require timestamp passed in with cache request

src/App.zig

@@ -55,7 +55,7 @@ pub fn init(allocator: Allocator, config: *const Config) !*App {
         .arena_pool = undefined,
     };
 
-    app.network = try Network.init(allocator, config);
+    app.network = try Network.init(allocator, app, config);
     errdefer app.network.deinit();
 
     app.platform = try Platform.init();

src/Config.zig

@@ -157,6 +157,13 @@ pub fn userAgentSuffix(self: *const Config) ?[]const u8 {
     };
 }
 
+pub fn cacheDir(self: *const Config) ?[]const u8 {
+    return switch (self.mode) {
+        inline .serve, .fetch, .mcp => |opts| opts.common.cache_dir,
+        else => null,
+    };
+}
+
 pub fn cdpTimeout(self: *const Config) usize {
     return switch (self.mode) {
         .serve => |opts| if (opts.timeout > 604_800) 604_800_000 else @as(usize, opts.timeout) * 1000,
@@ -266,6 +273,7 @@ pub const Common = struct {
     log_format: ?log.Format = null,
     log_filter_scopes: ?[]log.Scope = null,
     user_agent_suffix: ?[]const u8 = null,
+    cache_dir: ?[]const u8 = null,
 
     web_bot_auth_key_file: ?[]const u8 = null,
     web_bot_auth_keyid: ?[]const u8 = null,
@@ -1000,5 +1008,14 @@ fn parseCommonArg(
         return true;
     }
 
+    if (std.mem.eql(u8, "--cache_dir", opt)) {
+        const str = args.next() orelse {
+            log.fatal(.app, "missing argument value", .{ .arg = "--cache_dir" });
+            return error.InvalidArgument;
+        };
+        common.cache_dir = try allocator.dupe(u8, str);
+        return true;
+    }
+
     return false;
 }

src/browser/HttpClient.zig

@@ -32,6 +32,9 @@ const CookieJar = @import("webapi/storage/Cookie.zig").Jar;
 const http = @import("../network/http.zig");
 const Runtime = @import("../network/Runtime.zig");
 const Robots = @import("../network/Robots.zig");
+const Cache = @import("../network/cache/Cache.zig");
+const CacheMetadata = Cache.CachedMetadata;
+const CachedResponse = Cache.CachedResponse;
 
 const IS_DEBUG = builtin.mode == .Debug;
 
@@ -311,7 +314,69 @@ pub fn request(self: *Client, req: Request) !void {
     return self.fetchRobotsThenProcessRequest(robots_url, req);
 }
 
+fn serveFromCache(req: Request, cached: *const CachedResponse) !void {
+    const response = Response.fromCached(req.ctx, cached);
+
+    if (req.start_callback) |cb| {
+        try cb(response);
+    }
+
+    const proceed = try req.header_callback(response);
+    if (!proceed) {
+        switch (cached.data) {
+            .buffer => |_| {},
+            .file => |file| file.close(),
+        }
+        req.error_callback(req.ctx, error.Abort);
+        return;
+    }
+
+    switch (cached.data) {
+        .buffer => |data| {
+            if (data.len > 0) {
+                try req.data_callback(response, data);
+            }
+        },
+        .file => |file| {
+            defer file.close();
+            var buf: [1024]u8 = undefined;
+            var file_reader = file.reader(&buf);
+
+            const reader = &file_reader.interface;
+            var read_buf: [1024]u8 = undefined;
+
+            while (true) {
+                const curr = try reader.readSliceShort(&read_buf);
+                if (curr == 0) break;
+                try req.data_callback(response, read_buf[0..curr]);
+            }
+        },
+    }
+
+    try req.done_callback(req.ctx);
+}
+
 fn processRequest(self: *Client, req: Request) !void {
+    if (self.network.cache) |*cache| {
+        if (req.method == .GET) {
+            const arena = try self.network.app.arena_pool.acquire(.{ .debug = "HttpClient.processRequest.cache" });
+            defer self.network.app.arena_pool.release(arena);
+
+            if (cache.get(arena, .{ .url = req.url, .timestamp = std.time.timestamp() })) |cached| {
+                log.debug(.browser, "http.cache.get", .{
+                    .url = req.url,
+                    .found = true,
+                    .metadata = cached.metadata,
+                });
+
+                defer req.headers.deinit();
+                return serveFromCache(req, &cached);
+            } else {
+                log.debug(.browser, "http.cache.get", .{ .url = req.url, .found = false });
+            }
+        }
+    }
+
     const transfer = try self.makeTransfer(req);
 
     transfer.req.notification.dispatch(.http_request_start, &.{ .transfer = transfer });
@@ -399,8 +464,10 @@ fn fetchRobotsThenProcessRequest(self: *Client, robots_url: [:0]const u8, req: R
     try entry.value_ptr.append(self.allocator, req);
 }
 
-fn robotsHeaderCallback(transfer: *Transfer) !bool {
-    const ctx: *RobotsRequestContext = @ptrCast(@alignCast(transfer.ctx));
+fn robotsHeaderCallback(response: Response) !bool {
+    const ctx: *RobotsRequestContext = @ptrCast(@alignCast(response.ctx));
+    // Robots callbacks only happen on real live requests.
+    const transfer = response.inner.transfer;
 
     if (transfer.response_header) |hdr| {
         log.debug(.browser, "robots status", .{ .status = hdr.status, .robots_url = ctx.robots_url });
@@ -414,8 +481,8 @@ fn robotsHeaderCallback(transfer: *Transfer) !bool {
     return true;
 }
 
-fn robotsDataCallback(transfer: *Transfer, data: []const u8) !void {
-    const ctx: *RobotsRequestContext = @ptrCast(@alignCast(transfer.ctx));
+fn robotsDataCallback(response: Response, data: []const u8) !void {
+    const ctx: *RobotsRequestContext = @ptrCast(@alignCast(response.ctx));
     try ctx.buffer.appendSlice(ctx.client.allocator, data);
 }
 
@@ -634,13 +701,43 @@ fn makeTransfer(self: *Client, req: Request) !*Transfer {
         .id = id,
         .url = req.url,
         .req = req,
-        .ctx = req.ctx,
         .client = self,
         .max_response_size = self.network.config.httpMaxResponseSize(),
     };
     return transfer;
 }
 
+fn requestFailed(transfer: *Transfer, err: anyerror, comptime execute_callback: bool) void {
+    if (transfer._notified_fail) {
+        // we can force a failed request within a callback, which will eventually
+        // result in this being called again in the more general loop. We do this
+        // because we can raise a more specific error inside a callback in some cases
+        return;
+    }
+
+    transfer._notified_fail = true;
+
+    transfer.req.notification.dispatch(.http_request_fail, &.{
+        .transfer = transfer,
+        .err = err,
+    });
+
+    if (execute_callback) {
+        transfer.req.error_callback(transfer.req.ctx, err);
+    } else if (transfer.req.shutdown_callback) |cb| {
+        cb(transfer.req.ctx);
+    }
+}
+
+// Same restriction as changeProxy. Should be ok since this is only called on
+// BrowserContext deinit.
+pub fn restoreOriginalProxy(self: *Client) !void {
+    try self.ensureNoActiveConnection();
+
+    self.http_proxy = self.network.config.httpProxy();
+    self.use_proxy = self.http_proxy != null;
+}
+
 fn makeRequest(self: *Client, conn: *http.Connection, transfer: *Transfer) anyerror!void {
     {
         // Reset per-response state for retries (auth challenge, queue).
@@ -674,7 +771,7 @@ fn makeRequest(self: *Client, conn: *http.Connection, transfer: *Transfer) anyer
     self.active += 1;
 
     if (transfer.req.start_callback) |cb| {
-        cb(transfer) catch |err| {
+        cb(Response.fromTransfer(transfer)) catch |err| {
             transfer.deinit();
             return err;
         };
@@ -742,7 +839,10 @@ fn processOneMessage(self: *Client, msg: http.Handles.MultiMessage, transfer: *T
     // TODO give a way to configure the number of auth retries.
     if (transfer._auth_challenge != null and transfer._tries < 10) {
         var wait_for_interception = false;
-        transfer.req.notification.dispatch(.http_request_auth_required, &.{ .transfer = transfer, .wait_for_interception = &wait_for_interception });
+        transfer.req.notification.dispatch(
+            .http_request_auth_required,
+            &.{ .transfer = transfer, .wait_for_interception = &wait_for_interception },
+        );
         if (wait_for_interception) {
             self.intercepted += 1;
             if (comptime IS_DEBUG) {
@@ -841,10 +941,11 @@ fn processOneMessage(self: *Client, msg: http.Handles.MultiMessage, transfer: *T
         }
     }
 
+    const body = transfer._stream_buffer.items;
+
     // Replay buffered body through user's data_callback.
     if (transfer._stream_buffer.items.len > 0) {
-        const body = transfer._stream_buffer.items;
-        try transfer.req.data_callback(transfer, body);
+        try transfer.req.data_callback(Response.fromTransfer(transfer), body);
 
         transfer.req.notification.dispatch(.http_response_data, &.{
             .data = body,
@@ -857,11 +958,42 @@ fn processOneMessage(self: *Client, msg: http.Handles.MultiMessage, transfer: *T
         }
     }
 
+    const allocator = transfer.arena.allocator();
+    var header_list: std.ArrayList(http.Header) = .empty;
+
+    var it = transfer.responseHeaderIterator();
+    while (it.next()) |hdr| {
+        header_list.append(
+            allocator,
+            .{
+                .name = try allocator.dupe(u8, hdr.name),
+                .value = try allocator.dupe(u8, hdr.value),
+            },
+        ) catch |err| {
+            log.warn(.http, "cache header collect failed", .{ .err = err });
+            break;
+        };
+    }
+
     // release conn ASAP so that it's available; some done_callbacks
     // will load more resources.
     transfer.releaseConn();
 
-    try transfer.req.done_callback(transfer.ctx);
+    try transfer.req.done_callback(transfer.req.ctx);
+
+    if (transfer._pending_cache_metadata) |metadata| {
+        const cache = &self.network.cache.?;
+
+        // TODO: Support Vary Keying
+        const cache_key = transfer.req.url;
+
+        log.debug(.browser, "http cache", .{ .key = cache_key, .metadata = metadata });
+        cache.put(metadata, body) catch |err| {
+            log.warn(.http, "cache put failed", .{ .err = err });
+        };
+        log.debug(.browser, "http.cache.put", .{ .url = transfer.req.url });
+    }
+
     transfer.req.notification.dispatch(.http_request_done, &.{
         .transfer = transfer,
     });
@@ -939,9 +1071,9 @@ pub const Request = struct {
     // arbitrary data that can be associated with this request
     ctx: *anyopaque = undefined,
 
-    start_callback: ?*const fn (transfer: *Transfer) anyerror!void = null,
-    header_callback: *const fn (transfer: *Transfer) anyerror!bool,
-    data_callback: *const fn (transfer: *Transfer, data: []const u8) anyerror!void,
+    start_callback: ?*const fn (response: Response) anyerror!void = null,
+    header_callback: *const fn (response: Response) anyerror!bool,
+    data_callback: *const fn (response: Response, data: []const u8) anyerror!void,
     done_callback: *const fn (ctx: *anyopaque) anyerror!void,
     error_callback: *const fn (ctx: *anyopaque, err: anyerror) void,
     shutdown_callback: ?*const fn (ctx: *anyopaque) void = null,
@@ -967,16 +1099,84 @@ pub const Request = struct {
     };
 };
 
+pub const Response = struct {
+    ctx: *anyopaque,
+    inner: union(enum) {
+        transfer: *Transfer,
+        cached: *const CachedResponse,
+    },
+
+    pub fn fromTransfer(transfer: *Transfer) Response {
+        return .{ .ctx = transfer.req.ctx, .inner = .{ .transfer = transfer } };
+    }
+
+    pub fn fromCached(ctx: *anyopaque, resp: *const CachedResponse) Response {
+        return .{ .ctx = ctx, .inner = .{ .cached = resp } };
+    }
+
+    pub fn status(self: Response) ?u16 {
+        return switch (self.inner) {
+            .transfer => |t| if (t.response_header) |rh| rh.status else null,
+            .cached => |c| c.metadata.status,
+        };
+    }
+
+    pub fn contentType(self: Response) ?[]const u8 {
+        return switch (self.inner) {
+            .transfer => |t| if (t.response_header) |*rh| rh.contentType() else null,
+            .cached => |c| c.metadata.content_type,
+        };
+    }
+
+    pub fn contentLength(self: Response) ?u32 {
+        return switch (self.inner) {
+            .transfer => |t| t.getContentLength(),
+            .cached => |c| switch (c.data) {
+                .buffer => |buf| @intCast(buf.len),
+                .file => |f| @intCast(f.getEndPos() catch 0),
+            },
+        };
+    }
+
+    pub fn redirectCount(self: Response) ?u32 {
+        return switch (self.inner) {
+            .transfer => |t| if (t.response_header) |rh| rh.redirect_count else null,
+            .cached => 0,
+        };
+    }
+
+    pub fn url(self: Response) [:0]const u8 {
+        return switch (self.inner) {
+            .transfer => |t| t.url,
+            .cached => |c| c.metadata.url,
+        };
+    }
+
+    pub fn headerIterator(self: Response) HeaderIterator {
+        return switch (self.inner) {
+            .transfer => |t| t.responseHeaderIterator(),
+            .cached => |c| HeaderIterator{ .list = .{ .list = c.metadata.headers } },
+        };
+    }
+
+    pub fn abort(self: Response, err: anyerror) void {
+        switch (self.inner) {
+            .transfer => |t| t.abort(err),
+            .cached => {},
+        }
+    }
+};
+
 pub const Transfer = struct {
     arena: ArenaAllocator,
     id: u32 = 0,
     req: Request,
     url: [:0]const u8,
-    ctx: *anyopaque, // copied from req.ctx to make it easier for callback handlers
     client: *Client,
     // total bytes received in the response, including the response status line,
     // the headers, and the [encoded] body.
     bytes_received: usize = 0,
+    _pending_cache_metadata: ?CacheMetadata = null,
 
     aborted: bool = false,
 
@@ -1065,7 +1265,7 @@ pub const Transfer = struct {
     // as abort (doesn't send a notification, doesn't invoke an error callback)
     fn kill(self: *Transfer) void {
         if (self.req.shutdown_callback) |cb| {
-            cb(self.ctx);
+            cb(self.req.ctx);
         }
 
         if (self._performing or self.client.performing) {
@@ -1101,7 +1301,7 @@ pub const Transfer = struct {
         });
 
         if (execute_callback) {
-            self.req.error_callback(self.ctx, err);
+            self.req.error_callback(self.req.ctx, err);
         } else if (self.req.shutdown_callback) |cb| {
             cb(self.ctx);
         }
@@ -1342,11 +1542,45 @@ pub const Transfer = struct {
             }
         }
 
-        const proceed = transfer.req.header_callback(transfer) catch |err| {
+        const proceed = transfer.req.header_callback(Response.fromTransfer(transfer)) catch |err| {
             log.err(.http, "header_callback", .{ .err = err, .req = transfer });
             return err;
         };
 
+        if (transfer.client.network.cache != null and transfer.req.method == .GET) {
+            const rh = &transfer.response_header.?;
+            const allocator = transfer.arena.allocator();
+
+            const maybe_cm = try Cache.tryCache(
+                allocator,
+                std.time.timestamp(),
+                transfer.url,
+                rh.status,
+                rh.contentType(),
+                if (conn.getResponseHeader("cache-control", 0)) |h| h.value else null,
+                if (conn.getResponseHeader("vary", 0)) |h| h.value else null,
+                if (conn.getResponseHeader("etag", 0)) |h| h.value else null,
+                if (conn.getResponseHeader("last-modified", 0)) |h| h.value else null,
+                if (conn.getResponseHeader("age", 0)) |h| h.value else null,
+                conn.getResponseHeader("set-cookie", 0) != null,
+                conn.getResponseHeader("authorization", 0) != null,
+            );
+
+            if (maybe_cm) |cm| {
+                var header_list: std.ArrayList(http.Header) = .empty;
+                var it = transfer.responseHeaderIterator();
+                while (it.next()) |hdr| {
+                    try header_list.append(allocator, .{
+                        .name = try allocator.dupe(u8, hdr.name),
+                        .value = try allocator.dupe(u8, hdr.value),
+                    });
+                }
+
+                transfer._pending_cache_metadata = cm;
+                transfer._pending_cache_metadata.?.headers = header_list.items;
+            }
+        }
+
         transfer.req.notification.dispatch(.http_response_header_done, &.{
             .transfer = transfer,
         });
@@ -1449,7 +1683,7 @@ pub const Transfer = struct {
     fn _fulfill(transfer: *Transfer, status: u16, headers: []const http.Header, body: ?[]const u8) !void {
         const req = &transfer.req;
         if (req.start_callback) |cb| {
-            try cb(transfer);
+            try cb(Response.fromTransfer(transfer));
         }
 
         transfer.response_header = .{
@@ -1468,13 +1702,13 @@ pub const Transfer = struct {
         }
 
         lp.assert(transfer._header_done_called == false, "Transfer.fulfill header_done_called", .{});
-        if (try req.header_callback(transfer) == false) {
+        if (try req.header_callback(Response.fromTransfer(transfer)) == false) {
             transfer.abort(error.Abort);
             return;
         }
 
         if (body) |b| {
-            try req.data_callback(transfer, b);
+            try req.data_callback(Response.fromTransfer(transfer), b);
         }
 
         try req.done_callback(req.ctx);
@@ -1511,10 +1745,10 @@ pub const Transfer = struct {
 };
 
 const Noop = struct {
-    fn headerCallback(_: *Transfer) !bool {
+    fn headerCallback(_: Response) !bool {
         return true;
     }
-    fn dataCallback(_: *Transfer, _: []const u8) !void {}
+    fn dataCallback(_: Response, _: []const u8) !void {}
     fn doneCallback(_: *anyopaque) !void {}
     fn errorCallback(_: *anyopaque, _: anyerror) void {}
 };

src/browser/Mime.zig

@@ -27,6 +27,9 @@ charset: [41]u8 = default_charset,
 charset_len: usize = default_charset_len,
 is_default_charset: bool = true,
 
+type_buf: [127]u8 = @splat(0),
+sub_type_buf: [127]u8 = @splat(0),
+
 /// String "UTF-8" continued by null characters.
 const default_charset = .{ 'U', 'T', 'F', '-', '8' } ++ .{0} ** 36;
 const default_charset_len = 5;
@@ -61,7 +64,10 @@ pub const ContentType = union(ContentTypeEnum) {
     image_webp: void,
     application_json: void,
     unknown: void,
-    other: struct { type: []const u8, sub_type: []const u8 },
+    other: struct {
+        type: []const u8,
+        sub_type: []const u8,
+    },
 };
 
 pub fn contentTypeString(mime: *const Mime) []const u8 {
@@ -112,17 +118,18 @@ fn parseCharset(value: []const u8) error{ CharsetTooBig, Invalid }![]const u8 {
     return value;
 }
 
-pub fn parse(input: []u8) !Mime {
+pub fn parse(input: []const u8) !Mime {
     if (input.len > 255) {
         return error.TooBig;
     }
 
-    // Zig's trim API is broken. The return type is always `[]const u8`,
-    // even if the input type is `[]u8`. @constCast is safe here.
-    var normalized = @constCast(std.mem.trim(u8, input, &std.ascii.whitespace));
+    var buf: [255]u8 = undefined;
+    const normalized = std.ascii.lowerString(&buf, std.mem.trim(u8, input, &std.ascii.whitespace));
     _ = std.ascii.lowerString(normalized, normalized);
 
-    const content_type, const type_len = try parseContentType(normalized);
+    var mime = Mime{ .content_type = undefined };
+
+    const content_type, const type_len = try parseContentType(normalized, &mime.type_buf, &mime.sub_type_buf);
     if (type_len >= normalized.len) {
         return .{ .content_type = content_type };
     }
@@ -163,13 +170,12 @@ pub fn parse(input: []u8) !Mime {
         }
     }
 
-    return .{
-        .params = params,
-        .charset = charset,
-        .charset_len = charset_len,
-        .content_type = content_type,
-        .is_default_charset = !has_explicit_charset,
-    };
+    mime.params = params;
+    mime.charset = charset;
+    mime.charset_len = charset_len;
+    mime.content_type = content_type;
+    mime.is_default_charset = !has_explicit_charset;
+    return mime;
 }
 
 /// Prescan the first 1024 bytes of an HTML document for a charset declaration.
@@ -395,7 +401,7 @@ pub fn isText(mime: *const Mime) bool {
 }
 
 // we expect value to be lowercase
-fn parseContentType(value: []const u8) !struct { ContentType, usize } {
+fn parseContentType(value: []const u8, type_buf: []u8, sub_type_buf: []u8) !struct { ContentType, usize } {
     const end = std.mem.indexOfScalarPos(u8, value, 0, ';') orelse value.len;
     const type_name = trimRight(value[0..end]);
     const attribute_start = end + 1;
@@ -444,10 +450,18 @@ fn parseContentType(value: []const u8) !struct { ContentType, usize } {
         return error.Invalid;
     }
 
-    return .{ .{ .other = .{
-        .type = main_type,
-        .sub_type = sub_type,
-    } }, attribute_start };
+    @memcpy(type_buf[0..main_type.len], main_type);
+    @memcpy(sub_type_buf[0..sub_type.len], sub_type);
+
+    return .{
+        .{
+            .other = .{
+                .type = type_buf[0..main_type.len],
+                .sub_type = sub_type_buf[0..sub_type.len],
+            },
+        },
+        attribute_start,
+    };
 }
 
 const VALID_CODEPOINTS = blk: {
@@ -461,6 +475,13 @@ const VALID_CODEPOINTS = blk: {
     break :blk v;
 };
 
+pub fn typeString(self: *const Mime) []const u8 {
+    return switch (self.content_type) {
+        .other => |o| o.type[0..o.type_len],
+        else => "",
+    };
+}
+
 fn validType(value: []const u8) bool {
     for (value) |b| {
         if (VALID_CODEPOINTS[b] == false) {

src/browser/Page.zig

@@ -854,12 +854,10 @@ fn notifyParentLoadComplete(self: *Page) void {
     parent.iframeCompletedLoading(self.iframe.?);
 }
 
-fn pageHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
-    var self: *Page = @ptrCast(@alignCast(transfer.ctx));
+fn pageHeaderDoneCallback(response: HttpClient.Response) !bool {
+    var self: *Page = @ptrCast(@alignCast(response.ctx));
 
-    const header = &transfer.response_header.?;
-
-    const response_url = std.mem.span(header.url);
+    const response_url = response.url();
     if (std.mem.eql(u8, response_url, self.url) == false) {
         // would be different than self.url in the case of a redirect
         self.url = try self.arena.dupeZ(u8, response_url);
@@ -873,8 +871,8 @@ fn pageHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
     if (comptime IS_DEBUG) {
         log.debug(.page, "navigate header", .{
             .url = self.url,
-            .status = header.status,
-            .content_type = header.contentType(),
+            .status = response.status(),
+            .content_type = response.contentType(),
             .type = self._type,
         });
     }
@@ -882,14 +880,14 @@ fn pageHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
     return true;
 }
 
-fn pageDataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
-    var self: *Page = @ptrCast(@alignCast(transfer.ctx));
+fn pageDataCallback(response: HttpClient.Response, data: []const u8) !void {
+    var self: *Page = @ptrCast(@alignCast(response.ctx));
 
     if (self._parse_state == .pre) {
         // we lazily do this, because we might need the first chunk of data
         // to sniff the content type
         var mime: Mime = blk: {
-            if (transfer.response_header.?.contentType()) |ct| {
+            if (response.contentType()) |ct| {
                 break :blk try Mime.parse(ct);
             }
             break :blk Mime.sniff(data);

src/browser/ScriptManager.zig

@@ -694,82 +694,86 @@ pub const Script = struct {
         self.manager.page.releaseArena(self.arena);
     }
 
-    fn startCallback(transfer: *HttpClient.Transfer) !void {
-        log.debug(.http, "script fetch start", .{ .req = transfer });
+    fn startCallback(response: HttpClient.Response) !void {
+        log.debug(.http, "script fetch start", .{ .req = response });
     }
 
-    fn headerCallback(transfer: *HttpClient.Transfer) !bool {
-        const self: *Script = @ptrCast(@alignCast(transfer.ctx));
-        const header = &transfer.response_header.?;
-        self.status = header.status;
-        if (header.status != 200) {
+    fn headerCallback(response: HttpClient.Response) !bool {
+        const self: *Script = @ptrCast(@alignCast(response.ctx));
+
+        self.status = response.status().?;
+        if (response.status() != 200) {
             log.info(.http, "script header", .{
-                .req = transfer,
-                .status = header.status,
-                .content_type = header.contentType(),
+                .req = response,
+                .status = response.status(),
+                .content_type = response.contentType(),
             });
             return false;
         }
 
         if (comptime IS_DEBUG) {
             log.debug(.http, "script header", .{
-                .req = transfer,
-                .status = header.status,
-                .content_type = header.contentType(),
+                .req = response,
+                .status = response.status(),
+                .content_type = response.contentType(),
             });
         }
 
-        {
-            // temp debug, trying to figure out why the next assert sometimes
-            // fails. Is the buffer just corrupt or is headerCallback really
-            // being called twice?
-            lp.assert(self.header_callback_called == false, "ScriptManager.Header recall", .{
-                .m = @tagName(std.meta.activeTag(self.mode)),
-                .a1 = self.debug_transfer_id,
-                .a2 = self.debug_transfer_tries,
-                .a3 = self.debug_transfer_aborted,
-                .a4 = self.debug_transfer_bytes_received,
-                .a5 = self.debug_transfer_notified_fail,
-                .a7 = self.debug_transfer_intercept_state,
-                .a8 = self.debug_transfer_auth_challenge,
-                .a9 = self.debug_transfer_easy_id,
-                .b1 = transfer.id,
-                .b2 = transfer._tries,
-                .b3 = transfer.aborted,
-                .b4 = transfer.bytes_received,
-                .b5 = transfer._notified_fail,
-                .b7 = @intFromEnum(transfer._intercept_state),
-                .b8 = transfer._auth_challenge != null,
-                .b9 = if (transfer._conn) |c| @intFromPtr(c._easy) else 0,
-            });
-            self.header_callback_called = true;
-            self.debug_transfer_id = transfer.id;
-            self.debug_transfer_tries = transfer._tries;
-            self.debug_transfer_aborted = transfer.aborted;
-            self.debug_transfer_bytes_received = transfer.bytes_received;
-            self.debug_transfer_notified_fail = transfer._notified_fail;
-            self.debug_transfer_intercept_state = @intFromEnum(transfer._intercept_state);
-            self.debug_transfer_auth_challenge = transfer._auth_challenge != null;
-            self.debug_transfer_easy_id = if (transfer._conn) |c| @intFromPtr(c._easy) else 0;
+        switch (response.inner) {
+            .transfer => |transfer| {
+                // temp debug, trying to figure out why the next assert sometimes
+                // fails. Is the buffer just corrupt or is headerCallback really
+                // being called twice?
+                lp.assert(self.header_callback_called == false, "ScriptManager.Header recall", .{
+                    .m = @tagName(std.meta.activeTag(self.mode)),
+                    .a1 = self.debug_transfer_id,
+                    .a2 = self.debug_transfer_tries,
+                    .a3 = self.debug_transfer_aborted,
+                    .a4 = self.debug_transfer_bytes_received,
+                    .a5 = self.debug_transfer_notified_fail,
+                    .a7 = self.debug_transfer_intercept_state,
+                    .a8 = self.debug_transfer_auth_challenge,
+                    .a9 = self.debug_transfer_easy_id,
+                    .b1 = transfer.id,
+                    .b2 = transfer._tries,
+                    .b3 = transfer.aborted,
+                    .b4 = transfer.bytes_received,
+                    .b5 = transfer._notified_fail,
+                    .b7 = @intFromEnum(transfer._intercept_state),
+                    .b8 = transfer._auth_challenge != null,
+                    .b9 = if (transfer._conn) |c| @intFromPtr(c._easy) else 0,
+                });
+                self.header_callback_called = true;
+                self.debug_transfer_id = transfer.id;
+                self.debug_transfer_tries = transfer._tries;
+                self.debug_transfer_aborted = transfer.aborted;
+                self.debug_transfer_bytes_received = transfer.bytes_received;
+                self.debug_transfer_notified_fail = transfer._notified_fail;
+                self.debug_transfer_intercept_state = @intFromEnum(transfer._intercept_state);
+                self.debug_transfer_auth_challenge = transfer._auth_challenge != null;
+                self.debug_transfer_easy_id = if (transfer._conn) |c| @intFromPtr(c._easy) else 0;
+            },
+            else => {},
         }
 
         lp.assert(self.source.remote.capacity == 0, "ScriptManager.Header buffer", .{ .capacity = self.source.remote.capacity });
         var buffer: std.ArrayList(u8) = .empty;
-        if (transfer.getContentLength()) |cl| {
+        if (response.contentLength()) |cl| {
             try buffer.ensureTotalCapacity(self.arena, cl);
         }
         self.source = .{ .remote = buffer };
         return true;
     }
 
-    fn dataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
-        const self: *Script = @ptrCast(@alignCast(transfer.ctx));
-        self._dataCallback(transfer, data) catch |err| {
-            log.err(.http, "SM.dataCallback", .{ .err = err, .transfer = transfer, .len = data.len });
+    fn dataCallback(response: HttpClient.Response, data: []const u8) !void {
+        const self: *Script = @ptrCast(@alignCast(response.ctx));
+        self._dataCallback(response, data) catch |err| {
+            log.err(.http, "SM.dataCallback", .{ .err = err, .transfer = response, .len = data.len });
             return err;
         };
     }
-    fn _dataCallback(self: *Script, _: *HttpClient.Transfer, data: []const u8) !void {
+
+    fn _dataCallback(self: *Script, _: HttpClient.Response, data: []const u8) !void {
         try self.source.remote.appendSlice(self.arena, data);
     }
 

src/browser/webapi/net/Fetch.zig

@@ -127,16 +127,16 @@ fn handleBlobUrl(url: []const u8, resolver: js.PromiseResolver, page: *Page) !js
     return resolver.promise();
 }
 
-fn httpStartCallback(transfer: *HttpClient.Transfer) !void {
-    const self: *Fetch = @ptrCast(@alignCast(transfer.ctx));
+fn httpStartCallback(response: HttpClient.Response) !void {
+    const self: *Fetch = @ptrCast(@alignCast(response.ctx));
     if (comptime IS_DEBUG) {
         log.debug(.http, "request start", .{ .url = self._url, .source = "fetch" });
     }
-    self._response._transfer = transfer;
+    self._response._http_response = response;
 }
 
-fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
-    const self: *Fetch = @ptrCast(@alignCast(transfer.ctx));
+fn httpHeaderDoneCallback(response: HttpClient.Response) !bool {
+    const self: *Fetch = @ptrCast(@alignCast(response.ctx));
 
     if (self._signal) |signal| {
         if (signal._aborted) {
@@ -145,25 +145,24 @@ fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
     }
 
     const arena = self._response._arena;
-    if (transfer.getContentLength()) |cl| {
+    if (response.contentLength()) |cl| {
         try self._buf.ensureTotalCapacity(arena, cl);
     }
 
     const res = self._response;
-    const header = transfer.response_header.?;
 
     if (comptime IS_DEBUG) {
         log.debug(.http, "request header", .{
             .source = "fetch",
             .url = self._url,
-            .status = header.status,
+            .status = response.status(),
         });
     }
 
-    res._status = header.status;
-    res._status_text = std.http.Status.phrase(@enumFromInt(header.status)) orelse "";
-    res._url = try arena.dupeZ(u8, std.mem.span(header.url));
-    res._is_redirected = header.redirect_count > 0;
+    res._status = response.status().?;
+    res._status_text = std.http.Status.phrase(@enumFromInt(response.status().?)) orelse "";
+    res._url = try arena.dupeZ(u8, response.url());
+    res._is_redirected = response.redirectCount().? > 0;
 
     // Determine response type based on origin comparison
     const page_origin = URL.getOrigin(arena, self._page.url) catch null;
@@ -183,7 +182,7 @@ fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
         res._type = .basic;
     }
 
-    var it = transfer.responseHeaderIterator();
+    var it = response.headerIterator();
     while (it.next()) |hdr| {
         try res._headers.append(hdr.name, hdr.value, self._page);
     }
@@ -191,8 +190,8 @@ fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
     return true;
 }
 
-fn httpDataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
-    const self: *Fetch = @ptrCast(@alignCast(transfer.ctx));
+fn httpDataCallback(response: HttpClient.Response, data: []const u8) !void {
+    const self: *Fetch = @ptrCast(@alignCast(response.ctx));
 
     // Check if aborted
     if (self._signal) |signal| {
@@ -207,7 +206,7 @@ fn httpDataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
 fn httpDoneCallback(ctx: *anyopaque) !void {
     const self: *Fetch = @ptrCast(@alignCast(ctx));
     var response = self._response;
-    response._transfer = null;
+    response._http_response = null;
     response._body = self._buf.items;
 
     log.info(.http, "request complete", .{
@@ -230,7 +229,7 @@ fn httpErrorCallback(ctx: *anyopaque, _: anyerror) void {
     const self: *Fetch = @ptrCast(@alignCast(ctx));
 
     var response = self._response;
-    response._transfer = null;
+    response._http_response = null;
     // the response is only passed on v8 on success, if we're here, it's safe to
     // clear this. (defer since `self is in the response's arena).
 
@@ -256,7 +255,7 @@ fn httpShutdownCallback(ctx: *anyopaque) void {
 
     if (self._owns_response) {
         var response = self._response;
-        response._transfer = null;
+        response._http_response = null;
         response.deinit(self._page._session);
         // Do not access `self` after this point: the Fetch struct was
         // allocated from response._arena which has been released.

src/browser/webapi/net/Response.zig

@@ -48,7 +48,7 @@ _type: Type,
 _status_text: []const u8,
 _url: [:0]const u8,
 _is_redirected: bool,
-_transfer: ?*HttpClient.Transfer = null,
+_http_response: ?HttpClient.Response = null,
 
 const InitOpts = struct {
     status: u16 = 200,
@@ -81,9 +81,9 @@ pub fn init(body_: ?[]const u8, opts_: ?InitOpts, page: *Page) !*Response {
 }
 
 pub fn deinit(self: *Response, session: *Session) void {
-    if (self._transfer) |transfer| {
-        transfer.abort(error.Abort);
-        self._transfer = null;
+    if (self._http_response) |resp| {
+        resp.abort(error.Abort);
+        self._http_response = null;
     }
     session.releaseArena(self._arena);
 }
@@ -191,7 +191,7 @@ pub fn clone(self: *const Response, page: *Page) !*Response {
         ._type = self._type,
         ._is_redirected = self._is_redirected,
         ._headers = try Headers.init(.{ .obj = self._headers }, page),
-        ._transfer = null,
+        ._http_response = null,
     };
     return cloned;
 }

src/browser/webapi/net/XMLHttpRequest.zig

@@ -43,7 +43,7 @@ _rc: lp.RC(u8) = .{},
 _page: *Page,
 _proto: *XMLHttpRequestEventTarget,
 _arena: Allocator,
-_transfer: ?*HttpClient.Transfer = null,
+_http_response: ?HttpClient.Response = null,
 
 _url: [:0]const u8 = "",
 _method: net_http.Method = .GET,
@@ -99,9 +99,9 @@ pub fn init(page: *Page) !*XMLHttpRequest {
 }
 
 pub fn deinit(self: *XMLHttpRequest, session: *Session) void {
-    if (self._transfer) |transfer| {
-        transfer.abort(error.Abort);
-        self._transfer = null;
+    if (self._http_response) |resp| {
+        resp.abort(error.Abort);
+        self._http_response = null;
     }
 
     if (self._on_ready_state_change) |func| {
@@ -175,9 +175,9 @@ pub fn setWithCredentials(self: *XMLHttpRequest, value: bool) !void {
 // TODO: url should be a union, as it can be multiple things
 pub fn open(self: *XMLHttpRequest, method_: []const u8, url: [:0]const u8) !void {
     // Abort any in-progress request
-    if (self._transfer) |transfer| {
+    if (self._http_response) |transfer| {
         transfer.abort(error.Abort);
-        self._transfer = null;
+        self._http_response = null;
     }
 
     // Reset internal state
@@ -387,35 +387,33 @@ pub fn getResponseXML(self: *XMLHttpRequest, page: *Page) !?*Node.Document {
     };
 }
 
-fn httpStartCallback(transfer: *HttpClient.Transfer) !void {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
+fn httpStartCallback(response: HttpClient.Response) !void {
+    const self: *XMLHttpRequest = @ptrCast(@alignCast(response.ctx));
     if (comptime IS_DEBUG) {
         log.debug(.http, "request start", .{ .method = self._method, .url = self._url, .source = "xhr" });
     }
-    self._transfer = transfer;
+    self._http_response = response;
     self.acquireRef();
 }
 
-fn httpHeaderCallback(transfer: *HttpClient.Transfer, header: net_http.Header) !void {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
+fn httpHeaderCallback(response: HttpClient.Response, header: net_http.Header) !void {
+    const self: *XMLHttpRequest = @ptrCast(@alignCast(response.ctx));
     const joined = try std.fmt.allocPrint(self._arena, "{s}: {s}", .{ header.name, header.value });
     try self._response_headers.append(self._arena, joined);
 }
 
-fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
-
-    const header = &transfer.response_header.?;
+fn httpHeaderDoneCallback(response: HttpClient.Response) !bool {
+    const self: *XMLHttpRequest = @ptrCast(@alignCast(response.ctx));
 
     if (comptime IS_DEBUG) {
         log.debug(.http, "request header", .{
             .source = "xhr",
             .url = self._url,
-            .status = header.status,
+            .status = response.status(),
         });
     }
 
-    if (header.contentType()) |ct| {
+    if (response.contentType()) |ct| {
         self._response_mime = Mime.parse(ct) catch |e| {
             log.info(.http, "invalid content type", .{
                 .content_Type = ct,
@@ -426,18 +424,18 @@ fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
         };
     }
 
-    var it = transfer.responseHeaderIterator();
+    var it = response.headerIterator();
     while (it.next()) |hdr| {
         const joined = try std.fmt.allocPrint(self._arena, "{s}: {s}", .{ hdr.name, hdr.value });
         try self._response_headers.append(self._arena, joined);
     }
 
-    self._response_status = header.status;
-    if (transfer.getContentLength()) |cl| {
+    self._response_status = response.status().?;
+    if (response.contentLength()) |cl| {
         self._response_len = cl;
         try self._response_data.ensureTotalCapacity(self._arena, cl);
     }
-    self._response_url = try self._arena.dupeZ(u8, std.mem.span(header.url));
+    self._response_url = try self._arena.dupeZ(u8, response.url());
 
     const page = self._page;
 
@@ -452,8 +450,8 @@ fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
     return true;
 }
 
-fn httpDataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
+fn httpDataCallback(response: HttpClient.Response, data: []const u8) !void {
+    const self: *XMLHttpRequest = @ptrCast(@alignCast(response.ctx));
     try self._response_data.appendSlice(self._arena, data);
 
     const page = self._page;
@@ -476,7 +474,7 @@ fn httpDoneCallback(ctx: *anyopaque) !void {
 
     // Not that the request is done, the http/client will free the transfer
     // object. It isn't safe to keep it around.
-    self._transfer = null;
+    self._http_response = null;
 
     const page = self._page;
 
@@ -499,22 +497,22 @@ fn httpErrorCallback(ctx: *anyopaque, err: anyerror) void {
     const self: *XMLHttpRequest = @ptrCast(@alignCast(ctx));
     // http client will close it after an error, it isn't safe to keep around
     self.handleError(err);
-    if (self._transfer != null) {
-        self._transfer = null;
+    if (self._http_response != null) {
+        self._http_response = null;
         self.releaseRef(self._page._session);
     }
 }
 
 fn httpShutdownCallback(ctx: *anyopaque) void {
     const self: *XMLHttpRequest = @ptrCast(@alignCast(ctx));
-    self._transfer = null;
+    self._http_response = null;
 }
 
 pub fn abort(self: *XMLHttpRequest) void {
     self.handleError(error.Abort);
-    if (self._transfer) |transfer| {
-        self._transfer = null;
-        transfer.abort(error.Abort);
+    if (self._http_response) |resp| {
+        resp.abort(error.Abort);
+        self._http_response = null;
         self.releaseRef(self._page._session);
     }
 }

src/network/Runtime.zig

@@ -29,7 +29,9 @@ const libcurl = @import("../sys/libcurl.zig");
 const net_http = @import("http.zig");
 const RobotStore = @import("Robots.zig").RobotStore;
 const WebBotAuth = @import("WebBotAuth.zig");
+const Cache = @import("cache/Cache.zig");
 
+const App = @import("../App.zig");
 const Runtime = @This();
 
 const Listener = struct {
@@ -45,10 +47,12 @@ const MAX_TICK_CALLBACKS = 16;
 
 allocator: Allocator,
 
+app: *App,
 config: *const Config,
 ca_blob: ?net_http.Blob,
 robot_store: RobotStore,
 web_bot_auth: ?WebBotAuth,
+cache: ?Cache,
 
 connections: []net_http.Connection,
 available: std.DoublyLinkedList = .{},
@@ -200,7 +204,7 @@ fn globalDeinit() void {
     libcurl.curl_global_cleanup();
 }
 
-pub fn init(allocator: Allocator, config: *const Config) !Runtime {
+pub fn init(allocator: Allocator, app: *App, config: *const Config) !Runtime {
     globalInit(allocator);
     errdefer globalDeinit();
 
@@ -233,6 +237,11 @@ pub fn init(allocator: Allocator, config: *const Config) !Runtime {
     else
         null;
 
+    const cache = if (config.cacheDir()) |cache_dir_path|
+        Cache{ .kind = .{ .fs = try .init(cache_dir_path) } }
+    else
+        null;
+
     return .{
         .allocator = allocator,
         .config = config,
@@ -244,8 +253,10 @@ pub fn init(allocator: Allocator, config: *const Config) !Runtime {
         .available = available,
         .connections = connections,
 
+        .app = app,
         .robot_store = RobotStore.init(allocator),
         .web_bot_auth = web_bot_auth,
+        .cache = cache,
     };
 }
 

src/network/cache/Cache.zig

@@ -0,0 +1,173 @@
+// Copyright (C) 2023-2026  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+const Http = @import("../http.zig");
+const FsCache = @import("FsCache.zig");
+
+/// A browser-wide cache for resources across the network.
+/// This mostly conforms to RFC9111 with regards to caching behavior.
+pub const Cache = @This();
+
+kind: union(enum) {
+    fs: FsCache,
+},
+
+pub fn get(self: *Cache, arena: std.mem.Allocator, req: CacheRequest) ?CachedResponse {
+    return switch (self.kind) {
+        inline else => |*c| c.get(arena, req),
+    };
+}
+
+pub fn put(self: *Cache, metadata: CachedMetadata, body: []const u8) !void {
+    return switch (self.kind) {
+        inline else => |*c| c.put(metadata, body),
+    };
+}
+
+pub const CacheControl = struct {
+    max_age: u64,
+    must_revalidate: bool = false,
+    immutable: bool = false,
+
+    pub fn parse(value: []const u8) ?CacheControl {
+        var cc: CacheControl = .{ .max_age = undefined };
+
+        var max_age_set = false;
+        var max_s_age_set = false;
+        var is_public = false;
+
+        var iter = std.mem.splitScalar(u8, value, ',');
+        while (iter.next()) |part| {
+            const directive = std.mem.trim(u8, part, &std.ascii.whitespace);
+            if (std.ascii.eqlIgnoreCase(directive, "no-store")) {
+                return null;
+            } else if (std.ascii.eqlIgnoreCase(directive, "no-cache")) {
+                return null;
+            } else if (std.ascii.eqlIgnoreCase(directive, "must-revalidate")) {
+                cc.must_revalidate = true;
+            } else if (std.ascii.eqlIgnoreCase(directive, "immutable")) {
+                cc.immutable = true;
+            } else if (std.ascii.eqlIgnoreCase(directive, "public")) {
+                is_public = true;
+            } else if (std.ascii.startsWithIgnoreCase(directive, "max-age=")) {
+                if (!max_s_age_set) {
+                    if (std.fmt.parseInt(u64, directive[8..], 10) catch null) |max_age| {
+                        cc.max_age = max_age;
+                        max_age_set = true;
+                    }
+                }
+            } else if (std.ascii.startsWithIgnoreCase(directive, "s-maxage=")) {
+                if (std.fmt.parseInt(u64, directive[9..], 10) catch null) |max_age| {
+                    cc.max_age = max_age;
+                    max_age_set = true;
+                    max_s_age_set = true;
+                }
+            }
+        }
+
+        if (!max_age_set) return null;
+        if (!is_public) return null;
+        if (cc.max_age == 0) return null;
+
+        return cc;
+    }
+};
+
+pub const Vary = union(enum) {
+    wildcard: void,
+    value: []const u8,
+
+    pub fn parse(value: []const u8) Vary {
+        if (std.mem.eql(u8, value, "*")) return .wildcard;
+        return .{ .value = value };
+    }
+
+    pub fn toString(self: Vary) []const u8 {
+        return switch (self) {
+            .wildcard => "*",
+            .value => |v| v,
+        };
+    }
+};
+
+pub const CachedMetadata = struct {
+    url: [:0]const u8,
+    content_type: []const u8,
+
+    status: u16,
+    stored_at: i64,
+    age_at_store: u64,
+
+    // for If-None-Match
+    etag: ?[]const u8,
+    // for If-Modified-Since
+    last_modified: ?[]const u8,
+
+    cache_control: CacheControl,
+    vary: ?Vary,
+    headers: []const Http.Header,
+};
+
+pub const CacheRequest = struct {
+    url: []const u8,
+    timestamp: i64,
+};
+
+pub const CachedData = union(enum) {
+    buffer: []const u8,
+    file: std.fs.File,
+};
+
+pub const CachedResponse = struct {
+    metadata: CachedMetadata,
+    data: CachedData,
+};
+
+pub fn tryCache(
+    arena: std.mem.Allocator,
+    timestamp: i64,
+    url: [:0]const u8,
+    status: u16,
+    content_type: ?[]const u8,
+    cache_control: ?[]const u8,
+    vary: ?[]const u8,
+    etag: ?[]const u8,
+    last_modified: ?[]const u8,
+    age: ?[]const u8,
+    has_set_cookie: bool,
+    has_authorization: bool,
+) !?CachedMetadata {
+    if (status != 200) return null;
+    if (has_set_cookie) return null;
+    if (has_authorization) return null;
+    const cc = CacheControl.parse(cache_control orelse return null) orelse return null;
+
+    return .{
+        .url = url,
+        .content_type = if (content_type) |ct| try arena.dupe(u8, ct) else "application/octet-stream",
+        .status = status,
+        .stored_at = timestamp,
+        .age_at_store = if (age) |a| std.fmt.parseInt(u64, a, 10) catch 0 else 0,
+        .cache_control = cc,
+        .vary = if (vary) |v| Vary.parse(v) else null,
+        .etag = if (etag) |e| try arena.dupe(u8, e) else null,
+        .last_modified = if (last_modified) |lm| try arena.dupe(u8, lm) else null,
+        .headers = &.{},
+    };
+}

src/network/cache/FsCache.zig

@@ -0,0 +1,293 @@
+// Copyright (C) 2023-2026  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+const Cache = @import("Cache.zig");
+const Http = @import("../http.zig");
+const CacheRequest = Cache.CacheRequest;
+const CachedMetadata = Cache.CachedMetadata;
+const CachedResponse = Cache.CachedResponse;
+
+const CACHE_VERSION: usize = 1;
+const LOCK_STRIPES = 16;
+
+pub const FsCache = @This();
+
+dir: std.fs.Dir,
+locks: [LOCK_STRIPES]std.Thread.Mutex = .{std.Thread.Mutex{}} ** LOCK_STRIPES,
+
+const CacheMetadataFile = struct {
+    version: usize,
+    metadata: CachedMetadata,
+};
+
+fn getLockPtr(self: *FsCache, key: *const [HASHED_KEY_LEN]u8) *std.Thread.Mutex {
+    const lock_idx: usize = @truncate(std.hash.Wyhash.hash(0, key) % LOCK_STRIPES);
+    return &self.locks[lock_idx];
+}
+
+const HASHED_KEY_LEN = 64;
+const HASHED_PATH_LEN = HASHED_KEY_LEN + 5;
+const HASHED_TMP_PATH_LEN = HASHED_PATH_LEN + 4;
+
+fn hashKey(key: []const u8) [HASHED_KEY_LEN]u8 {
+    var digest: [std.crypto.hash.sha2.Sha256.digest_length]u8 = undefined;
+    std.crypto.hash.sha2.Sha256.hash(key, &digest, .{});
+    var hex: [HASHED_KEY_LEN]u8 = undefined;
+    _ = std.fmt.bufPrint(&hex, "{s}", .{std.fmt.bytesToHex(&digest, .lower)}) catch unreachable;
+    return hex;
+}
+
+fn metaPath(hashed_key: *const [HASHED_KEY_LEN]u8) [HASHED_PATH_LEN]u8 {
+    var path: [HASHED_PATH_LEN]u8 = undefined;
+    _ = std.fmt.bufPrint(&path, "{s}.meta", .{hashed_key}) catch unreachable;
+    return path;
+}
+
+fn bodyPath(hashed_key: *const [HASHED_KEY_LEN]u8) [HASHED_PATH_LEN]u8 {
+    var path: [HASHED_PATH_LEN]u8 = undefined;
+    _ = std.fmt.bufPrint(&path, "{s}.body", .{hashed_key}) catch unreachable;
+    return path;
+}
+
+fn metaTmpPath(hashed_key: *const [HASHED_KEY_LEN]u8) [HASHED_TMP_PATH_LEN]u8 {
+    var path: [HASHED_TMP_PATH_LEN]u8 = undefined;
+    _ = std.fmt.bufPrint(&path, "{s}.meta.tmp", .{hashed_key}) catch unreachable;
+    return path;
+}
+
+fn bodyTmpPath(hashed_key: *const [HASHED_KEY_LEN]u8) [HASHED_TMP_PATH_LEN]u8 {
+    var path: [HASHED_TMP_PATH_LEN]u8 = undefined;
+    _ = std.fmt.bufPrint(&path, "{s}.body.tmp", .{hashed_key}) catch unreachable;
+    return path;
+}
+
+pub fn init(path: []const u8) !FsCache {
+    const cwd = std.fs.cwd();
+
+    cwd.makeDir(path) catch |err| switch (err) {
+        error.PathAlreadyExists => {},
+        else => return err,
+    };
+
+    const dir = try cwd.openDir(path, .{ .iterate = true });
+    return .{ .dir = dir };
+}
+
+pub fn deinit(self: *FsCache) void {
+    self.dir.close();
+}
+
+pub fn get(self: *FsCache, arena: std.mem.Allocator, req: CacheRequest) ?Cache.CachedResponse {
+    const hashed_key = hashKey(req.url);
+    const meta_p = metaPath(&hashed_key);
+    const body_p = bodyPath(&hashed_key);
+
+    const lock = self.getLockPtr(&hashed_key);
+    lock.lock();
+    defer lock.unlock();
+
+    const meta_file = self.dir.openFile(&meta_p, .{ .mode = .read_only }) catch return null;
+    defer meta_file.close();
+
+    const contents = meta_file.readToEndAlloc(arena, 1 * 1024 * 1024) catch return null;
+    defer arena.free(contents);
+
+    const cache_file: CacheMetadataFile = std.json.parseFromSliceLeaky(
+        CacheMetadataFile,
+        arena,
+        contents,
+        .{ .allocate = .alloc_always },
+    ) catch {
+        self.dir.deleteFile(&meta_p) catch {};
+        self.dir.deleteFile(&body_p) catch {};
+        return null;
+    };
+
+    const metadata = cache_file.metadata;
+
+    if (cache_file.version != CACHE_VERSION) {
+        self.dir.deleteFile(&meta_p) catch {};
+        self.dir.deleteFile(&body_p) catch {};
+        return null;
+    }
+
+    const now = req.timestamp;
+    const age = (now - metadata.stored_at) + @as(i64, @intCast(metadata.age_at_store));
+    if (age < 0 or @as(u64, @intCast(age)) >= metadata.cache_control.max_age) {
+        self.dir.deleteFile(&meta_p) catch {};
+        self.dir.deleteFile(&body_p) catch {};
+        return null;
+    }
+
+    const body_file = self.dir.openFile(
+        &body_p,
+        .{ .mode = .read_only },
+    ) catch return null;
+
+    return .{
+        .metadata = metadata,
+        .data = .{ .file = body_file },
+    };
+}
+
+pub fn put(self: *FsCache, meta: CachedMetadata, body: []const u8) !void {
+    const hashed_key = hashKey(meta.url);
+    const meta_p = metaPath(&hashed_key);
+    const meta_tmp_p = metaTmpPath(&hashed_key);
+    const body_p = bodyPath(&hashed_key);
+    const body_tmp_p = bodyTmpPath(&hashed_key);
+    var writer_buf: [512]u8 = undefined;
+
+    const lock = self.getLockPtr(&hashed_key);
+    lock.lock();
+    defer lock.unlock();
+
+    {
+        const meta_file = try self.dir.createFile(&meta_tmp_p, .{});
+        errdefer {
+            meta_file.close();
+            self.dir.deleteFile(&meta_tmp_p) catch {};
+        }
+
+        var meta_file_writer = meta_file.writer(&writer_buf);
+        const meta_file_writer_iface = &meta_file_writer.interface;
+        try std.json.Stringify.value(
+            CacheMetadataFile{ .version = CACHE_VERSION, .metadata = meta },
+            .{ .whitespace = .minified },
+            meta_file_writer_iface,
+        );
+        try meta_file_writer_iface.flush();
+        meta_file.close();
+    }
+    errdefer self.dir.deleteFile(&meta_tmp_p) catch {};
+    try self.dir.rename(&meta_tmp_p, &meta_p);
+
+    {
+        const body_file = try self.dir.createFile(&body_tmp_p, .{});
+        errdefer {
+            body_file.close();
+            self.dir.deleteFile(&body_tmp_p) catch {};
+        }
+
+        var body_file_writer = body_file.writer(&writer_buf);
+        const body_file_writer_iface = &body_file_writer.interface;
+        try body_file_writer_iface.writeAll(body);
+        try body_file_writer_iface.flush();
+        body_file.close();
+    }
+    errdefer self.dir.deleteFile(&body_tmp_p) catch {};
+
+    errdefer self.dir.deleteFile(&meta_p) catch {};
+    try self.dir.rename(&body_tmp_p, &body_p);
+}
+
+const testing = std.testing;
+
+test "FsCache: basic put and get" {
+    var tmp = testing.tmpDir(.{});
+    defer tmp.cleanup();
+
+    const path = try tmp.dir.realpathAlloc(testing.allocator, ".");
+    defer testing.allocator.free(path);
+
+    var fs_cache = try FsCache.init(path);
+    defer fs_cache.deinit();
+    var cache = Cache{ .kind = .{ .fs = fs_cache } };
+
+    var arena = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena.deinit();
+
+    const now = std.time.timestamp();
+    const meta = CachedMetadata{
+        .url = "https://example.com",
+        .content_type = "text/html",
+        .status = 200,
+        .stored_at = now,
+        .age_at_store = 0,
+        .etag = null,
+        .last_modified = null,
+        .cache_control = .{ .max_age = 600 },
+        .vary = null,
+        .headers = &.{},
+    };
+
+    const body = "hello world";
+    try cache.put(meta, body);
+
+    const result = cache.get(arena.allocator(), .{ .url = "https://example.com", .timestamp = now }) orelse return error.CacheMiss;
+    defer result.data.file.close();
+
+    var buf: [64]u8 = undefined;
+    var file_reader = result.data.file.reader(&buf);
+
+    const read_buf = try file_reader.interface.allocRemaining(testing.allocator, .unlimited);
+    defer testing.allocator.free(read_buf);
+
+    try testing.expectEqualStrings(body, read_buf);
+}
+
+test "FsCache: get expiration" {
+    var tmp = testing.tmpDir(.{});
+    defer tmp.cleanup();
+
+    const path = try tmp.dir.realpathAlloc(testing.allocator, ".");
+    defer testing.allocator.free(path);
+
+    var fs_cache = try FsCache.init(path);
+    defer fs_cache.deinit();
+    var cache = Cache{ .kind = .{ .fs = fs_cache } };
+
+    var arena = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena.deinit();
+
+    const now = 5000;
+    const max_age = 1000;
+
+    const meta = CachedMetadata{
+        .url = "https://example.com",
+        .content_type = "text/html",
+        .status = 200,
+        .stored_at = now,
+        .age_at_store = 900,
+        .etag = null,
+        .last_modified = null,
+        .cache_control = .{ .max_age = max_age },
+        .vary = null,
+        .headers = &.{},
+    };
+
+    const body = "hello world";
+    try cache.put(meta, body);
+
+    const result = cache.get(
+        arena.allocator(),
+        .{ .url = "https://example.com", .timestamp = now + 50 },
+    ) orelse return error.CacheMiss;
+    result.data.file.close();
+
+    try testing.expectEqual(null, cache.get(
+        arena.allocator(),
+        .{ .url = "https://example.com", .timestamp = now + 200 },
+    ));
+
+    try testing.expectEqual(null, cache.get(
+        arena.allocator(),
+        .{ .url = "https://example.com", .timestamp = now },
+    ));
+}