http2: add ClientConnState, ClientConn.State accessor
So ClientConnPool can be implemented with the same functionality
as the built-in one. And for observability.
Change-Id: I855fbac3d9e4c02ab213a3e6a80b00f857648264
Reviewed-on: https://go-review.googlesource.com/c/net/+/354351
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Trust: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/http2/transport.go b/http2/transport.go
index 653a1a0..c88d227 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -759,6 +759,61 @@
return true
}
+// ClientConnState describes the state of a ClientConn.
+type ClientConnState struct {
+ // Closed is whether the connection is closed.
+ Closed bool
+
+ // Closing is whether the connection is in the process of
+ // closing. It may be closing due to shutdown, being a
+ // single-use connection, being marked as DoNotReuse, or
+ // having received a GOAWAY frame.
+ Closing bool
+
+ // StreamsActive is how many streams are active.
+ StreamsActive int
+
+ // StreamsReserved is how many streams have been reserved via
+ // ClientConn.ReserveNewRequest.
+ StreamsReserved int
+
+ // StreamsPending is how many requests have been sent in excess
+ // of the peer's advertised MaxConcurrentStreams setting and
+ // are waiting for other streams to complete.
+ StreamsPending int
+
+ // MaxConcurrentStreams is how many concurrent streams the
+ // peer advertised as acceptable. Zero means no SETTINGS
+ // frame has been received yet.
+ MaxConcurrentStreams uint32
+
+ // LastIdle, if non-zero, is when the connection last
+ // transitioned to idle state.
+ LastIdle time.Time
+}
+
+// State returns a snapshot of cc's state.
+func (cc *ClientConn) State() ClientConnState {
+ cc.wmu.Lock()
+ maxConcurrent := cc.maxConcurrentStreams
+ if !cc.seenSettings {
+ maxConcurrent = 0
+ }
+ cc.wmu.Unlock()
+
+ cc.mu.Lock()
+ defer cc.mu.Unlock()
+ return ClientConnState{
+ Closed: cc.closed,
+ Closing: cc.closing || cc.singleUse || cc.doNotReuse || cc.goAway != nil,
+ StreamsActive: len(cc.streams),
+ StreamsReserved: cc.streamsReserved,
+ StreamsPending: cc.pendingRequests,
+ LastIdle: cc.lastIdle,
+ MaxConcurrentStreams: maxConcurrent,
+ }
+}
+
// clientConnIdleState describes the suitability of a client
// connection to initiate a new RoundTrip request.
type clientConnIdleState struct {
