FileRequest: Make Stop() cancel the request as soon as possible

This commit implements a check for the flag raised by Stop() to cancel
a given request as soon as possible. Cancelled requests will return
B_INTERRUPTED regardless of whether the request has completed,
on par with how BHttpRequest is behaving at the moment.

Change-Id: Ia8a95b910cff158c710c5b2ed58b4675e705642e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3071
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

src/kits/network/libnetapi/FileRequest.cpp

@@ -79,12 +79,19 @@ BFileRequest::_ProtocolLoop()
 
 			fListener->HeadersReceived(this, fResult);
 
-			ssize_t chunkSize;
+			ssize_t chunkSize = 0;
 			char chunk[4096];
-			while ((chunkSize = file.Read(chunk, sizeof(chunk))) > 0) {
+			while (!fQuit) {
-				fListener->DataReceived(this, chunk, transferredSize, chunkSize);
+				chunkSize = file.Read(chunk, sizeof(chunk));
-				transferredSize += chunkSize;
+				if (chunkSize > 0) {
+					fListener->DataReceived(this, chunk, transferredSize,
+						chunkSize);
+					transferredSize += chunkSize;
+				} else
+					break;
 			}
+			if (fQuit)
+				return B_INTERRUPTED;
 			// Return error if we didn't transfer everything
 			if (transferredSize != size) {
 				if (chunkSize < 0)
@@ -122,7 +129,7 @@ BFileRequest::_ProtocolLoop()
 
 	char name[B_FILE_NAME_LENGTH];
 	BEntry entry;
-	while (directory.GetNextEntry(&entry) != B_ENTRY_NOT_FOUND) {
+	while (!fQuit && directory.GetNextEntry(&entry) != B_ENTRY_NOT_FOUND) {
 		// We read directories using the EPLF (Easily Parsed List Format)
 		// This happens to be one of the formats that WebKit can understand,
 		// and it is not too hard to parse or generate.
@@ -160,7 +167,8 @@ BFileRequest::_ProtocolLoop()
 
 	if (fListener != NULL)
 		fListener->DownloadProgress(this, transferredSize, transferredSize);
-	fResult.SetLength(transferredSize);
+	if (!fQuit)
+		fResult.SetLength(transferredSize);
 
-	return B_OK;
+	return fQuit ? B_INTERRUPTED : B_OK;
 }

src/tests/kits/net/service/FileTest.cpp

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2020, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+
+#include "FileTest.h"
+
+#include <stdlib.h>
+
+#include <File.h>
+#include <FileRequest.h>
+#include <Url.h>
+#include <UrlProtocolRoster.h>
+#include <UrlProtocolListener.h>
+
+#include <ThreadedTestCaller.h>
+#include <TestUtils.h>
+
+#include "TestServer.h"
+
+
+class StopTestListener : public BUrlProtocolListener {
+public:
+	StopTestListener() {}
+
+	void DataReceived(BUrlRequest *caller, const char*, off_t, ssize_t)
+	{
+		caller->Stop();
+	}
+};
+
+
+void
+FileTest::StopTest()
+{
+	StopTestListener listener;
+	char tmpl[] = "/tmp/filestoptestXXXXXX";
+	int fd = mkstemp(tmpl);
+	CHK(fd != -1);
+	close(fd);
+
+	BFile file(tmpl, O_WRONLY | O_CREAT);
+	CHK(file.InitCheck() == B_OK);
+	BString content;
+	/* number chosen to be larger than BFileRequest buffer, adjust as needed */
+	content.Append('f', 40960);
+
+	CHK(file.WriteExactly(content.String(), content.Length()) == B_OK);
+
+	BUrl url("file://");
+	url.SetPath(tmpl);
+	BUrlRequest *request = BUrlProtocolRoster::MakeRequest(url, &listener);
+	CHK(request != NULL);
+
+	thread_id thr = request->Run();
+	status_t dummy;
+	wait_for_thread(thr, &dummy);
+
+	CHK(request->Status() == B_INTERRUPTED);
+
+	delete request;
+
+	request = BUrlProtocolRoster::MakeRequest("file:///", &listener);
+	CHK(request != NULL);
+
+	thr = request->Run();
+	wait_for_thread(thr, &dummy);
+
+	CHK(request->Status() == B_INTERRUPTED);
+
+	delete request;
+}
+
+
+/* static */ void
+FileTest::AddTests(BTestSuite& parent)
+{
+	CppUnit::TestSuite *suite = new CppUnit::TestSuite("FileTest");
+
+	suite->addTest(new CppUnit::TestCaller<FileTest>("FileTest: Stop requests",
+		&FileTest::StopTest));
+
+	parent.addTest("FileTest", suite);
+}

src/tests/kits/net/service/FileTest.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2014-2020 Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+
+#ifndef FILE_TEST_H
+#define FILE_TEST_H
+
+
+#include <Url.h>
+
+#include <TestCase.h>
+#include <TestSuite.h>
+
+#include <cppunit/TestSuite.h>
+#include <tools/cppunit/ThreadedTestCase.h>
+
+#include "TestServer.h"
+
+
+class FileTest : public BThreadedTestCase {
+public:
+						FileTest() {};
+
+			void		StopTest();
+
+	static	void		AddTests(BTestSuite& suite);
+};
+
+
+#endif

src/tests/kits/net/service/Jamfile

@@ -9,6 +9,7 @@ UnitTestLib servicekittest.so :
 	DataTest.cpp
 	HttpTest.cpp
 	UrlTest.cpp
+	FileTest.cpp
 	TestServer.cpp
 
 	: be $(TARGET_NETWORK_LIBS) $(HAIKU_NETAPI_LIB) [ TargetLibstdc++ ]

src/tests/kits/net/service/ServiceKitTestAddon.cpp

@@ -11,6 +11,7 @@
 #include "DataTest.h"
 #include "HttpTest.h"
 #include "UrlTest.h"
+#include "FileTest.h"
 
 
 BTestSuite*
@@ -22,6 +23,7 @@ getTestSuite()
 	UrlTest::AddTests(*suite);
 	HttpTest::AddTests(*suite);
 	DataTest::AddTests(*suite);
+	FileTest::AddTests(*suite);
 
 	return suite;
 }