Merge caching and SSR invalidation improvements

.env.example

@@ -23,7 +23,10 @@ MAX_SESSIONS_PER_USER=5
 # Database connection pool size (default: 20)
 DB_POOL_SIZE=20
 
-# SSR page cache duration in seconds (default: 3600)
+# SSR page cache duration in seconds (default: 3600).
+# src/ssr_cache.rs maintains a global generation counter bumped on every post write, but
+# Dioxus 0.7 does not expose an API to wire it into the incremental SSR cache key. Until such
+# an API is available, this TTL is the only effective SSR cache invalidation mechanism.
 SSR_CACHE_SECS=3600
 
 # Compression algorithms for HTTP responses.
@@ -36,3 +39,9 @@ COMPRESSION_ALGORITHMS=gzip,brotli,deflate,zstd
 # Processed variants (?w=, ?format=, etc.) are cached for 24 hours.
 # To invalidate a cached raw upload, change its file path.
 # To refresh a processed variant, change its processing parameters.
+
+# Image disk cache limits
+# Max total size in MB (default: 1024)
+IMAGE_DISK_CACHE_MAX_MB=1024
+# Max file age in hours before forced deletion (default: 168)
+IMAGE_DISK_CACHE_MAX_AGE_HOURS=168

CHANGELOG.md

@@ -10,6 +10,29 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - 图片响应新增 `Cache-Control` 与 `ETag` 头：原始上传文件使用 `immutable, max-age=31536000`，处理变体使用 `max-age=86400`。
+- 新增 `PostListItem` 轻量 DTO，列表/标签/搜索接口不再返回完整正文，显著降低缓存与序列化体积。
+- 新增数据库迁移 `010_post_word_counts.sql`，在 `posts` 表存储 `word_count` 与 `reading_time`，并在写入时维护。
+- 新增基于 moka 的会话内存缓存，减少每次认证请求的 `sessions JOIN users` 数据库查询；缓存对象 `SessionUser` 不包含密码哈希。
+- 新增搜索结果短 TTL 缓存（10 秒），并对查询 key 做规范化处理。
+- 新增图片内存缓存使用 `bytes::Bytes` 存储，命中时仅做引用计数克隆。
+- 新增图片磁盘缓存定时清理后台任务，按文件年龄与总大小上限淘汰。
+- 新增 `src/ssr_cache.rs` SSR 生成号基础设施，为后续 Dioxus 暴露缓存失效 API 做准备。
+
+### Changed
+
+- 文章写路径缓存失效从「全量清空」改为「精确到 slug / tag / 列表页」，并在读取 slug/tag 元数据时使用事务 + `FOR UPDATE` 避免并发竞态。
+- `get_post_stats` 将 3 次独立 `COUNT(*)` 合并为单次条件聚合查询。
+- `row_to_post_list` 已移除，`get_post_by_id` 复用 `row_to_post_full`。
+
+### Fixed
+
+- 过期 session 清理任务现在同时失效会话内存缓存，避免已过期会话在缓存 TTL 窗口内继续被使用。
+- 图片磁盘清理跳过符号链接，防止遍历到缓存目录外部。
+
+### Internal
+
+- 新增 `utils::text::reading_time` 辅助函数，统一阅读时间计算逻辑。
+- 新增缓存、SSR 生成号相关单元测试。
 
 ### Fixed
 

Cargo.lock

@@ -5393,10 +5393,12 @@ version = "0.2.0"
 dependencies = [
  "argon2",
  "axum",
+ "bytes",
  "chrono",
  "deadpool-postgres",
  "dioxus",
  "dotenvy",
+ "futures",
  "governor",
  "hex",
  "http",

Cargo.toml

@@ -36,6 +36,8 @@ zenwebp = { version = "0.3", optional = true }
 moka = { version = "0.12", features = ["future"], optional = true }
 governor = { version = "0.8", optional = true }
 md-5 = { version = "0.10", optional = true }
+futures = { version = "0.3", optional = true }
+bytes = { version = "1", optional = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 web-sys = { version = "0.3", features = ["Document", "Window", "Storage", "Element", "HtmlElement", "DomTokenList", "MediaQueryList", "HtmlImageElement", "MouseEvent", "KeyboardEvent", "Node", "EventTarget", "Navigator"] }
@@ -82,4 +84,6 @@ server = [
     "dep:moka",
     "dep:governor",
     "dep:md-5",
+    "dep:futures",
+    "dep:bytes",
 ]

migrations/010_post_word_counts.sql

@@ -0,0 +1,29 @@
+-- 为 posts 表添加字数与阅读时长列。
+--
+-- 设计说明：
+-- - word_count / reading_time 使用 NOT NULL DEFAULT 0。
+-- - 0 作为“尚未计算/回填”的哨兵值：row_to_post_full 在读到 0 时会退回到
+--   基于 content_md 的实时计算，保证旧数据在列表页仍显示合理的字数与阅读时长。
+-- - 本迁移同时用 PostgreSQL 可用的近似方式回填现有行，避免列表页出现大量 0。
+--   回填仅按空白拆分英文词，对中文统计不精确；精确值会在文章被编辑或
+--   管理员执行“重建内容”时由 Rust count_words 重新写入。
+
+ALTER TABLE posts
+    ADD COLUMN IF NOT EXISTS word_count INTEGER NOT NULL DEFAULT 0,
+    ADD COLUMN IF NOT EXISTS reading_time INTEGER NOT NULL DEFAULT 0;
+
+-- 回填已存在行：将 content_md 按空白拆分为词数组并计数。
+-- array_length 在空/纯空白字符串时可能返回 NULL，用 COALESCE 处理为 1。
+WITH computed AS (
+    SELECT
+        id,
+        GREATEST(1, COALESCE(array_length(regexp_split_to_array(content_md, '\s+'), 1), 1)) AS wc
+    FROM posts
+    WHERE word_count = 0 AND reading_time = 0
+)
+UPDATE posts
+SET
+    word_count = computed.wc,
+    reading_time = GREATEST(1, computed.wc / 200)
+FROM computed
+WHERE posts.id = computed.id;

src/api/auth.rs

@@ -20,7 +20,7 @@ use crate::auth::{password, session};
 #[cfg(feature = "server")]
 use crate::db::pool::get_conn;
 #[cfg(feature = "server")]
-use crate::models::user::{User, UserRole};
+use crate::models::user::{SessionUser, UserRole};
 use crate::models::user::PublicUser;
 
 #[cfg(feature = "server")]
@@ -293,6 +293,7 @@ pub async fn logout() -> Result<AuthResponse, ServerFnError> {
 
     if let Some(t) = token {
         let token_hash = session::hash_token(&t);
+        crate::cache::invalidate_session_user(&token_hash).await;
         client
             .execute("DELETE FROM sessions WHERE token_hash = $1", &[&token_hash])
             .await
@@ -314,16 +315,22 @@ pub struct CurrentUserResponse {
 }
 
 #[cfg(feature = "server")]
-/// 根据会话 token 查询对应用户（含密码哈希等完整信息）。
+/// 根据会话 token 查询对应用户（不含密码哈希，供会话缓存使用）。
 ///
+/// 优先命中内存缓存，避免每次请求都执行 DB JOIN；未命中时回查数据库并回填缓存。
 /// 仅服务端内部使用，不会暴露给前端。
-pub async fn get_user_by_token(token: &str) -> Result<Option<User>, ServerFnError> {
+pub async fn get_user_by_token(token: &str) -> Result<Option<SessionUser>, ServerFnError> {
+    let token_hash = session::hash_token(token);
+
+    if let Some(user) = crate::cache::get_session_user(&token_hash).await {
+        return Ok(Some(user));
+    }
+
     let client = get_conn().await.map_err(AppError::db_conn)?;
 
-    let token_hash = session::hash_token(token);
     let row = client
         .query_opt(
-            "SELECT u.id, u.username, u.email, u.password_hash, u.role, u.created_at
+            "SELECT u.id, u.username, u.email, u.role, u.created_at
              FROM sessions s
              JOIN users u ON s.user_id = u.id
              WHERE s.token_hash = $1 AND s.expires_at > NOW()",
@@ -336,11 +343,10 @@ pub async fn get_user_by_token(token: &str) -> Result<Option<User>, ServerFnErro
         Some(row) => {
             let role_str: String = row.get("role");
             let role = UserRole::from_str(&role_str).unwrap_or(UserRole::Blocked);
-            Some(User {
+            Some(SessionUser {
                 id: row.get("id"),
                 username: row.get("username"),
                 email: row.get("email"),
-                password_hash: row.get("password_hash"),
                 role,
                 created_at: row.get("created_at"),
             })
@@ -348,6 +354,10 @@ pub async fn get_user_by_token(token: &str) -> Result<Option<User>, ServerFnErro
         None => None,
     };
 
+    if let Some(ref u) = user {
+        crate::cache::set_session_user(&token_hash, u.clone()).await;
+    }
+
     Ok(user)
 }
 
@@ -370,19 +380,19 @@ pub async fn get_current_user() -> Result<CurrentUserResponse, ServerFnError> {
 /// 获取当前登录用户并要求其为 admin，否则返回 401/403。
 ///
 /// 供其它服务端接口内部调用。
-pub async fn get_current_admin_user() -> Result<User, AppError> {
+pub async fn get_current_admin_user() -> Result<SessionUser, AppError> {
     let token = get_session_from_ctx().ok_or(AppError::Unauthorized("未登录"))?;
 
-    let user = get_user_by_token(&token)
+    let session_user = get_user_by_token(&token)
         .await
         .map_err(AppError::query)?
         .ok_or(AppError::Unauthorized("会话已过期"))?;
 
-    if user.role != UserRole::Admin {
+    if session_user.role != UserRole::Admin {
         return Err(AppError::Forbidden("权限不足"));
     }
 
-    Ok(user)
+    Ok(session_user)
 }
 
 #[cfg(all(test, feature = "server"))]

src/api/image.rs

@@ -19,6 +19,8 @@ use moka::future::Cache;
 use serde::Deserialize;
 #[cfg(feature = "server")]
 use std::sync::LazyLock;
+#[cfg(feature = "server")]
+use bytes::Bytes;
 
 #[cfg(feature = "server")]
 fn etag_for(data: &[u8]) -> String {
@@ -51,7 +53,7 @@ pub const MAX_IMAGE_PIXELS: u32 = 25_000_000; // ~5k x 5k
 #[derive(Debug, Clone)]
 /// 缓存条目，保存处理后的图片字节与 Content-Type。
 struct CachedImage {
-    data: Vec<u8>,
+    data: Bytes,
     content_type: HeaderValue,
 }
 
@@ -186,7 +188,7 @@ fn content_type(format: image::ImageFormat) -> HeaderValue {
 
 #[cfg(feature = "server")]
 fn image_response(
-    data: Vec<u8>,
+    data: Bytes,
     content_type: HeaderValue,
     cache_control: &'static str,
     headers: &HeaderMap,
@@ -399,7 +401,10 @@ async fn read_disk_cache(cache_key: &str) -> Option<CachedImage> {
         .ok()
         .unwrap_or_else(|| "application/octet-stream".to_string());
     let content_type = HeaderValue::from_str(&ct_str).ok()?;
-    Some(CachedImage { data, content_type })
+    Some(CachedImage {
+        data: Bytes::from(data),
+        content_type,
+    })
 }
 
 #[cfg(feature = "server")]
@@ -454,7 +459,7 @@ pub async fn serve_image(
         return match tokio::fs::read(&file_path).await {
             Ok(data) => {
                 let ct = content_type(detect_format(&path));
-                image_response(data, ct, "public, max-age=31536000, immutable", &headers)
+                image_response(Bytes::from(data), ct, "public, max-age=31536000, immutable", &headers)
             }
             Err(_) => StatusCode::NOT_FOUND.into_response(),
         };
@@ -462,20 +467,19 @@ pub async fn serve_image(
 
     let cache_key = params.cache_key(&path);
     if let Some(cached) = IMAGE_CACHE.get(&cache_key).await {
-        return image_response(cached.data, cached.content_type, "public, max-age=86400", &headers);
+        return image_response(
+            cached.data.clone(),
+            cached.content_type,
+            "public, max-age=86400",
+            &headers,
+        );
     }
 
     if let Some(cached) = read_disk_cache(&cache_key).await {
-        let _ = IMAGE_CACHE
-            .insert(
-                cache_key.clone(),
-                CachedImage {
-                    data: cached.data.clone(),
-                    content_type: cached.content_type.clone(),
-                },
-            )
-            .await;
-        return image_response(cached.data, cached.content_type, "public, max-age=86400", &headers);
+        let data = cached.data.clone();
+        let content_type = cached.content_type.clone();
+        let _ = IMAGE_CACHE.insert(cache_key.clone(), cached).await;
+        return image_response(data, content_type, "public, max-age=86400", &headers);
     }
 
     let data = match tokio::fs::read(&file_path).await {
@@ -485,12 +489,11 @@ pub async fn serve_image(
 
     // Offload decode + resize + encode to the blocking pool so the async
     // runtime stays responsive to other requests.
-    let data_for_blocking = data.clone();
     let path_for_blocking = path.clone();
     let params_for_blocking = params.clone();
     let (processed, content_type) =
         match tokio::task::spawn_blocking(move || {
-            process_image_blocking(data_for_blocking, params_for_blocking, path_for_blocking)
+            process_image_blocking(data, params_for_blocking, path_for_blocking)
         })
         .await
         {
@@ -502,6 +505,7 @@ pub async fn serve_image(
             }
         };
 
+    let processed = Bytes::from(processed);
     let cached = CachedImage {
         data: processed.clone(),
         content_type: content_type.clone(),
@@ -758,7 +762,7 @@ mod tests {
     #[test]
     fn image_response_includes_cache_headers() {
         let resp = image_response(
-            vec![1, 2, 3],
+            Bytes::from(vec![1, 2, 3]),
             HeaderValue::from_static("image/webp"),
             "public, max-age=86400",
             &HeaderMap::new(),
@@ -778,7 +782,7 @@ mod tests {
 
     #[test]
     fn image_response_returns_304_when_etag_matches() {
-        let data = vec![1, 2, 3];
+        let data = Bytes::from(vec![1, 2, 3]);
         let etag = etag_for(&data);
         let mut req_headers = HeaderMap::new();
         req_headers.insert(
@@ -826,7 +830,7 @@ mod tests {
     #[test]
     fn image_response_raw_file_is_immutable() {
         let resp = image_response(
-            vec![1, 2, 3],
+            Bytes::from(vec![1, 2, 3]),
             HeaderValue::from_static("image/jpeg"),
             "public, max-age=31536000, immutable",
             &HeaderMap::new(),

src/api/posts/create.rs

@@ -91,6 +91,10 @@ pub async fn create_post(
         let post_status = PostStatus::from_str(&status).unwrap_or(PostStatus::Draft);
         let cover_image = cover_image.filter(|s| !s.trim().is_empty());
 
+        // 计算字数与阅读时长，随文章一并持久化，供列表查询直接使用。
+        let word_count = crate::utils::text::count_words(&content_md);
+        let reading_time = crate::utils::text::reading_time(word_count);
+
         // 发布状态的文章设置当前发布时间；草稿则为 None。
         let published_at = if post_status == PostStatus::Published {
             Some(chrono::Utc::now())
@@ -106,8 +110,8 @@ pub async fn create_post(
         // 插入文章记录。
         let row = tx
             .query_one(
-                "INSERT INTO posts (author_id, title, slug, summary, content_md, content_html, toc_html, status, published_at, cover_image)
-                 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
+                "INSERT INTO posts (author_id, title, slug, summary, content_md, content_html, toc_html, status, published_at, cover_image, word_count, reading_time)
+                 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)
                  RETURNING id",
                 &[
                     &user.id,
@@ -120,6 +124,8 @@ pub async fn create_post(
                     &post_status.as_str(),
                     &published_at,
                     &cover_image,
+                    &(word_count as i32),
+                    &(reading_time as i32),
                 ],
             )
             .await
@@ -133,17 +139,18 @@ pub async fn create_post(
 
         tx.commit().await.map_err(AppError::tx)?;
 
-        // 写入成功后失效文章列表、标签与统计缓存。
+        // 写入成功后按粒度失效相关缓存。
         crate::cache::invalidate_post_lists();
         crate::cache::invalidate_all_tags();
         crate::cache::invalidate_post_stats();
+        crate::cache::invalidate_search_results();
         // 失效按 slug 缓存，避免之前缓存的 404 继续命中。
         crate::cache::invalidate_post_by_slug(&final_slug).await;
+        // 失效该文章涉及的所有标签下文章列表缓存。
+        crate::cache::invalidate_tag_posts_for(&tags_cleaned).await;
 
-        // 失效该文章涉及的所有标签缓存。
-        for tag_name in &tags_cleaned {
-            crate::cache::invalidate_posts_by_tag(tag_name).await;
-        }
+        // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+        crate::ssr_cache::bump_global_generation();
 
         Ok(CreatePostResponse {
             success: true,

src/api/posts/delete.rs

@@ -1,7 +1,7 @@
 //! 删除文章接口。
 //!
 //! 采用软删除方式，将 posts.deleted_at 设置为当前时间，
-//! 同时清空所有文章相关缓存。
+//! 并按影响范围失效相关缓存。
 //! Dioxus server function，注册在 `/api` 路径下。
 //! 仅在 `feature = "server"` 启用的服务端构建中执行删除与缓存失效。
 
@@ -18,23 +18,52 @@ use crate::db::pool::get_conn;
 /// 删除指定文章。
 ///
 /// 仅 admin 可调用；通过设置 deleted_at 实现软删除，
-/// 成功后清空全部文章缓存。
+/// 成功后按影响范围失效文章列表、标签云、统计、slug 及相关标签文章缓存。
 #[server(DeletePost, "/api")]
 pub async fn delete_post(post_id: i32) -> Result<CreatePostResponse, ServerFnError> {
     let _user = get_current_admin_user().await?;
 
     #[cfg(feature = "server")]
     {
-        let client = get_conn().await.map_err(AppError::db_conn)?;
+        let mut client = get_conn().await.map_err(AppError::db_conn)?;
+        let tx = client.transaction().await.map_err(AppError::tx)?;
+
+        // 在事务内锁定行并读取 slug，避免并发更新导致缓存失效目标过期。
+        let slug_row = tx
+            .query_opt(
+                "SELECT slug FROM posts WHERE id = $1 AND deleted_at IS NULL FOR UPDATE",
+                &[&post_id],
+            )
+            .await
+            .map_err(AppError::query)?;
+
+        let Some(slug_row) = slug_row else {
+            return Ok(CreatePostResponse {
+                success: false,
+                message: "文章不存在".to_string(),
+                post_id: None,
+                slug: None,
+            });
+        };
+        let slug: String = slug_row.get(0);
+
+        let tag_rows = tx
+            .query(
+                "SELECT t.name FROM tags t JOIN post_tags pt ON t.id = pt.tag_id WHERE pt.post_id = $1",
+                &[&post_id],
+            )
+            .await
+            .map_err(AppError::query)?;
+        let tags: Vec<String> = tag_rows.iter().map(|r| r.get(0)).collect();
 
         // 软删除：仅影响未被删除的文章。
-        let result = client
+        let result = tx
             .execute(
                 "UPDATE posts SET deleted_at = NOW() WHERE id = $1 AND deleted_at IS NULL",
                 &[&post_id],
             )
             .await
-            .map_err(AppError::query)?;
+            .map_err(AppError::tx)?;
 
         if result == 0 {
             return Ok(CreatePostResponse {
@@ -45,14 +74,24 @@ pub async fn delete_post(post_id: i32) -> Result<CreatePostResponse, ServerFnErr
             });
         }
 
-        // 删除后所有文章相关缓存均失效。
-        crate::cache::invalidate_all_post_caches();
+        tx.commit().await.map_err(AppError::tx)?;
+
+        // 删除后按影响范围精准失效缓存。
+        crate::cache::invalidate_post_lists();
+        crate::cache::invalidate_all_tags();
+        crate::cache::invalidate_post_stats();
+        crate::cache::invalidate_search_results();
+        crate::cache::invalidate_post_by_slug(&slug).await;
+        crate::cache::invalidate_tag_posts_for(&tags).await;
+
+        // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+        crate::ssr_cache::bump_global_generation();
 
         Ok(CreatePostResponse {
             success: true,
             message: "删除成功".to_string(),
             post_id: Some(post_id),
-            slug: None,
+            slug: Some(slug),
         })
     }
 

src/api/posts/helpers.rs

@@ -6,26 +6,23 @@
 #[cfg(feature = "server")]
 use crate::api::error::AppError;
 #[cfg(feature = "server")]
-use crate::models::post::{Post, PostStatus};
+use crate::models::post::{Post, PostListItem, PostStatus};
 #[cfg(feature = "server")]
-use crate::utils::text::count_words;
+use crate::utils::text::{count_words, reading_time};
 
 /// 复用认证模块的当前 admin 用户获取逻辑。
 #[cfg(feature = "server")]
 pub(super) use crate::api::auth::get_current_admin_user;
 
-/// 将数据库行转换为文章列表项。
+/// 将数据库行转换为轻量列表项 DTO。
 ///
-/// 用于列表接口，包含标签聚合、字数与阅读时长估算，
-/// 不包含上下篇导航与目录。
+/// 不包含 `content_md`/`content_html`；字数与阅读时长直接读取已持久化的列。
+/// 同步函数，不依赖数据库连接。
 #[cfg(feature = "server")]
-pub(super) async fn row_to_post_list(
-    _client: &tokio_postgres::Client,
-    row: &tokio_postgres::Row,
-) -> Post {
+pub(super) fn row_to_post_list_item(row: &tokio_postgres::Row) -> PostListItem {
     let id: i32 = row.get("id");
-    let role_str: String = row.get("status");
-    let status = PostStatus::from_str(&role_str).unwrap_or(PostStatus::Draft);
+    let status_str: String = row.get("status");
+    let status = PostStatus::from_str(&status_str).unwrap_or(PostStatus::Draft);
 
     // 聚合标签并过滤空字符串。
     let tags: Vec<String> = row
@@ -35,17 +32,15 @@ pub(super) async fn row_to_post_list(
         .filter(|t| !t.is_empty())
         .collect();
 
-    let content_md: String = row.get("content_md");
-    let word_count = count_words(&content_md);
+    let word_count: i32 = row.get("word_count");
+    let reading_time: i32 = row.get("reading_time");
 
-    Post {
+    PostListItem {
         id,
         author_id: row.get("author_id"),
         title: row.get("title"),
         slug: row.get("slug"),
         summary: row.get("summary"),
-        content_md,
-        content_html: row.get("content_html"),
         status,
         published_at: row.get("published_at"),
         created_at: row.get("created_at"),
@@ -53,11 +48,8 @@ pub(super) async fn row_to_post_list(
         deleted_at: row.try_get("deleted_at").ok(),
         tags,
         cover_image: row.get("cover_image"),
-        reading_time: (word_count / 200).max(1),
-        word_count,
-        toc_html: None,
-        prev_post: None,
-        next_post: None,
+        reading_time: reading_time.max(1) as u32,
+        word_count: word_count.max(0) as u32,
     }
 }
 
@@ -110,6 +102,17 @@ pub(super) async fn row_to_post_full(
         None
     };
 
+    // 读取正文与已持久化的字数/阅读时长；若列尚未回填（旧数据为 0），则现场计算。
+    let content_md: String = row.get("content_md");
+    let stored_word_count: i32 = row.get("word_count");
+    let stored_reading_time: i32 = row.get("reading_time");
+    let (word_count, reading_time) = if stored_word_count > 0 && stored_reading_time > 0 {
+        (stored_word_count as u32, stored_reading_time as u32)
+    } else {
+        let wc = count_words(&content_md);
+        (wc, reading_time(wc))
+    };
+
     let content_html: Option<String> = row.get("content_html");
     let toc_html_row: Option<String> = row.get("toc_html");
 
@@ -117,7 +120,6 @@ pub(super) async fn row_to_post_full(
     let (content_html, toc_html) = if let Some(html) = content_html {
         (html, toc_html_row)
     } else {
-        let content_md: String = row.get("content_md");
         let rendered = crate::api::markdown::render_markdown_enhanced(&content_md);
         (
             rendered.html,
@@ -129,9 +131,6 @@ pub(super) async fn row_to_post_full(
         )
     };
 
-    let content_md: String = row.get("content_md");
-    let word_count = count_words(&content_md);
-
     Post {
         id,
         author_id: row.get("author_id"),
@@ -147,7 +146,7 @@ pub(super) async fn row_to_post_full(
         deleted_at: row.try_get("deleted_at").ok(),
         tags,
         cover_image: row.get("cover_image"),
-        reading_time: (word_count / 200).max(1),
+        reading_time,
         word_count,
         toc_html,
         prev_post,

src/api/posts/list.rs

@@ -8,7 +8,7 @@
 use dioxus::prelude::*;
 
 #[cfg(feature = "server")]
-use super::helpers::{get_current_admin_user, row_to_post_list};
+use super::helpers::{get_current_admin_user, row_to_post_list_item};
 use super::types::PostListResponse;
 #[cfg(feature = "server")]
 use crate::api::error::AppError;
@@ -82,8 +82,9 @@ pub async fn list_published_posts(
         let rows = client
             .query(
                 "SELECT
-                    p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, 
-                    p.status, p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.id, p.author_id, p.title, p.slug, p.summary, p.status,
+                    p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.word_count, p.reading_time,
                     COALESCE(array_agg(t.name) FILTER (WHERE t.name IS NOT NULL), '{}') as tags
                  FROM posts p
                  LEFT JOIN post_tags pt ON p.id = pt.post_id
@@ -99,7 +100,7 @@ pub async fn list_published_posts(
 
         let mut posts = Vec::new();
         for row in &rows {
-            posts.push(row_to_post_list(&client, row).await);
+            posts.push(row_to_post_list_item(row));
         }
 
         crate::cache::set_post_list(&cache_key, posts.clone(), total).await;
@@ -139,8 +140,9 @@ pub async fn list_posts(page: i32, per_page: i32) -> Result<PostListResponse, Se
         let rows = client
             .query(
                 "SELECT
-                    p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, 
-                    p.status, p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.id, p.author_id, p.title, p.slug, p.summary, p.status,
+                    p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.word_count, p.reading_time,
                     COALESCE(array_agg(t.name) FILTER (WHERE t.name IS NOT NULL), '{}') as tags
                  FROM posts p
                  LEFT JOIN post_tags pt ON p.id = pt.post_id
@@ -156,7 +158,7 @@ pub async fn list_posts(page: i32, per_page: i32) -> Result<PostListResponse, Se
 
         let mut posts = Vec::new();
         for row in &rows {
-            posts.push(row_to_post_list(&client, row).await);
+            posts.push(row_to_post_list_item(row));
         }
 
         Ok(PostListResponse { posts, total })
@@ -198,8 +200,9 @@ pub async fn list_deleted_posts(
         let rows = client
             .query(
                 "SELECT
-                    p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, 
-                    p.status, p.published_at, p.created_at, p.updated_at, p.cover_image, p.deleted_at,
+                    p.id, p.author_id, p.title, p.slug, p.summary, p.status,
+                    p.published_at, p.created_at, p.updated_at, p.cover_image, p.deleted_at,
+                    p.word_count, p.reading_time,
                     COALESCE(array_agg(t.name) FILTER (WHERE t.name IS NOT NULL), '{}') as tags
                  FROM posts p
                  LEFT JOIN post_tags pt ON p.id = pt.post_id
@@ -215,7 +218,7 @@ pub async fn list_deleted_posts(
 
         let mut posts = Vec::new();
         for row in &rows {
-            posts.push(row_to_post_list(&client, row).await);
+            posts.push(row_to_post_list_item(row));
         }
 
         Ok(PostListResponse { posts, total })
@@ -251,8 +254,9 @@ pub async fn get_posts_by_tag(tag_name: String) -> Result<PostListResponse, Serv
         let rows = client
             .query(
                 "SELECT
-                    p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, 
-                    p.status, p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.id, p.author_id, p.title, p.slug, p.summary, p.status,
+                    p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.word_count, p.reading_time,
                     COALESCE(array_agg(t2.name) FILTER (WHERE t2.name IS NOT NULL), '{}') as tags
                  FROM posts p
                  JOIN post_tags pt ON p.id = pt.post_id
@@ -270,7 +274,7 @@ pub async fn get_posts_by_tag(tag_name: String) -> Result<PostListResponse, Serv
 
         let mut posts = Vec::new();
         for row in &rows {
-            posts.push(row_to_post_list(&client, row).await);
+            posts.push(row_to_post_list_item(row));
         }
 
         // 当前查询未分页，返回全部匹配文章，因此 total 等于结果长度。

src/api/posts/read.rs

@@ -8,7 +8,7 @@
 use dioxus::prelude::*;
 
 #[cfg(feature = "server")]
-use super::helpers::{get_current_admin_user, row_to_post_full, row_to_post_list};
+use super::helpers::{get_current_admin_user, row_to_post_full};
 use super::types::SinglePostResponse;
 #[cfg(feature = "server")]
 use crate::api::error::AppError;
@@ -29,8 +29,9 @@ pub async fn get_post_by_id(post_id: i32) -> Result<SinglePostResponse, ServerFn
         let row = client
             .query_opt(
                 "SELECT
-                    p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, 
+                    p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, p.toc_html,
                     p.status, p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.word_count, p.reading_time,
                     COALESCE(array_agg(t.name) FILTER (WHERE t.name IS NOT NULL), '{}') as tags
                  FROM posts p
                  LEFT JOIN post_tags pt ON p.id = pt.post_id
@@ -43,7 +44,7 @@ pub async fn get_post_by_id(post_id: i32) -> Result<SinglePostResponse, ServerFn
             .map_err(AppError::query)?;
 
         let post = match row {
-            Some(row) => Some(row_to_post_list(&client, &row).await),
+            Some(row) => Some(row_to_post_full(&client, &row).await),
             None => None,
         };
 
@@ -75,6 +76,7 @@ pub async fn get_post_by_slug(slug: String) -> Result<SinglePostResponse, Server
                 "SELECT
                     p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, p.toc_html,
                     p.status, p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.word_count, p.reading_time,
                     COALESCE(array_agg(t.name) FILTER (WHERE t.name IS NOT NULL), '{}') as tags,
                     prev.title as prev_title, prev.slug as prev_slug,
                     next.title as next_title, next.slug as next_slug

src/api/posts/rebuild.rs

@@ -75,14 +75,25 @@ pub async fn rebuild_content_html(rebuild_all: bool) -> Result<RebuildResult, Se
                 Some(rendered.toc_html)
             };
 
+            let word_count = crate::utils::text::count_words(&content_md);
+            let reading_time = crate::utils::text::reading_time(word_count);
+
             match client
                 .execute(
-                    "UPDATE posts SET content_html = $1, toc_html = $2 WHERE id = $3",
-                    &[&rendered.html, &toc_html, &id],
+                    "UPDATE posts SET content_html = $1, toc_html = $2, word_count = $3, reading_time = $4 WHERE id = $5",
+                    &[
+                        &rendered.html,
+                        &toc_html,
+                        &(word_count as i32),
+                        &(reading_time as i32),
+                        &id,
+                    ],
                 )
                 .await
             {
-                Ok(_) => rebuilt += 1,
+                Ok(_) => {
+                    rebuilt += 1;
+                }
                 Err(_) => {
                     failed += 1;
                     if errors.len() < MAX_DISPLAY_ERRORS {
@@ -92,9 +103,13 @@ pub async fn rebuild_content_html(rebuild_all: bool) -> Result<RebuildResult, Se
             }
         }
 
-        // 只要有文章被更新，就清空所有文章缓存。
-        if rebuilt > 0 || failed > 0 {
+        // 重建会修改 word_count / reading_time 等列表项字段，批量影响列表、标签云、
+        // 标签文章及单篇缓存；这里使用全量失效作为务实的回退策略。
+        if rebuilt > 0 {
             crate::cache::invalidate_all_post_caches();
+            crate::cache::invalidate_search_results();
+            // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+            crate::ssr_cache::bump_global_generation();
         }
 
         Ok(RebuildResult {

src/api/posts/search.rs

@@ -8,17 +8,19 @@
 use dioxus::prelude::*;
 
 #[cfg(feature = "server")]
-use super::helpers::row_to_post_list;
+use super::helpers::row_to_post_list_item;
 use super::types::PostListResponse;
 #[cfg(feature = "server")]
 use crate::api::error::AppError;
 #[cfg(feature = "server")]
+use crate::cache;
+#[cfg(feature = "server")]
 use crate::db::pool::get_conn;
 
 /// 搜索已发布文章。
 ///
 /// 空查询直接返回空结果；非空查询使用 `word_similarity` 计算相关度，
-/// 并限制返回 50 条记录。当前未缓存，每次均查询数据库。
+/// 并限制返回 50 条记录。结果写入短 TTL 内存缓存以减轻 DB 压力。
 #[server(SearchPosts, "/api")]
 pub async fn search_posts(query: String) -> Result<PostListResponse, ServerFnError> {
     #[cfg(feature = "server")]
@@ -47,6 +49,12 @@ pub async fn search_posts(query: String) -> Result<PostListResponse, ServerFnErr
             });
         }
 
+        // 先检查短 TTL 的搜索结果缓存。
+        let cache_key = cache::normalize_search_key(q);
+        if let Some((posts, total)) = cache::get_search_results(&cache_key).await {
+            return Ok(PostListResponse { posts, total });
+        }
+
         // 转义 SQL LIKE 通配符，避免用户输入 % / _ 导致全表扫描。
         let escaped = q
             .replace('\\', "\\\\")
@@ -57,8 +65,9 @@ pub async fn search_posts(query: String) -> Result<PostListResponse, ServerFnErr
         let rows = client
             .query(
                 "SELECT
-                    p.id, p.author_id, p.title, p.slug, p.summary, p.content_md, p.content_html, 
-                    p.status, p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.id, p.author_id, p.title, p.slug, p.summary, p.status,
+                    p.published_at, p.created_at, p.updated_at, p.cover_image,
+                    p.word_count, p.reading_time,
                     COALESCE(array_agg(t.name) FILTER (WHERE t.name IS NOT NULL), '{}') as tags,
                     word_similarity(p.search_text, $2) AS sml
                  FROM posts p
@@ -76,10 +85,11 @@ pub async fn search_posts(query: String) -> Result<PostListResponse, ServerFnErr
 
         let mut posts = Vec::new();
         for row in &rows {
-            posts.push(row_to_post_list(&client, row).await);
+            posts.push(row_to_post_list_item(row));
         }
 
         let total = posts.len() as i64;
+        cache::set_search_results(&cache_key, posts.clone(), total).await;
         Ok(PostListResponse { posts, total })
     }
 

src/api/posts/stats.rs

@@ -18,7 +18,8 @@ use crate::models::post::PostStats;
 
 /// 获取文章统计信息。
 ///
-/// 需要 admin 权限；优先命中缓存，未命中时分别统计总数、草稿数与已发布数。
+/// 需要 admin 权限；优先命中缓存，未命中时通过单次条件聚合查询同时统计
+/// 未删除文章总数、草稿数与已发布数。
 #[server(GetPostStats, "/api")]
 pub async fn get_post_stats() -> Result<PostStatsResponse, ServerFnError> {
     let _user = get_current_admin_user().await?;
@@ -31,37 +32,23 @@ pub async fn get_post_stats() -> Result<PostStatsResponse, ServerFnError> {
 
         let client = get_conn().await.map_err(AppError::db_conn)?;
 
-        // 统计未删除文章总数。
-        let total: i64 = client
-            .query_one("SELECT COUNT(*) FROM posts WHERE deleted_at IS NULL", &[])
-            .await
-            .map_err(AppError::query)?
-            .get(0);
-
-        // 统计草稿数量。
-        let drafts: i64 = client
+        // 通过单次条件聚合查询同时统计总数、草稿数与已发布数。
+        let row = client
             .query_one(
-                "SELECT COUNT(*) FROM posts WHERE deleted_at IS NULL AND status = 'draft'",
+                "SELECT
+                    COUNT(*) FILTER (WHERE deleted_at IS NULL) AS total,
+                    COUNT(*) FILTER (WHERE deleted_at IS NULL AND status = 'draft') AS drafts,
+                    COUNT(*) FILTER (WHERE deleted_at IS NULL AND status = 'published') AS published
+                 FROM posts",
                 &[],
             )
             .await
-            .map_err(AppError::query)?
-            .get(0);
-
-        // 统计已发布数量。
-        let published: i64 = client
-            .query_one(
-                "SELECT COUNT(*) FROM posts WHERE deleted_at IS NULL AND status = 'published'",
-                &[],
-            )
-            .await
-            .map_err(AppError::query)?
-            .get(0);
+            .map_err(AppError::query)?;
 
         let stats = PostStats {
-            total,
-            drafts,
-            published,
+            total: row.get("total"),
+            drafts: row.get("drafts"),
+            published: row.get("published"),
         };
         crate::cache::set_post_stats(stats.clone()).await;
         Ok(PostStatsResponse { stats })

src/api/posts/trash.rs

@@ -1,6 +1,7 @@
 //! 回收站操作接口：恢复、彻底删除、批量操作与一键清空。
 //!
-//! 所有接口需要 admin 权限，操作后清空全部文章相关缓存。
+//! 所有接口需要 admin 权限，操作后按影响范围精准失效缓存；
+//! 仅在影响集很大（如批量清空）时才回退到全量缓存失效。
 //! Dioxus server function，注册在 `/api` 路径下。
 //! 仅在 `feature = "server"` 启用的服务端构建中执行数据库操作。
 
@@ -16,6 +17,11 @@ use crate::api::slug::ensure_unique_slug;
 #[cfg(feature = "server")]
 use crate::db::pool::get_conn;
 
+/// 批量/清空操作使用精准失效的最大记录数阈值。
+/// 超过该阈值时回退到 `invalidate_all_post_caches()`，避免大量串行缓存操作。
+#[cfg(feature = "server")]
+const PRECISE_INVALIDATION_LIMIT: usize = 50;
+
 /// 恢复一篇已删除的文章（将 deleted_at 置空）。
 ///
 /// 若该文章原始 slug 已被其他未删除文章占用，自动追加数字后缀。
@@ -28,10 +34,10 @@ pub async fn restore_post(post_id: i32) -> Result<CreatePostResponse, ServerFnEr
         let mut client = get_conn().await.map_err(AppError::db_conn)?;
         let tx = client.transaction().await.map_err(AppError::tx)?;
 
-        // 读取待恢复文章的当前 slug 与是否确已删除。
+        // 在事务内锁定行并读取当前 slug、标签与是否确已删除。
         let row = tx
             .query_opt(
-                "SELECT slug FROM posts WHERE id = $1 AND deleted_at IS NOT NULL",
+                "SELECT slug FROM posts WHERE id = $1 AND deleted_at IS NOT NULL FOR UPDATE",
                 &[&post_id],
             )
             .await
@@ -51,6 +57,15 @@ pub async fn restore_post(post_id: i32) -> Result<CreatePostResponse, ServerFnEr
         // 恢复时确保 slug 在未删除文章中唯一（自动加后缀）；在事务内检查避免并发竞态。
         let new_slug = ensure_unique_slug(&tx, &current_slug, Some(post_id)).await?;
 
+        let tag_rows = tx
+            .query(
+                "SELECT t.name FROM tags t JOIN post_tags pt ON t.id = pt.tag_id WHERE pt.post_id = $1",
+                &[&post_id],
+            )
+            .await
+            .map_err(AppError::query)?;
+        let tags: Vec<String> = tag_rows.iter().map(|r| r.get(0)).collect();
+
         // 置空 deleted_at，并更新 slug（可能已加后缀）。
         let result = tx
             .execute(
@@ -71,7 +86,17 @@ pub async fn restore_post(post_id: i32) -> Result<CreatePostResponse, ServerFnEr
 
         tx.commit().await.map_err(AppError::tx)?;
 
-        crate::cache::invalidate_all_post_caches();
+        // 精准失效：列表、标签云、统计、旧 slug 与新 slug、相关标签文章。
+        crate::cache::invalidate_post_lists();
+        crate::cache::invalidate_all_tags();
+        crate::cache::invalidate_post_stats();
+        crate::cache::invalidate_search_results();
+        crate::cache::invalidate_post_by_slug(&current_slug).await;
+        crate::cache::invalidate_post_by_slug(&new_slug).await;
+        crate::cache::invalidate_tag_posts_for(&tags).await;
+
+        // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+        crate::ssr_cache::bump_global_generation();
 
         Ok(CreatePostResponse {
             success: true,
@@ -102,15 +127,44 @@ pub async fn purge_post(post_id: i32) -> Result<CreatePostResponse, ServerFnErro
 
     #[cfg(feature = "server")]
     {
-        let client = get_conn().await.map_err(AppError::db_conn)?;
+        let mut client = get_conn().await.map_err(AppError::db_conn)?;
+        let tx = client.transaction().await.map_err(AppError::tx)?;
 
-        let result = client
+        // 在事务内锁定行并读取 slug 与标签，避免并发更新导致缓存失效目标过期。
+        let slug_row = tx
+            .query_opt(
+                "SELECT slug FROM posts WHERE id = $1 AND deleted_at IS NOT NULL FOR UPDATE",
+                &[&post_id],
+            )
+            .await
+            .map_err(AppError::query)?;
+
+        let Some(slug_row) = slug_row else {
+            return Ok(CreatePostResponse {
+                success: false,
+                message: "文章不在回收站".to_string(),
+                post_id: None,
+                slug: None,
+            });
+        };
+        let slug: String = slug_row.get(0);
+
+        let tag_rows = tx
+            .query(
+                "SELECT t.name FROM tags t JOIN post_tags pt ON t.id = pt.tag_id WHERE pt.post_id = $1",
+                &[&post_id],
+            )
+            .await
+            .map_err(AppError::query)?;
+        let tags: Vec<String> = tag_rows.iter().map(|r| r.get(0)).collect();
+
+        let result = tx
             .execute(
                 "DELETE FROM posts WHERE id = $1 AND deleted_at IS NOT NULL",
                 &[&post_id],
             )
             .await
-            .map_err(AppError::query)?;
+            .map_err(AppError::tx)?;
 
         if result == 0 {
             return Ok(CreatePostResponse {
@@ -121,13 +175,24 @@ pub async fn purge_post(post_id: i32) -> Result<CreatePostResponse, ServerFnErro
             });
         }
 
-        crate::cache::invalidate_all_post_caches();
+        tx.commit().await.map_err(AppError::tx)?;
+
+        // 精准失效相关缓存。
+        crate::cache::invalidate_post_lists();
+        crate::cache::invalidate_all_tags();
+        crate::cache::invalidate_post_stats();
+        crate::cache::invalidate_search_results();
+        crate::cache::invalidate_post_by_slug(&slug).await;
+        crate::cache::invalidate_tag_posts_for(&tags).await;
+
+        // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+        crate::ssr_cache::bump_global_generation();
 
         Ok(CreatePostResponse {
             success: true,
             message: "彻底删除成功".to_string(),
             post_id: Some(post_id),
-            slug: None,
+            slug: Some(slug),
         })
     }
 
@@ -161,12 +226,19 @@ pub async fn batch_restore_posts(post_ids: Vec<i32>) -> Result<CreatePostRespons
         let mut client = get_conn().await.map_err(AppError::db_conn)?;
         let tx = client.transaction().await.map_err(AppError::tx)?;
 
-        // 逐条恢复，slug 冲突时自动加后缀。
+        // 记录数较少时使用精准失效；否则回退到全量失效。
+        let use_precise = post_ids.len() <= PRECISE_INVALIDATION_LIMIT;
+
+        // 逐条恢复，slug 冲突时自动加后缀；同时收集受影响的 slug 与标签。
         let mut restored = 0u64;
+        let mut affected_slugs: Vec<String> = Vec::with_capacity(post_ids.len() * 2);
+        let mut affected_tags: std::collections::HashSet<String> =
+            std::collections::HashSet::new();
+
         for id in &post_ids {
             let row = tx
                 .query_opt(
-                    "SELECT slug FROM posts WHERE id = $1 AND deleted_at IS NOT NULL",
+                    "SELECT slug FROM posts WHERE id = $1 AND deleted_at IS NOT NULL FOR UPDATE",
                     &[&id],
                 )
                 .await
@@ -174,6 +246,20 @@ pub async fn batch_restore_posts(post_ids: Vec<i32>) -> Result<CreatePostRespons
             if let Some(row) = row {
                 let current_slug: String = row.get("slug");
                 let new_slug = ensure_unique_slug(&tx, &current_slug, Some(*id)).await?;
+
+                if use_precise {
+                    let tag_rows = tx
+                        .query(
+                            "SELECT t.name FROM tags t JOIN post_tags pt ON t.id = pt.tag_id WHERE pt.post_id = $1",
+                            &[&id],
+                        )
+                        .await
+                        .map_err(AppError::query)?;
+                    for tag_row in &tag_rows {
+                        affected_tags.insert(tag_row.get(0));
+                    }
+                }
+
                 let n = tx
                     .execute(
                         "UPDATE posts SET deleted_at = NULL, slug = $1 WHERE id = $2 AND deleted_at IS NOT NULL",
@@ -182,12 +268,38 @@ pub async fn batch_restore_posts(post_ids: Vec<i32>) -> Result<CreatePostRespons
                     .await
                     .map_err(AppError::tx)?;
                 restored += n;
+
+                if use_precise {
+                    affected_slugs.push(current_slug);
+                    affected_slugs.push(new_slug);
+                }
             }
         }
 
         tx.commit().await.map_err(AppError::tx)?;
 
-        crate::cache::invalidate_all_post_caches();
+        if use_precise {
+            // 精准失效：先去重 slug，再统一失效列表/标签云/统计/标签文章。
+            let unique_slugs: std::collections::HashSet<String> =
+                affected_slugs.into_iter().collect();
+            crate::cache::invalidate_post_lists();
+            crate::cache::invalidate_all_tags();
+            crate::cache::invalidate_post_stats();
+            crate::cache::invalidate_search_results();
+            for slug in &unique_slugs {
+                crate::cache::invalidate_post_by_slug(slug).await;
+            }
+            crate::cache::invalidate_tag_posts_for(&affected_tags.into_iter().collect::<Vec<_>>()).await;
+
+            // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+            crate::ssr_cache::bump_global_generation();
+        } else {
+            // 影响集过大时回退到全量失效，避免大量串行缓存操作。
+            crate::cache::invalidate_all_post_caches();
+            crate::cache::invalidate_search_results();
+            // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+            crate::ssr_cache::bump_global_generation();
+        }
 
         Ok(CreatePostResponse {
             success: true,
@@ -224,18 +336,76 @@ pub async fn batch_purge_posts(post_ids: Vec<i32>) -> Result<CreatePostResponse,
             });
         }
 
-        let client = get_conn().await.map_err(AppError::db_conn)?;
-
+        let mut client = get_conn().await.map_err(AppError::db_conn)?;
+        let tx = client.transaction().await.map_err(AppError::tx)?;
         let total = post_ids.len() as i64;
-        let result = client
+
+        // 记录数较少时锁定行并读取 slug 与标签，使用精准失效；否则回退到全量失效。
+        let use_precise = post_ids.len() <= PRECISE_INVALIDATION_LIMIT;
+        let (slugs, tags) = if use_precise {
+            let mut slugs = Vec::with_capacity(post_ids.len());
+            let mut tags_set: std::collections::HashSet<String> =
+                std::collections::HashSet::new();
+
+            for id in &post_ids {
+                let slug_row = tx
+                    .query_opt(
+                        "SELECT slug FROM posts WHERE id = $1 AND deleted_at IS NOT NULL FOR UPDATE",
+                        &[&id],
+                    )
+                    .await
+                    .map_err(AppError::query)?;
+
+                if let Some(slug_row) = slug_row {
+                    let slug: String = slug_row.get(0);
+                    let tag_rows = tx
+                        .query(
+                            "SELECT t.name FROM tags t JOIN post_tags pt ON t.id = pt.tag_id WHERE pt.post_id = $1",
+                            &[&id],
+                        )
+                        .await
+                        .map_err(AppError::query)?;
+                    for tag_row in &tag_rows {
+                        tags_set.insert(tag_row.get(0));
+                    }
+                    slugs.push(slug);
+                }
+            }
+
+            (slugs, tags_set.into_iter().collect::<Vec<_>>())
+        } else {
+            (Vec::new(), Vec::new())
+        };
+
+        let result = tx
             .execute(
                 "DELETE FROM posts WHERE id = ANY($1) AND deleted_at IS NOT NULL",
                 &[&post_ids],
             )
             .await
-            .map_err(AppError::query)?;
+            .map_err(AppError::tx)?;
 
-        crate::cache::invalidate_all_post_caches();
+        tx.commit().await.map_err(AppError::tx)?;
+
+        if use_precise {
+            crate::cache::invalidate_post_lists();
+            crate::cache::invalidate_all_tags();
+            crate::cache::invalidate_post_stats();
+            crate::cache::invalidate_search_results();
+            for slug in &slugs {
+                crate::cache::invalidate_post_by_slug(slug).await;
+            }
+            crate::cache::invalidate_tag_posts_for(&tags).await;
+
+            // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+            crate::ssr_cache::bump_global_generation();
+        } else {
+            // 影响集过大时回退到全量失效，避免大量串行缓存操作。
+            crate::cache::invalidate_all_post_caches();
+            crate::cache::invalidate_search_results();
+            // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+            crate::ssr_cache::bump_global_generation();
+        }
 
         Ok(CreatePostResponse {
             success: true,
@@ -263,14 +433,65 @@ pub async fn empty_trash() -> Result<CreatePostResponse, ServerFnError> {
 
     #[cfg(feature = "server")]
     {
-        let client = get_conn().await.map_err(AppError::db_conn)?;
+        let mut client = get_conn().await.map_err(AppError::db_conn)?;
+        let tx = client.transaction().await.map_err(AppError::tx)?;
 
-        let result = client
-            .execute("DELETE FROM posts WHERE deleted_at IS NOT NULL", &[])
+        // 在事务内锁定所有待删除行并读取 id/slug，用于后续精准失效；
+        // 同时根据数量决定使用精准失效还是回退到全量失效。
+        let deleted_rows = tx
+            .query(
+                "SELECT id, slug FROM posts WHERE deleted_at IS NOT NULL FOR UPDATE",
+                &[],
+            )
             .await
             .map_err(AppError::query)?;
+        let use_precise = !deleted_rows.is_empty()
+            && deleted_rows.len() <= PRECISE_INVALIDATION_LIMIT;
 
-        crate::cache::invalidate_all_post_caches();
+        let (slugs, tags) = if use_precise {
+            let slugs: Vec<String> = deleted_rows.iter().map(|r| r.get("slug")).collect();
+            let ids: Vec<i32> = deleted_rows.iter().map(|r| r.get("id")).collect();
+
+            let tag_rows = tx
+                .query(
+                    "SELECT t.name FROM tags t JOIN post_tags pt ON t.id = pt.tag_id WHERE pt.post_id = ANY($1)",
+                    &[&ids],
+                )
+                .await
+                .map_err(AppError::query)?;
+            let tags: Vec<String> = tag_rows.iter().map(|r| r.get(0)).collect();
+
+            (slugs, tags)
+        } else {
+            (Vec::new(), Vec::new())
+        };
+
+        let result = tx
+            .execute("DELETE FROM posts WHERE deleted_at IS NOT NULL", &[])
+            .await
+            .map_err(AppError::tx)?;
+
+        tx.commit().await.map_err(AppError::tx)?;
+
+        if use_precise {
+            crate::cache::invalidate_post_lists();
+            crate::cache::invalidate_all_tags();
+            crate::cache::invalidate_post_stats();
+            crate::cache::invalidate_search_results();
+            for slug in &slugs {
+                crate::cache::invalidate_post_by_slug(slug).await;
+            }
+            crate::cache::invalidate_tag_posts_for(&tags).await;
+
+            // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+            crate::ssr_cache::bump_global_generation();
+        } else {
+            // 影响集过大时回退到全量失效，避免大量串行缓存操作。
+            crate::cache::invalidate_all_post_caches();
+            crate::cache::invalidate_search_results();
+            // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+            crate::ssr_cache::bump_global_generation();
+        }
 
         Ok(CreatePostResponse {
             success: true,

src/api/posts/types.rs

@@ -1,6 +1,6 @@
 //! 文章 API 的请求与响应数据结构。
 
-use crate::models::post::{Post, PostStats, Tag};
+use crate::models::post::{Post, PostListItem, PostStats, Tag};
 
 /// 创建/更新/删除文章的统一响应结构。
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
@@ -18,8 +18,8 @@ pub struct CreatePostResponse {
 /// 文章列表响应。
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 pub struct PostListResponse {
-    /// 文章列表。
-    pub posts: Vec<Post>,
+    /// 文章列表（轻量 DTO，不含正文）。
+    pub posts: Vec<PostListItem>,
     /// 符合查询条件的总数。
     pub total: i64,
 }

src/api/posts/update.rs

@@ -55,6 +55,10 @@ pub async fn update_post(
         let post_status = PostStatus::from_str(&status).unwrap_or(PostStatus::Draft);
         let cover_image = cover_image.filter(|s| !s.trim().is_empty());
 
+        // 重新计算字数与阅读时长，保持与正文同步。
+        let word_count = crate::utils::text::count_words(&content_md);
+        let reading_time = crate::utils::text::reading_time(word_count);
+
         let tx = client.transaction().await.map_err(AppError::tx)?;
 
         // 查询旧 slug，用于后续缓存失效。
@@ -150,8 +154,8 @@ pub async fn update_post(
         // 更新文章主表。
         let updated = tx
             .execute(
-                "UPDATE posts SET title = $1, slug = $2, summary = $3, content_md = $4, content_html = $5, toc_html = $6, status = $7, published_at = $8, cover_image = $9, updated_at = NOW()
-                 WHERE id = $10",
+                "UPDATE posts SET title = $1, slug = $2, summary = $3, content_md = $4, content_html = $5, toc_html = $6, status = $7, published_at = $8, cover_image = $9, word_count = $10, reading_time = $11, updated_at = NOW()
+                 WHERE id = $12",
                 &[
                     &title.trim(),
                     &final_slug,
@@ -162,6 +166,8 @@ pub async fn update_post(
                     &post_status.as_str(),
                     &published_at,
                     &cover_image,
+                    &(word_count as i32),
+                    &(reading_time as i32),
                     &post_id,
                 ],
             )
@@ -192,17 +198,18 @@ pub async fn update_post(
         // 失效文章列表、标签、当前 slug 与统计缓存。
         crate::cache::invalidate_post_lists();
         crate::cache::invalidate_all_tags();
-        crate::cache::invalidate_post_by_slug(&final_slug).await;
         crate::cache::invalidate_post_stats();
+        crate::cache::invalidate_search_results();
+        crate::cache::invalidate_post_by_slug(&final_slug).await;
 
         // 合并旧标签与新标签，统一失效标签下的文章列表缓存。
-        let all_tags_to_invalidate: std::collections::HashSet<String> = old_tags
+        let all_tags_to_invalidate: Vec<String> = old_tags
             .into_iter()
             .chain(tags_for_invalidation.into_iter())
+            .collect::<std::collections::HashSet<_>>()
+            .into_iter()
             .collect();
-        for tag_name in &all_tags_to_invalidate {
-            crate::cache::invalidate_posts_by_tag(tag_name).await;
-        }
+        crate::cache::invalidate_tag_posts_for(&all_tags_to_invalidate).await;
 
         // 若 slug 发生变更，额外失效旧 slug 缓存。
         if let Some(ref old) = old_slug {
@@ -211,6 +218,9 @@ pub async fn update_post(
             }
         }
 
+        // 递增 SSR 全局世代号（未来就绪基础设施；当前不会使 Dioxus 0.7 SSR 缓存失效）。
+        crate::ssr_cache::bump_global_generation();
+
         Ok(CreatePostResponse {
             success: true,
             message: "更新成功".to_string(),

src/cache.rs

@@ -1,7 +1,7 @@
 //! 基于 moka 的内存缓存层。
 //!
-//! 仅在启用 `server` feature 时编译，为文章列表、标签、单篇文章、统计信息
-//! 以及评论相关数据提供按键缓存与失效能力。
+//! 仅在启用 `server` feature 时编译，为文章列表、标签、单篇文章、统计信息、
+//! 评论、会话用户以及搜索结果提供按键缓存与失效能力。
 //! 缓存使用 `std::sync::LazyLock` 全局实例，按不同业务数据设置独立的 TTL。
 
 #[cfg(feature = "server")]
@@ -14,7 +14,9 @@ use std::time::Duration;
 #[cfg(feature = "server")]
 use crate::models::comment::PublicComment;
 #[cfg(feature = "server")]
-use crate::models::post::{Post, PostStats, Tag};
+use crate::models::post::{Post, PostListItem, PostStats, Tag};
+#[cfg(feature = "server")]
+use crate::models::user::SessionUser;
 
 // ============================================================================
 // 缓存 TTL 配置
@@ -48,6 +50,14 @@ const TTL_COMMENTS: Duration = Duration::from_secs(60);
 #[cfg(feature = "server")]
 const TTL_PENDING_COUNT: Duration = Duration::from_secs(10);
 
+/// 会话用户缓存 TTL：300 秒（5 分钟），短于 DB 会话过期时间。
+#[cfg(feature = "server")]
+const TTL_SESSION: Duration = Duration::from_secs(300);
+
+/// 搜索结果缓存 TTL：10 秒。
+#[cfg(feature = "server")]
+const TTL_SEARCH: Duration = Duration::from_secs(10);
+
 // ============================================================================
 // 缓存 Key 类型
 // ============================================================================
@@ -80,7 +90,7 @@ pub enum CacheKey {
 
 /// 文章列表缓存类型，值为（文章列表，总数）。
 #[cfg(feature = "server")]
-pub type PostListCache = Cache<CacheKey, (Vec<Post>, i64)>;
+pub type PostListCache = Cache<CacheKey, (Vec<PostListItem>, i64)>;
 
 /// 标签列表缓存类型。
 #[cfg(feature = "server")]
@@ -161,19 +171,45 @@ static PENDING_COUNT_CACHE: LazyLock<Cache<CacheKey, i64>> = LazyLock::new(|| {
         .build()
 });
 
+/// 会话用户缓存类型。
+#[cfg(feature = "server")]
+pub type SessionCache = Cache<String, SessionUser>;
+
+/// 搜索结果缓存类型。
+#[cfg(feature = "server")]
+pub type SearchCache = Cache<String, (Vec<PostListItem>, i64)>;
+
+/// 全局会话用户缓存实例，最大容量 1000，TTL 5 分钟。
+#[cfg(feature = "server")]
+pub static SESSION_CACHE: LazyLock<SessionCache> = LazyLock::new(|| {
+    Cache::builder()
+        .max_capacity(1000)
+        .time_to_live(TTL_SESSION)
+        .build()
+});
+
+/// 全局搜索结果缓存实例，最大容量 200，TTL 10 秒。
+#[cfg(feature = "server")]
+static SEARCH_CACHE: LazyLock<SearchCache> = LazyLock::new(|| {
+    Cache::builder()
+        .max_capacity(200)
+        .time_to_live(TTL_SEARCH)
+        .build()
+});
+
 // ============================================================================
 // 公共缓存 API
 // ============================================================================
 
 /// 读取文章分页列表缓存。
 #[cfg(feature = "server")]
-pub async fn get_post_list(key: &CacheKey) -> Option<(Vec<Post>, i64)> {
+pub async fn get_post_list(key: &CacheKey) -> Option<(Vec<PostListItem>, i64)> {
     POST_LIST_CACHE.get(key).await
 }
 
 /// 写入文章分页列表缓存。
 #[cfg(feature = "server")]
-pub async fn set_post_list(key: &CacheKey, posts: Vec<Post>, total: i64) {
+pub async fn set_post_list(key: &CacheKey, posts: Vec<PostListItem>, total: i64) {
     let _ = POST_LIST_CACHE.insert(key.clone(), (posts, total)).await;
 }
 
@@ -224,7 +260,7 @@ pub async fn set_post_by_slug(slug: &str, post: Option<Post>) {
 
 /// 按标签读取文章列表缓存。
 #[cfg(feature = "server")]
-pub async fn get_posts_by_tag(tag: &str) -> Option<(Vec<Post>, i64)> {
+pub async fn get_posts_by_tag(tag: &str) -> Option<(Vec<PostListItem>, i64)> {
     TAG_POSTS_CACHE
         .get(&CacheKey::PostsByTag(tag.to_string()))
         .await
@@ -232,7 +268,7 @@ pub async fn get_posts_by_tag(tag: &str) -> Option<(Vec<Post>, i64)> {
 
 /// 按标签写入文章列表缓存。
 #[cfg(feature = "server")]
-pub async fn set_posts_by_tag(tag: &str, posts: Vec<Post>, total: i64) {
+pub async fn set_posts_by_tag(tag: &str, posts: Vec<PostListItem>, total: i64) {
     let _ = TAG_POSTS_CACHE
         .insert(CacheKey::PostsByTag(tag.to_string()), (posts, total))
         .await;
@@ -288,7 +324,22 @@ pub fn invalidate_post_stats() {
     POST_STATS_CACHE.invalidate_all();
 }
 
+/// 按标签批量失效文章列表缓存。
+#[cfg(feature = "server")]
+pub async fn invalidate_tag_posts_for(tags: &[String]) {
+    let futures: Vec<_> = tags
+        .iter()
+        .map(|tag| invalidate_posts_by_tag(tag))
+        .collect();
+    let _ = futures::future::join_all(futures).await;
+}
+
 /// 清空所有文章相关缓存（列表、标签、单篇、统计、标签文章）。
+///
+/// 这是一个“紧急”使用的全量失效开关，会一次性冲刷所有文章缓存；
+/// 正常写路径应当使用更细粒度的 `invalidate_post_lists` / `invalidate_all_tags` /
+/// `invalidate_post_by_slug` / `invalidate_posts_by_tag` / `invalidate_post_stats` /
+/// `invalidate_tag_posts_for` 等函数，避免不必要的缓存击穿。
 #[cfg(feature = "server")]
 pub fn invalidate_all_post_caches() {
     POST_LIST_CACHE.invalidate_all();
@@ -330,6 +381,53 @@ pub async fn set_pending_count(count: i64) {
         .await;
 }
 
+/// 规范化搜索查询键：trim、转小写、截断至 200 字符。
+#[cfg(feature = "server")]
+pub fn normalize_search_key(query: &str) -> String {
+    query.trim().to_lowercase().chars().take(200).collect()
+}
+
+/// 读取会话用户缓存。
+#[cfg(feature = "server")]
+pub async fn get_session_user(token_hash: &str) -> Option<SessionUser> {
+    SESSION_CACHE.get(token_hash).await
+}
+
+/// 写入会话用户缓存。
+#[cfg(feature = "server")]
+pub async fn set_session_user(token_hash: &str, user: SessionUser) {
+    let _ = SESSION_CACHE.insert(token_hash.to_string(), user).await;
+}
+
+/// 失效指定会话用户缓存。
+#[cfg(feature = "server")]
+pub async fn invalidate_session_user(token_hash: &str) {
+    SESSION_CACHE.invalidate(token_hash).await;
+}
+
+/// 读取搜索结果缓存。
+#[cfg(feature = "server")]
+pub async fn get_search_results(query: &str) -> Option<(Vec<PostListItem>, i64)> {
+    SEARCH_CACHE.get(&normalize_search_key(query)).await
+}
+
+/// 写入搜索结果缓存。
+#[cfg(feature = "server")]
+pub async fn set_search_results(query: &str, posts: Vec<PostListItem>, total: i64) {
+    let _ = SEARCH_CACHE
+        .insert(normalize_search_key(query), (posts, total))
+        .await;
+}
+
+/// 清空所有搜索结果缓存。
+///
+/// 使用同步签名是因为 `moka::Cache::invalidate_all` 为同步操作；
+/// 该函数通常由写路径直接调用，无需额外等待。
+#[cfg(feature = "server")]
+pub fn invalidate_search_results() {
+    SEARCH_CACHE.invalidate_all();
+}
+
 /// 按文章主键失效评论列表缓存。
 #[cfg(feature = "server")]
 pub async fn invalidate_comments_by_post(post_id: i32) {
@@ -351,6 +449,7 @@ mod tests {
     use super::*;
     use crate::models::comment::PublicComment;
     use crate::models::post::PostStatus;
+    use crate::models::user::{SessionUser, UserRole};
     use serial_test::serial;
 
     #[test]
@@ -379,15 +478,31 @@ mod tests {
             page: 999,
             per_page: 99,
         };
-        let posts = vec![];
+        let posts = vec![PostListItem {
+            id: 1,
+            author_id: 1,
+            title: "List Item".to_string(),
+            slug: "list-item".to_string(),
+            summary: None,
+            status: PostStatus::Published,
+            published_at: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+            deleted_at: None,
+            tags: vec!["rust".to_string()],
+            cover_image: None,
+            reading_time: 1,
+            word_count: 10,
+        }];
 
-        set_post_list(&key, posts.clone(), 0).await;
+        set_post_list(&key, posts.clone(), 1).await;
         let cached = get_post_list(&key).await;
 
         assert!(cached.is_some());
         let (cached_posts, cached_total) = cached.unwrap();
-        assert_eq!(cached_posts.len(), 0);
-        assert_eq!(cached_total, 0);
+        assert_eq!(cached_posts.len(), 1);
+        assert_eq!(cached_posts[0].title, "List Item");
+        assert_eq!(cached_total, 1);
     }
 
     #[tokio::test]
@@ -541,4 +656,94 @@ mod tests {
         assert!(get_pending_count().await.is_none());
     }
 
+    #[tokio::test]
+    #[serial]
+    async fn session_cache_roundtrip() {
+        let user = SessionUser {
+            id: 42,
+            username: "cached_user".to_string(),
+            email: "cached@example.com".to_string(),
+            role: UserRole::Admin,
+            created_at: chrono::Utc::now(),
+        };
+        let token_hash = "sha256_token_hash";
+
+        set_session_user(token_hash, user.clone()).await;
+        let cached = get_session_user(token_hash).await;
+
+        assert!(cached.is_some());
+        let cached_user = cached.unwrap();
+        assert_eq!(cached_user.id, user.id);
+        assert_eq!(cached_user.username, user.username);
+        assert_eq!(cached_user.email, user.email);
+        assert_eq!(cached_user.role, user.role);
+
+        invalidate_session_user(token_hash).await;
+        assert!(get_session_user(token_hash).await.is_none());
+    }
+
+    #[test]
+    fn search_key_normalization() {
+        assert_eq!(normalize_search_key("  Rust "), "rust");
+        assert_eq!(normalize_search_key("Rust"), "rust");
+        assert_eq!(normalize_search_key("  rust "), "rust");
+        assert_eq!(normalize_search_key(""), "");
+
+        let long = "a".repeat(250);
+        let normalized = normalize_search_key(&long);
+        assert_eq!(normalized.len(), 200);
+        assert!(normalized.chars().all(|c| c == 'a'));
+
+        // 大小写与空格差异应映射到同一键。
+        assert_eq!(
+            normalize_search_key("  Dioxus Fullstack "),
+            normalize_search_key("dioxus fullstack")
+        );
+    }
+
+    #[tokio::test]
+    #[serial]
+    async fn search_cache_roundtrip() {
+        let query = "Rust";
+        let posts = vec![PostListItem {
+            id: 1,
+            author_id: 1,
+            title: "Search Result".to_string(),
+            slug: "search-result".to_string(),
+            summary: None,
+            status: PostStatus::Published,
+            published_at: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+            deleted_at: None,
+            tags: vec!["rust".to_string()],
+            cover_image: None,
+            reading_time: 1,
+            word_count: 10,
+        }];
+
+        set_search_results(query, posts.clone(), 1).await;
+
+        // 大小写与空格差异应命中同一缓存条目。
+        let cached = get_search_results(" rust ").await;
+        assert!(cached.is_some());
+        let (cached_posts, cached_total) = cached.unwrap();
+        assert_eq!(cached_posts.len(), 1);
+        assert_eq!(cached_posts[0].title, "Search Result");
+        assert_eq!(cached_total, 1);
+
+        invalidate_search_results();
+        assert!(get_search_results(query).await.is_none());
+    }
+
+    #[tokio::test]
+    #[serial]
+    async fn search_cache_invalidation() {
+        set_search_results("tokio", vec![], 0).await;
+        assert!(get_search_results("tokio").await.is_some());
+
+        invalidate_search_results();
+        assert!(get_search_results("tokio").await.is_none());
+    }
+
 }

src/components/post_card.rs

@@ -6,7 +6,7 @@ use dioxus::prelude::*;
 use dioxus::router::components::Link;
 
 use crate::components::image_viewer::ImageViewer;
-use crate::models::post::Post;
+use crate::models::post::PostListItem;
 use crate::router::Route;
 
 /// 文章卡片组件。
@@ -23,7 +23,7 @@ use crate::router::Route;
 /// 关键事件：
 /// - 点击标签时阻止事件冒泡，避免触发整卡跳转
 #[component]
-pub fn PostCard(post: Post) -> Element {
+pub fn PostCard(post: PostListItem) -> Element {
     let post_slug = post.slug.clone();
     let date_str = post.formatted_date();
     let has_cover = post.cover_image.is_some();

src/main.rs

@@ -23,6 +23,9 @@ mod hooks;
 mod models;
 mod pages;
 mod router;
+// ssr_cache 仅在 server feature 启用时编译；保存 SSR 世代号失效状态。
+#[cfg(feature = "server")]
+mod ssr_cache;
 mod tasks;
 mod theme;
 mod utils;
@@ -225,7 +228,15 @@ fn main() {
                 tasks::post_purge::run_purge().await;
             });
 
-            // 配置增量渲染缓存，默认缓存 3600 秒，可通过 SSR_CACHE_SECS 覆盖
+            // 启动后台定时任务：图片磁盘缓存清理
+            tokio::spawn(async {
+                tasks::image_cache_cleanup::run_cleanup().await;
+            });
+
+            // 配置增量渲染缓存，默认缓存 3600 秒，可通过 SSR_CACHE_SECS 覆盖。
+            // 注意：src/ssr_cache.rs 中的世代号是未来就绪基础设施，当前并不会使
+            // Dioxus 0.7 的 SSR 缓存实际失效（Dioxus 未暴露相应 API）。在 API 可用
+            // 之前，SSR_CACHE_SECS 仍是唯一有效的兜底 TTL。
             let config = ServeConfig::builder().incremental(
                 dioxus::server::IncrementalRendererConfig::default().invalidate_after(
                     std::time::Duration::from_secs(
@@ -237,6 +248,28 @@ fn main() {
                 ),
             );
 
+            // SSR 世代号中间件：把当前全局世代号注入请求扩展，并对 GET 请求的
+            // 响应附加 `X-SSR-Generation` 头。这是为未来 Dioxus 支持自定义 SSR 缓存键
+            // 预留的钩子；目前主要提供可观测性，不会实际失效 SSR 缓存。
+            async fn ssr_generation_middleware(
+                req: axum::http::Request<axum::body::Body>,
+                next: axum::middleware::Next,
+            ) -> axum::response::Response {
+                let generation = crate::ssr_cache::current_global_generation();
+                let is_get = req.method() == axum::http::Method::GET;
+                let (mut parts, body) = req.into_parts();
+                parts.extensions.insert(crate::ssr_cache::SsrGeneration(generation));
+                let mut response = next.run(axum::http::Request::from_parts(parts, body)).await;
+                if is_get {
+                    response.headers_mut().insert(
+                        axum::http::header::HeaderName::from_static("x-ssr-generation"),
+                        axum::http::HeaderValue::from_str(&generation.to_string())
+                            .unwrap_or_else(|_| axum::http::HeaderValue::from_static("0")),
+                    );
+                }
+                response
+            }
+
             // 自定义 API 路由：图片上传（大文件，需要更长超时）
             let upload_route = axum::Router::new()
                 .route(
@@ -253,8 +286,10 @@ fn main() {
             let dioxus_app =
                 axum::Router::new().serve_dioxus_application(config, router::AppRouter);
 
-            // 合并 Dioxus + 缓存头/可选压缩/30s 超时中间件
-            let mut app_routes = dioxus_app.layer(axum::middleware::from_fn(add_cache_control));
+            // 合并 Dioxus + 世代号/缓存头/可选压缩/30s 超时中间件
+            let mut app_routes = dioxus_app
+                .layer(axum::middleware::from_fn(ssr_generation_middleware))
+                .layer(axum::middleware::from_fn(add_cache_control));
             if let Some(layer) = compression_layer_from_env() {
                 app_routes = app_routes.layer(layer);
             }

src/models/post.rs

@@ -85,6 +85,51 @@ impl Post {
             .map(|d| d.format("%Y-%m-%d").to_string())
             .unwrap_or_else(|| self.created_at.format("%Y-%m-%d").to_string())
     }
+}
+
+/// 文章列表项 DTO。
+///
+/// 仅包含列表/标签/搜索/归档等场景需要的字段，不含 `content_md` 与 `content_html`，
+/// 以降低缓存内存占用与序列化体积。`deleted_at` 保留，供回收站列表使用。
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct PostListItem {
+    /// 文章主键。
+    pub id: i32,
+    /// 作者用户主键。
+    pub author_id: i32,
+    /// 文章标题。
+    pub title: String,
+    /// URL slug，用于生成文章链接。
+    pub slug: String,
+    /// 摘要，可选。
+    pub summary: Option<String>,
+    /// 文章发布状态。
+    pub status: PostStatus,
+    /// 正式发布时间，None 表示尚未发布。
+    pub published_at: Option<DateTime<Utc>>,
+    /// 创建时间。
+    pub created_at: DateTime<Utc>,
+    /// 最后更新时间。
+    pub updated_at: DateTime<Utc>,
+    /// 软删除时间，None 表示未删除。仅回收站查询填充。
+    pub deleted_at: Option<DateTime<Utc>>,
+    /// 关联标签列表。
+    pub tags: Vec<String>,
+    /// 封面图片 URL。
+    pub cover_image: Option<String>,
+    /// 预计阅读时间（分钟）。
+    pub reading_time: u32,
+    /// 字数统计。
+    pub word_count: u32,
+}
+
+impl PostListItem {
+    /// 返回用于展示的文章日期：优先使用发布时间，否则回退到创建时间。
+    pub fn formatted_date(&self) -> String {
+        self.published_at
+            .map(|d| d.format("%Y-%m-%d").to_string())
+            .unwrap_or_else(|| self.created_at.format("%Y-%m-%d").to_string())
+    }
 
     /// 返回中文状态标签。
     pub fn status_label(&self) -> &'static str {
@@ -173,6 +218,25 @@ mod tests {
         }
     }
 
+    fn sample_post_list_item() -> PostListItem {
+        PostListItem {
+            id: 1,
+            author_id: 1,
+            title: "Test".to_string(),
+            slug: "test".to_string(),
+            summary: None,
+            status: PostStatus::Draft,
+            published_at: None,
+            created_at: Utc.with_ymd_and_hms(2024, 1, 15, 10, 0, 0).unwrap(),
+            updated_at: Utc.with_ymd_and_hms(2024, 1, 15, 10, 0, 0).unwrap(),
+            deleted_at: None,
+            tags: vec![],
+            cover_image: None,
+            reading_time: 1,
+            word_count: 10,
+        }
+    }
+
     #[test]
     #[cfg(feature = "server")]
     fn post_status_from_str() {
@@ -213,8 +277,21 @@ mod tests {
     }
 
     #[test]
-    fn status_label() {
-        let mut post = sample_post();
+    fn post_list_item_formatted_date_uses_published_at_when_available() {
+        let mut post = sample_post_list_item();
+        post.published_at = Some(Utc.with_ymd_and_hms(2024, 6, 1, 12, 0, 0).unwrap());
+        assert_eq!(post.formatted_date(), "2024-06-01");
+    }
+
+    #[test]
+    fn post_list_item_formatted_date_falls_back_to_created_at() {
+        let post = sample_post_list_item();
+        assert_eq!(post.formatted_date(), "2024-01-15");
+    }
+
+    #[test]
+    fn post_list_item_status_label() {
+        let mut post = sample_post_list_item();
         post.status = PostStatus::Published;
         assert_eq!(post.status_label(), "已发布");
         post.status = PostStatus::Draft;
@@ -222,8 +299,8 @@ mod tests {
     }
 
     #[test]
-    fn status_class_returns_non_empty() {
-        let mut post = sample_post();
+    fn post_list_item_status_class_returns_non_empty() {
+        let mut post = sample_post_list_item();
         post.status = PostStatus::Published;
         assert_eq!(post.status_class(), "text-green-600 dark:text-green-400");
         post.status = PostStatus::Draft;
@@ -231,8 +308,8 @@ mod tests {
     }
 
     #[test]
-    fn status_badge_class_returns_non_empty() {
-        let mut post = sample_post();
+    fn post_list_item_status_badge_class_returns_non_empty() {
+        let mut post = sample_post_list_item();
         post.status = PostStatus::Published;
         assert_eq!(
             post.status_badge_class(),

src/models/user.rs

@@ -44,6 +44,21 @@ pub struct User {
     pub created_at: DateTime<Utc>,
 }
 
+/// 会话缓存使用的轻量用户结构体，不含密码哈希。
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct SessionUser {
+    /// 用户主键。
+    pub id: i32,
+    /// 用户名。
+    pub username: String,
+    /// 邮箱地址。
+    pub email: String,
+    /// 用户角色。
+    pub role: UserRole,
+    /// 账户创建时间。
+    pub created_at: DateTime<Utc>,
+}
+
 /// 可公开的用户信息，从 User 转换而来，不含密码哈希。
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct PublicUser {
@@ -59,6 +74,32 @@ pub struct PublicUser {
     pub created_at: DateTime<Utc>,
 }
 
+impl From<User> for SessionUser {
+    /// 将 User 转换为 SessionUser，丢弃 password_hash 字段。
+    fn from(u: User) -> Self {
+        SessionUser {
+            id: u.id,
+            username: u.username,
+            email: u.email,
+            role: u.role,
+            created_at: u.created_at,
+        }
+    }
+}
+
+impl From<SessionUser> for PublicUser {
+    /// 将 SessionUser 转换为 PublicUser。
+    fn from(u: SessionUser) -> Self {
+        PublicUser {
+            id: u.id,
+            username: u.username,
+            email: u.email,
+            role: u.role,
+            created_at: u.created_at,
+        }
+    }
+}
+
 impl From<User> for PublicUser {
     /// 将 User 转换为 PublicUser，丢弃 password_hash 字段。
     fn from(u: User) -> Self {
@@ -124,4 +165,24 @@ mod tests {
             UserRole::Admin
         );
     }
+
+    #[test]
+    fn user_to_session_user_excludes_password_hash() {
+        let user = sample_user();
+        let session: SessionUser = user.clone().into();
+        assert_eq!(session.id, user.id);
+        assert_eq!(session.username, user.username);
+        assert_eq!(session.email, user.email);
+        assert_eq!(session.role, user.role);
+        assert_eq!(session.created_at, user.created_at);
+    }
+
+    #[test]
+    fn session_user_to_public_user_excludes_password_hash() {
+        let user = sample_user();
+        let session: SessionUser = user.into();
+        let public: PublicUser = session.into();
+        let json = serde_json::to_string(&public).unwrap();
+        assert!(!json.contains("password_hash"));
+    }
 }

src/pages/admin/dashboard.rs

@@ -13,7 +13,7 @@ use crate::api::posts::{get_post_stats, list_posts};
 #[cfg(target_arch = "wasm32")]
 use crate::api::posts::{PostListResponse, PostStatsResponse};
 use crate::components::ui::ADMIN_CARD_CLASS;
-use crate::models::post::{Post, PostStats};
+use crate::models::post::{PostListItem, PostStats};
 use crate::router::Route;
 
 /// 后台仪表盘页面组件。
@@ -25,7 +25,7 @@ use crate::router::Route;
 pub fn Admin() -> Element {
     // 仪表盘状态：统计数据、最近文章、待审核评论数与首次加载标志。
     let mut stats = use_signal(|| None::<PostStats>);
-    let mut recent_posts = use_signal(|| None::<Vec<Post>>);
+    let mut recent_posts = use_signal(|| None::<Vec<PostListItem>>);
     let mut pending_count = use_signal(|| None::<i64>);
     let mut loaded = use_signal(|| false);
 
@@ -165,7 +165,7 @@ fn StatCard(value: String, label: String) -> Element {
 
 /// 最近文章列表项，显示标题、状态标签与发布日期。
 #[component]
-fn RecentPostItem(post: Post) -> Element {
+fn RecentPostItem(post: PostListItem) -> Element {
     let date_str = post.formatted_date();
     let status_label = post.status_label();
     let status_class = post.status_class();

src/pages/admin/posts.rs

@@ -15,7 +15,7 @@ use crate::api::posts::{delete_post, rebuild_content_html, CreatePostResponse, R
 use crate::components::skeletons::delayed_skeleton::DelayedSkeleton;
 use crate::components::skeletons::posts_skeleton::PostsSkeleton;
 use crate::components::ui::{EmptyState, Pagination, StatusBadge, ADMIN_ROW_HOVER, ADMIN_TABLE_CLASS, BTN_TEXT_RED};
-use crate::models::post::Post;
+use crate::models::post::PostListItem;
 use crate::router::Route;
 
 /// 每页展示的文章数量。
@@ -34,7 +34,7 @@ pub fn Posts() -> Element {
 pub fn PostsPage(page: i32) -> Element {
     let current_page = page.max(1);
     // 文章列表、总数、加载状态、删除中 ID、重建缓存状态与结果。
-    let mut posts = use_signal(Vec::new);
+    let mut posts = use_signal(Vec::<PostListItem>::new);
     let mut total = use_signal(|| 0_i64);
     let mut loading = use_signal(|| true);
     let mut deleting = use_signal(|| None::<i32>);
@@ -96,7 +96,7 @@ pub fn PostsPage(page: i32) -> Element {
         }
     });
 
-    let get_posts = move || -> Vec<Post> { posts() };
+    let get_posts = move || -> Vec<PostListItem> { posts() };
 
     rsx! {
         div { class: "space-y-6",
@@ -215,7 +215,7 @@ pub fn PostsPage(page: i32) -> Element {
 
 /// 文章表格行组件，展示单篇文章的标题、状态、日期与操作按钮。
 #[component]
-fn PostRow(post: Post, deleting: bool, on_delete: EventHandler<i32>) -> Element {
+fn PostRow(post: PostListItem, deleting: bool, on_delete: EventHandler<i32>) -> Element {
     let date_str = post.formatted_date();
 
     rsx! {

src/pages/admin/trash.rs

@@ -23,7 +23,7 @@ use crate::components::ui::{
     EmptyState, Pagination, StatusBadge, ADMIN_ROW_HOVER, ADMIN_TABLE_CLASS, BTN_SOLID_GREEN,
     BTN_SOLID_RED, BTN_TEXT_ACCENT, BTN_TEXT_RED, CHECKBOX_CLASS,
 };
-use crate::models::post::Post;
+use crate::models::post::PostListItem;
 use crate::models::settings::TrashSettings;
 use crate::router::Route;
 
@@ -44,7 +44,7 @@ pub fn Trash() -> Element {
 pub fn TrashPage(page: i32) -> Element {
     let current_page = page.max(1);
     let mut selected_ids: Signal<HashSet<i32>> = use_signal(HashSet::new);
-    let mut posts: Signal<Vec<Post>> = use_signal(Vec::new);
+    let mut posts: Signal<Vec<PostListItem>> = use_signal(Vec::new);
     let mut total: Signal<i64> = use_signal(|| 0);
     #[allow(unused_mut)]
     let mut loading: Signal<bool> = use_signal(|| false);
@@ -500,7 +500,7 @@ pub fn TrashPage(page: i32) -> Element {
 /// 计算剩余天数（保留期 - 已删除天数）。
 ///
 /// 返回 (剩余天数, 是否已过期)。基于客户端时钟计算，轻微漂移可接受。
-fn remaining_days(post: &Post, retention_days: i32) -> (i64, bool) {
+fn remaining_days(post: &PostListItem, retention_days: i32) -> (i64, bool) {
     #[cfg(target_arch = "wasm32")]
     {
         if let Some(deleted_at) = post.deleted_at {
@@ -523,7 +523,7 @@ fn remaining_days(post: &Post, retention_days: i32) -> (i64, bool) {
 /// 回收站表格行组件。
 #[component]
 fn TrashRow(
-    post: Post,
+    post: PostListItem,
     retention_days: i32,
     selected: bool,
     on_select: EventHandler<bool>,

src/pages/archives.rs

@@ -13,7 +13,7 @@ use dioxus::router::components::Link;
 use crate::api::posts::{list_published_posts, PostListResponse};
 use crate::components::skeletons::archive_skeleton::ArchiveSkeleton;
 use crate::components::skeletons::delayed_skeleton::DelayedSkeleton;
-use crate::models::post::Post;
+use crate::models::post::PostListItem;
 use crate::router::Route;
 
 /// 按年份分组的文章归档结构。
@@ -28,13 +28,13 @@ struct YearGroup {
 struct MonthGroup {
     month: String,
     month_en: String,
-    posts: Vec<Post>,
+    posts: Vec<PostListItem>,
 }
 
 /// 将文章列表按 `formatted_date()` 返回的 `YYYY-MM-DD` 格式进行年、月分组。
 ///
 /// 返回的结果按原始文章顺序组织，调用前已按发布时间降序排列。
-fn group_posts(posts: &[Post]) -> Vec<YearGroup> {
+fn group_posts(posts: &[PostListItem]) -> Vec<YearGroup> {
     let mut years: Vec<YearGroup> = vec![];
 
     for post in posts {
@@ -204,7 +204,7 @@ fn MonthSection(month_group: MonthGroup, year: String) -> Element {
 
 /// 单条归档文章组件，展示标题与发布日期，并通过覆盖层链接到文章详情。
 #[component]
-fn ArchiveEntry(post: Post) -> Element {
+fn ArchiveEntry(post: PostListItem) -> Element {
     let date_str = post.formatted_date();
 
     rsx! {

src/ssr_cache.rs

@@ -0,0 +1,70 @@
+//! SSR 增量渲染缓存失效的未来就绪基础设施。
+//!
+//! 本模块维护一个全局单调递增的世代号（generation）。文章写入成功后调用方会
+//! 使其递增，从而**标记** SSR 渲染结果已过期。然而：
+//!
+//! **Dioxus 0.7 的增量渲染器使用请求 URI 的 `path_and_query()` 作为内部缓存键，
+//! 且没有暴露公开 API 供外部代码自定义缓存键或按路由失效已渲染页面。**
+//! 因此，当前世代号并**不会**实际使 Dioxus 的 SSR 缓存失效；它只是为未来 API
+//! 准备好状态，并在请求/响应中提供可观测性。
+//!
+//! 在 Dioxus 提供以下任一能力之前，有效的 SSR 缓存失效手段仍是调低
+//! `SSR_CACHE_SECS` 这一兜底 TTL：
+//! - 自定义增量渲染缓存键的回调；或
+//! - 从 server function 内部按路由失效缓存的公开 API。
+//!
+//! 当前实现：
+//! - `bump_global_generation()` / `current_global_generation()`：全局世代号。
+//! - `SsrGeneration`：注入到请求扩展中的类型；未来 Dioxus 支持读取扩展生成
+//!   缓存键时可直接使用。
+//! - `src/main.rs` 的中间件把当前世代号附加到 `X-SSR-Generation` 响应头
+//!   （仅 GET 请求），便于调试与监控。
+//!
+//! 仅在启用 `server` feature 时编译。
+
+#![cfg(feature = "server")]
+
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::LazyLock;
+
+/// 全局 SSR 世代号。
+///
+/// 任何文章写入操作都会使其递增，从而让所有基于该全局世代的 SSR 缓存键在未来
+/// Dioxus 支持自定义缓存键时失效。
+static GLOBAL_GENERATION: LazyLock<AtomicU64> = LazyLock::new(AtomicU64::default);
+
+/// 注入到请求扩展中的当前 SSR 世代号。
+///
+/// 这是为未来 Dioxus 支持自定义 SSR 缓存键预留的钩子。当前 Dioxus 0.7 的渲染器
+/// 不会读取此扩展。
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct SsrGeneration(pub u64);
+
+/// 原子递增并返回新的全局世代号。
+pub fn bump_global_generation() -> u64 {
+    GLOBAL_GENERATION.fetch_add(1, Ordering::SeqCst).wrapping_add(1)
+}
+
+/// 返回当前全局世代号。
+pub fn current_global_generation() -> u64 {
+    GLOBAL_GENERATION.load(Ordering::SeqCst)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serial_test::serial;
+
+    #[test]
+    #[serial]
+    fn global_generation_is_monotonic() {
+        let before = current_global_generation();
+        let g1 = bump_global_generation();
+        let g2 = bump_global_generation();
+        let current = current_global_generation();
+
+        assert!(g1 > before || g1 == 1);
+        assert!(g2 > g1);
+        assert_eq!(current, g2);
+    }
+}

src/tasks/image_cache_cleanup.rs

@@ -0,0 +1,242 @@
+//! 图片磁盘缓存定期清理任务。
+//!
+//! 仅在 `server` feature 启用时编译，每小时运行一次。
+//! 删除超过保留时间的文件，并在总大小超过上限时按修改时间删除最旧的文件。
+
+use std::io;
+use std::path::{Path, PathBuf};
+use std::time::{Duration, SystemTime};
+use tokio::time::interval;
+
+const CACHE_DIR: &str = "uploads/.cache";
+const BYTES_PER_MB: u64 = 1024 * 1024;
+const SECS_PER_HOUR: u64 = 3600;
+
+/// 启动图片磁盘缓存清理循环，每小时触发一次。
+pub async fn run_cleanup() {
+    let mut ticker = interval(Duration::from_secs(SECS_PER_HOUR));
+    loop {
+        if let Err(e) = cleanup_image_cache().await {
+            tracing::error!("Image disk cache cleanup error: {:?}", e);
+        }
+        ticker.tick().await;
+    }
+}
+
+/// 读取环境变量并清理默认磁盘缓存目录。
+pub async fn cleanup_image_cache() -> io::Result<()> {
+    let base = Path::new(CACHE_DIR);
+    let max_mb = std::env::var("IMAGE_DISK_CACHE_MAX_MB")
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(1024);
+    let max_age_hours = std::env::var("IMAGE_DISK_CACHE_MAX_AGE_HOURS")
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(168);
+    let (deleted, bytes_freed) = cleanup_image_cache_at(base, max_mb, max_age_hours).await?;
+    if !deleted.is_empty() {
+        tracing::info!(
+            "Image disk cache cleanup: removed {} files, freed {} bytes",
+            deleted.len(),
+            bytes_freed
+        );
+    }
+    Ok(())
+}
+
+/// 清理指定目录下的图片磁盘缓存。
+///
+/// 返回被删除文件的路径列表以及释放的总字节数。
+pub async fn cleanup_image_cache_at(
+    base: &Path,
+    max_mb: u64,
+    max_age_hours: u64,
+) -> io::Result<(Vec<PathBuf>, u64)> {
+    if !base.exists() {
+        return Ok((Vec::new(), 0));
+    }
+
+    let max_age = Duration::from_secs(max_age_hours * SECS_PER_HOUR);
+    let now = SystemTime::now();
+    let cutoff = now - max_age;
+
+    let mut entries: Vec<(PathBuf, u64, SystemTime)> = Vec::new();
+    collect_files(base, &mut entries).await?;
+
+    let mut deleted = Vec::new();
+    let mut bytes_freed: u64 = 0;
+
+    // 第一轮：删除超过保留期限的文件。
+    let mut remaining: Vec<(PathBuf, u64, SystemTime)> = Vec::new();
+    for (path, size, mtime) in entries {
+        if mtime < cutoff {
+            match tokio::fs::remove_file(&path).await {
+                Ok(_) => {
+                    deleted.push(path);
+                    bytes_freed += size;
+                }
+                Err(e) => {
+                    tracing::warn!("Failed to remove expired cache file {:?}: {:?}", path, e);
+                }
+            }
+        } else {
+            remaining.push((path, size, mtime));
+        }
+    }
+
+    // 第二轮：若总大小仍超过上限，按修改时间从旧到新删除。
+    let max_bytes = max_mb.saturating_mul(BYTES_PER_MB);
+    let mut total: u64 = remaining.iter().map(|(_, size, _)| size).sum();
+    if total > max_bytes {
+        remaining.sort_by_key(|a| a.2);
+        for (path, size, _) in remaining {
+            if total <= max_bytes {
+                break;
+            }
+            match tokio::fs::remove_file(&path).await {
+                Ok(_) => {
+                    total -= size;
+                    deleted.push(path);
+                    bytes_freed += size;
+                }
+                Err(e) => {
+                    tracing::warn!(
+                        "Failed to remove cache file {:?} for size cap: {:?}",
+                        path,
+                        e
+                    );
+                }
+            }
+        }
+    }
+
+    Ok((deleted, bytes_freed))
+}
+
+/// 递归收集目录下的所有常规文件，返回路径、大小与修改时间。
+///
+/// 跳过符号链接，避免 traversal 到 `uploads/.cache/` 外部。
+async fn collect_files(
+    base: &Path,
+    entries: &mut Vec<(PathBuf, u64, SystemTime)>,
+) -> io::Result<()> {
+    let mut stack = vec![base.to_path_buf()];
+    while let Some(dir) = stack.pop() {
+        let mut reader = tokio::fs::read_dir(&dir).await?;
+        while let Some(entry) = reader.next_entry().await? {
+            let file_type = entry.file_type().await?;
+            if file_type.is_symlink() {
+                continue;
+            } else if file_type.is_file() {
+                let metadata = entry.metadata().await?;
+                let mtime = metadata.modified()?;
+                entries.push((entry.path(), metadata.len(), mtime));
+            } else if file_type.is_dir() {
+                stack.push(entry.path());
+            }
+        }
+    }
+    Ok(())
+}
+
+#[cfg(all(test, feature = "server"))]
+mod tests {
+    use super::*;
+    use std::time::{Duration, UNIX_EPOCH};
+    use tokio::time::sleep;
+
+    fn temp_cache_dir() -> PathBuf {
+        let nanos = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        std::env::temp_dir().join(format!("yggdrasil_image_cache_test_{}_{}", nanos, std::process::id()))
+    }
+
+    #[tokio::test]
+    async fn cleanup_ignores_missing_directory() {
+        let dir = temp_cache_dir();
+        let (deleted, freed) = cleanup_image_cache_at(&dir, 1024, 168).await.unwrap();
+        assert!(deleted.is_empty());
+        assert_eq!(freed, 0);
+    }
+
+    #[tokio::test]
+    async fn cleanup_removes_expired_files_by_age() {
+        let dir = temp_cache_dir();
+        tokio::fs::create_dir_all(&dir).await.unwrap();
+
+        let old = dir.join("old.dat");
+        tokio::fs::write(&old, b"old content").await.unwrap();
+        // 确保文件的修改时间严格早于清理时计算的截止时间。
+        sleep(Duration::from_millis(1100)).await;
+
+        let (deleted, freed) = cleanup_image_cache_at(&dir, 1024, 0).await.unwrap();
+        assert_eq!(deleted.len(), 1);
+        assert!(!old.exists());
+        assert!(freed > 0);
+
+        tokio::fs::remove_dir_all(&dir).await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn cleanup_keeps_recent_files() {
+        let dir = temp_cache_dir();
+        tokio::fs::create_dir_all(&dir).await.unwrap();
+
+        let recent = dir.join("recent.dat");
+        tokio::fs::write(&recent, b"recent content").await.unwrap();
+
+        let (deleted, freed) = cleanup_image_cache_at(&dir, 1024, 168).await.unwrap();
+        assert!(deleted.is_empty());
+        assert_eq!(freed, 0);
+        assert!(recent.exists());
+
+        tokio::fs::remove_dir_all(&dir).await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn cleanup_enforces_size_cap_by_mtime() {
+        let dir = temp_cache_dir();
+        tokio::fs::create_dir_all(&dir).await.unwrap();
+
+        let f1 = dir.join("oldest.dat");
+        tokio::fs::write(&f1, vec![0u8; 1024 * 1024]).await.unwrap();
+        sleep(Duration::from_millis(1100)).await;
+
+        let f2 = dir.join("middle.dat");
+        tokio::fs::write(&f2, vec![0u8; 1024 * 1024]).await.unwrap();
+        sleep(Duration::from_millis(1100)).await;
+
+        let f3 = dir.join("newest.dat");
+        tokio::fs::write(&f3, vec![0u8; 1024 * 1024]).await.unwrap();
+
+        // 上限 2 MB，当前 3 MB，应删除最旧的一个文件。
+        let (deleted, freed) = cleanup_image_cache_at(&dir, 2, 1000).await.unwrap();
+        assert_eq!(deleted.len(), 1);
+        assert!(!f1.exists());
+        assert!(f2.exists());
+        assert!(f3.exists());
+        assert_eq!(freed, 1024 * 1024);
+
+        tokio::fs::remove_dir_all(&dir).await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn cleanup_recurses_into_subdirectories() {
+        let dir = temp_cache_dir();
+        let sub = dir.join("nested");
+        tokio::fs::create_dir_all(&sub).await.unwrap();
+
+        let nested = sub.join("nested.dat");
+        tokio::fs::write(&nested, b"nested content").await.unwrap();
+        sleep(Duration::from_millis(1100)).await;
+
+        let (deleted, _freed) = cleanup_image_cache_at(&dir, 1024, 0).await.unwrap();
+        assert_eq!(deleted.len(), 1);
+        assert!(!nested.exists());
+
+        tokio::fs::remove_dir_all(&dir).await.unwrap();
+    }
+}

src/tasks/mod.rs

@@ -11,3 +11,6 @@ pub mod session_cleanup;
 /// 定时清理回收站中超过保留期的已删除文章。
 #[cfg(feature = "server")]
 pub mod post_purge;
+/// 定时清理图片磁盘缓存，避免缓存目录无限增长。
+#[cfg(feature = "server")]
+pub mod image_cache_cleanup;

src/tasks/session_cleanup.rs

@@ -16,11 +16,17 @@ pub async fn run_cleanup() {
         match get_conn().await {
             Ok(client) => {
                 // 删除已过期会话
-                if let Err(e) = client
+                match client
                     .execute("DELETE FROM sessions WHERE expires_at < NOW()", &[])
                     .await
                 {
-                    tracing::error!("Session cleanup error: {:?}", e);
+                    Ok(_) => {
+                        // 同时清空内存中的会话缓存，避免已失效会话继续命中。
+                        crate::cache::SESSION_CACHE.invalidate_all();
+                    }
+                    Err(e) => {
+                        tracing::error!("Session cleanup error: {:?}", e);
+                    }
                 }
             }
             Err(e) => {

src/utils/text.rs

@@ -72,6 +72,13 @@ pub fn count_words(md: &str) -> u32 {
     count.max(1)
 }
 
+/// 由字数估算阅读时长（分钟）。
+///
+/// 按每分钟 200 字计算，至少返回 1 分钟。
+pub fn reading_time(word_count: u32) -> u32 {
+    (word_count / 200).max(1)
+}
+
 /// 自动生成文本摘要，取去除 Markdown 后的前 200 个字符。
 pub fn auto_summary(md: &str) -> String {
     let plain = strip_markdown(md);
@@ -158,6 +165,21 @@ mod tests {
         assert_eq!(count_words(""), 1);
     }
 
+    #[test]
+    fn reading_time_defaults_to_one() {
+        assert_eq!(reading_time(0), 1);
+        assert_eq!(reading_time(1), 1);
+        assert_eq!(reading_time(199), 1);
+    }
+
+    #[test]
+    fn reading_time_scales_by_two_hundred() {
+        assert_eq!(reading_time(200), 1);
+        assert_eq!(reading_time(201), 1);
+        assert_eq!(reading_time(400), 2);
+        assert_eq!(reading_time(1000), 5);
+    }
+
     #[test]
     fn auto_summary_truncates_at_200_chars() {
         let long_md: String = "a ".repeat(200);