MXS-1461 Add mock Backend class

server/modules/filter/dbfwfilter/test/maxscale/mock/backend.hh

@@ -0,0 +1,117 @@
+#pragma once
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2020-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#include <maxscale/cppdefs.hh>
+#include <map>
+#include "routersession.hh"
+
+namespace maxscale
+{
+
+namespace mock
+{
+
+/**
+ * The abstract class Backend represents a backend.
+ */
+class Backend
+{
+    Backend(const Backend&);
+    Backend& operator = (const Backend&);
+
+public:
+    virtual ~Backend();
+
+    /**
+     * Called to handle a statement from a "client".
+     *
+     * @param pSession    The originating router session.
+     * @param pStatement  A buffer containing a statement.
+     */
+    virtual void handle_statement(RouterSession* pSession, GWBUF* pStatement) = 0;
+
+    /**
+     * Called when the backend should respond to the client.
+     *
+     * @param pSession  The router session to respond to.
+     *
+     * @return True, if the backend has additional responses to the router session.
+     */
+    virtual bool respond(RouterSession* pSession) = 0;
+
+    /**
+     * Whether the backend has a response for some router.
+     *
+     * @param pSession  A router session.
+     *
+     * @return True if there are responses for the router session.
+     */
+    virtual bool idle(const RouterSession* pSession) const = 0;
+
+protected:
+    Backend();
+};
+
+/**
+ * The abstract class BufferBackend is a helper class for concrete
+ * backend classes.
+ */
+class BufferBackend : public Backend
+{
+    BufferBackend(const BufferBackend&);
+    BufferBackend& operator = (const BufferBackend&);
+
+public:
+    ~BufferBackend();
+
+    bool respond(RouterSession* pSession);
+
+    bool idle(const RouterSession* pSession) const;
+
+protected:
+    BufferBackend();
+
+    /**
+     * Enqueues a response for a particular router session.
+     *
+     * @param pSession   The session to enqueue the response for.
+     * @param pResponse  The response.
+     */
+    void enqueue_response(RouterSession* pSession, GWBUF* pResponse);
+
+private:
+    typedef std::deque<GWBUF*> Responses;
+    typedef std::map<const RouterSession*, Responses> SessionResponses;
+
+    SessionResponses m_session_responses;
+};
+
+/**
+ * The OkBackend is a concrete backend class that response with an
+ * OK packet to all statements.
+ */
+class OkBackend : public BufferBackend
+{
+    OkBackend(const OkBackend&);
+    OkBackend& operator = (const OkBackend&);
+
+public:
+    OkBackend();
+
+    void handle_statement(RouterSession* pSession, GWBUF* pStatement);
+};
+
+}
+
+}

server/modules/filter/dbfwfilter/test/mock_backend.cc

@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2020-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#include "maxscale/mock/backend.hh"
+#include <maxscale/protocol/mysql.h>
+#include <iostream>
+
+using namespace std;
+
+namespace maxscale
+{
+
+namespace mock
+{
+
+//
+// Backend
+//
+
+Backend::Backend()
+{
+}
+
+Backend::~Backend()
+{
+}
+
+//
+// BufferBackend
+//
+BufferBackend::BufferBackend()
+{
+}
+
+BufferBackend::~BufferBackend()
+{
+}
+
+bool BufferBackend::respond(RouterSession* pSession)
+{
+    ss_dassert(!idle(pSession));
+
+    bool rv = false;
+
+    if (!idle(pSession))
+    {
+        Responses& responses = m_session_responses[pSession];
+        ss_dassert(!responses.empty());
+
+        GWBUF* pResponse = responses.front();
+        responses.pop_front();
+
+        pSession->clientReply(pResponse);
+
+        rv = !responses.empty();
+    }
+
+    return rv;
+}
+
+bool BufferBackend::idle(const RouterSession* pSession) const
+{
+    bool rv = true;
+
+    SessionResponses::const_iterator i = m_session_responses.find(pSession);
+    ss_dassert(i != m_session_responses.end());
+
+    if (i != m_session_responses.end())
+    {
+        const Responses& responses = i->second;
+        rv = responses.empty();
+    }
+
+    return rv;
+}
+
+void BufferBackend::enqueue_response(RouterSession* pSession, GWBUF* pResponse)
+{
+    Responses& responses = m_session_responses[pSession];
+
+    responses.push_back(pResponse);
+}
+
+//
+// OkBackend
+//
+
+OkBackend::OkBackend()
+{
+}
+
+void OkBackend::handle_statement(RouterSession* pSession, GWBUF* pStatement)
+{
+    /* Note: sequence id is always 01 (4th byte) */
+    const static uint8_t ok[MYSQL_OK_PACKET_MIN_LEN] =
+        { 07, 00, 00, 01, 00, 00, 00, 02, 00, 00, 00 };
+
+    GWBUF* pResponse = gwbuf_alloc_and_load(sizeof(ok), &ok);
+    ss_dassert(pResponse);
+
+    enqueue_response(pSession, pResponse);
+
+    gwbuf_free(pStatement);
+}
+
+} // mock
+
+} // maxscale