Add type to store bandwidths.

api/bandwidth.go

@@ -0,0 +1,79 @@
+/**
+ * Standalone signaling server for the Nextcloud Spreed app.
+ * Copyright (C) 2025 struktur AG
+ *
+ * @author Joachim Bauch <bauch@struktur.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package api
+
+import (
+	"sync/atomic"
+
+	"github.com/strukturag/nextcloud-spreed-signaling/internal"
+)
+
+// Bandwidth stores a bandwidth in bits per second.
+type Bandwidth uint64
+
+// Bits returns the bandwidth in bits per second.
+func (b Bandwidth) Bits() uint64 {
+	return uint64(b)
+}
+
+// Bytes returns the bandwidth in bytes per second.
+func (b Bandwidth) Bytes() uint64 {
+	return b.Bits() / 8
+}
+
+// BandwidthFromBits creates a bandwidth from bits per second.
+func BandwidthFromBits(b uint64) Bandwidth {
+	return Bandwidth(b)
+}
+
+// BandwithFromBits creates a bandwidth from megabits per second.
+func BandwidthFromMegabits(b uint64) Bandwidth {
+	return Bandwidth(b * 1024 * 1024)
+}
+
+// BandwidthFromBytes creates a bandwidth from bytes per second.
+func BandwidthFromBytes(b uint64) Bandwidth {
+	return Bandwidth(b * 8)
+}
+
+// AtomicBandwidth is an atomic Bandwidth. The zero value is zero.
+// AtomicBandwidth must not be copied after first use.
+type AtomicBandwidth struct {
+	// 64-bit members that are accessed atomically must be 64-bit aligned.
+	v uint64
+	_ internal.NoCopy
+}
+
+// Load atomically loads and returns the value stored in b.
+func (b *AtomicBandwidth) Load() Bandwidth {
+	return Bandwidth(atomic.LoadUint64(&b.v)) // +checklocksignore
+}
+
+// Store atomically stores v into b.
+func (b *AtomicBandwidth) Store(v Bandwidth) {
+	atomic.StoreUint64(&b.v, uint64(v)) // +checklocksignore
+}
+
+// Swap atomically stores v into b and returns the previous value.
+func (b *AtomicBandwidth) Swap(v Bandwidth) Bandwidth {
+	return Bandwidth(atomic.SwapUint64(&b.v, uint64(v))) // +checklocksignore
+}

api/bandwidth_test.go

@@ -0,0 +1,58 @@
+/**
+ * Standalone signaling server for the Nextcloud Spreed app.
+ * Copyright (C) 2025 struktur AG
+ *
+ * @author Joachim Bauch <bauch@struktur.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package api
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBandwidth(t *testing.T) {
+	t.Parallel()
+
+	assert := assert.New(t)
+
+	var b Bandwidth
+	assert.EqualValues(0, b.Bits())
+	assert.EqualValues(0, b.Bytes())
+
+	b = BandwidthFromBits(8000)
+	assert.EqualValues(8000, b.Bits())
+	assert.EqualValues(1000, b.Bytes())
+
+	b = BandwidthFromBytes(1000)
+	assert.EqualValues(8000, b.Bits())
+	assert.EqualValues(1000, b.Bytes())
+
+	b = BandwidthFromMegabits(2)
+	assert.EqualValues(2*1024*1024, b.Bits())
+	assert.EqualValues(2*1024*1024/8, b.Bytes())
+
+	var a AtomicBandwidth
+	assert.EqualValues(0, a.Load())
+	a.Store(1000)
+	assert.EqualValues(1000, a.Load())
+	old := a.Swap(2000)
+	assert.EqualValues(1000, old)
+	assert.EqualValues(2000, a.Load())
+}

internal/nocopy.go

@@ -0,0 +1,35 @@
+/**
+ * Standalone signaling server for the Nextcloud Spreed app.
+ * Copyright (C) 2025 struktur AG
+ *
+ * @author Joachim Bauch <bauch@struktur.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package internal
+
+// NoCopy may be added to structs which must not be copied
+// after the first use.
+//
+// See https://golang.org/issues/8005#issuecomment-190753527
+// for details.
+//
+// Note that it must not be embedded, due to the Lock and Unlock methods.
+type NoCopy struct{}
+
+// Lock is a no-op used by -copylocks checker from `go vet`.
+func (*NoCopy) Lock()   {}
+func (*NoCopy) Unlock() {}