webnet
/
tailscale
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

net/art: add more exhaustive table testing

Browse Source 
Updates #7781

Signed-off-by: David Anderson <danderson@tailscale.com>
main
David Anderson 3 years ago committed by Dave Anderson
parent 9cc3f7a3d6
commit b145a22f55
1 changed files with 705 additions and 12 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 717
      net/art/table_test.go

717
net/art/table_test.go
Unescape View File

@ -16,7 +16,571 @@ import (
"tailscale.com/types/ptr"
)
func TestRegression(t *testing.T) {
// These tests are specific triggers for subtle correctness issues
// that came up during initial implementation. Even if they seem
// arbitrary, please do not clean them up. They are checking edge
// cases that are very easy to get wrong, and quite difficult for
// the other statistical tests to trigger promptly.
t.Run("prefixes_aligned_on_stride_boundary", func(t *testing.T) {
// Regression test for computePrefixSplit called with equal
// arguments.
tbl := &Table[int]{}
slow := slowPrefixTable[int]{}
p := netip.MustParsePrefix
v := ptr.To(1)
tbl.Insert(p("226.205.197.0/24"), v)
slow.insert(p("226.205.197.0/24"), v)
v = ptr.To(2)
tbl.Insert(p("226.205.0.0/16"), v)
slow.insert(p("226.205.0.0/16"), v)
probe := netip.MustParseAddr("226.205.121.152")
got, want := tbl.Get(probe), slow.get(probe)
if got != want {
t.Fatalf("got %v, want %v", got, want)
}
})
t.Run("parent_prefix_inserted_in_different_orders", func(t *testing.T) {
// Regression test for the off-by-one correction applied
// within computePrefixSplit.
t1, t2 := &Table[int]{}, &Table[int]{}
p := netip.MustParsePrefix
v1, v2 := ptr.To(1), ptr.To(2)
t1.Insert(p("136.20.0.0/16"), v1)
t1.Insert(p("136.20.201.62/32"), v2)
t2.Insert(p("136.20.201.62/32"), v2)
t2.Insert(p("136.20.0.0/16"), v1)
a := netip.MustParseAddr("136.20.54.139")
got, want := t2.Get(a), t1.Get(a)
if got != want {
t.Errorf("Get(%q) is insertion order dependent (t1=%v, t2=%v)", a, want, got)
}
})
}
func TestComputePrefixSplit(t *testing.T) {
// These tests are partially redundant with other tests. Please
// keep them anyway. computePrefixSplit's behavior is remarkably
// subtle, and all the test cases listed below come from
// hard-earned debugging of malformed route tables.
var tests = []struct {
// prefixA can be a /8, /16 or /24 (v4).
// prefixB can be anything /9 or more specific.
prefixA, prefixB string
lastCommon string
aStride, bStride uint8
}{
{"192.168.1.0/24", "192.168.5.5/32", "192.168.0.0/16", 1, 5},
{"192.168.129.0/24", "192.168.128.0/17", "192.168.0.0/16", 129, 128},
{"192.168.5.0/24", "192.168.0.0/16", "192.0.0.0/8", 168, 168},
{"192.168.0.0/16", "192.168.0.0/16", "192.0.0.0/8", 168, 168},
{"ff:aaaa:aaaa::1/128", "ff:aaaa::/120", "ff:aaaa::/32", 170, 0},
}
for _, test := range tests {
a, b := netip.MustParsePrefix(test.prefixA), netip.MustParsePrefix(test.prefixB)
gotLastCommon, gotAStride, gotBStride := computePrefixSplit(a, b)
if want := netip.MustParsePrefix(test.lastCommon); gotLastCommon != want || gotAStride != test.aStride || gotBStride != test.bStride {
t.Errorf("computePrefixSplit(%q, %q) = %s, %d, %d; want %s, %d, %d", a, b, gotLastCommon, gotAStride, gotBStride, want, test.aStride, test.bStride)
}
}
}
func TestInsert(t *testing.T) {
tbl := &Table[int]{}
p := netip.MustParsePrefix
// Create a new leaf strideTable, with compressed path
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", -1},
{"192.168.0.3", -1},
{"192.168.0.255", -1},
{"192.168.1.1", -1},
{"192.170.1.1", -1},
{"192.180.0.1", -1},
{"192.180.3.5", -1},
{"10.0.0.5", -1},
{"10.0.0.15", -1},
})
// Insert into previous leaf, no tree changes
tbl.Insert(p("192.168.0.2/32"), ptr.To(2))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", -1},
{"192.168.0.255", -1},
{"192.168.1.1", -1},
{"192.170.1.1", -1},
{"192.180.0.1", -1},
{"192.180.3.5", -1},
{"10.0.0.5", -1},
{"10.0.0.15", -1},
})
// Insert into previous leaf, unaligned prefix covering the /32s
tbl.Insert(p("192.168.0.0/26"), ptr.To(7))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", 7},
{"192.168.0.255", -1},
{"192.168.1.1", -1},
{"192.170.1.1", -1},
{"192.180.0.1", -1},
{"192.180.3.5", -1},
{"10.0.0.5", -1},
{"10.0.0.15", -1},
})
// Create a different leaf elsewhere
tbl.Insert(p("10.0.0.0/27"), ptr.To(3))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", 7},
{"192.168.0.255", -1},
{"192.168.1.1", -1},
{"192.170.1.1", -1},
{"192.180.0.1", -1},
{"192.180.3.5", -1},
{"10.0.0.5", 3},
{"10.0.0.15", 3},
})
// Insert that creates a new intermediate table and a new child
tbl.Insert(p("192.168.1.1/32"), ptr.To(4))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", 7},
{"192.168.0.255", -1},
{"192.168.1.1", 4},
{"192.170.1.1", -1},
{"192.180.0.1", -1},
{"192.180.3.5", -1},
{"10.0.0.5", 3},
{"10.0.0.15", 3},
})
// Insert that creates a new intermediate table but no new child
tbl.Insert(p("192.170.0.0/16"), ptr.To(5))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", 7},
{"192.168.0.255", -1},
{"192.168.1.1", 4},
{"192.170.1.1", 5},
{"192.180.0.1", -1},
{"192.180.3.5", -1},
{"10.0.0.5", 3},
{"10.0.0.15", 3},
})
// New leaf in a different subtree, so the next insert can test a
// variant of decompression.
tbl.Insert(p("192.180.0.1/32"), ptr.To(8))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", 7},
{"192.168.0.255", -1},
{"192.168.1.1", 4},
{"192.170.1.1", 5},
{"192.180.0.1", 8},
{"192.180.3.5", -1},
{"10.0.0.5", 3},
{"10.0.0.15", 3},
})
// Insert that creates a new intermediate table but no new child,
// with an unaligned intermediate
tbl.Insert(p("192.180.0.0/21"), ptr.To(9))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", 7},
{"192.168.0.255", -1},
{"192.168.1.1", 4},
{"192.170.1.1", 5},
{"192.180.0.1", 8},
{"192.180.3.5", 9},
{"10.0.0.5", 3},
{"10.0.0.15", 3},
})
// Insert a default route, those have their own codepath.
tbl.Insert(p("0.0.0.0/0"), ptr.To(6))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.168.0.3", 7},
{"192.168.0.255", 6},
{"192.168.1.1", 4},
{"192.170.1.1", 5},
{"192.180.0.1", 8},
{"192.180.3.5", 9},
{"10.0.0.5", 3},
{"10.0.0.15", 3},
})
// Now all of the above again, but for IPv6.
// Create a new leaf strideTable, with compressed path
tbl.Insert(p("ff:aaaa::1/128"), ptr.To(1))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", -1},
{"ff:aaaa::3", -1},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", -1},
{"ff:aaaa:aaaa:bbbb::1", -1},
{"ff:cccc::1", -1},
{"ff:cccc::ff", -1},
{"ffff:bbbb::5", -1},
{"ffff:bbbb::15", -1},
})
// Insert into previous leaf, no tree changes
tbl.Insert(p("ff:aaaa::2/128"), ptr.To(2))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", -1},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", -1},
{"ff:aaaa:aaaa:bbbb::1", -1},
{"ff:cccc::1", -1},
{"ff:cccc::ff", -1},
{"ffff:bbbb::5", -1},
{"ffff:bbbb::15", -1},
})
// Insert into previous leaf, unaligned prefix covering the /128s
tbl.Insert(p("ff:aaaa::/125"), ptr.To(7))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", 7},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", -1},
{"ff:aaaa:aaaa:bbbb::1", -1},
{"ff:cccc::1", -1},
{"ff:cccc::ff", -1},
{"ffff:bbbb::5", -1},
{"ffff:bbbb::15", -1},
})
// Create a different leaf elsewhere
tbl.Insert(p("ffff:bbbb::/120"), ptr.To(3))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", 7},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", -1},
{"ff:aaaa:aaaa:bbbb::1", -1},
{"ff:cccc::1", -1},
{"ff:cccc::ff", -1},
{"ffff:bbbb::5", 3},
{"ffff:bbbb::15", 3},
})
// Insert that creates a new intermediate table and a new child
tbl.Insert(p("ff:aaaa:aaaa::1/128"), ptr.To(4))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", 7},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", 4},
{"ff:aaaa:aaaa:bbbb::1", -1},
{"ff:cccc::1", -1},
{"ff:cccc::ff", -1},
{"ffff:bbbb::5", 3},
{"ffff:bbbb::15", 3},
})
// Insert that creates a new intermediate table but no new child
tbl.Insert(p("ff:aaaa:aaaa:bb00::/56"), ptr.To(5))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", 7},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", 4},
{"ff:aaaa:aaaa:bbbb::1", 5},
{"ff:cccc::1", -1},
{"ff:cccc::ff", -1},
{"ffff:bbbb::5", 3},
{"ffff:bbbb::15", 3},
})
// New leaf in a different subtree, so the next insert can test a
// variant of decompression.
tbl.Insert(p("ff:cccc::1/128"), ptr.To(8))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", 7},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", 4},
{"ff:aaaa:aaaa:bbbb::1", 5},
{"ff:cccc::1", 8},
{"ff:cccc::ff", -1},
{"ffff:bbbb::5", 3},
{"ffff:bbbb::15", 3},
})
// Insert that creates a new intermediate table but no new child,
// with an unaligned intermediate
tbl.Insert(p("ff:cccc::/37"), ptr.To(9))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", 7},
{"ff:aaaa::255", -1},
{"ff:aaaa:aaaa::1", 4},
{"ff:aaaa:aaaa:bbbb::1", 5},
{"ff:cccc::1", 8},
{"ff:cccc::ff", 9},
{"ffff:bbbb::5", 3},
{"ffff:bbbb::15", 3},
})
// Insert a default route, those have their own codepath.
tbl.Insert(p("::/0"), ptr.To(6))
checkRoutes(t, tbl, []tableTest{
{"ff:aaaa::1", 1},
{"ff:aaaa::2", 2},
{"ff:aaaa::3", 7},
{"ff:aaaa::255", 6},
{"ff:aaaa:aaaa::1", 4},
{"ff:aaaa:aaaa:bbbb::1", 5},
{"ff:cccc::1", 8},
{"ff:cccc::ff", 9},
{"ffff:bbbb::5", 3},
{"ffff:bbbb::15", 3},
})
}
func TestDelete(t *testing.T) {
t.Parallel()
p := netip.MustParsePrefix
t.Run("prefix_in_root", func(t *testing.T) {
// Add/remove prefix from root table.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("10.0.0.0/8"), ptr.To(1))
checkRoutes(t, tbl, []tableTest{
{"10.0.0.1", 1},
{"255.255.255.255", -1},
})
checkSize(t, tbl, 2)
tbl.Delete(p("10.0.0.0/8"))
checkRoutes(t, tbl, []tableTest{
{"10.0.0.1", -1},
{"255.255.255.255", -1},
})
checkSize(t, tbl, 2)
})
t.Run("prefix_in_leaf", func(t *testing.T) {
// Create, then delete a single leaf table.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"255.255.255.255", -1},
})
checkSize(t, tbl, 3)
tbl.Delete(p("192.168.0.1/32"))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", -1},
{"255.255.255.255", -1},
})
checkSize(t, tbl, 2)
})
t.Run("intermediate_no_routes", func(t *testing.T) {
// Create an intermediate with 2 children, then delete one leaf.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
tbl.Insert(p("192.180.0.1/32"), ptr.To(2))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.180.0.1", 2},
{"192.40.0.1", -1},
})
checkSize(t, tbl, 5) // 2 roots, 1 intermediate, 2 leaves
tbl.Delete(p("192.180.0.1/32"))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.180.0.1", -1},
{"192.40.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
})
t.Run("intermediate_with_route", func(t *testing.T) {
// Same, but the intermediate carries a route as well.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
tbl.Insert(p("192.180.0.1/32"), ptr.To(2))
tbl.Insert(p("192.0.0.0/10"), ptr.To(3))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.180.0.1", 2},
{"192.40.0.1", 3},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 5) // 2 roots, 1 intermediate, 2 leaves
tbl.Delete(p("192.180.0.1/32"))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.180.0.1", -1},
{"192.40.0.1", 3},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 4) // 2 roots, 1 intermediate w/route, 1 leaf
})
t.Run("intermediate_many_leaves", func(t *testing.T) {
// Intermediate with 3 leaves, then delete one leaf.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
tbl.Insert(p("192.180.0.1/32"), ptr.To(2))
tbl.Insert(p("192.200.0.1/32"), ptr.To(3))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.180.0.1", 2},
{"192.200.0.1", 3},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 6) // 2 roots, 1 intermediate, 3 leaves
tbl.Delete(p("192.180.0.1/32"))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.180.0.1", -1},
{"192.200.0.1", 3},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 5) // 2 roots, 1 intermediate, 2 leaves
})
t.Run("nosuchprefix_missing_child", func(t *testing.T) {
// Delete non-existent prefix, missing strideTable path.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
tbl.Delete(p("200.0.0.0/32")) // lookup miss in root
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
})
t.Run("nosuchprefix_wrong_turn", func(t *testing.T) {
// Delete non-existent prefix, strideTable path exists but
// with a wrong turn.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
tbl.Delete(p("192.40.0.0/32")) // finds wrong child
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
})
t.Run("nosuchprefix_not_in_leaf", func(t *testing.T) {
// Delete non-existent prefix, strideTable path exists but
// leaf doesn't contain route.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
tbl.Delete(p("192.168.0.5/32")) // right leaf, no route
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
})
t.Run("intermediate_with_deleted_route", func(t *testing.T) {
// Intermediate table loses its last route and becomes
// compactable.
tbl := &Table[int]{}
checkSize(t, tbl, 2)
tbl.Insert(p("192.168.0.1/32"), ptr.To(1))
tbl.Insert(p("192.168.0.0/22"), ptr.To(2))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", 2},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 4) // 2 roots, 1 intermediate w/route, 1 leaf
tbl.Delete(p("192.168.0.0/22"))
checkRoutes(t, tbl, []tableTest{
{"192.168.0.1", 1},
{"192.168.0.2", -1},
{"192.255.0.1", -1},
})
checkSize(t, tbl, 3) // 2 roots, 1 leaf
})
t.Run("default_route", func(t *testing.T) {
// Default routes have a special case in the code.
tbl := &Table[int]{}
tbl.Insert(p("0.0.0.0/0"), ptr.To(1))
tbl.Delete(p("0.0.0.0/0"))
checkRoutes(t, tbl, []tableTest{
{"1.2.3.4", -1},
})
checkSize(t, tbl, 2) // 2 roots
})
}
func TestInsertCompare(t *testing.T) {
// Create large route tables repeatedly, and compare Table's
// behavior to a naive and slow but correct implementation.
t.Parallel()
pfxs := randomPrefixes(10_000)
@ -27,7 +591,9 @@ func TestInsert(t *testing.T) {
fast.Insert(pfx.pfx, pfx.val)
}
t.Logf(fast.debugSummary())
if debugInsert {
t.Logf(fast.debugSummary())
}
seenVals4 := map[*int]bool{}
seenVals6 := map[*int]bool{}
@ -44,6 +610,7 @@ func TestInsert(t *testing.T) {
t.Errorf("get(%q) = %p, want %p", a, fastVal, slowVal)
}
}
// Empirically, 10k probes into 5k v4 prefixes and 5k v6 prefixes results in
// ~1k distinct values for v4 and ~300 for v6. distinct routes. This sanity
// check that we didn't just return a single route for everything should be
@ -57,36 +624,65 @@ func TestInsert(t *testing.T) {
}
func TestInsertShuffled(t *testing.T) {
// The order in which you insert prefixes into a route table
// should not matter, as long as you're inserting the same set of
// routes. Verify that this is true, because ART does execute
// vastly different code depending on the order of insertion, even
// if the end result is identical.
//
// If you're here because this package's tests are slow and you
// want to make them faster, please do not delete this test (or
// any test, really). It may seem excessive to test this, but
// these shuffle tests found a lot of very nasty edge cases during
// development, and you _really_ don't want to be debugging a
// faulty route table in production.
t.Parallel()
pfxs := randomPrefixes(10_000)
pfxs := randomPrefixes(1000)
var pfxs2 []slowPrefixEntry[int]
rt := Table[int]{}
for _, pfx := range pfxs {
rt.Insert(pfx.pfx, pfx.val)
}
defer func() {
if t.Failed() {
t.Logf("pre-shuffle: %#v", pfxs)
t.Logf("post-shuffle: %#v", pfxs2)
}
}()
for i := 0; i < 10; i++ {
pfxs2 := append([]slowPrefixEntry[int](nil), pfxs...)
rand.Shuffle(len(pfxs2), func(i, j int) { pfxs2[i], pfxs2[j] = pfxs2[j], pfxs2[i] })
addrs := make([]netip.Addr, 0, 10_000)
for i := 0; i < 10_000; i++ {
addrs = append(addrs, randomAddr())
}
rt := Table[int]{}
rt2 := Table[int]{}
for _, pfx := range pfxs {
rt.Insert(pfx.pfx, pfx.val)
}
for _, pfx := range pfxs2 {
rt2.Insert(pfx.pfx, pfx.val)
}
// Diffing a deep tree of tables gives cmp.Diff a nervous breakdown, so
// test for equivalence statistically with random probes instead.
for i := 0; i < 10_000; i++ {
a := randomAddr()
for _, a := range addrs {
val1 := rt.Get(a)
val2 := rt2.Get(a)
if val1 == nil && val2 == nil {
continue
}
if (val1 == nil && val2 != nil) || (val1 != nil && val2 == nil) || (*val1 != *val2) {
t.Errorf("get(%q) = %s, want %s", a, printIntPtr(val2), printIntPtr(val1))
t.Fatalf("get(%q) = %s, want %s", a, printIntPtr(val2), printIntPtr(val1))
}
}
}
}
func TestDelete(t *testing.T) {
func TestDeleteCompare(t *testing.T) {
// Create large route tables repeatedly, delete half of their
// prefixes, and compare Table's behavior to a naive and slow but
// correct implementation.
t.Parallel()
const (
@ -104,6 +700,19 @@ func TestDelete(t *testing.T) {
toDelete := append([]slowPrefixEntry[int](nil), all4[deleteCut:]...)
toDelete = append(toDelete, all6[deleteCut:]...)
defer func() {
if t.Failed() {
for _, pfx := range pfxs {
fmt.Printf("%q, ", pfx.pfx)
}
fmt.Println("")
for _, pfx := range toDelete {
fmt.Printf("%q, ", pfx.pfx)
}
fmt.Println("")
}
}()
slow := slowPrefixTable[int]{pfxs}
fast := Table[int]{}
@ -146,6 +755,18 @@ func TestDelete(t *testing.T) {
}
func TestDeleteShuffled(t *testing.T) {
// The order in which you delete prefixes from a route table
// should not matter, as long as you're deleting the same set of
// routes. Verify that this is true, because ART does execute
// vastly different code depending on the order of deletions, even
// if the end result is identical.
//
// If you're here because this package's tests are slow and you
// want to make them faster, please do not delete this test (or
// any test, really). It may seem excessive to test this, but
// these shuffle tests found a lot of very nasty edge cases during
// development, and you _really_ don't want to be debugging a
// faulty route table in production.
t.Parallel()
const (
@ -205,6 +826,29 @@ func TestDeleteShuffled(t *testing.T) {
}
}
type tableTest struct {
// addr is an IP address string to look up in a route table.
addr string
// want is the expected >=0 value associated with the route, or -1
// if we expect a lookup miss.
want int
}
// checkRoutes verifies that the route lookups in tt return the
// expected results on tbl.
func checkRoutes(t *testing.T, tbl *Table[int], tt []tableTest) {
t.Helper()
for _, tc := range tt {
v := tbl.Get(netip.MustParseAddr(tc.addr))
if v == nil && tc.want != -1 {
t.Errorf("lookup %q got nil, want %d", tc.addr, tc.want)
}
if v != nil && *v != tc.want {
t.Errorf("lookup %q got %d, want %d", tc.addr, *v, tc.want)
}
}
}
// 100k routes for IPv6, at the current size of strideTable and strideEntry, is
// in the ballpark of 4GiB if you assume worst-case prefix distribution. Future
// optimizations will knock down the memory consumption by over an order of
@ -402,6 +1046,32 @@ func (t *runningTimer) Elapsed() time.Duration {
return t.cumulative
}
func checkSize(t *testing.T, tbl *Table[int], want int) {
t.Helper()
if got := tbl.numStrides(); got != want {
t.Errorf("wrong table size, got %d strides want %d", got, want)
}
}
func (t *Table[T]) numStrides() int {
seen := map[*strideTable[T]]bool{}
return t.numStridesRec(seen, &t.v4) + t.numStridesRec(seen, &t.v6)
}
func (t *Table[T]) numStridesRec(seen map[*strideTable[T]]bool, st *strideTable[T]) int {
ret := 1
if st.childRefs == 0 {
return ret
}
for i := firstHostIndex; i <= lastHostIndex; i++ {
if c := st.entries[i].child; c != nil && !seen[c] {
seen[c] = true
ret += t.numStridesRec(seen, c)
}
}
return ret
}
// slowPrefixTable is a routing table implemented as a set of prefixes that are
// explicitly scanned in full for every route lookup. It is very slow, but also
// reasonably easy to verify by inspection, and so a good correctness reference
@ -548,3 +1218,26 @@ func roundFloat64(f float64) float64 {
}
return ret
}
func minimize(pfxs []slowPrefixEntry[int], f func(skip map[netip.Prefix]bool) error) (map[netip.Prefix]bool, error) {
if f(nil) == nil {
return nil, nil
}
remove := map[netip.Prefix]bool{}
for lastLen := -1; len(remove) != lastLen; lastLen = len(remove) {
fmt.Println("len is ", len(remove))
for i, pfx := range pfxs {
if remove[pfx.pfx] {
continue
}
remove[pfx.pfx] = true
fmt.Printf("%d %d: trying without %s\n", i, len(remove), pfx.pfx)
if f(remove) == nil {
delete(remove, pfx.pfx)
}
}
}
return remove, f(remove)
}

Write Preview
Loading…
Cancel
Save