#include <das2/packet.h>

Inheritance diagram for PktDesc:

Detailed Description

Holds information for a single packet type in a Das2 stream.

A Das2 Stream may consist of up to 99 different types of packets. In the following Das2 Stream snippet two different types of packets are defined:

* [00]000234<stream>
*   <properties xMonotonic="true" xLabel="Time (s)" yLabel="Frequency (s!U-1!N)"
*               zLabel="Electric Field (V m!U-1!N)" title="Voyager 1 PWS SA"
*               Datum:xTagWidth="256.0 s" double:zFill="0.0" />
* </stream>
* 

* [01]000201<packet>
*   <x type="time24" units="us2000" ></x>
*   <yscan name="averages" nitems="5" type="ascii9" yUnits="Hz" zUnits="V/m" 
*          yTags="10.0,17.8,31.1,56.2,100.0">
*     <properties zSummary="Average value within the interval"/>
*   </yscan>
* </packet>
* 

* [02]000201<packet>
*   <x type="time24" units="us2000" ></x>
*   <yscan name="peaks" nitems="5" type="ascii9" yUnits="Hz" zUnits="V/m" 
*          yTags="10.0,17.8,31.1,56.2,100.0">
*     <properties zSummary="Peak value within the interval"/>
*   </yscan>
* </packet>
* 

* :01:2012-01-01T12:56:22.792 1.91e-06 8.92e-07 7.80e-07 6.04e-07 2.43e-07
* :02:2012-01-01T12:56:22.792 3.12e-06 4.10e-06 2.47e-06 1.42e-06 9.36e-07 
* :01:2012-01-01T13:00:38.792 1.98e-06 4.63e-07 7.64e-07 7.56e-07 5.09e-07 
* :02:2012-01-01T13:00:38.792 2.91e-06 1.46e-06 2.97e-06 1.42e-06 1.55e-06 
* 

Each <packet> element above is a serialized PacketDescriptor. This structure and it's associated functions are responsible for:

Holding the definition of a single packet type within the stream
Writing data values onto the stream
Serializing data values from a stream

To help them do their jobs, PacketDescriptors hold and array of PlaneDescriptors, as well a byte field containing up to one data packet's worth of bytes.

Creating Packet Descriptors

Packet Descriptors are part of a Das2 Stream. To define a new packet type call:

* createPacketDescriptor(StreamDesc* sd, DataType xDataType, UnitType xUnits)

*

or a similar function. This particular version creates a PacketDescriptor that only has an <x> plane. Using the following to add <y> and/or <yscan> planes to the packet.

*   addPlaneY()
*   addPlaneYScan()
* 

Optionally additions properties such as labels may be added to each <y> or <yscan> plane using:

* setPropertyString()

*

and related functions.

When reading Das2 Streams PacketDescriptors are created automatically as the input is read by the processStream() method of the StreamHandler.

Emitting Packet Data

The PacketDiscriptor has a 1-Packet wide buffer. This buffer is used to build up the output data for a single packet. To set the value for the various planes use:

* setDataPacketDouble()       // For <x> and <y> planes
* setDataPacketYScanDouble()  // For <yscan> planes
* 

and related functions. Once that job is complete, transmit the data packet using:

* sendPacket()

*

The details of encoding the data according the format stored in the packet descriptor are handled by the library.

Reading Data

Public Member Functions
PktDesc *	new_PktDesc (void)
	Creates a packet descriptor with the default settings. More...

PktDesc *	new_PktDesc_xml (DasBuf pBuf, DasDesc pParent, int nPktId)
	Create a PktDesc from XML data. More...

int	PktDesc_getId (const PktDesc *pThis)
	Get the packet ID for this packet. More...

const char *	PktDesc_getGroup (const PktDesc *pThis)
	Get the data group for this packet. More...

void	PktDesc_setGroup (PktDesc pThis, const char sGroup)
	Set the data group for this packet. More...

size_t	PktDesc_recBytes (const PktDesc *pThis)
	Get the size of data records defined by a packet descriptor. More...

size_t	PktDesc_getNPlanes (const PktDesc *pThis)
	Get the number of planes in this type of packet. More...

size_t	PktDesc_getNPlanesOfType (const PktDesc *pThis, plane_type_t pt)
	Get the number of planes of a particular type in a packet. More...

int	PktDesc_addPlane (PktDesc pThis, PlaneDesc pPlane)
	Add a plane to a packet. More...

DasErrCode	PktDesc_copyPlanes (PktDesc pThis, const PktDesc pOther)
	Copy in all planes from another a packet descriptor. More...

bool	PktDesc_validate (PktDesc *pThis)
	Check to see if a legal plane layout is present. More...

plane_type_t	PktDesc_getPlaneType (const PktDesc *pThis, int iPlane)
	Determine the type of plane by index. More...

PlaneDesc *	PktDesc_getPlane (PktDesc *pThis, int iplane)
	returns the PlaneDescriptor for plane number iplane This can be used to query properties of the plane, such as units and the name. More...

int	PktDesc_getPlaneIdxByType (const PktDesc *pThis, plane_type_t ptype, int iRelIndex)
	Gets the Nth plane of a given type. More...

int	PktDesc_getPlaneIdxByName (PktDesc pThis, const char name, plane_type_t planeType)
	returns the plane number for the named plane. More...

PlaneDesc *	PktDesc_getXPlane (PktDesc *pThis)
	returns the PlaneDescriptor for the 1st X Tag plane.

DasErrCode	PktDesc_encode (const PktDesc pThis, DasBuf pBuf)
	Serialize a packet descriptor as XML data. More...

DasErrCode	PktDesc_encodeData (const PktDesc pThis, DasBuf pBuf)
	Serialize a packet's current data In addition to holding the format information for Das2 Stream packets PktDesc objects also hold a a single packet's worth of data. More...

DasErrCode	PktDesc_decodeData (PktDesc pThis, DasBuf pBuf)
	Decode 1 packet's worth of data from a buffer. More...

DasErrCode	PktDesc_setValue (PktDesc *pThis, size_t uPlane, size_t uItem, double val)
	Convenience function for setting a single value in a plane This is just a shortcut for: More...

DasErrCode	PktDesc_setValues (PktDesc pThis, size_t uPlane, const double pVals)
	Convenience function for setting an array of values in a plane This is just a shortcut for: More...

Data Fields
void *	pUser
	User data pointer. More...

Descriptor Functions
These work for any type of Descriptor, including PlaneDesc , PktDesc, StreamDesc, DasDs and DasVar. To make your compiler happy you will need to cast Plane, Packet and Stream Descriptor pointers to just the generic type of Descriptor pointer when using these functions. For example: * PktDesc* pPktDesc; * hasProperty((Descriptor)pPktDesc, "SomePropName"); DasDesc
bool	DasDesc_equals (const DasDesc pOne, const DasDesc pTwo)
	Check to see if two descriptors contain the same properties Note, the order of the properties may be different between the descriptors but if the contents are the same then the descriptors are considered to be equal. More...

const DasDesc *	DasDesc_parent (DasDesc *pThis)
	The the parent of a Descriptor. More...

size_t	DasDesc_length (const DasDesc *pThis)
	Get the number of properties in a descriptor. More...

const char *	DasDesc_getNameByIdx (const DasDesc *pThis, size_t uIdx)
	Get a property name by an index. More...

const char *	DasDesc_getValByIdx (const DasDesc *pThis, size_t uIdx)
	Get a property value by an index. More...

const char *	DasDesc_getTypeByIdx (const DasDesc *pThis, size_t uIdx)
	Get a data type of a property by an index.

bool	DasDesc_has (const DasDesc pThis, const char propertyName)
	Determine if a property is present in a Descriptor or it's ancestors. More...

DasErrCode	DasDesc_set (DasDesc pThis, const char sType, const char sName, const char sVal)
	Generic property setter. More...

bool	DasDesc_remove (DasDesc pThis, const char propretyName)
	Remove a property from a descriptor, if preset. More...

const char *	DasDesc_getStr (const DasDesc pThis, const char propertyName)
	read the property of type String named propertyName.

DasErrCode	DasDesc_setStr (DasDesc pThis, const char sName, const char *sVal)
	SetProperty methods add properties to any Descriptor (stream,packet,plane). More...

DasErrCode	DasDesc_vSetStr (DasDesc pThis, const char sName, const char *sFmt,...)
	Set a string property in the manner of sprintf.

double	DasDesc_getDouble (const DasDesc pThis, const char propertyName)
	Read the property of type double named propertyName. More...

DasErrCode	DasDesc_setDouble (DasDesc pThis, const char propertyName, double value)
	Set property of type double.

double	DasDesc_getDatum (DasDesc pThis, const char sPropName, das_units units)
	Get the a numeric property in the specified units. More...

DasErrCode	DasDesc_setDatum (DasDesc pThis, const char sName, double rVal, das_units units)
	Set property of type Datum (double, UnitType pair) More...

double *	DasDesc_getDoubleAry (DasDesc pThis, const char propertyName, int *nitems)
	Get the values of an array property. More...

DasErrCode	DasDesc_setDoubleArray (DasDesc pThis, const char propertyName, int nitems, double *value)
	Set the property of type double array.

int	DasDesc_getInt (const DasDesc pThis, const char propertyName)
	Get a property integer value. More...

DasErrCode	DasDesc_setInt (DasDesc pThis, const char sName, int nVal)
	Set the property of type int.

bool	DasDesc_getBool (DasDesc pThis, const char sPropName)
	Get a property boolean value. More...

DasErrCode	DasDesc_setDatumRng (DasDesc pThis, const char sName, double beg, double end, das_units units)
	Set property of type DatumRange (double, double, UnitType triple)

DasErrCode	DasDesc_getStrRng (DasDesc pThis, const char sName, char sMin, char sMax, das_units *pUnits, size_t uLen)
	Get a property of type DatumRange with unconverted strings. More...

DasErrCode	DasDesc_setFloatAry (DasDesc pThis, const char propertyName, int nitems, float *value)
	Set the property of type float array. More...

void	DasDesc_copyIn (DasDesc pThis, const DasDesc source)
	Deepcopy properties into a descriptor. More...

DasErrCode	DasDesc_encode (DasDesc pThis, DasBuf pBuf, const char *sIndent)
	Encode a generic set of properties to a buffer. More...

Member Function Documentation

PktDesc * new_PktDesc ( void )

Creates a packet descriptor with the default settings.

Returns: A pointer to a new PktDesc allocated on the heap, or NULL on an error.

PktDesc * new_PktDesc_xml	(	DasBuf *	pBuf,
		DasDesc *	pParent,
		int	nPktId
	)

Create a PktDesc from XML data.

Parameters

pBuf	The buffer to read. Reading will start with the read point and will run until DasBuf_remaining() is 0 or the end tag is found, which ever comes first.
pParent	The parent packet descriptor, this may be NULL
nPktId	The packet's ID within it's parent's array. May be 0 if and only if the pParent is NULL

Returns: A pointer to a new PktDesc allocated on the heap, or NULL on an error.

int PktDesc_getId ( const PktDesc * pThis )

Get the packet ID for this packet.

Each packet type within a Das 2 Stream has a unique ID form 1 to 99 inclusive. Note that ID's can be reused! So processing code must be on the lookout for re-definition packets.

Returns: the packet id, a number between 1 and 99 or -1 if there is on packet id assigned.

const char * PktDesc_getGroup ( const PktDesc * pThis )

Get the data group for this packet.

Packets with the same group should be able to be plotted on the same graph. This is the same as a join in QDataset terms

Parameters

pThis A pointer to a packet desciptor structure

Returns: NULL if the packet has no specified group, or the group string which follows the rules for valid identifers in das_assert_valid_id()

void PktDesc_setGroup	(	PktDesc *	pThis,
		const char *	sGroup
	)

Set the data group for this packet.

Parameters

pThis	A pointer to a packet descriptor structure
sGroup	The new group name which must be a valid id.

size_t PktDesc_recBytes ( const PktDesc * pThis )

Get the size of data records defined by a packet descriptor.

Parameters

pThis The packet descriptor to query

Returns: The size in bytes of a single packet's worth of data.

size_t PktDesc_getNPlanes ( const PktDesc * pThis )

Get the number of planes in this type of packet.

Parameters

pThis the packet descriptor in question

Returns: The number of planes defined in this packet.

size_t PktDesc_getNPlanesOfType	(	const PktDesc *	pThis,
		plane_type_t	pt
	)

Get the number of planes of a particular type in a packet.

Parameters

pThis	The packet descriptor to check
pt	the plane type to check

Returns: The number of planes of a particular type in this packet descriptor

int PktDesc_addPlane	(	PktDesc *	pThis,
		PlaneDesc *	pPlane
	)

Add a plane to a packet.

All data in a das2 stream are sent via packets, each packet type has 1-100 planes. A plane can be a single column of numbers, which has one value per data packet, or in the case of <yscan> planes they can be more like sub-tables which have many values per packet. The newly added plane will have this PktDesc assigned as it's parent.

Planes have types. A Packet must have at least 1 <x> plane. In general it may have as many <y> <yscan> planes as it likes up to the plane limit. For packets with <z> planes, no <yscan> planes are allowed and one and only one <y> plane must be preset. This function enforces the packet formation rules. In summary the following patterns are legal.

X [X]
X [X] Y [Y Y ...]
X [X] YScan [YScan YScan ...]
X [X] Y [Y Y ...] YScan [YScan YScan ...] (see note)
X [X] Z [Z Z ...]

where [] indicates optional planes. Note: Y and YScan planes can be interleaved in any order.

This function adds the plane after all existing planes. Thus the index of any existing planes is not altered.

Parameters

pThis	The packet descriptor to receive the new plane definition
pPlane	The plane to add

Returns: On success the index of the new plane is returned, or -1 on an error

DasErrCode PktDesc_copyPlanes	(	PktDesc *	pThis,
		const PktDesc *	pOther
	)

Copy in all planes from another a packet descriptor.

Deepcopy's the plane descriptors in pOther and attaches the newly allocated planes to this PktDesc object. This packet descriptor must not already have any planes defined or this function will fail.

Parameters

pThis	the destination for the newly allocated PlaneDescriptors
pOther	the source of the PlaneDescriptors

Returns: 0 on success or a positive error number if there is a problem

bool PktDesc_validate ( PktDesc * pThis )

Check to see if a legal plane layout is present.

Since not all checks for a legal packet layout can be made while the sub-objects are being added to the packet descriptor, this function is provided to check the layout after adding all planes to a packet.

See Also: PktDesc_addPlane()

Parameters

pThis The packet descriptor to check

Returns: true if this packet descriptor has a legal set of planes, false otherwise.

plane_type_t PktDesc_getPlaneType	(	const PktDesc *	pThis,
		int	iPlane
	)

Determine the type of plane by index.

Parameters

pThis	the packet descriptor to query
iPlane	the index in question. Valid values for this parameter are 0 to MAXPLANES - 1

Returns

If the index corresponds to a data plane, then one of the enum values is return:

X
Y
YSCAN
Z

is returned, otherwise:

Invalid

is returned

PlaneDesc * PktDesc_getPlane	(	PktDesc *	pThis,
		int	iplane
	)

returns the PlaneDescriptor for plane number iplane This can be used to query properties of the plane, such as units and the name.

Parameters

pThis	The packet descriptor to query
iplane	The index of the plane to retrieve. The 0th plane is an <x> plane if one is present in the stream.

int PktDesc_getPlaneIdxByType	(	const PktDesc *	pThis,
		plane_type_t	ptype,
		int	iRelIndex
	)

Gets the Nth plane of a given type.

This is useful for iterating over all planes of a given type.

Parameters

pThis	A packet descriptor structure pointer.
ptype	The plane type, one X, Y, Z, YScan
iRelIndex	The number of the plane of a given type to find. The lowest index will be 0 for a given type.

Returns: The absolute plane index for the Nth plane of a given type. If No planes of the given type are present, or iIndex is out of range -1 is returned.

int PktDesc_getPlaneIdxByName	(	PktDesc *	pThis,
		const char *	name,
		plane_type_t	planeType
	)

returns the plane number for the named plane.

Parameters

pThis	The packet descriptor to query.
name	The name in of the plane to find
planeType	if not set to 0, then PlaneType must also match. Note that typically the 0th plane is typically the <x> plane.

DasErrCode PktDesc_encode	(	const PktDesc *	pThis,
		DasBuf *	pBuf
	)

Serialize a packet descriptor as XML data.

Parameters

pThis	The packet descriptor to store as string data
pBuf	A buffer object to received the string data

Returns: 0 if successful, or a positive integer if not.

DasErrCode PktDesc_encodeData	(	const PktDesc *	pThis,
		DasBuf *	pBuf
	)

Serialize a packet's current data In addition to holding the format information for Das2 Stream packets PktDesc objects also hold a a single packet's worth of data.

Use this function to encode the current data values for output.

Parameters

pThis	The packet descriptor that has been loaded with data
pBuf	A buffer to receive the encoded bytes

Returns: 0 if successful, or a positive integer if not.

DasErrCode PktDesc_decodeData	(	PktDesc *	pThis,
		DasBuf *	pBuf
	)

Decode 1 packet's worth of data from a buffer.

Parameters

pThis	the packet descriptor to handle decoding
pBuf	The buffer with the data, data will be read from the current read point.

Returns: 0 if successful, or a positive integer if not.

DasErrCode PktDesc_setValue	(	PktDesc *	pThis,
		size_t	uPlane,
		size_t	uItem,
		double	val
	)

Convenience function for setting a single value in a plane This is just a shortcut for:

* PlaneDesc* pPlane = PktDesc_getPlane(pPkt, uPlane);
* PlaneDesc_setValue(pPlane, uItem, value);
* 

Parameters

pThis	The packet descriptor in question.
uPlane	The index of the plane to receive the values
uItem	The index of the item in the plane to be set to the new value
val	The new value for this item in this plane.

Returns: 0 on success or a positive error code if there is a problem

DasErrCode PktDesc_setValues	(	PktDesc *	pThis,
		size_t	uPlane,
		const double *	pVals
	)

Convenience function for setting an array of values in a plane This is just a shortcut for:

* PlaneDesc* pPlane = PktDesc_getPlane(pPkt, uPlane);
* PlaneDesc_setValues(pPlane, pVals);
* 

Parameters

pThis	The packet descriptor in question.
uPlane	The index of the plane to receive the values
pVals	The array of values to set. The array is assumed to be the same length as the number of items in plane uPlane

Returns: 0 on success or a positive error code if there is a problem

bool DasDesc_equals	(	const DasDesc *	pOne,
		const DasDesc *	pTwo
	)

inherited

Check to see if two descriptors contain the same properties Note, the order of the properties may be different between the descriptors but if the contents are the same then the descriptors are considered to be equal.

Note that parent descriptor properties are not checked when handling the comparison.

Todo:: maybe check parents too.

Parameters

pOne	The first descriptor
pTwo	The second descriptor

const DasDesc * DasDesc_parent ( DasDesc * pThis )

inherited

The the parent of a Descriptor.

Plane descriptors are owned by packet descriptors and packet descriptors are owned by stream descriptors. This function lets you craw the ownership hierarchy

Parameters

pThis

Returns: The owner of a descriptor, or NULL if this is a top level descriptor, (i.e. a Stream Descriptor)

size_t DasDesc_length ( const DasDesc * pThis )

inherited

Get the number of properties in a descriptor.

Descriptor's have a hierarchy. In general when a property is requested, if a given Descriptor does not have a property the request is passed to the parent descriptor. This function only returns the number of properties in the given descriptor. It does not include properties owned by parents or ancestors.

This is useful when iterating over all properties in a descriptor.

See Also: DasDesc_getNameByIdx(); DasDesc_getValByIdx(); DasDesc_getTypeByIdx()

Parameters

pThis A pointer to the descriptor to query

Returns: The number of properties in this, and only this, descriptor.

const char * DasDesc_getNameByIdx	(	const DasDesc *	pThis,
		size_t	uIdx
	)

inherited

Get a property name by an index.

This is useful when iterating over all properties in a Descriptor. Only properties owed by a descriptor are queried in this manner. Parent descriptors are not consulted.

See Also: DasDesc_length()

Parameters

pThis	A pointer to the descriptor to query
uIdx	The index of the property, will be a value between 0 and the return value from Desc_getNProps()

Returns: A pointer the requested property name or NULL if there is no property at the given index.

const char * DasDesc_getValByIdx	(	const DasDesc *	pThis,
		size_t	uIdx
	)

inherited

Get a property value by an index.

This is useful when iterating over all properties in a Descriptor. Only properties owned by a descriptor are queried in this manner. Parent descriptors are not consulted.

See Also: DasDesc_length()

Parameters

pThis	A pointer to the descriptor to query
uIdx	The number of the property, will be a value from 0 and 1 less than the return value from Desc_getNProps()

Returns: A pointer the requested property value or NULL if there is no property at the given index.

bool DasDesc_has	(	const DasDesc *	pThis,
		const char *	propertyName
	)

inherited

Determine if a property is present in a Descriptor or it's ancestors.

Parameters

pThis	the descriptor object to query
propertyName	the name of the property to retrieve.

Returns: true if the descriptor or one of it's ancestors has a property with the given name, false otherwise.

DasErrCode DasDesc_set	(	DasDesc *	pThis,
		const char *	sType,
		const char *	sName,
		const char *	sVal
	)

inherited

Generic property setter.

All properties are stored internally as strings. The various typed Desc_setProp* functions all call this function after converting their arguments to strings.

Warning: To insure that the string to type conversions are consistent it is strongly recommended that you use one of the typed functions instead of this generic version unless you have no choice.

Parameters

pThis	The Descriptor to receive the property
sType	The Type of property should be one of the strings: boolean double doubleArray Datum DatumRange int String Time TimeRange
sName	The property name, which cannot contain spaces
sVal	The value, which may be anything including NULL

Returns: 0 on success or a positive error code if there is a problem.

bool DasDesc_remove	(	DasDesc *	pThis,
		const char *	propretyName
	)

inherited

Remove a property from a descriptor, if preset.

It is safe to call this function for properties not present on the descriptor, it simply does nothing and returns false.

Returns: false if the property wasn't present to begin with, true otherwise

DasErrCode DasDesc_setStr	(	DasDesc *	pThis,
		const char *	sName,
		const char *	sVal
	)

inherited

SetProperty methods add properties to any Descriptor (stream,packet,plane).

The typed methods (e.g. setPropertyDatum) property tag the property with a type so that it will be parsed into the given type.

double DasDesc_getDouble	(	const DasDesc *	pThis,
		const char *	propertyName
	)

inherited

Read the property of type double named propertyName.

The property value is parsed using sscanf.

double DasDesc_getDatum	(	DasDesc *	pThis,
		const char *	sPropName,
		das_units	units
	)

inherited

Get the a numeric property in the specified units.

Descriptor properties my be provided as Datums. Datums are a double value along with a specified measurement unit.

Parameters

pThis	The Descriptor containing the property in question.
sPropName	The name of the property to retrieve.
units	The units of measure in which the return value will be represented. If the property value is stored in a different set of units than those indicated by this parameter than the output will be converted to the given unit type.

Returns: The converted value or DAS_FILL_VALUE if conversion to the desired units is not possible.

DasErrCode DasDesc_setDatum	(	DasDesc *	pThis,
		const char *	sName,
		double	rVal,
		das_units	units
	)

inherited

Set property of type Datum (double, UnitType pair)

If a property with this name already exists it is 1st deleted and then the new property is added in its place.

Parameters

pThis	The descriptor to receive the property
sName	The name of the property to set
rVal	The numeric value of the property
units	The units of measure for the property

double * DasDesc_getDoubleAry	(	DasDesc *	pThis,
		const char *	propertyName,
		int *	nitems
	)

inherited

Get the values of an array property.

Space for the array is allocated by getDoubleArrayFromString. and nitems is set to indicate the size of the array.

Parameters

[in]	pThis	the descriptor object to query
[in]	propertyName	the name of the proprety to retrieve
[out]	nitems	a pointer to a an integer containing the number of values in the returned array.

Returns: A pointer to a double array allocated on the heap. It is the caller's responsibility to depose of the memory when it is no longer needed. If the named property doesn't exist the program exits.

See Also: hasProperty()

int DasDesc_getInt	(	const DasDesc *	pThis,
		const char *	propertyName
	)

inherited

Get a property integer value.

Parameters

pThis	the descriptor object to query
propertyName	the name of the proprety to retrieve

Returns: The value of the named property or exits the program if the named proprety doesn't exist in this descriptor.

See Also: hasProperty()

bool DasDesc_getBool	(	DasDesc *	pThis,
		const char *	sPropName
	)

inherited

Get a property boolean value.

Parameters

pThis	the descriptor object to query
sPropName	the name of the proprety to retrieve

Returns: True if the value is "true", or any positive integer, false otherwise.

DasErrCode DasDesc_getStrRng	(	DasDesc *	pThis,
		const char *	sName,
		char *	sMin,
		char *	sMax,
		das_units *	pUnits,
		size_t	uLen
	)

inherited

Get a property of type DatumRange with unconverted strings.

This version is handy if you just want to know the intrinsic units of the range without converting the values to some specific type of double value.

DasErrCode DasDesc_setFloatAry	(	DasDesc *	pThis,
		const char *	propertyName,
		int	nitems,
		float *	value
	)

inherited

Set the property of type float array.

Note the array is cast to a double array before encoding.

void DasDesc_copyIn	(	DasDesc *	pThis,
		const DasDesc *	source
	)

inherited

Deepcopy properties into a descriptor.

Parameters

pThis	the descriptor to receive a copy of the properties
source	the descriptor with the properties to be copied.

DasErrCode DasDesc_encode	(	DasDesc *	pThis,
		DasBuf *	pBuf,
		const char *	sIndent
	)

inherited

Encode a generic set of properties to a buffer.

Parameters

pThis	The descriptors who's properties should be encoded
pBuf	A buffer object to receive the XML data
sIndent	An indent level for the property strings, makes 'em look nice

Returns: 0 if the operation succeeded, a non-zero return code otherwise.

Field Documentation

void* pUser

User data pointer.

The stream->packet->plane hierarchy provides a good organizational structure for application data, especially for applications whose purpose is to filter streams. This pointer can be used to hold a reference to information that is not serialized. It is initialized to NULL when a packet descriptor is created otherwise the library doesn't deal with it in any other way.

The documentation for this struct was generated from the following file:

das2/packet.h

Detailed Description

Creating Packet Descriptors

Emitting Packet Data

Reading Data

Public Member Functions

Data Fields

Descriptor Functions

Member Function Documentation

Field Documentation