strengthen priority tree code and add tests
The priority tree codes has been strengthened to handle some new
corner cases.
- Handle setting the parent to itself.
- Handle exclusive reprioritization to the root stream.
- Handle reprioritization to stream dependent of stream being
reprioritized.
In addition, split out the adjustment function so that it can be
tested independently of the serverConn and add tests.
diff --git a/priority_test.go b/priority_test.go
new file mode 100644
index 0000000..d9648fd
--- /dev/null
+++ b/priority_test.go
@@ -0,0 +1,121 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+// See https://code.google.com/p/go/source/browse/CONTRIBUTORS
+// Licensed under the same terms as Go itself:
+// https://code.google.com/p/go/source/browse/LICENSE
+
+package http2
+
+import (
+ "testing"
+)
+
+func TestPriority(t *testing.T) {
+ // A -> B
+ // move A's parent to B
+ streams := make(map[uint32]*stream)
+ a := &stream{
+ parent: nil,
+ weight: 16,
+ }
+ streams[1] = a
+ b := &stream{
+ parent: a,
+ weight: 16,
+ }
+ streams[2] = b
+ adjustStreamPriority(streams, 1, PriorityParam{
+ Weight: 20,
+ StreamDep: 2,
+ })
+ if a.parent != b {
+ t.Errorf("Expected A's parent to be B")
+ }
+ if a.weight != 20 {
+ t.Errorf("Expected A's weight to be 20; got %d", a.weight)
+ }
+ if b.parent != nil {
+ t.Errorf("Expected B to have no parent")
+ }
+ if b.weight != 16 {
+ t.Errorf("Expected B's weight to be 16; got %d", b.weight)
+ }
+}
+
+func TestPriorityExclusiveZero(t *testing.T) {
+ // A B and C are all children of the 0 stream.
+ // Exclusive reprioritization to any of the streams
+ // should bring the rest of the streams under the
+ // reprioritized stream
+ streams := make(map[uint32]*stream)
+ a := &stream{
+ parent: nil,
+ weight: 16,
+ }
+ streams[1] = a
+ b := &stream{
+ parent: nil,
+ weight: 16,
+ }
+ streams[2] = b
+ c := &stream{
+ parent: nil,
+ weight: 16,
+ }
+ streams[3] = c
+ adjustStreamPriority(streams, 3, PriorityParam{
+ Weight: 20,
+ StreamDep: 0,
+ Exclusive: true,
+ })
+ if a.parent != c {
+ t.Errorf("Expected A's parent to be C")
+ }
+ if a.weight != 16 {
+ t.Errorf("Expected A's weight to be 16; got %d", a.weight)
+ }
+ if b.parent != c {
+ t.Errorf("Expected B's parent to be C")
+ }
+ if b.weight != 16 {
+ t.Errorf("Expected B's weight to be 16; got %d", b.weight)
+ }
+ if c.parent != nil {
+ t.Errorf("Expected C to have no parent")
+ }
+ if c.weight != 20 {
+ t.Errorf("Expected C's weight to be 20; got %d", b.weight)
+ }
+}
+
+func TestPriorityOwnParent(t *testing.T) {
+ streams := make(map[uint32]*stream)
+ a := &stream{
+ parent: nil,
+ weight: 16,
+ }
+ streams[1] = a
+ b := &stream{
+ parent: a,
+ weight: 16,
+ }
+ streams[2] = b
+ adjustStreamPriority(streams, 1, PriorityParam{
+ Weight: 20,
+ StreamDep: 1,
+ })
+ if a.parent != nil {
+ t.Errorf("Expected A's parent to be nil")
+ }
+ if a.weight != 20 {
+ t.Errorf("Expected A's weight to be 20; got %d", a.weight)
+ }
+ if b.parent != a {
+ t.Errorf("Expected B's parent to be A")
+ }
+ if b.weight != 16 {
+ t.Errorf("Expected B's weight to be 16; got %d", b.weight)
+ }
+
+}
