Merge pull request #502 from lightpanda-io/cdp_node_children

Cdp node children

src/cdp/Node.zig

@@ -22,79 +22,19 @@ const Allocator = std.mem.Allocator;
 
 pub const Id = u32;
 
+const log = std.log.scoped(.cdp_node);
+
 const Node = @This();
 
 id: Id,
-parent_id: ?Id = null,
-node_type: u32,
-backend_node_id: Id,
-node_name: []const u8,
-local_name: []const u8,
-node_value: []const u8,
-child_node_count: u32,
-children: []const *Node,
-document_url: ?[]const u8,
-base_url: ?[]const u8,
-xml_version: []const u8,
-compatibility_mode: CompatibilityMode,
-is_scrollable: bool,
 _node: *parser.Node,
 
-const CompatibilityMode = enum {
-    NoQuirksMode,
-};
-
-pub fn jsonStringify(self: *const Node, writer: anytype) !void {
-    try writer.beginObject();
-    try writer.objectField("nodeId");
-    try writer.write(self.id);
-
-    try writer.objectField("parentId");
-    try writer.write(self.parent_id);
-
-    try writer.objectField("backendNodeId");
-    try writer.write(self.backend_node_id);
-
-    try writer.objectField("nodeType");
-    try writer.write(self.node_type);
-
-    try writer.objectField("nodeName");
-    try writer.write(self.node_name);
-
-    try writer.objectField("localName");
-    try writer.write(self.local_name);
-
-    try writer.objectField("nodeValue");
-    try writer.write(self.node_value);
-
-    try writer.objectField("childNodeCount");
-    try writer.write(self.child_node_count);
-
-    try writer.objectField("children");
-    try writer.write(self.children);
-
-    try writer.objectField("documentURL");
-    try writer.write(self.document_url);
-
-    try writer.objectField("baseURL");
-    try writer.write(self.base_url);
-
-    try writer.objectField("xmlVersion");
-    try writer.write(self.xml_version);
-
-    try writer.objectField("compatibilityMode");
-    try writer.write(self.compatibility_mode);
-
-    try writer.objectField("isScrollable");
-    try writer.write(self.is_scrollable);
-    try writer.endObject();
-}
-
 // Whenever we send a node to the client, we register it here for future lookup.
 // We maintain a node -> id and id -> node lookup.
 pub const Registry = struct {
     node_id: u32,
     allocator: Allocator,
+    arena: std.heap.ArenaAllocator,
     node_pool: std.heap.MemoryPool(Node),
     lookup_by_id: std.AutoHashMapUnmanaged(Id, *Node),
     lookup_by_node: std.HashMapUnmanaged(*parser.Node, *Node, NodeContext, std.hash_map.default_max_load_percentage),
@@ -102,9 +42,10 @@ pub const Registry = struct {
     pub fn init(allocator: Allocator) Registry {
         return .{
             .node_id = 0,
-            .allocator = allocator,
             .lookup_by_id = .{},
             .lookup_by_node = .{},
+            .allocator = allocator,
+            .arena = std.heap.ArenaAllocator.init(allocator),
             .node_pool = std.heap.MemoryPool(Node).init(allocator),
         };
     }
@@ -114,12 +55,14 @@ pub const Registry = struct {
         self.lookup_by_id.deinit(allocator);
         self.lookup_by_node.deinit(allocator);
         self.node_pool.deinit();
+        self.arena.deinit();
     }
 
     pub fn reset(self: *Registry) void {
         self.lookup_by_id.clearRetainingCapacity();
         self.lookup_by_node.clearRetainingCapacity();
-        _ = self.node_pool.reset(.{ .retain_capacity = {} });
+        _ = self.arena.reset(.{ .retain_with_limit = 1024 });
+        _ = self.node_pool.reset(.{ .retain_with_limit = 1024 });
     }
 
     pub fn register(self: *Registry, n: *parser.Node) !*Node {
@@ -132,38 +75,17 @@ pub const Registry = struct {
         // but, just in case, let's try to keep things tidy.
         errdefer _ = self.lookup_by_node.remove(n);
 
-        const children = try parser.nodeGetChildNodes(n);
-        const children_count = try parser.nodeListLength(children);
-
-        const id = self.node_id;
-        defer self.node_id = id + 1;
-
         const node = try self.node_pool.create();
         errdefer self.node_pool.destroy(node);
 
+        const id = self.node_id;
+        self.node_id = id + 1;
+
         node.* = .{
             ._node = n,
             .id = id,
-            .parent_id = null, // TODO
-            .backend_node_id = id, // ??
-            .node_name = try parser.nodeName(n),
-            .local_name = try parser.nodeLocalName(n),
-            .node_value = try parser.nodeValue(n) orelse "",
-            .node_type = @intFromEnum(try parser.nodeType(n)),
-            .child_node_count = children_count,
-            .children = &.{}, // TODO
-            .document_url = null,
-            .base_url = null,
-            .xml_version = "",
-            .compatibility_mode = .NoQuirksMode,
-            .is_scrollable = false,
         };
 
-        // if (try parser.nodeParentNode(n)) |pn| {
-        //     _  = pn;
-        //     // TODO
-        // }
-
         node_lookup_gop.value_ptr.* = node;
         try self.lookup_by_id.putNoClobber(self.allocator, id, node);
         return node;
@@ -271,8 +193,107 @@ pub const Search = struct {
     };
 };
 
+// Need a custom writer, because we can't just serialize the node as-is.
+// Sometimes we want to serializ the node without chidren, sometimes with just
+// its direct children, and sometimes the entire tree.
+// (For now, we only support direct children)
+
+pub const Writer = struct {
+    opts: Opts,
+    node: *const Node,
+    registry: *Registry,
+
+    pub const Opts = struct {};
+
+    pub fn jsonStringify(self: *const Writer, w: anytype) !void {
+        self.toJSON(w) catch |err| {
+            // The only error our jsonStringify method can return is
+            // @TypeOf(w).Error. In other words, our code can't return its own
+            // error, we can only return a writer error. Kinda sucks.
+            log.err("json stringify: {}", .{err});
+            return error.OutOfMemory;
+        };
+    }
+
+    fn toJSON(self: *const Writer, w: anytype) !void {
+        try w.beginObject();
+        try writeCommon(self.node, false, w);
+
+        {
+            var registry = self.registry;
+            const child_nodes = try parser.nodeGetChildNodes(self.node._node);
+            const child_count = try parser.nodeListLength(child_nodes);
+
+            var i: usize = 0;
+            try w.objectField("children");
+            try w.beginArray();
+            for (0..child_count) |_| {
+                const child = (try parser.nodeListItem(child_nodes, @intCast(i))) orelse break;
+                const child_node = try registry.register(child);
+                try w.beginObject();
+                try writeCommon(child_node, true, w);
+                try w.endObject();
+                i += 1;
+            }
+            try w.endArray();
+
+            try w.objectField("childNodeCount");
+            try w.write(i);
+        }
+
+        try w.endObject();
+    }
+
+    fn writeCommon(node: *const Node, include_child_count: bool, w: anytype) !void {
+        try w.objectField("nodeId");
+        try w.write(node.id);
+
+        try w.objectField("backendNodeId");
+        try w.write(node.id);
+
+        const n = node._node;
+
+        // TODO:
+        // try w.objectField("parentId");
+        // try w.write(pid);
+
+        try w.objectField("nodeType");
+        try w.write(@intFromEnum(try parser.nodeType(n)));
+
+        try w.objectField("nodeName");
+        try w.write(try parser.nodeName(n));
+
+        try w.objectField("localName");
+        try w.write(try parser.nodeLocalName(n));
+
+        try w.objectField("nodeValue");
+        try w.write((try parser.nodeValue(n)) orelse "");
+
+        if (include_child_count) {
+            try w.objectField("childNodeCount");
+            const child_nodes = try parser.nodeGetChildNodes(n);
+            try w.write(try parser.nodeListLength(child_nodes));
+        }
+
+        try w.objectField("documentURL");
+        try w.write(null);
+
+        try w.objectField("baseURL");
+        try w.write(null);
+
+        try w.objectField("xmlVersion");
+        try w.write("");
+
+        try w.objectField("compatibilityMode");
+        try w.write("NoQuirksMode");
+
+        try w.objectField("isScrollable");
+        try w.write(false);
+    }
+};
+
 const testing = @import("testing.zig");
-test "CDP Node: Registry register" {
+test "cdp Node: Registry register" {
     var registry = Registry.init(testing.allocator);
     defer registry.deinit();
 
@@ -291,19 +312,6 @@ test "CDP Node: Registry register" {
         try testing.expectEqual(node, n1c);
 
         try testing.expectEqual(0, node.id);
-        try testing.expectEqual(null, node.parent_id);
-        try testing.expectEqual(1, node.node_type);
-        try testing.expectEqual(0, node.backend_node_id);
-        try testing.expectEqual("A", node.node_name);
-        try testing.expectEqual("a", node.local_name);
-        try testing.expectEqual("", node.node_value);
-        try testing.expectEqual(1, node.child_node_count);
-        try testing.expectEqual(0, node.children.len);
-        try testing.expectEqual(null, node.document_url);
-        try testing.expectEqual(null, node.base_url);
-        try testing.expectEqual("", node.xml_version);
-        try testing.expectEqual(.NoQuirksMode, node.compatibility_mode);
-        try testing.expectEqual(false, node.is_scrollable);
         try testing.expectEqual(n, node._node);
     }
 
@@ -316,24 +324,11 @@ test "CDP Node: Registry register" {
         try testing.expectEqual(node, n1c);
 
         try testing.expectEqual(1, node.id);
-        try testing.expectEqual(null, node.parent_id);
-        try testing.expectEqual(1, node.node_type);
-        try testing.expectEqual(1, node.backend_node_id);
-        try testing.expectEqual("P", node.node_name);
-        try testing.expectEqual("p", node.local_name);
-        try testing.expectEqual("", node.node_value);
-        try testing.expectEqual(1, node.child_node_count);
-        try testing.expectEqual(0, node.children.len);
-        try testing.expectEqual(null, node.document_url);
-        try testing.expectEqual(null, node.base_url);
-        try testing.expectEqual("", node.xml_version);
-        try testing.expectEqual(.NoQuirksMode, node.compatibility_mode);
-        try testing.expectEqual(false, node.is_scrollable);
         try testing.expectEqual(n, node._node);
     }
 }
 
-test "CDP Node: search list" {
+test "cdp Node: search list" {
     var registry = Registry.init(testing.allocator);
     defer registry.deinit();
 
@@ -383,3 +378,102 @@ test "CDP Node: search list" {
         try testing.expectEqual(2, registry.lookup_by_node.count());
     }
 }
+
+test "cdp Node: Writer" {
+    var registry = Registry.init(testing.allocator);
+    defer registry.deinit();
+
+    var doc = try testing.Document.init("<a id=a1></a><a id=a2></a>");
+    defer doc.deinit();
+
+    {
+        const node = try registry.register(doc.asNode());
+        const json = try std.json.stringifyAlloc(testing.allocator, Writer{
+            .node = node,
+            .opts = .{},
+            .registry = &registry,
+        }, .{});
+        defer testing.allocator.free(json);
+
+        try testing.expectJson(.{
+            .nodeId = 0,
+            .backendNodeId = 0,
+            .nodeType = 9,
+            .nodeName = "#document",
+            .localName = "",
+            .nodeValue = "",
+            .documentURL = null,
+            .baseURL = null,
+            .xmlVersion = "",
+            .isScrollable = false,
+            .compatibilityMode = "NoQuirksMode",
+            .childNodeCount = 1,
+            .children = &.{.{
+                .nodeId = 1,
+                .backendNodeId = 1,
+                .nodeType = 1,
+                .nodeName = "HTML",
+                .localName = "html",
+                .nodeValue = "",
+                .childNodeCount = 2,
+                .documentURL = null,
+                .baseURL = null,
+                .xmlVersion = "",
+                .compatibilityMode = "NoQuirksMode",
+                .isScrollable = false,
+            }},
+        }, json);
+    }
+
+    {
+        const node = registry.lookup_by_id.get(1).?;
+        const json = try std.json.stringifyAlloc(testing.allocator, Writer{
+            .node = node,
+            .opts = .{},
+            .registry = &registry,
+        }, .{});
+        defer testing.allocator.free(json);
+
+        try testing.expectJson(.{
+            .nodeId = 1,
+            .backendNodeId = 1,
+            .nodeType = 1,
+            .nodeName = "HTML",
+            .localName = "html",
+            .nodeValue = "",
+            .childNodeCount = 2,
+            .documentURL = null,
+            .baseURL = null,
+            .xmlVersion = "",
+            .compatibilityMode = "NoQuirksMode",
+            .isScrollable = false,
+            .children = &.{ .{
+                .nodeId = 2,
+                .backendNodeId = 2,
+                .nodeType = 1,
+                .nodeName = "HEAD",
+                .localName = "head",
+                .nodeValue = "",
+                .childNodeCount = 0,
+                .documentURL = null,
+                .baseURL = null,
+                .xmlVersion = "",
+                .compatibilityMode = "NoQuirksMode",
+                .isScrollable = false,
+            }, .{
+                .nodeId = 3,
+                .backendNodeId = 3,
+                .nodeType = 1,
+                .nodeName = "BODY",
+                .localName = "body",
+                .nodeValue = "",
+                .childNodeCount = 2,
+                .documentURL = null,
+                .baseURL = null,
+                .xmlVersion = "",
+                .compatibilityMode = "NoQuirksMode",
+                .isScrollable = false,
+            } },
+        }, json);
+    }
+}

src/cdp/cdp.zig

@@ -325,6 +325,14 @@ pub fn BrowserContext(comptime CDP_T: type) type {
             self.node_search_list.reset();
         }
 
+        pub fn nodeWriter(self: *Self, node: *const Node, opts: Node.Writer.Opts) Node.Writer {
+            return .{
+                .node = node,
+                .opts = opts,
+                .registry = &self.node_registry,
+            };
+        }
+
         pub fn onInspectorResponse(ctx: *anyopaque, _: u32, msg: []const u8) void {
             if (std.log.defaultLogEnabled(.debug)) {
                 // msg should be {"id":<id>,...

src/cdp/domains/dom.zig

@@ -51,9 +51,7 @@ fn getDocument(cmd: anytype) !void {
     const doc = page.doc orelse return error.DocumentNotLoaded;
 
     const node = try bc.node_registry.register(parser.documentToNode(doc));
-    return cmd.sendResult(.{
+    return cmd.sendResult(.{ .root = bc.nodeWriter(node, .{}) }, .{});
-        .root = node,
-    }, .{});
 }
 
 // https://chromedevtools.github.io/devtools-protocol/tot/DOM/#method-performSearch
@@ -118,6 +116,7 @@ fn getSearchResults(cmd: anytype) !void {
 }
 
 const testing = @import("../testing.zig");
+
 test "cdp.dom: getSearchResults unknown search id" {
     var ctx = testing.context();
     defer ctx.deinit();

src/cdp/testing.zig

@@ -26,11 +26,12 @@ const main = @import("cdp.zig");
 const parser = @import("netsurf");
 const App = @import("../app.zig").App;
 
-pub const allocator = @import("../testing.zig").allocator;
+const base = @import("../testing.zig");
-
+pub const allocator = base.allocator;
-pub const expectEqual = @import("../testing.zig").expectEqual;
+pub const expectJson = base.expectJson;
-pub const expectError = @import("../testing.zig").expectError;
+pub const expectEqual = base.expectEqual;
-pub const expectEqualSlices = @import("../testing.zig").expectEqualSlices;
+pub const expectError = base.expectError;
+pub const expectEqualSlices = base.expectEqualSlices;
 
 pub const Document = @import("../testing.zig").Document;
 
@@ -284,6 +285,7 @@ const TestContext = struct {
             _ = self.client.?.serialized.orderedRemove(i);
             return;
         }
+
         std.debug.print("Error not found. Expecting:\n{s}\n\nGot:\n", .{serialized});
         for (self.client.?.serialized.items, 0..) |sent, i| {
             std.debug.print("#{d}\n{s}\n\n", .{ i, sent });
@@ -310,47 +312,5 @@ pub fn context() TestContext {
 fn compareExpectedToSent(expected: []const u8, actual: json.Value) !bool {
     const expected_value = try std.json.parseFromSlice(json.Value, std.testing.allocator, expected, .{});
     defer expected_value.deinit();
-    return compareJsonValues(expected_value.value, actual);
+    return base.isEqualJson(expected_value.value, actual);
-}
-
-fn compareJsonValues(a: std.json.Value, b: std.json.Value) bool {
-    if (!std.mem.eql(u8, @tagName(a), @tagName(b))) {
-        return false;
-    }
-
-    switch (a) {
-        .null => return true,
-        .bool => return a.bool == b.bool,
-        .integer => return a.integer == b.integer,
-        .float => return a.float == b.float,
-        .number_string => return std.mem.eql(u8, a.number_string, b.number_string),
-        .string => return std.mem.eql(u8, a.string, b.string),
-        .array => {
-            const a_len = a.array.items.len;
-            const b_len = b.array.items.len;
-            if (a_len != b_len) {
-                return false;
-            }
-            for (a.array.items, b.array.items) |a_item, b_item| {
-                if (compareJsonValues(a_item, b_item) == false) {
-                    return false;
-                }
-            }
-            return true;
-        },
-        .object => {
-            var it = a.object.iterator();
-            while (it.next()) |entry| {
-                const key = entry.key_ptr.*;
-                if (b.object.get(key)) |b_item| {
-                    if (compareJsonValues(entry.value_ptr.*, b_item) == false) {
-                        return false;
-                    }
-                } else {
-                    return false;
-                }
-            }
-            return true;
-        },
-    }
 }

src/testing.zig

@@ -17,14 +17,15 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const parser = @import("netsurf");
 
+const parser = @import("netsurf");
 pub const allocator = std.testing.allocator;
 pub const expectError = std.testing.expectError;
 pub const expectString = std.testing.expectEqualStrings;
 pub const expectEqualSlices = std.testing.expectEqualSlices;
 
 const App = @import("app.zig").App;
+const Allocator = std.mem.Allocator;
 
 // Merged std.testing.expectEqual and std.testing.expectString
 // can be useful when testing fields of an anytype an you don't know
@@ -217,12 +218,135 @@ pub const Document = struct {
 
     pub fn querySelectorAll(self: *Document, selector: []const u8) ![]const *parser.Node {
         const css = @import("dom/css.zig");
-        const node_list = try css.querySelectorAll(self.arena.allocator(), parser.documentToNode(self.doc), selector);
+        const node_list = try css.querySelectorAll(self.arena.allocator(), self.asNode(), selector);
         return node_list.nodes.items;
     }
 
     pub fn querySelector(self: *Document, selector: []const u8) !?*parser.Node {
         const css = @import("dom/css.zig");
-        return css.querySelector(self.arena.allocator(), parser.documentToNode(self.doc), selector);
+        return css.querySelector(self.arena.allocator(), self.asNode(), selector);
+    }
+
+    pub fn asNode(self: *const Document) *parser.Node {
+        return parser.documentToNode(self.doc);
     }
 };
+
+pub fn expectJson(a: anytype, b: anytype) !void {
+    var arena = std.heap.ArenaAllocator.init(allocator);
+    defer arena.deinit();
+
+    const aa = arena.allocator();
+
+    const a_value = try convertToJson(aa, a);
+    const b_value = try convertToJson(aa, b);
+
+    errdefer {
+        const a_json = std.json.stringifyAlloc(aa, a_value, .{ .whitespace = .indent_2 }) catch unreachable;
+        const b_json = std.json.stringifyAlloc(aa, b_value, .{ .whitespace = .indent_2 }) catch unreachable;
+        std.debug.print("== Expected ==\n{s}\n\n== Actual ==\n{s}", .{ a_json, b_json });
+    }
+
+    try expectJsonValue(a_value, b_value);
+}
+
+pub fn isEqualJson(a: anytype, b: anytype) !bool {
+    var arena = std.heap.ArenaAllocator.init(allocator);
+    defer arena.deinit();
+
+    const aa = arena.allocator();
+    const a_value = try convertToJson(aa, a);
+    const b_value = try convertToJson(aa, b);
+    return isJsonValue(a_value, b_value);
+}
+
+fn convertToJson(arena: Allocator, value: anytype) !std.json.Value {
+    const T = @TypeOf(value);
+    if (T == std.json.Value) {
+        return value;
+    }
+
+    var str: []const u8 = undefined;
+    if (T == []u8 or T == []const u8 or comptime isStringArray(T)) {
+        str = value;
+    } else {
+        str = try std.json.stringifyAlloc(arena, value, .{});
+    }
+    return std.json.parseFromSliceLeaky(std.json.Value, arena, str, .{});
+}
+
+fn expectJsonValue(a: std.json.Value, b: std.json.Value) !void {
+    try expectEqual(@tagName(a), @tagName(b));
+
+    // at this point, we know that if a is an int, b must also be an int
+    switch (a) {
+        .null => return,
+        .bool => try expectEqual(a.bool, b.bool),
+        .integer => try expectEqual(a.integer, b.integer),
+        .float => try expectEqual(a.float, b.float),
+        .number_string => try expectEqual(a.number_string, b.number_string),
+        .string => try expectEqual(a.string, b.string),
+        .array => {
+            const a_len = a.array.items.len;
+            const b_len = b.array.items.len;
+            try expectEqual(a_len, b_len);
+            for (a.array.items, b.array.items) |a_item, b_item| {
+                try expectJsonValue(a_item, b_item);
+            }
+        },
+        .object => {
+            var it = a.object.iterator();
+            while (it.next()) |entry| {
+                const key = entry.key_ptr.*;
+                if (b.object.get(key)) |b_item| {
+                    try expectJsonValue(entry.value_ptr.*, b_item);
+                } else {
+                    return error.MissingKey;
+                }
+            }
+        },
+    }
+}
+
+fn isJsonValue(a: std.json.Value, b: std.json.Value) bool {
+    if (std.mem.eql(u8, @tagName(a), @tagName(b)) == false) {
+        return false;
+    }
+
+    // at this point, we know that if a is an int, b must also be an int
+    switch (a) {
+        .null => return true,
+        .bool => return a.bool == b.bool,
+        .integer => return a.integer == b.integer,
+        .float => return a.float == b.float,
+        .number_string => return std.mem.eql(u8, a.number_string, b.number_string),
+        .string => return std.mem.eql(u8, a.string, b.string),
+        .array => {
+            const a_len = a.array.items.len;
+            const b_len = b.array.items.len;
+            if (a_len != b_len) {
+                return false;
+            }
+            for (a.array.items, b.array.items) |a_item, b_item| {
+                if (isJsonValue(a_item, b_item) == false) {
+                    return false;
+                }
+            }
+            return true;
+        },
+        .object => {
+            var it = a.object.iterator();
+            while (it.next()) |entry| {
+                const key = entry.key_ptr.*;
+                if (b.object.get(key)) |b_item| {
+                    if (isJsonValue(entry.value_ptr.*, b_item) == false) {
+                        return false;
+                    }
+                } else {
+                    return false;
+                }
+            }
+            return true;
+        },
+    }
+}