From 8e4f8c2fcc77515f20a8cb1cd03b305a4695629c Mon Sep 17 00:00:00 2001
From: Tordarus <tordarus@protonmail.com>
Date: Thu, 31 Jul 2025 18:34:16 +0200
Subject: [PATCH] initial commit

---
 go.mod         | 12 +++++++
 go.sum         |  6 ++++
 multiwriter.go | 28 ++++++++++++++++
 server.go      | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 135 insertions(+)
 create mode 100644 go.mod
 create mode 100644 go.sum
 create mode 100644 multiwriter.go
 create mode 100644 server.go

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..9cafa32
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,12 @@
+module git.tordarus.net/tordarus/sock
+
+go 1.24.1
+
+toolchain go1.24.5
+
+require (
+	git.tordarus.net/tordarus/cmap v0.0.5
+	git.tordarus.net/tordarus/slices v0.0.15
+)
+
+require git.tordarus.net/tordarus/gmath v0.0.7 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..e51f87b
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,6 @@
+git.tordarus.net/tordarus/cmap v0.0.5 h1:g2STu3iMXCLn96JZ/f0iN5hbzct9cI5B8+V8ATB4ryE=
+git.tordarus.net/tordarus/cmap v0.0.5/go.mod h1:Wx2snnIzdDrmONR9X5bt5aFq8E8EDCK5Zy50DmRwK1M=
+git.tordarus.net/tordarus/gmath v0.0.7 h1:tR48idt9AUL0r556ww3ZxByTKJEr6NWCTlhl2ihzYxQ=
+git.tordarus.net/tordarus/gmath v0.0.7/go.mod h1:mO7aPlvNrGVE9UFXEuuACjZgMDsM63l3OcQy6xSQnoE=
+git.tordarus.net/tordarus/slices v0.0.15 h1:qxKS+7BCZ/LzQbRCvdDFoLQXaJZ2C0GfVju/kPt1r3g=
+git.tordarus.net/tordarus/slices v0.0.15/go.mod h1:eJBw6pSDNivPI0l4e0sGKUJzou/lbzHflXdAUzp1g4o=
diff --git a/multiwriter.go b/multiwriter.go
new file mode 100644
index 0000000..98fc8e2
--- /dev/null
+++ b/multiwriter.go
@@ -0,0 +1,28 @@
+package sock
+
+import "io"
+
+type multiWriter struct {
+	writers []io.Writer
+}
+
+var _ io.Writer = &multiWriter{}
+
+func (t *multiWriter) Write(p []byte) (n int, err error) {
+	for _, w := range t.writers {
+		w.Write(p)
+	}
+	return len(p), nil
+}
+
+func newMultiWriter(writers ...io.Writer) io.Writer {
+	allWriters := make([]io.Writer, 0, len(writers))
+	for _, w := range writers {
+		if mw, ok := w.(*multiWriter); ok {
+			allWriters = append(allWriters, mw.writers...)
+		} else {
+			allWriters = append(allWriters, w)
+		}
+	}
+	return &multiWriter{allWriters}
+}
diff --git a/server.go b/server.go
new file mode 100644
index 0000000..6f1a92f
--- /dev/null
+++ b/server.go
@@ -0,0 +1,89 @@
+package sock
+
+import (
+	"io"
+	"net"
+	"os"
+	"path/filepath"
+
+	"git.tordarus.net/tordarus/cmap"
+	"git.tordarus.net/tordarus/slices"
+)
+
+type Server struct {
+	socketPath string
+	server     net.Listener
+	clients    *cmap.Map[net.Conn, struct{}]
+
+	onNewClient func(client net.Conn)
+}
+
+func Listen(socketPath string, onNewClient func(client net.Conn)) (*Server, error) {
+	absPath, err := filepath.Abs(socketPath)
+	if err != nil {
+		return nil, err
+	}
+
+	os.Remove(absPath)
+	server, err := net.Listen("unix", absPath)
+	if err != nil {
+		return nil, err
+	}
+
+	s := &Server{
+		socketPath:  absPath,
+		server:      server,
+		clients:     cmap.New[net.Conn, struct{}](),
+		onNewClient: onNewClient,
+	}
+
+	go s.handleClients()
+
+	return s, nil
+}
+
+func (s *Server) Broadcast(r io.Reader) error {
+	clients := slices.Map(s.clients.Keys(), func(c net.Conn) io.Writer { return c })
+	w := newMultiWriter(clients...)
+
+	if _, err := io.Copy(w, r); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (s *Server) handleClients() {
+	for client, err := s.server.Accept(); err == nil; client, err = s.server.Accept() {
+		go s.handleClient(client)
+	}
+}
+
+func (s *Server) handleClient(client net.Conn) {
+	s.clients.Put(client, struct{}{})
+	defer s.clients.Delete(client)
+
+	if s.onNewClient != nil {
+		s.onNewClient(client)
+	}
+
+	data := make([]byte, 1024)
+	for _, err := client.Read(data); err == nil; _, err = client.Read(data) {
+	}
+}
+
+func (s *Server) Close() error {
+	for client := range s.clients.Iterate() {
+		client.Close()
+	}
+
+	if err := s.server.Close(); err != nil {
+		return err
+	}
+
+	if err := os.Remove(s.socketPath); err != nil {
+		return err
+	}
+
+	return nil
+}