reweave/weave
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Donate power-of-2-aligned ranges instead of just slicing at the mid-point.

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Also fix up space tests to match.
This commit is contained in:
Bryan Boreham committed 2016-05-13 16:27:28 +01:00
1 parent f37e742536
commit 64dc7a1f69
5 files changed
+99 -37
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ipam/allocator_test.go
+1 -1
View File
@@ -343,7 +343,7 @@ func TestNoFrag(t *testing.T) {
allocs[2].actionChan <- func() {
resultChan <- len(allocs[2].ring.Entries)
}
require.True(t, <-resultChan < 5, "excessive ring fragmentation")
require.True(t, <-resultChan < 7, "excessive ring fragmentation")
stopNetworkOfAllocators(allocs, router)
}
}
ipam/space/space.go
+11 -5
View File
@@ -122,8 +122,11 @@ func (s *Space) biggestFreeRange(r address.Range) (biggest address.Range) {
biggestSize := address.Count(0)
s.walkFree(r, func(chunk address.Range) bool {
if size := chunk.Size(); size >= biggestSize {
biggest = chunk
biggestSize = size
chunk = chunk.BiggestPow2AlignedRange()
if size = chunk.Size(); size >= biggestSize {
biggest = chunk
biggestSize = size
}
}
return false
})
@@ -137,9 +140,12 @@ func (s *Space) Donate(r address.Range) (address.Range, bool) {
return address.Range{}, false
}
// Donate half of that biggest free range. Note size/2 rounds down, so
// the resulting donation size rounds up, and in particular can't be empty.
biggest.Start = address.Add(biggest.Start, address.Offset(biggest.Size()/2))
// Donate no more than half what we have available
if biggest.Size() > s.NumFreeAddressesInRange(r)/2 {
// Note size/2 rounds down, so the resulting donation size
// rounds up, and in particular can't be empty.
biggest.Start = address.Add(biggest.Start, address.Offset(biggest.Size()/2))
}
s.ours = subtract(s.ours, biggest.Start, biggest.End)
s.free = subtract(s.free, biggest.Start, biggest.End)
ipam/space/space_test.go
+32 -31
View File
@@ -68,7 +68,7 @@ func TestLowlevel(t *testing.T) {
wt.AssertErrorInterface(t, (*error)(nil), s.Free(100), "double free")
r, ok := s.Donate(address.NewRange(0, 1000))
require.True(t, ok && r.Start == 125 && r.Size() == 25, "donate")
require.Equal(t, address.NewRange(0xa0, 0x20), r, "donate")
// test Donate when addresses are scarce
s = New()
@@ -78,7 +78,7 @@ func TestLowlevel(t *testing.T) {
require.NoError(t, s.Claim(0))
require.NoError(t, s.Claim(2))
r, ok = s.Donate(address.NewRange(0, 1000))
require.True(t, ok && r.Start == 1 && r.End == 2, "donate")
require.Equal(t, address.NewRange(1, 1), r, "donate")
r, ok = s.Donate(address.NewRange(0, 1000))
require.True(t, !ok, "donate should fail")
}
@@ -124,20 +124,21 @@ func TestSpaceAllocate(t *testing.T) {
func TestSpaceFree(t *testing.T) {
const (
testAddr1 = "10.0.3.4"
testAddr1 = "10.0.3.16"
testAddrx = "10.0.3.19"
testAddry = "10.0.9.19"
containerID = "deadbeef"
size = 16
)
entireRange := address.NewRange(ip(testAddr1), 20)
space := makeSpace(ip(testAddr1), 20)
entireRange := address.NewRange(ip(testAddr1), size)
space := makeSpace(ip(testAddr1), size)
// Check we are prepared to give up the entire space
r := space.biggestFreeRange(entireRange)
require.True(t, r.Start == ip(testAddr1) && r.Size() == 20, "Wrong space")
require.Equal(t, address.NewRange(ip(testAddr1), size), r, "Wrong space")
for i := 0; i < 20; i++ {
for i := 0; i < size; i++ {
ok, _ := space.Allocate(entireRange)
require.True(t, ok, "Failed to get address")
}
@@ -149,44 +150,44 @@ func TestSpaceFree(t *testing.T) {
require.True(t, r.Size() == 0, "Wrong space")
// Free in the middle
require.NoError(t, space.Free(ip("10.0.3.13")))
r = space.biggestFreeRange(entireRange)
require.True(t, r.Start == ip("10.0.3.13") && r.Size() == 1, "Wrong space")
// Free one at the end
require.NoError(t, space.Free(ip("10.0.3.23")))
r = space.biggestFreeRange(entireRange)
require.True(t, r.Start == ip("10.0.3.23") && r.Size() == 1, "Wrong space")
// Free one at the end
require.NoError(t, space.Free(ip("10.0.3.31")))
r = space.biggestFreeRange(entireRange)
require.True(t, r.Start == ip("10.0.3.31") && r.Size() == 1, "Wrong space")
// Now free a few at the end
require.NoError(t, space.Free(ip("10.0.3.22")))
require.NoError(t, space.Free(ip("10.0.3.21")))
require.NoError(t, space.Free(ip("10.0.3.30")))
require.NoError(t, space.Free(ip("10.0.3.29")))
require.Equal(t, address.Count(4), space.NumFreeAddresses())
// Now get the biggest free space; should be 3.21
// Now get the biggest free space; should be 3.30
r = space.biggestFreeRange(entireRange)
require.True(t, r.Start == ip("10.0.3.21") && r.Size() == 3, "Wrong space")
require.Equal(t, address.NewRange(ip("10.0.3.30"), 2), r, "Wrong space")
// Now free a few in the middle
require.NoError(t, space.Free(ip("10.0.3.12")))
require.NoError(t, space.Free(ip("10.0.3.11")))
require.NoError(t, space.Free(ip("10.0.3.10")))
require.NoError(t, space.Free(ip("10.0.3.24")))
require.NoError(t, space.Free(ip("10.0.3.22")))
require.NoError(t, space.Free(ip("10.0.3.21")))
require.Equal(t, address.Count(7), space.NumFreeAddresses())
// Now get the biggest free space; should be 3.21
// Now get the biggest free space; should be 3.30
r = space.biggestFreeRange(entireRange)
require.True(t, r.Start == ip("10.0.3.10") && r.Size() == 4, "Wrong space")
require.Equal(t, address.NewRange(ip("10.0.3.30"), 2), r, "Wrong space")
require.Equal(t, []address.Range{{Start: ip("10.0.3.4"), End: ip("10.0.3.24")}}, space.OwnedRanges())
require.Equal(t, []address.Range{{Start: ip("10.0.3.16"), End: ip("10.0.3.32")}}, space.OwnedRanges())
}
func TestDonateSimple(t *testing.T) {
const (
testAddr1 = "10.0.1.0"
testAddr2 = "10.0.1.32"
size = 48
size = 64
)
var (
@@ -199,7 +200,7 @@ func TestDonateSimple(t *testing.T) {
r, ok := ps1.Donate(address.NewRange(ip(testAddr1), size))
numGivenUp := r.Size()
require.True(t, ok, "Donate result")
require.Equal(t, "10.0.1.24", r.Start.String(), "Invalid start")
require.Equal(t, "10.0.1.32", r.Start.String(), "Invalid start")
require.Equal(t, address.Count(size/2), numGivenUp)
require.Equal(t, address.Count(size/2), ps1.NumFreeAddresses())
@@ -241,13 +242,13 @@ func TestDonateHard(t *testing.T) {
// Now split
newRange, ok := spaceset.Donate(address.NewRange(start, size))
require.True(t, ok, "GiveUpSpace result")
require.Equal(t, ip("10.0.1.23"), newRange.Start)
require.Equal(t, address.Count(24), newRange.Size())
require.Equal(t, address.Count(23), spaceset.NumFreeAddresses())
require.Equal(t, address.NewRange(ip("10.0.1.16"), 16), newRange, "Wrong space")
require.Equal(t, address.Count(31), spaceset.NumFreeAddresses())
//Space set should now have 2 spaces
expected := New()
expected.Add(start, 23)
expected.ours = add(nil, ip("10.0.1.47"), ip("10.0.1.48"))
//Space set should now have 3 spaces
expected := &Space{
ours: add(nil, ip("10.0.1.47"), ip("10.0.1.48")),
free: add(add(nil, ip("10.0.1.0"), ip("10.0.1.16")), ip("10.0.1.32"), ip("10.0.1.47")),
}
require.Equal(t, expected, spaceset)
}
net/address/address.go
+29
View File
@@ -35,6 +35,35 @@ func (r Range) AsCIDRString() string {
return CIDR{Addr: r.Start, PrefixLen: prefixLen}.String()
}
// return the highest bit set in a
// algorithm from http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
func msb(v Count) Count {
v |= v >> 1
v |= v >> 2
v |= v >> 4
v |= v >> 8
v |= v >> 16
// Cast to 64-bit to avoid overflow when original v >= 0x80000000
return Count((uint64(v) + 1) / 2)
}
func (r Range) BiggestPow2AlignedRange() Range {
sizeMsb := Offset(msb(r.Size()))
maskedSize := Offset(r.Size()) & (sizeMsb - 1)
maskedStart := Offset(r.Start) & (sizeMsb - 1)
if maskedStart == 0 {
return NewRange(r.Start, sizeMsb)
}
if sizeMsb-maskedStart <= maskedSize {
return NewRange(Add(r.Start, sizeMsb-maskedStart), sizeMsb)
}
size := sizeMsb / 2
if size >= maskedStart {
return NewRange(Add(r.Start, size-maskedStart), size)
}
return NewRange(Add(r.Start, sizeMsb-maskedStart), size)
}
func MakeCIDR(subnet CIDR, addr Address) CIDR {
return CIDR{Addr: addr, PrefixLen: subnet.PrefixLen}
}
net/address/address_test.go
+26
View File
@@ -0,0 +1,26 @@
package address
import (
"testing"
"github.com/stretchr/testify/require"
)
func TestBiggestPow2AlignedRange(t *testing.T) {
require.Equal(t, NewRange(0, 1), NewRange(0, 1).BiggestPow2AlignedRange())
require.Equal(t, NewRange(0, 2), NewRange(0, 2).BiggestPow2AlignedRange())
require.Equal(t, NewRange(0, 2), NewRange(0, 3).BiggestPow2AlignedRange())
require.Equal(t, NewRange(0, 4), NewRange(0, 7).BiggestPow2AlignedRange())
require.Equal(t, NewRange(1, 1), NewRange(1, 1).BiggestPow2AlignedRange())
require.Equal(t, NewRange(1, 1), NewRange(1, 2).BiggestPow2AlignedRange())
require.Equal(t, NewRange(2, 2), NewRange(1, 3).BiggestPow2AlignedRange())
require.Equal(t, NewRange(2, 2), NewRange(1, 4).BiggestPow2AlignedRange())
require.Equal(t, NewRange(4, 4), NewRange(1, 8).BiggestPow2AlignedRange())
require.Equal(t, NewRange(4, 4), NewRange(2, 8).BiggestPow2AlignedRange())
require.Equal(t, NewRange(4, 4), NewRange(4, 8).BiggestPow2AlignedRange())
require.Equal(t, NewRange(8, 4), NewRange(8, 7).BiggestPow2AlignedRange())
require.Equal(t, NewRange(8, 8), NewRange(8, 8).BiggestPow2AlignedRange())
require.Equal(t, NewRange(0, 0x4000), NewRange(0, 0x7fff).BiggestPow2AlignedRange())
require.Equal(t, NewRange(0x2000, 2), NewRange(0x2000, 3).BiggestPow2AlignedRange())
require.Equal(t, NewRange(0xffff, 1), NewRange(0xffff, 1).BiggestPow2AlignedRange())
}