From cded122a2da36f7c24f2ea1acf131de0968bb625 Mon Sep 17 00:00:00 2001
From: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
Date: Wed, 20 May 2026 13:08:47 +0200
Subject: [PATCH] LibIPC: Support DistinctNumeric serialization

IPC currently needs each distinct numeric wrapper to provide its own
serialization specialization. That makes compositor resource ids and
pixel-unit wrappers grow one-off glue as soon as they cross an endpoint.

Teach LibIPC to serialize AK::DistinctNumeric wrappers through their
underlying value type and remove the redundant Web-side specializations
for UniqueNodeID and DevicePixels. Existing compound pixel-unit
serializers now rely on generic wrapper support for their components.

This is preparatory work required to add IPC between the main and
compositor threads.
---
 Libraries/LibIPC/Concepts.h     |  4 ++++
 Libraries/LibIPC/Decoder.h      |  6 ++++++
 Libraries/LibIPC/Encoder.h      |  6 ++++++
 Libraries/LibWeb/DOM/Node.cpp   | 19 -------------------
 Libraries/LibWeb/Forward.h      | 10 ----------
 Libraries/LibWeb/PixelUnits.cpp | 14 --------------
 Libraries/LibWeb/PixelUnits.h   |  5 -----
 7 files changed, 16 insertions(+), 48 deletions(-)

diff --git a/Libraries/LibIPC/Concepts.h b/Libraries/LibIPC/Concepts.h
index 4573aa189a..e51a750989 100644
--- a/Libraries/LibIPC/Concepts.h
+++ b/Libraries/LibIPC/Concepts.h
@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/DistinctNumeric.h>
 #include <AK/HashMap.h>
 #include <AK/Optional.h>
 #include <AK/Span.h>
@@ -64,4 +65,7 @@ concept Optional = SpecializationOf<T, AK::Optional>;
 template<typename T>
 concept Variant = SpecializationOf<T, AK::Variant>;
 
+template<typename T>
+concept DistinctNumeric = SpecializationOf<T, AK::DistinctNumeric>;
+
 }
diff --git a/Libraries/LibIPC/Decoder.h b/Libraries/LibIPC/Decoder.h
index 3cf01ab26d..5a2abd1b2f 100644
--- a/Libraries/LibIPC/Decoder.h
+++ b/Libraries/LibIPC/Decoder.h
@@ -84,6 +84,12 @@ ErrorOr<T> decode(Decoder& decoder)
     return static_cast<T>(value);
 }
 
+template<Concepts::DistinctNumeric T>
+ErrorOr<T> decode(Decoder& decoder)
+{
+    return T { TRY(decoder.decode<typename T::Type>()) };
+}
+
 template<>
 ErrorOr<String> decode(Decoder&);
 
diff --git a/Libraries/LibIPC/Encoder.h b/Libraries/LibIPC/Encoder.h
index 206b6f1ac3..07274ddd34 100644
--- a/Libraries/LibIPC/Encoder.h
+++ b/Libraries/LibIPC/Encoder.h
@@ -76,6 +76,12 @@ ErrorOr<void> encode(Encoder& encoder, T const& value)
     return encoder.encode(to_underlying(value));
 }
 
+template<Concepts::DistinctNumeric T>
+ErrorOr<void> encode(Encoder& encoder, T const& value)
+{
+    return encoder.encode(value.value());
+}
+
 template<>
 ErrorOr<void> encode(Encoder&, float const&);
 
diff --git a/Libraries/LibWeb/DOM/Node.cpp b/Libraries/LibWeb/DOM/Node.cpp
index a87b3f9b94..601541ff94 100644
--- a/Libraries/LibWeb/DOM/Node.cpp
+++ b/Libraries/LibWeb/DOM/Node.cpp
@@ -12,8 +12,6 @@
 #include <AK/JsonObjectSerializer.h>
 #include <AK/StringBuilder.h>
 #include <LibGC/DeferGC.h>
-#include <LibIPC/Decoder.h>
-#include <LibIPC/Encoder.h>
 #include <LibJS/Runtime/ExternalMemory.h>
 #include <LibJS/Runtime/FunctionObject.h>
 #include <LibWeb/Animations/Animation.h>
@@ -3428,20 +3426,3 @@ GC::Ptr<ShadowRoot> Node::containing_shadow_root()
 }
 
 }
-
-namespace IPC {
-
-template<>
-ErrorOr<void> encode(Encoder& encoder, Web::UniqueNodeID const& value)
-{
-    return encode(encoder, value.value());
-}
-
-template<>
-ErrorOr<Web::UniqueNodeID> decode(Decoder& decoder)
-{
-    auto value = TRY(decoder.decode<i64>());
-    return Web::UniqueNodeID(value);
-}
-
-}
diff --git a/Libraries/LibWeb/Forward.h b/Libraries/LibWeb/Forward.h
index dc9d397074..2d380a7f3f 100644
--- a/Libraries/LibWeb/Forward.h
+++ b/Libraries/LibWeb/Forward.h
@@ -1393,16 +1393,6 @@ struct FormDataEntry;
 
 }
 
-namespace IPC {
-
-template<>
-WEB_API ErrorOr<void> encode(Encoder&, Web::UniqueNodeID const&);
-
-template<>
-WEB_API ErrorOr<Web::UniqueNodeID> decode(Decoder&);
-
-}
-
 namespace Web::TrustedTypes {
 
 class TrustedHTML;
diff --git a/Libraries/LibWeb/PixelUnits.cpp b/Libraries/LibWeb/PixelUnits.cpp
index a65752a6f0..77d25c22d5 100644
--- a/Libraries/LibWeb/PixelUnits.cpp
+++ b/Libraries/LibWeb/PixelUnits.cpp
@@ -15,20 +15,6 @@ namespace Web {
 
 namespace IPC {
 
-template<>
-ErrorOr<void> encode(Encoder& encoder, Web::DevicePixels const& value)
-{
-    TRY(encoder.encode(value.value()));
-    return {};
-}
-
-template<>
-ErrorOr<Web::DevicePixels> decode(Decoder& decoder)
-{
-    auto value = TRY(decoder.decode<int>());
-    return Web::DevicePixels(value);
-}
-
 template<>
 ErrorOr<void> encode(Encoder& encoder, Web::DevicePixelPoint const& value)
 {
diff --git a/Libraries/LibWeb/PixelUnits.h b/Libraries/LibWeb/PixelUnits.h
index ebfb370feb..dee398288e 100644
--- a/Libraries/LibWeb/PixelUnits.h
+++ b/Libraries/LibWeb/PixelUnits.h
@@ -536,11 +536,6 @@ struct Formatter<Web::DevicePixels> : Formatter<Web::DevicePixels::Type> {
 
 namespace IPC {
 
-template<>
-WEB_API ErrorOr<void> encode(Encoder& encoder, Web::DevicePixels const& value);
-template<>
-WEB_API ErrorOr<Web::DevicePixels> decode(Decoder& decoder);
-
 template<>
 WEB_API ErrorOr<void> encode(Encoder& encoder, Web::DevicePixelPoint const& value);
 template<>