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Diffstat (limited to 'lib/libdevdctl/consumer.h')
| -rw-r--r-- | lib/libdevdctl/consumer.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/lib/libdevdctl/consumer.h b/lib/libdevdctl/consumer.h new file mode 100644 index 0000000..0f15b79 --- /dev/null +++ b/lib/libdevdctl/consumer.h @@ -0,0 +1,174 @@ +/*- + * Copyright (c) 2011, 2012, 2013, 2014 Spectra Logic Corporation + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. Redistributions in binary form must reproduce at minimum a disclaimer + * substantially similar to the "NO WARRANTY" disclaimer below + * ("Disclaimer") and any redistribution must be conditioned upon + * including a substantially similar Disclaimer requirement for further + * binary redistribution. + * + * NO WARRANTY + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGES. + * + * Authors: Justin T. Gibbs (Spectra Logic Corporation) + * + * $FreeBSD$ + */ + +/** + * \file devdctl_consumer.h + */ +#ifndef _DEVDCTL_CONSUMER_H_ +#define _DEVDCTL_CONSUMER_H_ + +/*============================ Namespace Control =============================*/ +namespace DevdCtl +{ + +/*=========================== Forward Declarations ===========================*/ +class Event; + +/*============================ Class Declarations ============================*/ +/*----------------------------- DevdCtl::Consumer ----------------------------*/ + +/** + */ +class Consumer +{ +public: + Consumer(Event::BuildMethod *defBuilder = NULL, + EventFactory::Record *regEntries = NULL, + size_t numEntries = 0); + virtual ~Consumer(); + + bool Connected() const; + + /** + * Return file descriptor useful for client's wishing to poll(2) + * for new events. + */ + int GetPollFd(); + + /** + * Queue an event for deferred processing or replay. + */ + bool SaveEvent(const Event &event); + + /** + * Reprocess any events saved via the SaveEvent() facility. + * + * \param discardUnconsumed If true, events that are not consumed + * during replay are discarded. + */ + void ReplayUnconsumedEvents(bool discardUnconsumed); + + /** Return an event, if one is available. */ + Event *NextEvent(); + + /** + * Extract events and invoke each event's Process method. + */ + void ProcessEvents(); + + /** Discard all data pending in m_devdSockFD. */ + void FlushEvents(); + + /** + * Test for data pending in m_devdSockFD + * + * \return True if data is pending. Otherwise false. + */ + bool EventsPending(); + + /** + * Open a connection to devd's unix domain socket. + * + * \return True if the connection attempt is successsful. Otherwise + * false. + */ + bool ConnectToDevd(); + + /** + * Close a connection (if any) to devd's unix domain socket. + */ + void DisconnectFromDevd(); + + EventFactory GetFactory(); + +protected: + /** + * \brief Reads the most recent record + * + * On error, "" is returned, and errno will be set by the OS + * + * \returns A string containing the record + */ + std::string ReadEvent(); + + enum { + /* + * The maximum event size supported by libdevdctl. + */ + MAX_EVENT_SIZE = 8192, + }; + + static const char s_devdSockPath[]; + + /** + * File descriptor representing the unix domain socket + * connection with devd. + */ + int m_devdSockFD; + + EventFactory m_eventFactory; + + /** Queued events for replay. */ + EventList m_unconsumedEvents; + + /** + * Flag controlling whether events can be queued. This boolean + * is set during event replay to ensure that previosuly deferred + * events are not requeued and thus retained forever. + */ + bool m_replayingEvents; +}; + +//- Consumer Const Public Inline Methods --------------------------------------- +inline bool +Consumer::Connected() const +{ + return (m_devdSockFD != -1); +} + +//- Consumer Public Inline Methods --------------------------------------------- +inline int +Consumer::GetPollFd() +{ + return (m_devdSockFD); +} + +inline EventFactory +Consumer::GetFactory() +{ + return (m_eventFactory); +} + +} // namespace DevdCtl +#endif /* _DEVDCTL_CONSUMER_H_ */ |
