From fc3d78fe010f9e3c22a058723bf816570553c0da Mon Sep 17 00:00:00 2001
From: Ophestra <cat@gensokyo.uk>
Date: Tue, 25 Nov 2025 08:52:06 +0900
Subject: [PATCH] internal/pipewire: implement Core::Sync

Once again, already entirely supported, the offset is not yet fully verified but makes intuitive sense. Will verify this on future occurrences of the message.

Signed-off-by: Ophestra <cat@gensokyo.uk>
---
 internal/pipewire/core.go                     |  28 ++++++++++++++++++
 internal/pipewire/core_test.go                |   9 ++++++
 internal/pipewire/header_test.go              |   6 ++++
 internal/pipewire/pipewire_test.go            |   5 ++++
 .../testdata/06-sendmsg00-message03-header    | Bin 0 -> 16 bytes
 .../testdata/07-sendmsg00-message03-POD       | Bin 0 -> 40 bytes
 6 files changed, 48 insertions(+)
 create mode 100644 internal/pipewire/testdata/06-sendmsg00-message03-header
 create mode 100644 internal/pipewire/testdata/07-sendmsg00-message03-POD

diff --git a/internal/pipewire/core.go b/internal/pipewire/core.go
index 137c9bc..7a05208 100644
--- a/internal/pipewire/core.go
+++ b/internal/pipewire/core.go
@@ -83,6 +83,34 @@ func (c *CoreHello) UnmarshalBinary(data []byte) error {
 	return err
 }
 
+const (
+	// CoreSyncSequenceOffset is the offset to [Header.Sequence] to produce [CoreSync.Sequence].
+	CoreSyncSequenceOffset = 0x40000000
+)
+
+// The CoreSync message will result in a Done event from the server.
+// When the Done event is received, the client can be sure that all
+// operations before the Sync method have been completed.
+type CoreSync struct {
+	// The id will be returned in the Done event,
+	// ends up as [Header.ID] in a future message.
+	ID Int
+	// Usually generated automatically and will be
+	// returned in the Done event.
+	Sequence Int
+}
+
+// MarshalBinary satisfies [encoding.BinaryMarshaler] via [MarshalAppend].
+func (c *CoreSync) MarshalBinary() ([]byte, error) {
+	return MarshalAppend(make([]byte, 0, 40), c)
+}
+
+// UnmarshalBinary satisfies [encoding.BinaryUnmarshaler] via [Unmarshal].
+func (c *CoreSync) UnmarshalBinary(data []byte) error {
+	_, err := Unmarshal(data, c)
+	return err
+}
+
 // CoreGetRegistry is sent when a client requests to bind to the
 // registry object and list the available objects on the server.
 //
diff --git a/internal/pipewire/core_test.go b/internal/pipewire/core_test.go
index b47c426..a04013c 100644
--- a/internal/pipewire/core_test.go
+++ b/internal/pipewire/core_test.go
@@ -14,6 +14,15 @@ func TestCoreHello(t *testing.T) {
 	}.run(t)
 }
 
+func TestCoreSync(t *testing.T) {
+	encodingTestCases[pipewire.CoreSync, *pipewire.CoreSync]{
+		{"sample", []byte(sendmsg00Message03POD), pipewire.CoreSync{
+			ID:       pipewire.PW_ID_CORE,
+			Sequence: pipewire.CoreSyncSequenceOffset + 3,
+		}, nil},
+	}.run(t)
+}
+
 func TestCoreGetRegistry(t *testing.T) {
 	encodingTestCases[pipewire.CoreGetRegistry, *pipewire.CoreGetRegistry]{
 		{"sample", []byte(sendmsg00Message02POD), pipewire.CoreGetRegistry{
diff --git a/internal/pipewire/header_test.go b/internal/pipewire/header_test.go
index 2d05508..d7ca468 100644
--- a/internal/pipewire/header_test.go
+++ b/internal/pipewire/header_test.go
@@ -29,6 +29,12 @@ func TestHeader(t *testing.T) {
 			Size:   0x28, Sequence: 2, FileCount: 0,
 		}, nil},
 
+		{"PW_CORE_METHOD_SYNC", []byte(sendmsg00Message03Header), pipewire.Header{
+			ID:     pipewire.PW_ID_CORE,
+			Opcode: pipewire.PW_CORE_METHOD_SYNC,
+			Size:   0x28, Sequence: 3, FileCount: 0,
+		}, nil},
+
 		{"PW_SECURITY_CONTEXT_METHOD_CREATE", []byte{
 			// Id
 			3, 0, 0, 0,
diff --git a/internal/pipewire/pipewire_test.go b/internal/pipewire/pipewire_test.go
index fe16bb5..28ba329 100644
--- a/internal/pipewire/pipewire_test.go
+++ b/internal/pipewire/pipewire_test.go
@@ -19,4 +19,9 @@ var (
 	sendmsg00Message02Header string
 	//go:embed testdata/05-sendmsg00-message02-POD
 	sendmsg00Message02POD string
+
+	//go:embed testdata/06-sendmsg00-message03-header
+	sendmsg00Message03Header string
+	//go:embed testdata/07-sendmsg00-message03-POD
+	sendmsg00Message03POD string
 )
diff --git a/internal/pipewire/testdata/06-sendmsg00-message03-header b/internal/pipewire/testdata/06-sendmsg00-message03-header
new file mode 100644
index 0000000000000000000000000000000000000000..4ee05589646c0002ca569647733fa4cab7949b99
GIT binary patch
literal 16
UcmZQzU|`T-U|?bfF&G#a00J5SE&u=k

literal 0
HcmV?d00001

diff --git a/internal/pipewire/testdata/07-sendmsg00-message03-POD b/internal/pipewire/testdata/07-sendmsg00-message03-POD
new file mode 100644
index 0000000000000000000000000000000000000000..e54dc273736ef693e6d44330b1a68934223c5d08
GIT binary patch
literal 40
bcmY#jU|`^5U|?W@Vg@LH@tGMI96&+<3D^LF

literal 0
HcmV?d00001