add all files from Hong

plugins/allocators/bitmap/bitmap_test.go

@@ -0,0 +1,137 @@
+// Copyright 2018-present the CoreDHCP Authors. All rights reserved
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+package bitmap
+
+import (
+	"math"
+	"math/rand"
+	"net"
+	"testing"
+
+	"github.com/bits-and-blooms/bitset"
+)
+
+func getAllocator(bits int) *Allocator {
+	_, prefix, err := net.ParseCIDR("2001:db8::/56")
+	if err != nil {
+		panic(err)
+	}
+	alloc, err := NewBitmapAllocator(*prefix, 56+bits)
+	if err != nil {
+		panic(err)
+	}
+
+	return alloc
+}
+func TestAlloc(t *testing.T) {
+	alloc := getAllocator(8)
+
+	net, err := alloc.Allocate(net.IPNet{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = alloc.Free(net)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = alloc.Free(net)
+	if err == nil {
+		t.Fatal("Expected DoubleFree error")
+	}
+}
+
+func TestExhaust(t *testing.T) {
+	_, prefix, _ := net.ParseCIDR("2001:db8::/62")
+	alloc, _ := NewBitmapAllocator(*prefix, 64)
+
+	allocd := []net.IPNet{}
+	for i := 0; i < 4; i++ {
+		net, err := alloc.Allocate(net.IPNet{Mask: net.CIDRMask(64, 128)})
+		if err != nil {
+			t.Fatalf("Error before exhaustion: %v", err)
+		}
+		allocd = append(allocd, net)
+	}
+
+	_, err := alloc.Allocate(net.IPNet{})
+	if err == nil {
+		t.Fatalf("Successfully allocated more prefixes than there are in the pool")
+	}
+
+	err = alloc.Free(allocd[1])
+	if err != nil {
+		t.Fatalf("Could not free: %v", err)
+	}
+	net, err := alloc.Allocate(allocd[1])
+	if err != nil {
+		t.Fatalf("Could not reallocate after free: %v", err)
+	}
+	if !net.IP.Equal(allocd[1].IP) || net.Mask.String() != allocd[1].Mask.String() {
+		t.Fatalf("Did not obtain the right network after free: got %v, expected %v", net, allocd[1])
+	}
+
+}
+
+func TestOutOfPool(t *testing.T) {
+	alloc := getAllocator(8)
+	_, prefix, _ := net.ParseCIDR("fe80:abcd::/48")
+
+	res, err := alloc.Allocate(*prefix)
+	if err != nil {
+		t.Fatalf("Failed to allocate with invalid hint: %v", err)
+	}
+	if !alloc.containing.Contains(res.IP) {
+		t.Fatal("Obtained prefix outside of range: ", res)
+	}
+	if prefLen, totalLen := res.Mask.Size(); prefLen != 64 || totalLen != 128 {
+		t.Fatalf("Prefixes have wrong size %d/%d", prefLen, totalLen)
+	}
+}
+
+func prefixSizeForAllocs(allocs int) int {
+	return int(math.Ceil(math.Log2(float64(allocs))))
+}
+
+// Benchmark parallel Allocate, when the bitmap is mostly empty and we're allocating few values
+// compared to the available allocations
+func BenchmarkParallelAllocInitiallyEmpty(b *testing.B) {
+	// Run with -race to debug concurrency issues
+
+	alloc := getAllocator(prefixSizeForAllocs(b.N) + 2) // Use max 25% of the bitmap (initially empty)
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			if net, err := alloc.Allocate(net.IPNet{}); err != nil {
+				b.Logf("Could not allocate (got %v and an error): %v", net, err)
+				b.Fail()
+			}
+		}
+	})
+}
+
+func BenchmarkParallelAllocPartiallyFilled(b *testing.B) {
+	// We'll make a bitmap with 2x the number of allocs we want to make.
+	// Then randomly fill it to about 50% utilization
+	alloc := getAllocator(prefixSizeForAllocs(b.N) + 1)
+
+	// Build a replacement bitmap that we'll put in the allocator, with approx. 50% of values filled
+	newbmap := make([]uint64, alloc.bitmap.Len())
+	for i := uint(0); i < alloc.bitmap.Len(); i++ {
+		newbmap[i] = rand.Uint64()
+	}
+	alloc.bitmap = bitset.From(newbmap)
+
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			if net, err := alloc.Allocate(net.IPNet{}); err != nil {
+				b.Logf("Could not allocate (got %v and an error): %v", net, err)
+				b.Fail()
+			}
+		}
+	})
+}