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PIPacketExtractor Class Reference

Packets extractor. More...

+ Inheritance diagram for PIPacketExtractor:

Public Member Functions

 PIPacketExtractor (PIIODevice *device_=0, SplitMode mode=None)
 Contructs extractor with child device "device_", header content pointer "recHeaderPtr", header size "recHeaderSize" and payload size "recDataSize".
 
PIIODevicedevice ()
 Returns child device.
 
void setDevice (PIIODevice *device_)
 Set child device to "device_".
 
int bufferSize () const
 Returns buffer size.
 
void setBufferSize (int new_size)
 Set buffer size to "new_size" bytes, should be at least greater than whole packet size.
 
ullong missedBytes () const
 Returns missed by validating functions bytes count.
 
ullong missedPackets () const
 Returns missed by validating functions packets count, = missedBytes() / packetSize.
 
const ullong * missedBytes_ptr () const
 Returns pointer to missedBytes() count. Useful for output to PIConsole.
 
const ullong * missedPackets_ptr () const
 Returns pointer to missedPackets() count. Useful for output to PIConsole.
 
PIByteArray lastHeader ()
 Returns last successfully validated header as byte array.
 
int read (void *read_to, int max_size)
 Directly call read() function of child device.
 
int write (const void *data, int max_size)
 Directly call write() function of child device.
 
PIString constructFullPath () const
 Reimplement to construct full unambiguous string, describes this device, default returns path()
 
- Public Member Functions inherited from PIIODevice
 PIIODevice ()
 Constructs a empty PIIODevice.
 
 PIIODevice (const PIString &path, DeviceMode mode=ReadWrite)
 Constructs a PIIODevice with path and mode. More...
 
DeviceMode mode () const
 Current open mode of device.
 
PIString path () const
 Current path of device.
 
void setPath (const PIString &path)
 Set path of device.
 
bool isReadable () const
 Return true if mode is ReadOnly or ReadWrite.
 
bool isWriteable () const
 Return true if mode is WriteOnly or ReadWrite.
 
bool isOpened () const
 Return true if device is successfully opened.
 
bool isClosed () const
 Return true if device is closed.
 
bool canRead () const
 Return true if device can read now.
 
bool canWrite () const
 Return true if device can write now.
 
void setReopenEnabled (bool yes=true)
 Set execution of open enabled while threaded read on closed device.
 
void setReopenTimeout (int msecs)
 Set timeout in milliseconds between open tryings if reopen is enabled.
 
bool isReopenEnabled () const
 Return reopen enable.
 
int reopenTimeout ()
 Return reopen timeout.
 
void setThreadedReadSlot (ReadRetFunc func)
 Set "threaded read slot". More...
 
void setThreadedReadData (void *d)
 Set custom data that will be passed to "threaded read slot".
 
void setThreadedReadBufferSize (int new_size)
 Set size of threaded read buffer. More...
 
int threadedReadBufferSize () const
 Return size of threaded read buffer.
 
const uchar * threadedReadBuffer () const
 Return content of threaded read buffer.
 
void * threadedReadData () const
 Return custom data that will be passed to "threaded read slot".
 
bool isThreadedRead () const
 Return true if threaded read is started.
 
void startThreadedRead ()
 Start threaded read.
 
void startThreadedRead (ReadRetFunc func)
 Start threaded read and assign "threaded read slot" to "func".
 
void stopThreadedRead ()
 Stop threaded read.
 
bool isThreadedWrite () const
 Return true if threaded write is started.
 
void startThreadedWrite ()
 Start threaded write.
 
void stopThreadedWrite ()
 Stop threaded write.
 
void clearThreadedWriteQueue ()
 Clear threaded write task queue.
 
void start ()
 Start both threaded read and threaded write.
 
void stop (bool wait=false)
 Stop both threaded read and threaded write and if "wait" block until both threads are stop.
 
PIByteArray read (int max_size)
 Read from device maximum "max_size" bytes and return them as PIByteArray.
 
PIByteArray readForTime (double timeout_ms)
 Read from device for "timeout_ms" milliseconds and return readed data as PIByteArray. Timeout should to be greater than 0.
 
int write (const PIByteArray &data)
 Write "data" to device.
 
ullong writeThreaded (const void *data, int max_size)
 Add task to threaded write queue and return task ID.
 
ullong writeThreaded (const PIByteArray &data)
 Add task to threaded write queue and return task ID.
 
bool configure (const PIString &config_file, const PIString &section, bool parent_section=false)
 Configure device from section "section" of file "config_file", if "parent_section" parent section also will be read.
 
bool open ()
 Open device.
 
bool open (const PIString &_path)
 Open device with path "path".
 
bool open (const DeviceMode &_mode)
 Open device with mode "mode".
 
bool open (const PIString &_path, const DeviceMode &_mode)
 Open device with path "path" and mode "mode".
 
bool close ()
 Close device.
 
bool initialize ()
 Initialize device.
 
virtual void flush ()
 Immediate write all buffers.
 
void opened ()
 Raise if succesfull open.
 
void closed ()
 Raise if succesfull close.
 
void threadedReadEvent (uchar *readed, int size)
 Raise if read thread succesfull read some data.
 
void threadedWriteEvent (ullong id, int written_size)
 Raise if write thread succesfull write some data of task with ID "id".
 
- Public Member Functions inherited from PIThread
 PIThread (void *data, ThreadFunc func, bool startNow=false, int timer_delay=-1)
 Contructs thread with custom data "data", external function "func" and main cycle delay "timer_delay".
 
 PIThread (bool startNow=false, int timer_delay=-1)
 Contructs thread with main cycle delay "timer_delay".
 
void setData (void *d)
 Set common data passed to external function.
 
void setSlot (ThreadFunc func)
 Set external function that will be executed after every run()
 
void setPriority (PIThread::Priority prior)
 Set priority of thread.
 
PIThread::Priority priority () const
 Return priority of thread.
 
bool isRunning () const
 Return true if thread is running.
 
void needLockRun (bool need)
 Set necessity of lock every run with internal mutex.
 
PIMutexmutex ()
 Return internal mutex.
 
bool start (int timer_delay)
 Start thread. More...
 
bool start (ThreadFunc func, int timer_delay)
 Start thread. More...
 
bool startOnce ()
 Start thread without internal loop. More...
 
bool startOnce (ThreadFunc func)
 Start thread without internal loop. More...
 
void stop (bool wait)
 Stop thread. More...
 
void terminate ()
 Strongly stop thread. More...
 
bool waitForStart (int timeout_msecs)
 Wait for thread start. More...
 
bool waitForFinish (int timeout_msecs)
 Wait for thread finish. More...
 
void lock ()
 Lock internal mutex.
 
void unlock ()
 Unlock internal mutex.
 
void started ()
 Raise on thread start.
 
void stopped ()
 Raise on thread stop.
 
- Public Member Functions inherited from PIObject
 PIObject (const PIString &name=PIString())
 Contructs PIObject with name "name".
 
PIString name () const
 Returns object name.
 
virtual const char * className () const
 Returns object class name.
 
bool debug () const
 Return if debug of this object is active.
 
void setName (const PIString &name)
 Set object name.
 
void setDebug (bool debug)
 Set object debug active.
 
const PIMap< PIString,
PIVariant > & 
properties () const
 Returns properties of the object.
 
int propertiesCount () const
 Returns properties count of the object.
 
PIVariant property (const PIString &name) const
 Returns property with name "name".
 
void setProperty (const PIString &name, const PIVariant &value)
 Set property with name "name" to "value". If there is no such property in object it will be added.
 
bool isPropertyExists (const PIString &name) const
 Returns if property with name "name" exists.
 

Protected Member Functions

virtual bool validateHeader (uchar *src, uchar *rec, int size)
 Function to validate header. More...
 
virtual bool validateFooter (uchar *src, uchar *rec, int size)
 Function to validate footer. More...
 
virtual bool validatePayload (uchar *rec, int size)
 Function to validate payload. More...
 
- Protected Member Functions inherited from PIIODevice
virtual bool init ()
 Function executed before first openDevice() or from constructor.
 
virtual bool configureDevice (const void *e_main, const void *e_parent=0)
 Reimplement to configure device from entries "e_main" and "e_parent", cast arguments to PIConfig::Entry*.
 
virtual bool closeDevice ()
 Reimplement to close device, inverse return value will be set to "opened_" variable.
 
virtual void configureFromFullPath (const PIString &full_path)
 Reimplement to configure your device with parameters of full unambiguous string. Default implementation does nothing.
 
- Protected Member Functions inherited from PIObject
PIObjectemitter () const
 Returns PIObject* which has raised an event. This value is correct only in definition of some event handler.
 

Events

void packetReceived (uchar *data, int size)
 Raise on successfull packetValidate() function.
 

Additional Inherited Members

- Public Types inherited from PIIODevice
enum  DeviceMode { ReadOnly = 0x01, WriteOnly = 0x02, ReadWrite = 0x03 }
 Open modes for PIIODevice. More...
 
- Public Types inherited from PIThread
enum  Priority {
  piHighest, piHigh, piNormal, piLow,
  piLowerst
}
 Priority of thread. More...
 
- Static Public Member Functions inherited from PIIODevice
static PIIODevicecreateFromFullPath (const PIString &full_path)
 Try to determine suitable device, create new one, configure it with configureFromFullPath() and returns it. More...
 
- Static Public Member Functions inherited from PIObject
static void piDisconnect (PIObject *src, const PIString &sig)
 Disconnect object "src" from all connections with event name "sig".
 
static void piDisconnect (PIObject *src)
 Disconnect object "src" from all connections, i.e. all connections where object "src" is emitter.
 
static PIObjectfindByName (const PIString &name)
 Returns PIObject* with name "name" or 0, if there is no object found.
 
- Public Attributes inherited from PIIODevice
bool reopenEnabled
 setReopenEnabled, default "true"
 
int reopenTimeout
 setReopenTimeout in ms, default 1000
 
int threadedReadBufferSize
 setThreadedReadBufferSize in bytes, default 4096
 

Detailed Description

Packets extractor.

Synopsis

This class implements packet recognition by header and custom validating algorithm from data stream. Stream is formed from child PIIODevice passed from contructor or with function setDevice().

Principle of work

PIPacketExtractor works with child PIIODevice. read and write functions directly call child device functions. You should start threaded read of extractor to proper work. Extractor read data from child device, form continuous buffer and analyze it.

Analysis

There is three parameters:

  • header content
  • header size
  • payload size

Extractor can detect packet with compare your header with readed data. It is default implementation of function packetHeaderValidate(). If header validating passed, function packetValidate() will be called. If either of this function return false extractor shifts by one byte and takes next header. If both functions returns true extractor shifts by whole packet size.

packet_detection.png

Variants

If header size = 0 and payload size = 0 there is no analysis will be done, and function packetValidate() anyway will be called immediately after successfully read from child device.
If header size = 0 but payload size != 0 extractor will be call function packetValidate() each payload size bytes.

Member Function Documentation

virtual bool PIPacketExtractor::validateHeader ( uchar *  src,
uchar *  rec,
int  size 
)
inlineprotectedvirtual

Function to validate header.

Parameters
srcYour header content
recReceived header
sizeHeader size

Default implementation returns by-byte "src" with "rec" compare result

virtual bool PIPacketExtractor::validateFooter ( uchar *  src,
uchar *  rec,
int  size 
)
inlineprotectedvirtual

Function to validate footer.

Parameters
srcYour footer content
recReceived footer
sizeFooter size

Default implementation returns by-byte "src" with "rec" compare result

virtual bool PIPacketExtractor::validatePayload ( uchar *  rec,
int  size 
)
inlineprotectedvirtual

Function to validate payload.

Parameters
recReceived payload
sizepayload size

Default implementation returns true