Remove heap allocation for Session

And adapt to similar changes on zig-js-runtime for Env

Signed-off-by: Francis Bouvier <francis@lightpanda.io>

src/browser/browser.zig

@@ -49,29 +49,33 @@ const log = std.log.scoped(.browser);
 // A browser contains only one session.
 // TODO allow multiple sessions per browser.
 pub const Browser = struct {
-    session: *Session,
+    session: Session = undefined,
 
-    pub fn init(alloc: std.mem.Allocator, loop: *Loop, vm: jsruntime.VM) !Browser {
+    const uri = "about:blank";
+
+    pub fn init(self: *Browser, alloc: std.mem.Allocator, loop: *Loop, vm: jsruntime.VM) !void {
         // We want to ensure the caller initialised a VM, but the browser
         // doesn't use it directly...
         _ = vm;
 
-        return Browser{
-            .session = try Session.init(alloc, loop, "about:blank"),
-        };
+        try Session.init(&self.session, alloc, loop, uri);
     }
 
     pub fn deinit(self: *Browser) void {
         self.session.deinit();
     }
 
-    pub fn newSession(self: *Browser, alloc: std.mem.Allocator, loop: *jsruntime.Loop) !void {
+    pub fn newSession(
+        self: *Browser,
+        alloc: std.mem.Allocator,
+        loop: *jsruntime.Loop,
+    ) !void {
         self.session.deinit();
-        self.session = try Session.init(alloc, loop, "about:blank");
+        try Session.init(&self.session, alloc, loop, uri);
     }
 
     pub fn currentSession(self: *Browser) *Session {
-        return self.session;
+        return &self.session;
     }
 };
 
@@ -99,13 +103,12 @@ pub const Session = struct {
     window: Window,
     // TODO move the shed to the browser?
     storageShed: storage.Shed,
-    page: ?*Page = null,
+    _page: ?Page = null,
     httpClient: HttpClient,
 
     jstypes: [Types.len]usize = undefined,
 
-    fn init(alloc: std.mem.Allocator, loop: *Loop, uri: []const u8) !*Session {
-        var self = try alloc.create(Session);
+    fn init(self: *Session, alloc: std.mem.Allocator, loop: *Loop, uri: []const u8) !void {
         self.* = Session{
             .uri = uri,
             .alloc = alloc,
@@ -116,15 +119,13 @@ pub const Session = struct {
             .httpClient = undefined,
         };
 
-        self.env = try Env.init(self.arena.allocator(), loop, null);
+        Env.init(&self.env, self.arena.allocator(), loop, null);
         self.httpClient = .{ .allocator = alloc, .loop = loop };
         try self.env.load(&self.jstypes);
-
-        return self;
     }
 
     fn deinit(self: *Session) void {
-        if (self.page) |page| page.end();
+        if (self._page) |*p| p.end();
 
         if (self.inspector) |inspector| {
             inspector.deinit(self.alloc);
@@ -136,7 +137,6 @@ pub const Session = struct {
         self.httpClient.deinit();
         self.loader.deinit();
         self.storageShed.deinit();
-        self.alloc.destroy(self);
     }
 
     pub fn initInspector(
@@ -158,8 +158,17 @@ pub const Session = struct {
         }
     }
 
-    pub fn createPage(self: *Session) !Page {
-        return Page.init(self.alloc, self);
+    pub fn createPage(self: *Session) !void {
+        if (self._page != null) return error.SessionPageExists;
+        const p: Page = undefined;
+        self._page = p;
+        Page.init(&self._page.?, self.alloc, self);
+    }
+
+    // shortcut
+    pub fn page(self: *Session) *Page {
+        if (self._page) |*p| return p;
+        @panic("No Page on this session");
     }
 };
 
@@ -181,16 +190,14 @@ pub const Page = struct {
     raw_data: ?[]const u8 = null,
 
     fn init(
+        self: *Page,
         alloc: std.mem.Allocator,
         session: *Session,
-    ) !Page {
-        if (session.page != null) return error.SessionPageExists;
-        var page = Page{
+    ) void {
+        self.* = .{
             .arena = std.heap.ArenaAllocator.init(alloc),
             .session = session,
         };
-        session.page = &page;
-        return page;
     }
 
     // reset js env and mem arena.

src/cdp/page.zig

@@ -281,7 +281,7 @@ fn navigate(
     try sendEvent(alloc, ctx, "Runtime.executionContextsCleared", void, {}, msg.sessionID);
 
     // Launch navigate
-    var p = try ctx.browser.currentSession().createPage();
+    try ctx.browser.session.createPage();
     ctx.state.executionContextId += 1;
     const auxData = try std.fmt.allocPrint(
         alloc,
@@ -290,7 +290,7 @@ fn navigate(
         .{ctx.state.frameID},
     );
     defer alloc.free(auxData);
-    _ = try p.navigate(params.url, auxData);
+    try ctx.browser.session.page().navigate(params.url, auxData);
 
     // Events
 

src/main.zig

@@ -224,18 +224,10 @@ pub fn main() !void {
     defer srv.close();
     std.log.info("Listening on: {s}:{d}...", .{ host, port });
 
-    // create v8 vm
-    const vm = jsruntime.VM.init();
-    defer vm.deinit();
-
     // loop
     var loop = try jsruntime.Loop.init(arena.allocator());
     defer loop.deinit();
 
-    // browser
-    var browser = try Browser.init(arena.allocator(), &loop, vm);
-    defer browser.deinit();
-
     // listen
-    try server.listen(&browser, &loop, srv.sockfd.?, std.time.ns_per_s * @as(u64, timeout));
+    try server.listen(arena.allocator(), &loop, srv.sockfd.?, std.time.ns_per_s * @as(u64, timeout));
 }

src/main_get.zig

@@ -83,18 +83,18 @@ pub fn main() !void {
     var loop = try jsruntime.Loop.init(allocator);
     defer loop.deinit();
 
-    var browser = try Browser.init(allocator, &loop, vm);
+    var browser = Browser{};
+    try Browser.init(&browser, allocator, &loop, vm);
     defer browser.deinit();
 
-    var page = try browser.currentSession().createPage();
-    defer page.deinit();
+    try browser.session.createPage();
 
-    try page.navigate(url, null);
-    defer page.end();
+    try browser.session.page().navigate(url, null);
+    defer browser.session.page().end();
 
-    try page.wait();
+    try browser.session.page().wait();
 
     if (dump) {
-        try page.dump(std.io.getStdOut());
+        try browser.session.page().dump(std.io.getStdOut());
     }
 }

src/server.zig

@@ -249,12 +249,12 @@ pub const Ctx = struct {
 
     // allocator of the current session
     inline fn alloc(self: *Ctx) std.mem.Allocator {
-        return self.browser.currentSession().alloc;
+        return self.browser.session.alloc;
     }
 
     // JS env of the current session
     inline fn env(self: Ctx) jsruntime.Env {
-        return self.browser.currentSession().env;
+        return self.browser.session.env;
     }
 
     // actions
@@ -300,7 +300,7 @@ pub const Ctx = struct {
 
     fn newSession(self: *Ctx) !void {
         try self.browser.newSession(self.alloc(), self.loop);
-        try self.browser.currentSession().initInspector(
+        try self.browser.session.initInspector(
             self,
             Ctx.onInspectorResp,
             Ctx.onInspectorNotif,
@@ -398,12 +398,21 @@ pub fn sendSync(ctx: *Ctx, msg: []const u8) !void {
 // ------
 
 pub fn listen(
-    browser: *Browser,
+    alloc: std.mem.Allocator,
     loop: *jsruntime.Loop,
     server_socket: std.posix.socket_t,
     timeout: u64,
 ) anyerror!void {
 
+    // create v8 vm
+    const vm = jsruntime.VM.init();
+    defer vm.deinit();
+
+    // browser
+    var browser: Browser = undefined;
+    try Browser.init(&browser, alloc, loop, vm);
+    defer browser.deinit();
+
     // create buffers
     var read_buf: [BufReadSize]u8 = undefined;
     var msg_buf = try MsgBuffer.init(loop.alloc, BufReadSize * 256); // 256KB
@@ -417,7 +426,7 @@ pub fn listen(
     // for accepting connections and receving messages
     var ctx = Ctx{
         .loop = loop,
-        .browser = browser,
+        .browser = &browser,
         .sessionNew = true,
         .read_buf = &read_buf,
         .msg_buf = &msg_buf,
@@ -426,7 +435,7 @@ pub fn listen(
         .conn_completion = &conn_completion,
         .timeout_completion = &timeout_completion,
     };
-    try browser.currentSession().initInspector(
+    try browser.session.initInspector(
         &ctx,
         Ctx.onInspectorResp,
         Ctx.onInspectorNotif,