.run(request).await;
+
+    let is_html = response
+        .headers()
+        .get(header::CONTENT_TYPE)
+        .and_then(|v| v.to_str().ok())
+        .map(|ct| ct.starts_with("text/html"))
+        .unwrap_or(false);
+
+    if !is_html {
+        return response;
+    }
+
+    // 命中缓存则直接返回
+    let cache_key = uri.to_string();
+    if let Some(cached) = MINIFY_CACHE.get(&cache_key).await {
+        return build_response(response, cached);
+    }
+
+    let (parts, body) = response.into_parts();
+    let bytes = match body.collect().await {
+        Ok(collected) => collected.to_bytes(),
+        Err(_) => {
+            return Response::builder()
+                .status(StatusCode::INTERNAL_SERVER_ERROR)
+                .body(Body::empty())
+                .expect("failed to build error response");
+        }
+    };
+
+    let original = String::from_utf8_lossy(&bytes);
+    let minified = crate::utils::html_minify::minify_html(&original);
+
+    // 写入缓存（忽略失败）
+    let _ = MINIFY_CACHE.insert(cache_key, minified.clone()).await;
+
+    let mut response = Response::builder()
+        .status(parts.status)
+        .header(header::CONTENT_TYPE, "text/html; charset=utf-8")
+        .body(Body::from(minified.clone()))
+        .expect("failed to build minified response");
+
+    // 保留原响应的其他 header，并修正 Content-Length
+    *response.headers_mut() = parts.headers;
+    response.headers_mut().remove(header::TRANSFER_ENCODING);
+    response
+        .headers_mut()
+        .insert(header::CONTENT_LENGTH, minified.len().into());
+
+    response
+}
+
+fn build_response(original: Response, body: String) -> Response {
+    let (parts, _body) = original.into_parts();
+    let mut response = Response::builder()
+        .status(parts.status)
+        .header(header::CONTENT_TYPE, "text/html; charset=utf-8")
+        .body(Body::from(body.clone()))
+        .expect("failed to build cached response");
+
+    *response.headers_mut() = parts.headers;
+    response.headers_mut().remove(header::TRANSFER_ENCODING);
+    response
+        .headers_mut()
+        .insert(header::CONTENT_LENGTH, body.len().into());
+
+    response
+}
diff --git a/src/middleware/mod.rs b/src/middleware/mod.rs
new file mode 100644
index 0000000..b276e30
--- /dev/null
+++ b/src/middleware/mod.rs
@@ -0,0 +1,2 @@
+#[cfg(feature = "server")]
+pub mod minify_html;
diff --git a/src/utils/html_minify.rs b/src/utils/html_minify.rs
new file mode 100644
index 0000000..d5a6b5e
--- /dev/null
+++ b/src/utils/html_minify.rs
@@ -0,0 +1,75 @@
+//! HTML 空白压缩工具函数。
+//!
+//! 仅服务端使用。对 HTML 片段做轻量 minify：
+//! - 合并标签之间连续空白为一个空格；
+//! - 移除 HTML 注释；
+//! - 保留 `<pre>`、`<code>`、`<textarea>`、`<script>`、`<style>` 内部原样空白。
+
+use lol_html::{doc_comments, doc_text, element, rewrite_str, RewriteStrSettings};
+use std::cell::Cell;
+use std::rc::Rc;
+
+/// 压缩 HTML 中的无用空白。
+pub fn minify_html(input: &str) -> String {
+    let protected_depth: Rc<Cell<usize>> = Rc::new(Cell::new(0));
+
+    rewrite_str(
+        input,
+        RewriteStrSettings {
+            element_content_handlers: vec![element!(
+                "pre, code, textarea, script, style",
+                {
+                    let depth = protected_depth.clone();
+                    move |el| {
+                        depth.set(depth.get() + 1);
+                        let depth_end = depth.clone();
+                        let _ = el.on_end_tag(lol_html::end_tag!(move |_end| {
+                            depth_end.set(depth_end.get().saturating_sub(1));
+                            Ok(())
+                        }));
+                        Ok(())
+                    }
+                }
+            )],
+            document_content_handlers: vec![
+                doc_text!({
+                    let depth = protected_depth.clone();
+                    move |text| {
+                        if depth.get() == 0 {
+                            let s = text.as_str();
+                            let collapsed = collapse_whitespace(s);
+                            if collapsed != s {
+                                text.set_str(collapsed);
+                            }
+                        }
+                        Ok(())
+                    }
+                }),
+                doc_comments!(|c| {
+                    c.remove();
+                    Ok(())
+                }),
+            ],
+            ..RewriteStrSettings::default()
+        },
+    )
+    .unwrap_or_else(|_| input.to_string())
+}
+
+/// 将连续空白字符合并为一个空格。
+fn collapse_whitespace(s: &str) -> String {
+    let mut out = String::with_capacity(s.len());
+    let mut prev_ws = false;
+    for ch in s.chars() {
+        if ch.is_whitespace() {
+            if !prev_ws {
+                out.push(' ');
+                prev_ws = true;
+            }
+        } else {
+            out.push(ch);
+            prev_ws = false;
+        }
+    }
+    out
+}
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index 90cd467..1015182 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -7,3 +7,6 @@
 pub mod text;
 /// 跨平台的异步睡眠等时间工具。
 pub mod time;
+/// HTML 空白压缩工具。
+#[cfg(feature = "server")]
+pub mod html_minify;