add layers to HttpClient

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

@@ -156,6 +156,13 @@ 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,
@@ -267,6 +274,7 @@ 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,
@@ -1047,5 +1055,14 @@ 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/Server.zig

@@ -260,14 +260,14 @@ pub const Client = struct {
 
     fn start(self: *Client) void {
         const http = self.http;
-        http.cdp_client = .{
+        http.setCdpClient(.{
             .socket = self.ws.socket,
             .ctx = self,
             .blocking_read_start = Client.blockingReadStart,
             .blocking_read = Client.blockingRead,
             .blocking_read_end = Client.blockingReadStop,
-        };
+        });
-        defer http.cdp_client = null;
+        defer http.setCdpClient(null);
 
         self.httpLoop(http) catch |err| {
             log.err(.app, "CDP client loop", .{ .err = err });

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`,
+    var buf: [255]u8 = undefined;
-    // even if the input type is `[]u8`. @constCast is safe here.
+    const normalized = std.ascii.lowerString(&buf, std.mem.trim(u8, input, &std.ascii.whitespace));
-    var normalized = @constCast(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 .{
+    mime.params = params;
-        .params = params,
+    mime.charset = charset;
-        .charset = charset,
+    mime.charset_len = charset_len;
-        .charset_len = charset_len,
+    mime.content_type = content_type;
-        .content_type = content_type,
+    mime.is_default_charset = !has_explicit_charset;
-        .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 = .{
+    @memcpy(type_buf[0..main_type.len], main_type);
-        .type = main_type,
+    @memcpy(sub_type_buf[0..sub_type.len], sub_type);
-        .sub_type = sub_type,
+
-    } }, attribute_start };
+    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 {
+fn pageHeaderDoneCallback(response: HttpClient.Response) !bool {
-    var self: *Page = @ptrCast(@alignCast(transfer.ctx));
+    var self: *Page = @ptrCast(@alignCast(response.ctx));
 
-    const header = &transfer.response_header.?;
+    const response_url = response.url();
-
-    const response_url = std.mem.span(header.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,
+            .status = response.status(),
-            .content_type = header.contentType(),
+            .content_type = response.contentType(),
             .type = self._type,
         });
     }
@@ -895,14 +893,14 @@ fn pageHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
     return true;
 }
 
-fn pageDataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
+fn pageDataCallback(response: HttpClient.Response, data: []const u8) !void {
-    var self: *Page = @ptrCast(@alignCast(transfer.ctx));
+    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/Runner.zig

@@ -137,7 +137,7 @@ fn _tick(self: *Runner, comptime is_cdp: bool, opts: TickOpts) !CDPTickResult {
         .pre, .raw, .text, .image => {
             // The main page hasn't started/finished navigating.
             // There's no JS to run, and no reason to run the scheduler.
-            if (http_client.active == 0 and (comptime is_cdp) == false) {
+            if (http_client.active() == 0 and (comptime is_cdp) == false) {
                 // haven't started navigating, I guess.
                 return .done;
             }
@@ -171,8 +171,8 @@ fn _tick(self: *Runner, comptime is_cdp: bool, opts: TickOpts) !CDPTickResult {
             // Each call to this runs scheduled load events.
             try page.dispatchLoad();
 
-            const http_active = http_client.active;
+            const http_active = http_client.active();
-            const total_network_activity = http_active + http_client.intercepted;
+            const total_network_activity = http_active + http_client.intercepted();
             if (page._notified_network_almost_idle.check(total_network_activity <= 2)) {
                 page.notifyNetworkAlmostIdle();
             }
@@ -185,7 +185,7 @@ fn _tick(self: *Runner, comptime is_cdp: bool, opts: TickOpts) !CDPTickResult {
                 // because is_cdp is true, and that can only be
                 // the case when interception isn't possible.
                 if (comptime IS_DEBUG) {
-                    std.debug.assert(http_client.intercepted == 0);
+                    std.debug.assert(http_client.intercepted() == 0);
                 }
 
                 if (browser.hasBackgroundTasks()) {

src/browser/ScriptManager.zig

@@ -694,82 +694,86 @@ pub const Script = struct {
         self.manager.page.releaseArena(self.arena);
     }
 
-    fn startCallback(transfer: *HttpClient.Transfer) !void {
+    fn startCallback(response: HttpClient.Response) !void {
-        log.debug(.http, "script fetch start", .{ .req = transfer });
+        log.debug(.http, "script fetch start", .{ .req = response });
     }
 
-    fn headerCallback(transfer: *HttpClient.Transfer) !bool {
+    fn headerCallback(response: HttpClient.Response) !bool {
-        const self: *Script = @ptrCast(@alignCast(transfer.ctx));
+        const self: *Script = @ptrCast(@alignCast(response.ctx));
-        const header = &transfer.response_header.?;
+
-        self.status = header.status;
+        self.status = response.status().?;
-        if (header.status != 200) {
+        if (response.status() != 200) {
             log.info(.http, "script header", .{
-                .req = transfer,
+                .req = response,
-                .status = header.status,
+                .status = response.status(),
-                .content_type = header.contentType(),
+                .content_type = response.contentType(),
             });
             return false;
         }
 
         if (comptime IS_DEBUG) {
             log.debug(.http, "script header", .{
-                .req = transfer,
+                .req = response,
-                .status = header.status,
+                .status = response.status(),
-                .content_type = header.contentType(),
+                .content_type = response.contentType(),
             });
         }
 
-        {
+        switch (response.inner) {
-            // temp debug, trying to figure out why the next assert sometimes
+            .transfer => |transfer| {
-            // fails. Is the buffer just corrupt or is headerCallback really
+                // temp debug, trying to figure out why the next assert sometimes
-            // being called twice?
+                // fails. Is the buffer just corrupt or is headerCallback really
-            lp.assert(self.header_callback_called == false, "ScriptManager.Header recall", .{
+                // being called twice?
-                .m = @tagName(std.meta.activeTag(self.mode)),
+                lp.assert(self.header_callback_called == false, "ScriptManager.Header recall", .{
-                .a1 = self.debug_transfer_id,
+                    .m = @tagName(std.meta.activeTag(self.mode)),
-                .a2 = self.debug_transfer_tries,
+                    .a1 = self.debug_transfer_id,
-                .a3 = self.debug_transfer_aborted,
+                    .a2 = self.debug_transfer_tries,
-                .a4 = self.debug_transfer_bytes_received,
+                    .a3 = self.debug_transfer_aborted,
-                .a5 = self.debug_transfer_notified_fail,
+                    .a4 = self.debug_transfer_bytes_received,
-                .a7 = self.debug_transfer_intercept_state,
+                    .a5 = self.debug_transfer_notified_fail,
-                .a8 = self.debug_transfer_auth_challenge,
+                    .a7 = self.debug_transfer_intercept_state,
-                .a9 = self.debug_transfer_easy_id,
+                    .a8 = self.debug_transfer_auth_challenge,
-                .b1 = transfer.id,
+                    .a9 = self.debug_transfer_easy_id,
-                .b2 = transfer._tries,
+                    .b1 = transfer.id,
-                .b3 = transfer.aborted,
+                    .b2 = transfer._tries,
-                .b4 = transfer.bytes_received,
+                    .b3 = transfer.aborted,
-                .b5 = transfer._notified_fail,
+                    .b4 = transfer.bytes_received,
-                .b7 = @intFromEnum(transfer._intercept_state),
+                    .b5 = transfer._notified_fail,
-                .b8 = transfer._auth_challenge != null,
+                    .b7 = @intFromEnum(transfer._intercept_state),
-                .b9 = if (transfer._conn) |c| @intFromPtr(c._easy) else 0,
+                    .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.header_callback_called = true;
-            self.debug_transfer_tries = transfer._tries;
+                self.debug_transfer_id = transfer.id;
-            self.debug_transfer_aborted = transfer.aborted;
+                self.debug_transfer_tries = transfer._tries;
-            self.debug_transfer_bytes_received = transfer.bytes_received;
+                self.debug_transfer_aborted = transfer.aborted;
-            self.debug_transfer_notified_fail = transfer._notified_fail;
+                self.debug_transfer_bytes_received = transfer.bytes_received;
-            self.debug_transfer_intercept_state = @intFromEnum(transfer._intercept_state);
+                self.debug_transfer_notified_fail = transfer._notified_fail;
-            self.debug_transfer_auth_challenge = transfer._auth_challenge != null;
+                self.debug_transfer_intercept_state = @intFromEnum(transfer._intercept_state);
-            self.debug_transfer_easy_id = if (transfer._conn) |c| @intFromPtr(c._easy) else 0;
+                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 {
+    fn dataCallback(response: HttpClient.Response, data: []const u8) !void {
-        const self: *Script = @ptrCast(@alignCast(transfer.ctx));
+        const self: *Script = @ptrCast(@alignCast(response.ctx));
-        self._dataCallback(transfer, data) catch |err| {
+        self._dataCallback(response, data) catch |err| {
-            log.err(.http, "SM.dataCallback", .{ .err = err, .transfer = transfer, .len = data.len });
+            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 {
+fn httpStartCallback(response: HttpClient.Response) !void {
-    const self: *Fetch = @ptrCast(@alignCast(transfer.ctx));
+    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 {
+fn httpHeaderDoneCallback(response: HttpClient.Response) !bool {
-    const self: *Fetch = @ptrCast(@alignCast(transfer.ctx));
+    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 = response.status().?;
-    res._status_text = std.http.Status.phrase(@enumFromInt(header.status)) orelse "";
+    res._status_text = std.http.Status.phrase(@enumFromInt(response.status().?)) orelse "";
-    res._url = try arena.dupeZ(u8, std.mem.span(header.url));
+    res._url = try arena.dupeZ(u8, response.url());
-    res._is_redirected = header.redirect_count > 0;
+    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 {
+fn httpDataCallback(response: HttpClient.Response, data: []const u8) !void {
-    const self: *Fetch = @ptrCast(@alignCast(transfer.ctx));
+    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| {
+    if (self._http_response) |resp| {
-        transfer.abort(error.Abort);
+        resp.abort(error.Abort);
-        self._transfer = null;
+        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,
 _active_request: bool = false,
 
 _url: [:0]const u8 = "",
@@ -100,9 +100,9 @@ pub fn init(page: *Page) !*XMLHttpRequest {
 }
 
 pub fn deinit(self: *XMLHttpRequest, session: *Session) void {
-    if (self._transfer) |transfer| {
+    if (self._http_response) |resp| {
-        transfer.abort(error.Abort);
+        resp.abort(error.Abort);
-        self._transfer = null;
+        self._http_response = null;
     }
 
     if (self._on_ready_state_change) |func| {
@@ -184,9 +184,9 @@ 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
@@ -398,34 +398,32 @@ pub fn getResponseXML(self: *XMLHttpRequest, page: *Page) !?*Node.Document {
     };
 }
 
-fn httpStartCallback(transfer: *HttpClient.Transfer) !void {
+fn httpStartCallback(response: HttpClient.Response) !void {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
+    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;
 }
 
-fn httpHeaderCallback(transfer: *HttpClient.Transfer, header: http.Header) !void {
+fn httpHeaderCallback(response: HttpClient.Response, header: http.Header) !void {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
+    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 {
+fn httpHeaderDoneCallback(response: HttpClient.Response) !bool {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
+    const self: *XMLHttpRequest = @ptrCast(@alignCast(response.ctx));
-
-    const header = &transfer.response_header.?;
 
     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,
@@ -436,18 +434,18 @@ 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;
+    self._response_status = response.status().?;
-    if (transfer.getContentLength()) |cl| {
+    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;
 
@@ -462,8 +460,8 @@ fn httpHeaderDoneCallback(transfer: *HttpClient.Transfer) !bool {
     return true;
 }
 
-fn httpDataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
+fn httpDataCallback(response: HttpClient.Response, data: []const u8) !void {
-    const self: *XMLHttpRequest = @ptrCast(@alignCast(transfer.ctx));
+    const self: *XMLHttpRequest = @ptrCast(@alignCast(response.ctx));
     try self._response_data.appendSlice(self._arena, data);
 
     const page = self._page;
@@ -486,7 +484,7 @@ 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;
 
@@ -509,22 +507,22 @@ 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) {
+    if (self._http_response != null) {
-        self._transfer = null;
+        self._http_response = null;
     }
     self.releaseSelfRef();
 }
 
 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| {
+    if (self._http_response) |resp| {
-        self._transfer = null;
+        self._http_response = null;
-        transfer.abort(error.Abort);
+        resp.abort(error.Abort);
     }
     self.releaseSelfRef();
 }

src/cdp/domains/page.zig

@@ -139,8 +139,8 @@ fn setLifecycleEventsEnabled(cmd: *CDP.Command) !void {
         try sendPageLifecycle(bc, "load", now, frame_id, loader_id);
 
         const http_client = page._session.browser.http_client;
-        const http_active = http_client.active;
+        const http_active = http_client.active();
-        const total_network_activity = http_active + http_client.intercepted;
+        const total_network_activity = http_active + http_client.intercepted();
         if (page._notified_network_almost_idle.check(total_network_activity <= 2)) {
             try sendPageLifecycle(bc, "networkAlmostIdle", now, frame_id, loader_id);
         }

src/log.zig

@@ -39,6 +39,7 @@ pub const Scope = enum {
     telemetry,
     unknown_prop,
     mcp,
+    cache,
 };
 
 const Opts = struct {

src/network/Network.zig

@@ -29,7 +29,9 @@ const libcurl = @import("../sys/libcurl.zig");
 const 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 Network = @This();
 
 const Listener = struct {
@@ -45,10 +47,12 @@ const MAX_TICK_CALLBACKS = 16;
 
 allocator: Allocator,
 
+app: *App,
 config: *const Config,
 ca_blob: ?http.Blob,
 robot_store: RobotStore,
 web_bot_auth: ?WebBotAuth,
+cache: ?Cache,
 
 connections: []http.Connection,
 available: std.DoublyLinkedList = .{},
@@ -200,7 +204,7 @@ fn globalDeinit() void {
     libcurl.curl_global_cleanup();
 }
 
-pub fn init(allocator: Allocator, config: *const Config) !Network {
+pub fn init(allocator: Allocator, app: *App, config: *const Config) !Network {
     globalInit(allocator);
     errdefer globalDeinit();
 
@@ -233,6 +237,11 @@ pub fn init(allocator: Allocator, config: *const Config) !Network {
     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) !Network {
         .available = available,
         .connections = connections,
 
+        .app = app,
         .robot_store = RobotStore.init(allocator),
         .web_bot_auth = web_bot_auth,
+        .cache = cache,
     };
 }
 
@@ -278,6 +289,8 @@ pub fn deinit(self: *Network) void {
         wba.deinit(self.allocator);
     }
 
+    if (self.cache) |*cache| cache.deinit();
+
     globalDeinit();
 }
 

src/network/cache/Cache.zig

@@ -0,0 +1,156 @@
+// 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 deinit(self: *Cache) void {
+    return switch (self.kind) {
+        inline else => |*c| c.deinit(),
+    };
+}
+
+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,
+
+    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, "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 CachedMetadata = struct {
+    url: [:0]const u8,
+    content_type: []const u8,
+
+    status: u16,
+    stored_at: i64,
+    age_at_store: u64,
+
+    cache_control: CacheControl,
+    /// Response Headers
+    headers: []const Http.Header,
+
+    /// These are Request Headers used by Vary.
+    vary_headers: []const Http.Header,
+};
+
+pub const CacheRequest = struct {
+    url: []const u8,
+    timestamp: i64,
+    request_headers: []const Http.Header,
+};
+
+pub const CachedData = union(enum) {
+    buffer: []const u8,
+    file: struct {
+        file: std.fs.File,
+        offset: usize,
+        len: usize,
+    },
+};
+
+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,
+    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;
+    if (vary) |v| if (std.mem.eql(u8, v, "*")) 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,
+        .headers = &.{},
+        .vary_headers = &.{},
+    };
+}

src/network/cache/FsCache.zig

@@ -0,0 +1,580 @@
+// 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 log = @import("../../log.zig");
+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;
+comptime {
+    std.debug.assert(std.math.isPowerOfTwo(LOCK_STRIPES));
+}
+
+pub const FsCache = @This();
+
+dir: std.fs.Dir,
+locks: [LOCK_STRIPES]std.Thread.Mutex = .{std.Thread.Mutex{}} ** LOCK_STRIPES,
+
+const CacheMetadataJson = struct {
+    version: usize,
+    metadata: CachedMetadata,
+};
+
+fn getLockPtr(self: *FsCache, key: *const [HASHED_KEY_LEN]u8) *std.Thread.Mutex {
+    const lock_idx = std.hash.Wyhash.hash(0, key[0..]) & (LOCK_STRIPES - 1);
+    return &self.locks[lock_idx];
+}
+
+const BODY_LEN_HEADER_LEN = 8;
+const HASHED_KEY_LEN = 64;
+const HASHED_PATH_LEN = HASHED_KEY_LEN + 6;
+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 cachePath(hashed_key: *const [HASHED_KEY_LEN]u8) [HASHED_PATH_LEN]u8 {
+    var path: [HASHED_PATH_LEN]u8 = undefined;
+    _ = std.fmt.bufPrint(&path, "{s}.cache", .{hashed_key}) catch unreachable;
+    return path;
+}
+
+fn cacheTmpPath(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}.cache.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 cache_p = cachePath(&hashed_key);
+
+    const lock = self.getLockPtr(&hashed_key);
+    lock.lock();
+    defer lock.unlock();
+
+    const file = self.dir.openFile(&cache_p, .{ .mode = .read_only }) catch |e| {
+        switch (e) {
+            std.fs.File.OpenError.FileNotFound => {
+                log.debug(.cache, "miss", .{ .url = req.url, .hash = &hashed_key });
+            },
+            else => |err| {
+                log.warn(.cache, "open file err", .{ .url = req.url, .err = err });
+            },
+        }
+        return null;
+    };
+
+    var cleanup = false;
+    defer if (cleanup) {
+        file.close();
+        self.dir.deleteFile(&cache_p) catch |e| {
+            log.err(.cache, "clean fail", .{ .url = req.url, .file = &cache_p, .err = e });
+        };
+    };
+
+    var file_buf: [1024]u8 = undefined;
+    var len_buf: [BODY_LEN_HEADER_LEN]u8 = undefined;
+
+    var file_reader = file.reader(&file_buf);
+    const file_reader_iface = &file_reader.interface;
+
+    file_reader_iface.readSliceAll(&len_buf) catch |e| {
+        log.warn(.cache, "read header", .{ .url = req.url, .err = e });
+        cleanup = true;
+        return null;
+    };
+    const body_len = std.mem.readInt(u64, &len_buf, .little);
+
+    // Now we read metadata.
+    file_reader.seekTo(body_len + BODY_LEN_HEADER_LEN) catch |e| {
+        log.warn(.cache, "seek metadata", .{ .url = req.url, .err = e });
+        cleanup = true;
+        return null;
+    };
+
+    var json_reader = std.json.Reader.init(arena, file_reader_iface);
+    const cache_file: CacheMetadataJson = std.json.parseFromTokenSourceLeaky(
+        CacheMetadataJson,
+        arena,
+        &json_reader,
+        .{ .allocate = .alloc_always },
+    ) catch |e| {
+        log.warn(.cache, "metadata parse", .{ .url = req.url, .err = e });
+        cleanup = true;
+        return null;
+    };
+
+    if (cache_file.version != CACHE_VERSION) {
+        log.warn(.cache, "version", .{ .url = req.url, .expected = CACHE_VERSION, .got = cache_file.version });
+        cleanup = true;
+        return null;
+    }
+
+    const metadata = cache_file.metadata;
+
+    // Check entry expiration.
+    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) {
+        log.debug(.cache, "expired", .{ .url = req.url });
+        cleanup = true;
+        return null;
+    }
+
+    // If we have Vary headers, ensure they are present & matching.
+    for (metadata.vary_headers) |vary_hdr| {
+        const name = vary_hdr.name;
+        const value = vary_hdr.value;
+
+        const incoming = for (req.request_headers) |h| {
+            if (std.ascii.eqlIgnoreCase(h.name, name)) break h.value;
+        } else "";
+
+        if (!std.ascii.eqlIgnoreCase(value, incoming)) {
+            log.debug(.cache, "vary mismatch", .{ .url = req.url, .header = name });
+            return null;
+        }
+    }
+
+    // On the case of a hash collision.
+    if (!std.ascii.eqlIgnoreCase(metadata.url, req.url)) {
+        log.warn(.cache, "collision", .{ .url = req.url, .expected = metadata.url, .got = req.url });
+        cleanup = true;
+        return null;
+    }
+
+    return .{
+        .metadata = metadata,
+        .data = .{
+            .file = .{
+                .file = file,
+                .offset = BODY_LEN_HEADER_LEN,
+                .len = body_len,
+            },
+        },
+    };
+}
+
+pub fn put(self: *FsCache, meta: CachedMetadata, body: []const u8) !void {
+    const hashed_key = hashKey(meta.url);
+    const cache_p = cachePath(&hashed_key);
+    const cache_tmp_p = cacheTmpPath(&hashed_key);
+
+    const lock = self.getLockPtr(&hashed_key);
+    lock.lock();
+    defer lock.unlock();
+
+    const file = try self.dir.createFile(&cache_tmp_p, .{ .truncate = true });
+    defer file.close();
+
+    var writer_buf: [1024]u8 = undefined;
+
+    var file_writer = file.writer(&writer_buf);
+    var file_writer_iface = &file_writer.interface;
+
+    var len_buf: [8]u8 = undefined;
+    std.mem.writeInt(u64, &len_buf, body.len, .little);
+    try file_writer_iface.writeAll(&len_buf);
+    try file_writer_iface.writeAll(body);
+
+    try std.json.Stringify.value(
+        CacheMetadataJson{ .version = CACHE_VERSION, .metadata = meta },
+        .{ .whitespace = .minified },
+        file_writer_iface,
+    );
+
+    try file_writer_iface.flush();
+    try self.dir.rename(&cache_tmp_p, &cache_p);
+}
+
+const testing = std.testing;
+
+fn setupCache() !struct { tmp: testing.TmpDir, cache: Cache } {
+    var tmp = testing.tmpDir(.{});
+    errdefer tmp.cleanup();
+
+    const path = try tmp.dir.realpathAlloc(testing.allocator, ".");
+    defer testing.allocator.free(path);
+
+    return .{
+        .tmp = tmp,
+        .cache = Cache{ .kind = .{ .fs = try FsCache.init(path) } },
+    };
+}
+
+test "FsCache: basic put and get" {
+    var setup = try setupCache();
+    defer {
+        setup.cache.deinit();
+        setup.tmp.cleanup();
+    }
+
+    const cache = &setup.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,
+        .cache_control = .{ .max_age = 600 },
+        .headers = &.{},
+        .vary_headers = &.{},
+    };
+
+    const body = "hello world";
+    try cache.put(meta, body);
+
+    const result = cache.get(
+        arena.allocator(),
+        .{
+            .url = "https://example.com",
+            .timestamp = now,
+            .request_headers = &.{},
+        },
+    ) orelse return error.CacheMiss;
+    const f = result.data.file;
+    const file = f.file;
+    defer file.close();
+
+    var buf: [64]u8 = undefined;
+    var file_reader = file.reader(&buf);
+    try file_reader.seekTo(f.offset);
+
+    const read_buf = try file_reader.interface.readAlloc(testing.allocator, f.len);
+    defer testing.allocator.free(read_buf);
+    try testing.expectEqualStrings(body, read_buf);
+}
+
+test "FsCache: get expiration" {
+    var setup = try setupCache();
+    defer {
+        setup.cache.deinit();
+        setup.tmp.cleanup();
+    }
+
+    const cache = &setup.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,
+        .cache_control = .{ .max_age = max_age },
+        .headers = &.{},
+        .vary_headers = &.{},
+    };
+
+    const body = "hello world";
+    try cache.put(meta, body);
+
+    const result = cache.get(
+        arena.allocator(),
+        .{
+            .url = "https://example.com",
+            .timestamp = now + 50,
+            .request_headers = &.{},
+        },
+    ) orelse return error.CacheMiss;
+    result.data.file.file.close();
+
+    try testing.expectEqual(null, cache.get(
+        arena.allocator(),
+        .{
+            .url = "https://example.com",
+            .timestamp = now + 200,
+            .request_headers = &.{},
+        },
+    ));
+
+    try testing.expectEqual(null, cache.get(
+        arena.allocator(),
+        .{
+            .url = "https://example.com",
+            .timestamp = now,
+            .request_headers = &.{},
+        },
+    ));
+}
+
+test "FsCache: put override" {
+    var setup = try setupCache();
+    defer {
+        setup.cache.deinit();
+        setup.tmp.cleanup();
+    }
+
+    const cache = &setup.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,
+            .cache_control = .{ .max_age = max_age },
+            .headers = &.{},
+            .vary_headers = &.{},
+        };
+
+        const body = "hello world";
+        try cache.put(meta, body);
+
+        const result = cache.get(
+            arena.allocator(),
+            .{
+                .url = "https://example.com",
+                .timestamp = now,
+                .request_headers = &.{},
+            },
+        ) orelse return error.CacheMiss;
+        const f = result.data.file;
+        const file = f.file;
+        defer file.close();
+
+        var buf: [64]u8 = undefined;
+        var file_reader = file.reader(&buf);
+        try file_reader.seekTo(f.offset);
+
+        const read_buf = try file_reader.interface.readAlloc(testing.allocator, f.len);
+        defer testing.allocator.free(read_buf);
+
+        try testing.expectEqualStrings(body, read_buf);
+    }
+
+    {
+        const now = 10000;
+        const max_age = 2000;
+
+        const meta = CachedMetadata{
+            .url = "https://example.com",
+            .content_type = "text/html",
+            .status = 200,
+            .stored_at = now,
+            .age_at_store = 0,
+            .cache_control = .{ .max_age = max_age },
+            .headers = &.{},
+            .vary_headers = &.{},
+        };
+
+        const body = "goodbye world";
+        try cache.put(meta, body);
+
+        const result = cache.get(
+            arena.allocator(),
+            .{
+                .url = "https://example.com",
+                .timestamp = now,
+                .request_headers = &.{},
+            },
+        ) orelse return error.CacheMiss;
+        const f = result.data.file;
+        const file = f.file;
+        defer file.close();
+
+        var buf: [64]u8 = undefined;
+        var file_reader = file.reader(&buf);
+        try file_reader.seekTo(f.offset);
+
+        const read_buf = try file_reader.interface.readAlloc(testing.allocator, f.len);
+        defer testing.allocator.free(read_buf);
+
+        try testing.expectEqualStrings(body, read_buf);
+    }
+}
+
+test "FsCache: garbage file" {
+    var setup = try setupCache();
+    defer {
+        setup.cache.deinit();
+        setup.tmp.cleanup();
+    }
+
+    const hashed_key = hashKey("https://example.com");
+    const cache_p = cachePath(&hashed_key);
+    const file = try setup.cache.kind.fs.dir.createFile(&cache_p, .{});
+    try file.writeAll("this is not a valid cache file !@#$%");
+    file.close();
+
+    var arena = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena.deinit();
+
+    try testing.expectEqual(
+        null,
+        setup.cache.get(arena.allocator(), .{
+            .url = "https://example.com",
+            .timestamp = 5000,
+            .request_headers = &.{},
+        }),
+    );
+}
+
+test "FsCache: vary hit and miss" {
+    var setup = try setupCache();
+    defer {
+        setup.cache.deinit();
+        setup.tmp.cleanup();
+    }
+
+    const cache = &setup.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,
+        .cache_control = .{ .max_age = 600 },
+        .headers = &.{},
+        .vary_headers = &.{
+            .{ .name = "Accept-Encoding", .value = "gzip" },
+        },
+    };
+
+    try cache.put(meta, "hello world");
+
+    const result = cache.get(arena.allocator(), .{
+        .url = "https://example.com",
+        .timestamp = now,
+        .request_headers = &.{
+            .{ .name = "Accept-Encoding", .value = "gzip" },
+        },
+    }) orelse return error.CacheMiss;
+    result.data.file.file.close();
+
+    try testing.expectEqual(null, cache.get(arena.allocator(), .{
+        .url = "https://example.com",
+        .timestamp = now,
+        .request_headers = &.{
+            .{ .name = "Accept-Encoding", .value = "br" },
+        },
+    }));
+
+    try testing.expectEqual(null, cache.get(arena.allocator(), .{
+        .url = "https://example.com",
+        .timestamp = now,
+        .request_headers = &.{},
+    }));
+
+    const result2 = cache.get(arena.allocator(), .{
+        .url = "https://example.com",
+        .timestamp = now,
+        .request_headers = &.{
+            .{ .name = "Accept-Encoding", .value = "gzip" },
+        },
+    }) orelse return error.CacheMiss;
+    result2.data.file.file.close();
+}
+
+test "FsCache: vary multiple headers" {
+    var setup = try setupCache();
+    defer {
+        setup.cache.deinit();
+        setup.tmp.cleanup();
+    }
+
+    const cache = &setup.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,
+        .cache_control = .{ .max_age = 600 },
+        .headers = &.{},
+        .vary_headers = &.{
+            .{ .name = "Accept-Encoding", .value = "gzip" },
+            .{ .name = "Accept-Language", .value = "en" },
+        },
+    };
+
+    try cache.put(meta, "hello world");
+
+    const result = cache.get(arena.allocator(), .{
+        .url = "https://example.com",
+        .timestamp = now,
+        .request_headers = &.{
+            .{ .name = "Accept-Encoding", .value = "gzip" },
+            .{ .name = "Accept-Language", .value = "en" },
+        },
+    }) orelse return error.CacheMiss;
+    result.data.file.file.close();
+
+    try testing.expectEqual(null, cache.get(arena.allocator(), .{
+        .url = "https://example.com",
+        .timestamp = now,
+        .request_headers = &.{
+            .{ .name = "Accept-Encoding", .value = "gzip" },
+            .{ .name = "Accept-Language", .value = "fr" },
+        },
+    }));
+}

src/network/http.zig

@@ -79,7 +79,7 @@ pub const Headers = struct {
         self.headers = updated_headers;
     }
 
-    fn parseHeader(header_str: []const u8) ?Header {
+    pub fn parseHeader(header_str: []const u8) ?Header {
         const colon_pos = std.mem.indexOfScalar(u8, header_str, ':') orelse return null;
 
         const name = std.mem.trim(u8, header_str[0..colon_pos], " \t");
@@ -88,22 +88,9 @@ pub const Headers = struct {
         return .{ .name = name, .value = value };
     }
 
-    pub fn iterator(self: *Headers) Iterator {
+    pub fn iterator(self: Headers) HeaderIterator {
-        return .{
+        return .{ .curl_slist = .{ .header = self.headers } };
-            .header = self.headers,
-        };
     }
-
-    const Iterator = struct {
-        header: [*c]libcurl.CurlSList,
-
-        pub fn next(self: *Iterator) ?Header {
-            const h = self.header orelse return null;
-
-            self.header = h.*.next;
-            return parseHeader(std.mem.span(@as([*:0]const u8, @ptrCast(h.*.data))));
-        }
-    };
 };
 
 // In normal cases, the header iterator comes from the curl linked list.
@@ -112,6 +99,7 @@ pub const Headers = struct {
 // This union, is an iterator that exposes the same API for either case.
 pub const HeaderIterator = union(enum) {
     curl: CurlHeaderIterator,
+    curl_slist: CurlSListIterator,
     list: ListHeaderIterator,
 
     pub fn next(self: *HeaderIterator) ?Header {
@@ -120,6 +108,19 @@ pub const HeaderIterator = union(enum) {
         }
     }
 
+    pub fn collect(self: *HeaderIterator, allocator: std.mem.Allocator) !std.ArrayList(Header) {
+        var list: std.ArrayList(Header) = .empty;
+
+        while (self.next()) |hdr| {
+            try list.append(allocator, .{
+                .name = try allocator.dupe(u8, hdr.name),
+                .value = try allocator.dupe(u8, hdr.value),
+            });
+        }
+
+        return list;
+    }
+
     const CurlHeaderIterator = struct {
         conn: *const Connection,
         prev: ?*libcurl.CurlHeader = null,
@@ -136,6 +137,16 @@ pub const HeaderIterator = union(enum) {
         }
     };
 
+    const CurlSListIterator = struct {
+        header: [*c]libcurl.CurlSList,
+
+        pub fn next(self: *CurlSListIterator) ?Header {
+            const h = self.header orelse return null;
+            self.header = h.*.next;
+            return Headers.parseHeader(std.mem.span(@as([*:0]const u8, @ptrCast(h.*.data))));
+        }
+    };
+
     const ListHeaderIterator = struct {
         index: usize = 0,
         list: []const Header,