Hulk did something

[bytom/vapor.git] / vendor / golang.org / x / net / http2 / flow.go

diff --git a/vendor/golang.org/x/net/http2/flow.go b/vendor/golang.org/x/net/http2/flow.go
new file mode 100644 (file)
index 0000000..957de25
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/flow.go
@@ -0,0 +1,50 @@
+// 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.
+
+// Flow control
+
+package http2
+
+// flow is the flow control window's size.
+type flow struct {
+       // n is the number of DATA bytes we're allowed to send.
+       // A flow is kept both on a conn and a per-stream.
+       n int32
+
+       // conn points to the shared connection-level flow that is
+       // shared by all streams on that conn. It is nil for the flow
+       // that's on the conn directly.
+       conn *flow
+}
+
+func (f *flow) setConnFlow(cf *flow) { f.conn = cf }
+
+func (f *flow) available() int32 {
+       n := f.n
+       if f.conn != nil && f.conn.n < n {
+               n = f.conn.n
+       }
+       return n
+}
+
+func (f *flow) take(n int32) {
+       if n > f.available() {
+               panic("internal error: took too much")
+       }
+       f.n -= n
+       if f.conn != nil {
+               f.conn.n -= n
+       }
+}
+
+// add adds n bytes (positive or negative) to the flow control window.
+// It returns false if the sum would exceed 2^31-1.
+func (f *flow) add(n int32) bool {
+       remain := (1<<31 - 1) - f.n
+       if n > remain {
+               return false
+       }
+       f.n += n
+       return true
+}