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francisbouvierfrancisbouvier
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Handle CDP messages with different order
The 'method' still needs to be the first or the second key (in this case after the 'id'). Signed-off-by: Francis Bouvier <[email protected]>
1 parent 3ad19df commit dc1456f

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8 files changed

+257
-213
lines changed

8 files changed

+257
-213
lines changed

‎src/cdp/browser.zig‎

Lines changed: 17 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@ const server = @import("../server.zig");
44
const Ctx = server.Cmd;
55
const cdp = @import("cdp.zig");
66
const result = cdp.result;
7-
const getParams = cdp.getParams;
7+
const getMsg = cdp.getMsg;
88

99
const BrowserMethods = enum {
1010
getVersion,
@@ -15,7 +15,7 @@ const BrowserMethods = enum {
1515

1616
pub fn browser(
1717
alloc: std.mem.Allocator,
18-
id: u64,
18+
id: ?u16,
1919
action: []const u8,
2020
scanner: *std.json.Scanner,
2121
ctx: *Ctx,
@@ -38,10 +38,12 @@ const JsVersion = "12.4.254.8";
3838

3939
fn browserGetVersion(
4040
alloc: std.mem.Allocator,
41-
id: u64,
42-
_: *std.json.Scanner,
41+
id: ?u16,
42+
scanner: *std.json.Scanner,
4343
_: *Ctx,
4444
) ![]const u8 {
45+
const msg = try getMsg(alloc, void, scanner);
46+
4547
const Res = struct {
4648
protocolVersion: []const u8,
4749
product: []const u8,
@@ -57,12 +59,12 @@ fn browserGetVersion(
5759
.userAgent = UserAgent,
5860
.jsVersion = JsVersion,
5961
};
60-
return result(alloc, id, Res, res, null);
62+
return result(alloc, id orelse msg.id.?, Res, res, null);
6163
}
6264

6365
fn browserSetDownloadBehavior(
6466
alloc: std.mem.Allocator,
65-
id: u64,
67+
id: ?u16,
6668
scanner: *std.json.Scanner,
6769
_: *Ctx,
6870
) ![]const u8 {
@@ -72,15 +74,15 @@ fn browserSetDownloadBehavior(
7274
downloadPath: ?[]const u8 = null,
7375
eventsEnabled: ?bool = null,
7476
};
75-
_ = try getParams(alloc, Params, scanner);
76-
return result(alloc, id, null, null, null);
77+
const msg = try getMsg(alloc, Params, scanner);
78+
return result(alloc, id orelse msg.id.?, null, null, null);
7779
}
7880

7981
const DevToolsWindowID = 1923710101;
8082

8183
fn getWindowForTarget(
8284
alloc: std.mem.Allocator,
83-
id: u64,
85+
id: ?u16,
8486
scanner: *std.json.Scanner,
8587
_: *Ctx,
8688
) ![]const u8 {
@@ -89,8 +91,8 @@ fn getWindowForTarget(
8991
const Params = struct {
9092
targetId: ?[]const u8 = null,
9193
};
92-
const content = try cdp.getContent(alloc, ?Params, scanner);
93-
std.debug.assert(content.sessionID != null);
94+
const msg = try cdp.getMsg(alloc, ?Params, scanner);
95+
std.debug.assert(msg.sessionID != null);
9496

9597
// output
9698
const Resp = struct {
@@ -103,16 +105,16 @@ fn getWindowForTarget(
103105
windowState: []const u8 = "normal",
104106
} = .{},
105107
};
106-
return result(alloc, id, Resp, Resp{}, content.sessionID.?);
108+
return result(alloc, id orelse msg.id.?, Resp, Resp{}, msg.sessionID.?);
107109
}
108110

109111
fn setWindowBounds(
110112
alloc: std.mem.Allocator,
111-
id: u64,
113+
id: ?u16,
112114
scanner: *std.json.Scanner,
113115
_: *Ctx,
114116
) ![]const u8 {
115117
// NOTE: noop
116-
const content = try cdp.getContent(alloc, void, scanner);
117-
return result(alloc, id, null, null, content.sessionID);
118+
const msg = try cdp.getMsg(alloc, void, scanner);
119+
return result(alloc, id orelse msg.id.?, null, null, msg.sessionID);
118120
}

‎src/cdp/cdp.zig‎

Lines changed: 71 additions & 89 deletions
Original file line numberDiff line numberDiff line change
@@ -53,26 +53,22 @@ pub fn do(
5353
// handle 2 possible orders:
5454
// - id, method <...>
5555
// - method, id <...>
56-
var id_key = (try scanner.next()).string;
57-
var id_token = try scanner.next();
5856
var method_key = (try scanner.next()).string;
59-
var method_token = try scanner.next();
57+
var method_token: std.json.Token = undefined;
58+
var id: ?u16 = null;
6059
// check swap order
61-
if (!std.mem.eql(u8, id_key, "id")) {
62-
const swap_key = method_key;
63-
const swap_token = method_token;
64-
method_key = id_key;
65-
method_token = id_token;
66-
id_key = swap_key;
67-
id_token = swap_token;
60+
if (std.mem.eql(u8, method_key, "id")) {
61+
id = try getId(&scanner, method_key);
62+
method_key = (try scanner.next()).string;
63+
method_token = try scanner.next();
64+
} else {
65+
method_token = try scanner.next();
6866
}
69-
try checkKey(id_key, "id");
7067
try checkKey(method_key, "method");
7168

72-
// retrieve id and method
73-
const id = try std.fmt.parseUnsigned(u64, id_token.number, 10);
69+
// retrieve method
7470
const method_name = method_token.string;
75-
std.log.debug("cmd: id {any}, method {s}", .{ id, method_name });
71+
std.log.debug("cmd: method {s}, id {any}", .{ method_name, id });
7672

7773
// retrieve domain from method
7874
var iter = std.mem.splitScalar(u8, method_name, '.');
@@ -128,7 +124,7 @@ const resultNullSession = "{{\"id\": {d}, \"result\": {{}}, \"sessionId\": \"{s}
128124
// caller owns the slice returned
129125
pub fn result(
130126
alloc: std.mem.Allocator,
131-
id: u64,
127+
id: u16,
132128
comptime T: ?type,
133129
res: anytype,
134130
sessionID: ?[]const u8,
@@ -142,7 +138,7 @@ pub fn result(
142138
}
143139

144140
const Resp = struct {
145-
id: u64,
141+
id: u16,
146142
result: T.?,
147143
sessionId: ?[]const u8,
148144
};
@@ -171,108 +167,94 @@ pub fn sendEvent(
171167
try server.sendSync(ctx, event_msg);
172168
}
173169

174-
pub fn getParams(
170+
fn getParams(
175171
alloc: std.mem.Allocator,
176172
comptime T: type,
177173
scanner: *std.json.Scanner,
174+
key: []const u8,
178175
) !?T {
179176

180-
// if next token is the end of the object, there is no "params"
181-
const t = try scanner.next();
182-
if (t == .object_end) return null;
183-
184-
// if next token is not "params" there is no "params"
185-
if (!std.mem.eql(u8, "params", t.string)) return null;
177+
// check key key is "params"
178+
if (!std.mem.eql(u8, "params", key)) return null;
179+
180+
// skip "params" if not requested
181+
if (T == void) {
182+
var finished: usize = 0;
183+
while (true) {
184+
switch (try scanner.next()) {
185+
.object_begin => finished += 1,
186+
.object_end => finished -= 1,
187+
else => continue,
188+
}
189+
if (finished == 0) break;
190+
}
191+
return void{};
192+
}
186193

187194
// parse "params"
188195
const options = std.json.ParseOptions{
189196
.max_value_len = scanner.input.len,
190197
.allocate = .alloc_if_needed,
191198
};
192-
const params = try std.json.innerParse(T, alloc, scanner, options);
193-
return params;
199+
return try std.json.innerParse(T, alloc, scanner, options);
194200
}
195201

196-
pub fn getSessionID(scanner: *std.json.Scanner) !?[]const u8 {
202+
fn getId(scanner: *std.json.Scanner, key: []const u8) !?u16 {
197203

198-
// if next token is the end of the object, there is no "sessionId"
199-
const t = try scanner.next();
200-
if (t == .object_end) return null;
204+
// check key is "id"
205+
if (!std.mem.eql(u8, "id", key)) return null;
201206

202-
var n = t.string;
207+
// parse "id"
208+
return try std.fmt.parseUnsigned(u16, (try scanner.next()).number, 10);
209+
}
203210

204-
// if next token is "params" ignore them
205-
// NOTE: will panic if it's not an empty "params" object
206-
// TODO: maybe we should return a custom error here
207-
if (std.mem.eql(u8, n, "params")) {
208-
// ignore empty params
209-
_ = (try scanner.next()).object_begin;
210-
_ = (try scanner.next()).object_end;
211-
n = (try scanner.next()).string;
212-
}
211+
fn getSessionId(scanner: *std.json.Scanner, key: []const u8) !?[]const u8 {
213212

214-
// if next token is not "sessionId" there is no "sessionId"
215-
if (!std.mem.eql(u8, n, "sessionId")) return null;
213+
// check key is "sessionId"
214+
if (!std.mem.eql(u8, "sessionId", key)) return null;
216215

217216
// parse "sessionId"
218217
return (try scanner.next()).string;
219218
}
220219

221-
pub fn getContent(
220+
pub fn getMsg(
222221
alloc: std.mem.Allocator,
223-
comptime T: type,
222+
comptime params_T: type,
224223
scanner: *std.json.Scanner,
225-
) !struct { params: T, sessionID: ?[]const u8 } {
226-
227-
// if next token is the end of the object, error
228-
const t = try scanner.next();
229-
if (t == .object_end) return error.CDPNoContent;
230-
231-
var params: T = undefined;
224+
) !struct { id: ?u16, params: ?params_T, sessionID: ?[]const u8 } {
225+
var id: ?u16 = null;
226+
var params: ?params_T = null;
232227
var sessionID: ?[]const u8 = null;
233228

234-
var n = t.string;
235-
236-
// params
237-
if (std.mem.eql(u8, n, "params")) {
238-
if (T == void) {
239-
240-
// ignore params
241-
var finished: usize = 0;
242-
while (true) {
243-
switch (try scanner.next()) {
244-
.object_begin => finished += 1,
245-
.object_end => finished -= 1,
246-
else => continue,
247-
}
248-
if (finished == 0) break;
249-
}
250-
params = void{};
251-
} else {
252-
253-
// parse "params"
254-
const options = std.json.ParseOptions{
255-
.max_value_len = scanner.input.len,
256-
.allocate = .alloc_if_needed,
257-
};
258-
params = try std.json.innerParse(T, alloc, scanner, options);
259-
}
260-
261-
// go next
262-
n = (try scanner.next()).string;
263-
} else {
264-
params = switch (@typeInfo(T)) {
265-
.Void => void{},
266-
.Optional => null,
267-
else => return error.CDPNoParams,
268-
};
269-
}
229+
var t: std.json.Token = undefined;
270230

271-
if (std.mem.eql(u8, n, "sessionId")) {
272-
sessionID = (try scanner.next()).string;
231+
while (true) {
232+
t = try scanner.next();
233+
if (t == .object_end) break;
234+
if (t != .string) {
235+
return error.CDPMsgWrong;
236+
}
237+
if (id == null) {
238+
id = try getId(scanner, t.string);
239+
if (id != null) continue;
240+
}
241+
if (params == null) {
242+
params = try getParams(alloc, params_T, scanner, t.string);
243+
if (params != null) continue;
244+
}
245+
if (sessionID == null) {
246+
sessionID = try getSessionId(scanner, t.string);
247+
}
273248
}
274249

275-
return .{ .params = params, .sessionID = sessionID };
250+
// end
251+
std.log.debug(
252+
"id {any}, params {any}, sessionID: {any}, token {any}",
253+
.{ id, params, sessionID, t },
254+
);
255+
t = try scanner.next();
256+
if (t != .end_of_document) return error.CDPMsgEnd;
257+
return .{ .id = id, .params = params, .sessionID = sessionID };
276258
}
277259

278260
// Common

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