PIPacketExtractor Class Reference

Extracts packets from data produced by a child PIIODevice. The PIPacketExtractor class provides packet recognition from data stream using various algorithms. More...

#include <pipacketextractor.h>

Inheritance diagram for PIPacketExtractor:

Public Types
enum	SplitMode {   None , Header , Footer , HeaderAndFooter ,   Size , Timeout }
	Packet splitting modes. More...
Public Types inherited from PIIODevice
enum	DeviceMode { ReadOnly = 0x01 , WriteOnly = 0x02 , ReadWrite = 0x03 }
	Open modes for PIIODevice. More...
enum	DeviceOption { BlockingRead = 0x01 , BlockingWrite = 0x02 }
	Generic options supported by some devices. More...
enum	DeviceInfoFlag { Sequential = 0x01 , Reliable = 0x02 }
	Characteristics of the device channel. More...
typedef PIFlags< DeviceOption >	DeviceOptions
	Bitmask of DeviceOption values.
typedef PIFlags< DeviceInfoFlag >	DeviceInfoFlags
	Bitmask of DeviceInfoFlag values.

Public Member Functions
	PIPacketExtractor (PIIODevice *device_=nullptr, SplitMode mode=None)
	Constructs extractor bound to "device_" and configured with split mode "mode".
virtual	~PIPacketExtractor ()
	Stops extractor background activity and destroys the object.
PIIODevice *	device ()
	Returns the current child device.
void	setDevice (PIIODevice *device_)
	Replaces the child device with "device_".
ssize_t	bytesAvailable () const override
	Returns unread bytes currently available from the child device.
void	setHeaderCheckSlot (PacketExtractorHeaderFunc f)
	Sets custom header validation callback.
void	setPayloadCheckSlot (PacketExtractorPayloadFunc f)
	Sets custom payload validation callback.
void	setFooterCheckSlot (PacketExtractorFooterFunc f)
	Sets custom footer validation callback.
void	setSplitMode (SplitMode mode)
	Switches packet extraction to mode "mode".
void	setPayloadSize (int size)
	Sets fixed payload size used by the size-based extraction modes.
void	setHeader (const PIByteArray &data)
	Sets reference header bytes.
void	setFooter (const PIByteArray &data)
	Sets reference footer bytes.
void	setTimeout (PISystemTime tm)
	Sets accumulation timeout for Timeout mode.
SplitMode	splitMode () const
	Returns current packet splitting mode.
int	payloadSize () const
	Returns configured payload size.
PIByteArray	header () const
	Returns configured reference header.
PIByteArray	footer () const
	Returns configured reference footer.
PISystemTime	timeout () const
	Returns timeout used by Timeout mode.
ullong	missedBytes () const
	Returns number of bytes skipped during resynchronization.
void	appendData (const uchar *d, int s)
	Feeds raw bytes into the extractor. Emits packetReceived() when a complete packet is recognized.
void	appendData (const PIByteArray &data)
	Feeds byte-array data into the extractor. Emits packetReceived() when a complete packet is recognized.
Public Member Functions inherited from PIIODevice
	PIIODevice ()
	Constructs an empty PIIODevice.
	PIIODevice (const PIString &path, DeviceMode mode=ReadWrite)
	Constructs PIIODevice with path "path" and open mode "mode".
virtual	~PIIODevice ()
	Destroys the device base object.
DeviceMode	mode () const
	Returns current open mode.
void	setMode (DeviceMode m)
	Sets open mode without reopening the device.
DeviceOptions	options () const
	Returns current device options.
bool	isOptionSet (DeviceOption o) const
	Returns whether option "o" is enabled.
void	setOptions (DeviceOptions o)
	Replaces all current device options with "o".
bool	setOption (DeviceOption o, bool yes=true)
	Sets option "o" to "yes" and returns its previous state.
DeviceInfoFlags	infoFlags () const
	Returns device channel characteristics.
PIString	path () const
	Returns current device path.
void	setPath (const PIString &path)
	Sets device path without reopening the device.
bool	isReadable () const
	Returns whether the current mode allows reading.
bool	isWriteable () const
	Returns whether the current mode allows writing.
bool	isOpened () const
	Returns whether the device is currently opened.
bool	isClosed () const
	Returns whether the device is currently closed.
virtual bool	canRead () const
	Returns whether reading is possible right now.
virtual bool	canWrite () const
	Returns whether writing is possible right now.
void	setReopenEnabled (bool yes=true)
	Enables or disables automatic reopen attempts during threaded read.
void	setReopenTimeout (PISystemTime timeout)
	Sets delay between automatic reopen attempts.
bool	isReopenEnabled () const
	Returns whether automatic reopen is enabled.
PISystemTime	reopenTimeout ()
	Returns delay between automatic reopen attempts.
void	setThreadedReadSlot (ReadRetFunc func)
	Sets callback invoked after successful threaded reads. More...
void	setThreadedReadData (void *d)
	Sets custom user data passed to threaded read callback.
void	setThreadedReadBufferSize (int new_size)
	Sets background read buffer size in bytes. More...
int	threadedReadBufferSize () const
	Returns background read buffer size in bytes.
const uchar *	threadedReadBuffer () const
	Returns pointer to the internal threaded-read buffer.
void *	threadedReadData () const
	Returns custom data passed to threaded read callback.
bool	isThreadedRead () const
	Returns whether threaded read is running.
bool	isThreadedReadStopping () const
	Returns whether threaded read is stopping.
void	startThreadedRead ()
	Starts threaded read.
void	startThreadedRead (ReadRetFunc func)
	Sets threaded read callback to "func" and starts threaded read.
void	stopThreadedRead ()
	Requests threaded read stop.
void	terminateThreadedRead ()
	Terminate threaded read. More...
bool	waitThreadedReadFinished (PISystemTime timeout={})
	Waits until threaded read finishes or "timeout" expires.
uint	threadedReadTimeout () const
	Returns delay between unsuccessful threaded read attempts in milliseconds.
void	setThreadedReadTimeout (uint ms)
	Sets delay between unsuccessful threaded read attempts in milliseconds.
bool	isThreadedWrite () const
	Returns whether threaded write is running.
void	startThreadedWrite ()
	Starts threaded write.
void	stopThreadedWrite ()
	Requests threaded write stop.
void	terminateThreadedWrite ()
	Terminate threaded write. More...
bool	waitThreadedWriteFinished (PISystemTime timeout={})
	Waits until threaded write finishes or "timeout" expires.
void	clearThreadedWriteQueue ()
	Clears queued threaded-write tasks.
void	start ()
	Starts both threaded read and threaded write.
void	stop ()
	Requests stop for both threaded read and threaded write.
void	stopAndWait (PISystemTime timeout={})
	Stops both background threads and waits for completion.
virtual void	interrupt ()
	Interrupts a blocking device operation.
ssize_t	read (void *read_to, ssize_t max_size)
	Reads at most "max_size" bytes into "read_to".
ssize_t	read (PIMemoryBlock mb)
	Reads data into memory block "mb".
PIByteArray	read (ssize_t max_size)
	Reads at most "max_size" bytes and returns them as PIByteArray.
virtual ssize_t	bytesAvailable () const
	Returns the number of bytes that are available for reading. More...
ssize_t	write (const void *data, ssize_t max_size)
	Writes at most "max_size" bytes from "data".
PIByteArray	readForTime (PISystemTime timeout)
	Reads data for up to "timeout" and returns collected bytes.
ullong	writeThreaded (const void *data, ssize_t max_size)
	Queues "data" for threaded write and returns task ID.
ullong	writeThreaded (const PIByteArray &data)
	Queues byte array "data" for threaded write and returns task ID.
bool	configure (const PIString &config_file, const PIString &section, bool parent_section=false)
	Configures the device from section "section" of file "config_file". More...
virtual PIConstChars	fullPathPrefix () const
	Returns device prefix used in full-path notation. Creating devices by unambiguous string.
PIString	constructFullPath () const
	Returns full-path representation of this device, fullPathPrefix() + "://" + ...
void	configureFromFullPath (const PIString &full_path)
	Configures the device from full-path parameters.
PIVariantTypes::IODevice	constructVariant () const
	Builds PIVariantTypes::IODevice description for this device.
void	configureFromVariant (const PIVariantTypes::IODevice &d)
	Configures the device from PIVariantTypes::IODevice.
ssize_t	write (const PIMemoryBlock &mb)
	Writes memory block "mb" to the device.
bool	open ()
	Opens the device with current path and mode.
bool	open (const PIString &_path)
	Opens the device with path "path".
bool	open (DeviceMode _mode)
	Opens the device with mode "mode".
bool	open (const PIString &_path, DeviceMode _mode)
	Opens the device with path "path" and mode "mode".
bool	close ()
	Closes the device.
ssize_t	write (PIByteArray data)
	Writes "data" to the device.
virtual void	flush ()
	Immediately flushes device buffers.
void	opened ()
	Raised after successful opening.
void	closed ()
	Raised after successful closing.
void	threadedReadEvent (const uchar *readed, ssize_t size)
	Raised after threaded read receives some data.
void	threadedWriteEvent (ullong id, ssize_t written_size)
	Raised after threaded write processes task with ID "id".
Public Member Functions inherited from PIObject
	PIObject (const PIString &name=PIString())
	Constructs an object and initializes its name property.
virtual	~PIObject ()
	Destroys the object, raises deleted() and disconnects it from the event graph.
PIString	name () const
	Returns the name property of this object.
virtual const char *	className () const
	Returns the registered class name of this object.
virtual uint	classNameID () const
	Returns the hash of className().
virtual const char *	parentClassName () const
	Returns the registered parent class name, or an empty string for the root.
bool	debug () const
	Returns whether piCoutObj output is enabled for this object.
void	setName (const PIString &name)
	Sets the name property of this object.
void	setDebug (bool debug)
	Enables or disables piCoutObj output for this object.
PIVariant	property (const char *name) const
	Returns the property with name "name".
void	setProperty (const char *name, const PIVariant &value)
	Sets the property "name" to "value" and creates it if needed. More...
bool	isPropertyExists (const char *name) const
	Returns whether the property "name" exists.
void	setThreadSafe (bool yes)
	Enables or disables the internal object mutex during handler execution. More...
bool	isThreadSafe () const
	Returns whether the internal object mutex is enabled for handler execution.
bool	execute (const PIString &method, const PIVector< PIVariantSimple > &vl)
	Executes a registered method or handler method by name with the supplied arguments. More...
bool	execute (const PIString &method)
	Overload of execute() for a method without arguments.
bool	execute (const PIString &method, const PIVariantSimple &v0)
	Overload of execute() for one argument.
bool	execute (const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1)
	Overload of execute() for two arguments.
bool	execute (const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2)
	Overload of execute() for three arguments.
bool	execute (const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2, const PIVariantSimple &v3)
	Overload of execute() for four arguments.
bool	executeQueued (PIObject *performer, const PIString &method, const PIVector< PIVariantSimple > &vl)
	Queues execution of a registered method on the performer object. More...
bool	executeQueued (PIObject *performer, const PIString &method)
	Overload of executeQueued() for a method without arguments.
bool	executeQueued (PIObject *performer, const PIString &method, const PIVariantSimple &v0)
	Overload of executeQueued() for one argument.
bool	executeQueued (PIObject *performer, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1)
	Overload of executeQueued() for two arguments.
bool	executeQueued (PIObject *performer, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2)
	Overload of executeQueued() for three arguments.
bool	executeQueued (PIObject *performer, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2, const PIVariantSimple &v3)
	Overload of executeQueued() for four arguments.
void	dump (const PIString &line_prefix=PIString()) const
	Dumps object diagnostics to the project output stream.
PIStringList	scopeList () const
	Returns the registered inheritance scope of this object, including its own class.
PIStringList	methodsEH () const
	Returns full signatures of all registered event and handler methods for this class scope.
bool	isMethodEHContains (const PIString &name) const
	Returns whether a registered event or handler method with this name exists.
PIString	methodEHArguments (const PIString &name) const
	Returns the comma-separated argument type list of a registered method.
PIString	methodEHFullFormat (const PIString &name) const
	Returns the full registered signature of a method.
PIString	methodEHFromAddr (const void *addr) const
	Returns the registered method name for the specified entry-point address.
void	piDisconnect (const PIString &sig, PIObject *dest, void *ev_h)
	Disconnects this source object from a specific destination handler for event "sig".
void	piDisconnect (const PIString &sig, PIObject *dest)
	Disconnects this source object from all connections of event "sig" to destination object "dest".
void	piDisconnect (const PIString &sig)
	Disconnects this source object from all connections of event "sig".
bool	isPIObject () const
	Returns whether this pointer still refers to a live PIObject instance.
template<typename T >
bool	isTypeOf () const
	Returns whether this object belongs to class "T" or one of its registered descendants.
template<typename T >
T *	cast () const
	Returns this object cast to "T" when isTypeOf<T>() succeeds, otherwise nullptr.
void	callQueuedEvents ()
	Executes all queued deliveries posted to this performer object.
bool	maybeCallQueuedEvents ()
	Executes queued deliveries only when this object was used as a performer. More...
void	deleteLater ()
	Schedules the object for deferred deletion. More...
void	deleted (PIObject *o)
	Raised immediately before object destruction. More...

Protected Member Functions
virtual int	validateHeader (const uchar *src, const uchar *rec, int size)
	Validates packet header and optionally returns payload size. More...
virtual bool	validateFooter (const uchar *src, const uchar *rec, int size)
	Validates packet footer. The default implementation compares "src" and "rec" byte by byte.
virtual bool	validatePayload (const uchar *rec, int size)
	Validates packet payload. The default implementation accepts any payload.
Protected Member Functions inherited from PIIODevice
virtual bool	configureDevice (const void *e_main, const void *e_parent=0)
	Reimplement to configure the device from "e_main" and optional "e_parent" entries cast to PIConfig::Entry*.
virtual bool	openDevice ()=0
	Reimplement to open device, return value will be set to "opened_" variable. Don't call this function in subclass, use open()!
virtual bool	closeDevice ()
	Reimplement to close the device; inverse return value is stored into "opened_".
virtual ssize_t	readDevice (void *read_to, ssize_t max_size)
	Reimplement this function to read from your device.
virtual ssize_t	writeDevice (const void *data, ssize_t max_size)
	Reimplement this function to write to your device.
virtual bool	threadedRead (const uchar *readed, ssize_t size)
	Called after threaded read receives data; default implementation calls the external callback set by setThreadedReadSlot().
virtual PIString	constructFullPathDevice () const
	Reimplement to build device-specific part of full-path string. Default implementation returns path().
virtual void	configureFromFullPathDevice (const PIString &full_path)
	Reimplement to configure the device from device-specific full-path parameters. Default implementation calls setPath().
virtual PIPropertyStorage	constructVariantDevice () const
	Reimplement to build device-specific variant properties. Default implementation returns PIPropertyStorage with "path".
virtual void	configureFromVariantDevice (const PIPropertyStorage &d)
	Reimplement to configure the device from PIPropertyStorage. Mode and options are already applied. Default implementation applies "path".
virtual void	optionsChanged ()
	Reimplement to react to changed device options.
virtual DeviceInfoFlags	deviceInfoFlags () const
	Reimplement to report actual DeviceInfoFlags. Default implementation returns 0.
virtual void	threadedReadBufferSizeChanged ()
	Reimplement to react to new threadedReadBufferSize().
Protected Member Functions inherited from PIObject
PIObject *	emitter () const
	Returns the source object that raised the current event. More...
virtual void	propertyChanged (const char *name)
	Virtual method called after property "name" has been changed by setProperty().

Events
void	packetReceived (const uchar *data, int size)
	Emitted when the current input chunk passes the configured extraction rules.

Additional Inherited Members
Static Public Member Functions inherited from PIIODevice
static PIIODevice *	createFromFullPath (const PIString &full_path)
	Try to create new device by prefix, configure it with configureFromFullPath() and returns it. More...
static PIIODevice *	createFromVariant (const PIVariantTypes::IODevice &d)
	Try to create new device by prefix, configure it with configureFromVariant() and returns it.
static PIString	normalizeFullPath (const PIString &full_path)
	Returns normalized full-path representation for "full_path".
static void	splitFullPath (PIString fpwm, PIString *full_path, DeviceMode *mode=0, DeviceOptions *opts=0)
	Splits full-path string into path, mode and options.
static PIStringList	availablePrefixes ()
	Returns fullPath prefixes of all registered devices.
static PIStringList	availableClasses ()
	Returns class names of all registered devices.
Static Public Member Functions inherited from PIObject
static bool	execute (PIObject *o, const PIString &method, const PIVector< PIVariantSimple > &vl)
	Static convenience wrapper for execute().
static bool	execute (PIObject *o, const PIString &method)
	Static overload of execute() without arguments.
static bool	execute (PIObject *o, const PIString &method, const PIVariantSimple &v0)
	Static overload of execute() for one argument.
static bool	execute (PIObject *o, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1)
	Static overload of execute() for two arguments.
static bool	execute (PIObject *o, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2)
	Static overload of execute() for three arguments.
static bool	execute (PIObject *o, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2, const PIVariantSimple &v3)
	Static overload of execute() for four arguments.
static bool	executeQueued (PIObject *o, PIObject *performer, const PIString &method, const PIVector< PIVariantSimple > &vl)
	Static convenience wrapper for executeQueued().
static bool	executeQueued (PIObject *o, PIObject *performer, const PIString &method)
	Static overload of executeQueued() without arguments.
static bool	executeQueued (PIObject *o, PIObject *performer, const PIString &method, const PIVariantSimple &v0)
	Static overload of executeQueued() for one argument.
static bool	executeQueued (PIObject *o, PIObject *performer, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1)
	Static overload of executeQueued() for two arguments.
static bool	executeQueued (PIObject *o, PIObject *performer, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2)
	Static overload of executeQueued() for three arguments.
static bool	executeQueued (PIObject *o, PIObject *performer, const PIString &method, const PIVariantSimple &v0, const PIVariantSimple &v1, const PIVariantSimple &v2, const PIVariantSimple &v3)
	Static overload of executeQueued() for four arguments.
static PIObject::Connection	piConnect (PIObject *src, const PIString &sig, PIObject *dest_o, void *dest, void *ev_h, void *e_h, int args, const char *loc)
	Low-level direct connection helper behind the legacy CONNECT* macros.
static PIObject::Connection	piConnectU (PIObject *src, const PIString &sig, PIObject *dest_o, void *dest, const PIString &hname, const char *loc, PIObject *performer=0)
	Low-level name-based connection helper behind CONNECTU() and CONNECTU_QUEUED().
static PIObject::Connection	piConnectLS (PIObject *src, const PIString &sig, std::function< void()> *f, const char *loc)
	Low-level helper that connects an event to a lambda or functor wrapper.
static void	piDisconnect (PIObject *src, const PIString &sig, PIObject *dest, void *ev_h)
	Disconnects source object "src" from a specific destination handler for event "sig".
static void	piDisconnect (PIObject *src, const PIString &sig, PIObject *dest)
	Disconnects source object "src" from all connections of event "sig" to destination object "dest".
static void	piDisconnect (PIObject *src, const PIString &sig)
	Disconnects source object "src" from all connections of event "sig".
static void	raiseEvent (PIObject *sender, const uint eventID)
	Internal event delivery helper for registered events without arguments.
template<typename T0 >
static void	raiseEvent (PIObject *sender, const uint eventID, const T0 &v0=T0())
	Internal event delivery helper for registered events with one argument.
template<typename T0 , typename T1 >
static void	raiseEvent (PIObject *sender, const uint eventID, const T0 &v0=T0(), const T1 &v1=T1())
	Internal event delivery helper for registered events with two arguments.
template<typename T0 , typename T1 , typename T2 >
static void	raiseEvent (PIObject *sender, const uint eventID, const T0 &v0=T0(), const T1 &v1=T1(), const T2 &v2=T2())
	Internal event delivery helper for registered events with three arguments.
template<typename T0 , typename T1 , typename T2 , typename T3 >
static void	raiseEvent (PIObject *sender, const uint eventID, const T0 &v0=T0(), const T1 &v1=T1(), const T2 &v2=T2(), const T3 &v3=T3())
	Internal event delivery helper for registered events with four arguments.
static PIObject *	findByName (const PIString &name)
	Returns the first live object with name "name", or nullptr.
static bool	isPIObject (const PIObject *o)
	Returns whether "o" points to a live PIObject instance.
static bool	isPIObject (const void *o)
	Overload of isPIObject() for an untyped pointer.
template<typename T >
static bool	isTypeOf (const PIObject *o)
	Returns whether "o" belongs to class "T" or one of its registered descendants.
template<typename T >
static bool	isTypeOf (const void *o)
	Overload of isTypeOf() for an untyped pointer.
static PIString	simplifyType (const char *a, bool readable=true)
	Simplifies a C++ type spelling for registered-method metadata.
Public Attributes inherited from PIIODevice
bool	reopenEnabled
	setReopenEnabled, default "true".
int	reopenTimeout
	setReopenTimeout, default 1_s.
int	threadedReadBufferSize
	setThreadedReadBufferSize in bytes, default 4096.
Related Functions inherited from PIIODevice
template<typename T >
T	readDeviceSetting (const PIString &name, const T &def, const PIConfig::Entry *em, const PIConfig::Entry *ep)
	Helper for reading device settings from configuration entries. More...
#define	REGISTER_DEVICE(class)
	Enable device instances creation with PIIODevice::createFromFullPath() function. More...
#define	PIIODEVICE(class, prefix)
	Use this macro instead of PIOBJECT when describe your own PIIODevice. More...
Related Functions inherited from PIObject
#define	piCoutObj
	Macro used for conditional (piDebug && PIObject::debug()) output to PICout(StdOut) for subclasses of PIObject.
#define	piCerrObj
	Macro used for conditional (piDebug && PIObject::debug()) output to PICout(StdErr) for subclasses of PIObject.
#define	PIOBJECT(name)
	Put this macro inside a direct PIObject subclass definition to enable registered events, event handlers and class metadata.
#define	PIOBJECT_SUBCLASS(name, parent)
	Put this macro inside a PIObject subclass definition to inherit registered methods and class scope from "parent".
#define	EVENT_HANDLER0(ret, name)   ret name()
	Declare a registered event handler method with signature ret name().
#define	EVENT_HANDLER1(ret, name, type0, var0)   ret name(type0 var0)
	Declare a registered event handler method with one argument.
#define	EVENT_HANDLER2(ret, name, type0, var0, type1, var1)   ret name(type0 var0, type1 var1)
	Declare a registered event handler method with two arguments.
#define	EVENT_HANDLER3(ret, name, type0, var0, type1, var1, type2, var2)   ret name(type0 var0, type1 var1, type2 var2)
	Declare a registered event handler method with three arguments.
#define	EVENT_HANDLER4(ret, name, type0, var0, type1, var1, type2, var2, type3, var3)    ret name(type0 var0, type1 var1, type2 var2, type3 var3)
	Declare a registered event handler method with four arguments.
#define	EVENT_HANDLER   EVENT_HANDLER0
	Synonym of EVENT_HANDLER0.
#define	EVENT_VHANDLER0(ret, name)   virtual ret name()
	Declare a virtual registered event handler method with signature virtual ret name().
#define	EVENT_VHANDLER1(ret, name, type0, var0)   virtual ret name(type0 var0)
	Declare a virtual registered event handler method with one argument.
#define	EVENT_VHANDLER2(ret, name, type0, var0, type1, var1)   virtual ret name(type0 var0, type1 var1)
	Declare a virtual registered event handler method with two arguments.
#define	EVENT_VHANDLER3(ret, name, type0, var0, type1, var1, type2, var2)   virtual ret name(type0 var0, type1 var1, type2 var2)
	Declare a virtual registered event handler method with three arguments.
#define	EVENT_VHANDLER4(ret, name, type0, var0, type1, var1, type2, var2, type3, var3)    virtual ret name(type0 var0, type1 var1, type2 var2, type3 var3)
	Declare a virtual registered event handler method with four arguments.
#define	EVENT_VHANDLER   EVENT_VHANDLER0
	Synonym of EVENT_VHANDLER0.
#define	EVENT0(name)   void name();
	Declare an event method with no arguments.
#define	EVENT1(name, type0, var0)   void name(type0 var0);
	Declare an event method with one argument.
#define	EVENT2(name, type0, var0, type1, var1)   void name(type0 var0, type1 var1);
	Declare an event method with two arguments.
#define	EVENT3(name, type0, var0, type1, var1, type2, var2)   void name(type0 var0, type1 var1, type2 var2);
	Declare an event method with three arguments.
#define	EVENT4(name, type0, var0, type1, var1, type2, var2, type3, var3)   void name(type0 var0, type1 var1, type2 var2, type3 var3);
	Declare an event method with four arguments.
#define	EVENT   EVENT0
	Synonym of EVENT0.
#define	RAISE_EVENT0(src, event)
	Compatibility helper that raises event "event" on source object "src".
#define	RAISE_EVENT1(src, event, v0)
	Compatibility helper that raises event "event" with one argument.
#define	RAISE_EVENT2(src, event, v0, v1)
	Compatibility helper that raises event "event" with two arguments.
#define	RAISE_EVENT3(src, event, v0, v1, v2)
	Compatibility helper that raises event "event" with three arguments.
#define	RAISE_EVENT4(src, event, v0, v1, v2, v3)
	Compatibility helper that raises event "event" with four arguments.
#define	CONNECTU(src, event, dest, handler)
	Connect event "event" from object "src" to event handler or event "handler" of object "dest". More...
#define	CONNECTU_QUEUED(src, event, dest, handler, performer)
	Connect event "event" from object "src" to event handler or event "handler" of object "dest". More...
#define	CONNECTL(src, event, functor)
	Connect event "event" from object "src" to lambda-expression "functor". More...
#define	CONNECT0(ret, src, event, dest, handler)
	Legacy compatibility helper that connects an event to a registered handler with compile-time signature spelling. More...
#define	CONNECT1(ret, type0, src, event, dest, handler)
	Legacy compatibility helper for a one-argument registered event or handler. More...
#define	CONNECT2(ret, type0, type1, src, event, dest, handler)
	Legacy compatibility helper for a two-argument registered event or handler. More...
#define	CONNECT3(ret, type0, type1, type2, src, event, dest, handler)
	Legacy compatibility helper for a three-argument registered event or handler. More...
#define	CONNECT4(ret, type0, type1, type2, type3, src, event, dest, handler)
	Legacy compatibility helper for a four-argument registered event or handler. More...
#define	CONNECT   CONNECT0
	Synonym of CONNECT0. More...
#define	WEAK_CONNECT0(ret, src, event, dest, handler)
	Legacy compatibility helper that skips source method verification. More...
#define	WEAK_CONNECT1(ret, type0, src, event, dest, handler)
	Legacy compatibility helper that skips source method verification for one argument. More...
#define	WEAK_CONNECT2(ret, type0, type1, src, event, dest, handler)
	Legacy compatibility helper that skips source method verification for two arguments. More...
#define	WEAK_CONNECT3(ret, type0, type1, type2, src, event, dest, handler)
	Legacy compatibility helper that skips source method verification for three arguments. More...
#define	WEAK_CONNECT4(ret, type0, type1, type2, type3, src, event, dest, handler)
	Legacy compatibility helper that skips source method verification for four arguments. More...
#define	WEAK_CONNECT   WEAK_CONNECT0
	Synonym of WEAK_CONNECT0. More...
#define	DISCONNECT0(ret, src, event, dest, handler)
	Disconnect a registered event from a registered event handler.
#define	DISCONNECT1(ret, type0, src, event, dest, handler)
	Disconnect a one-argument registered event from a registered event handler.
#define	DISCONNECT2(ret, type0, type1, src, event, dest, handler)
	Disconnect a two-argument registered event from a registered event handler.
#define	DISCONNECT3(ret, type0, type1, type2, src, event, dest, handler)
	Disconnect a three-argument registered event from a registered event handler.
#define	DISCONNECT4(ret, type0, type1, type2, type3, src, event, dest, handler)
	Disconnect a four-argument registered event from a registered event handler.
#define	DISCONNECT   DISCONNECT0
	Synonym of DISCONNECT0.
#define	HANDLER(handler)
	Low-level helper that expands to the registered handler entry point.

Detailed Description

Extracts packets from data produced by a child PIIODevice. The PIPacketExtractor class provides packet recognition from data stream using various algorithms.

Packets extractor.

Synopsis

This class implements packet recognition by various algorithms and custom validating 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 (not child device) to proper work. Extractor read data from child device, try to detect packet from readed data and raise packetReceived() event on success.

Algorithms

There are 6 algorithms:

• PIPacketExtractor::None
  Packet is successfully received on every read without any validation.
  
  
• PIPacketExtractor::Header
  Wait for at least header() bytes + payloadSize(), then validate header with virtual function validateHeader() and if it fail, shifts for next 1 byte. If header is successfully validated check payload with function validatePayload() and if it fail, shifts for next 1 byte. If all validations were successful raise packetReceived() event.
  
  
• PIPacketExtractor::Footer
  This algorithm similar to previous, but instead of header() first validate footer() at after payloadSize() bytes with function validateFooter().
  
  
• PIPacketExtractor::HeaderAndFooter
  Wait for at least header() bytes + footer() bytes, then validate header with virtual function validateHeader() and if it fail, shifts for next 1 byte. If header is successfully validated check footer with function validateFooter() and if it fail, shifts footer position for next 1 byte. Then validate payload and if it fail, search header again, starts from next byte of previous header. If all validations were successful raise packetReceived() event.
  
  
• PIPacketExtractor::Size
  Wait for at least packetSize() bytes, then validate packet with function validatePayload() and if it fail, shifts for next 1 byte. If validating was successfull raise packetReceived() event.
  
  
• PIPacketExtractor::Timeout
  Wait for first read, then read for timeout() milliseconds and raise packetReceived() event.
  

Control validating

There are 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.

Member Enumeration Documentation

SplitMode

enum PIPacketExtractor::SplitMode

Packet splitting modes.

Enumerator
None	Accept every read chunk as a packet
Header	Search for header() and use configured payload size or callback result
Footer	Use fixed payload size and validate trailing footer()
HeaderAndFooter	Search for packets bounded by header() and footer()
Size	Treat payloadSize() as full packet size
Timeout	Collect bytes until timeout() expires after the first read

Member Function Documentation

validateHeader()

int PIPacketExtractor::validateHeader ( const uchar *  src, const uchar *  rec, int  size  )

protectedvirtual

Validates packet header and optionally returns payload size.

The default implementation compares "src" and "rec" byte by byte and returns the configured payloadSize() on success.