http2: add diagnostics channel 'http2.client.stream.close'

Signed-off-by: Darshan Sen <raisinten@gmail.com>
PR-URL: #58329
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Kohei Ueno <kohei.ueno119@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>

Author: RaisinTen

doc/api/diagnostics_channel.md

@@ -1232,6 +1232,13 @@ Emitted when an error occurs during the processing of a stream on the client.
 
 Emitted when a stream is received on the client.
 
+`http2.client.stream.close`
+
+*`stream` {ClientHttp2Stream}
+
+Emitted when a stream is closed on the client. The HTTP/2 error code used when
+closing the stream can be retrieved using the `stream.rstCode` property.
+
 #### Modules
 
 > Stability: 1 - Experimental

lib/internal/http2/core.js

@@ -189,6 +189,7 @@ const onClientStreamCreatedChannel = dc.channel('http2.client.stream.created');
 constonClientStreamStartChannel=dc.channel('http2.client.stream.start');
 constonClientStreamErrorChannel=dc.channel('http2.client.stream.error');
 constonClientStreamFinishChannel=dc.channel('http2.client.stream.finish');
+constonClientStreamCloseChannel=dc.channel('http2.client.stream.close');
 
 letdebug=require('internal/util/debuglog').debuglog('http2',(fn)=>{
 debug=fn;
@@ -1979,6 +1980,7 @@ const kSubmitRstStream = 1;
 constkForceRstStream=2;
 
 functioncloseStream(stream,code,rstStreamStatus=kSubmitRstStream){
+consttype=stream[kSession][kType];
 conststate=stream[kState];
 state.flags|=STREAM_FLAGS_CLOSED;
 state.rstCode=code;
@@ -2009,6 +2011,11 @@ function closeStream(stream, code, rstStreamStatus = kSubmitRstStream) {
 else
 stream.once('finish',finishFn);
 }
+
+if(type===NGHTTP2_SESSION_CLIENT&&
+onClientStreamCloseChannel.hasSubscribers){
+onClientStreamCloseChannel.publish({ stream });
+}
 }
 
 functionfinishCloseStream(code){

test/parallel/test-diagnostics-channel-http2-client-stream-close-error.js

@@ -0,0 +1,44 @@
+'use strict';
+
+constcommon=require('../common');
+if(!common.hasCrypto)
+common.skip('missing crypto');
+
+// This test ensures that the built-in HTTP/2 diagnostics channels are reporting
+// the diagnostics messages for the 'http2.client.stream.close' channel when
+// a ClientHttp2Stream is destroyed because of an error.
+
+constassert=require('assert');
+constdc=require('diagnostics_channel');
+consthttp2=require('http2');
+const{ Duplex }=require('stream');
+
+dc.subscribe('http2.client.stream.close',common.mustCall(({ stream })=>{
+// Since ClientHttp2Stream is not exported from any module, this just checks
+// if the stream is an instance of Duplex and the constructor name is
+// 'ClientHttp2Stream'.
+assert.ok(streaminstanceofDuplex);
+assert.strictEqual(stream.constructor.name,'ClientHttp2Stream');
+assert.strictEqual(stream.closed,true);
+assert.strictEqual(stream.destroyed,true);
+
+assert.strictEqual(stream.rstCode,http2.constants.NGHTTP2_CANCEL);
+}));
+
+constserver=http2.createServer();
+server.listen(0,common.mustCall(()=>{
+constport=server.address().port;
+constclient=http2.connect(`http://localhost:${port}`);
+
+constac=newAbortController();
+conststream=client.request({},{signal: ac.signal});
+ac.abort();
+
+stream.on('error',common.mustCall((err)=>{
+assert.strictEqual(err.code,'ABORT_ERR');
+assert.strictEqual(err.name,'AbortError');
+
+client.close();
+server.close();
+}));
+}));

test/parallel/test-diagnostics-channel-http2-client-stream-close.js

@@ -0,0 +1,63 @@
+'use strict';
+
+constcommon=require('../common');
+if(!common.hasCrypto)
+common.skip('missing crypto');
+
+// This test ensures that the built-in HTTP/2 diagnostics channels are reporting
+// the diagnostics messages for the 'http2.client.stream.close' channel when
+// ClientHttp2Streams created by these actions are closed:
+// - the client calling ClientHttp2Session#request()
+// - in response to an incoming 'push' event from the server
+
+constCountdown=require('../common/countdown');
+constassert=require('assert');
+constdc=require('diagnostics_channel');
+consthttp2=require('http2');
+const{ Duplex }=require('stream');
+
+constclientHttp2StreamCloseCount=2;
+
+dc.subscribe('http2.client.stream.close',common.mustCall(({ stream })=>{
+// Since ClientHttp2Stream is not exported from any module, this just checks
+// if the stream is an instance of Duplex and the constructor name is
+// 'ClientHttp2Stream'.
+assert.ok(streaminstanceofDuplex);
+assert.strictEqual(stream.constructor.name,'ClientHttp2Stream');
+assert.strictEqual(stream.closed,true);
+assert.strictEqual(stream.destroyed,false);
+
+assert.strictEqual(stream.rstCode,http2.constants.NGHTTP2_NO_ERROR);
+},clientHttp2StreamCloseCount));
+
+constserver=http2.createServer();
+server.on('stream',common.mustCall((stream)=>{
+stream.respond();
+stream.end();
+
+stream.pushStream({},common.mustSucceed((pushStream)=>{
+pushStream.respond();
+pushStream.end();
+}));
+}));
+
+server.listen(0,common.mustCall(()=>{
+constport=server.address().port;
+constclient=http2.connect(`http://localhost:${port}`);
+
+constcountdown=newCountdown(clientHttp2StreamCloseCount,()=>{
+client.close();
+server.close();
+});
+
+conststream=client.request({});
+stream.on('response',common.mustCall(()=>{
+countdown.dec();
+}));
+
+client.on('stream',common.mustCall((pushStream)=>{
+pushStream.on('push',common.mustCall(()=>{
+countdown.dec();
+}));
+}));
+}));