Base structure for Stream Header Items. More...

#include <das2/descriptor.h>

Inheritance diagram for DasDesc:

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Collaboration diagram for DasDesc:

Public Member Functions
#define	DasDesc_type(P) ((P)->type)
	Get the type of this descriptor. More...

DAS_API void	DasDesc_init (DasDesc *pThis, desc_type_t type)
	Initialize a memory location as a valid das descriptor.

DAS_API char *	DasDesc_info (const DasDesc pThis, char sBuf, int nLen, char *sIndent)
	Print 1-line versions of each property in a descriptor.

DAS_API bool	DasDesc_equals (const DasDesc pThis, const DasDesc pOther)
	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...

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

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

DAS_API const DasProp *	DasDesc_getPropByIdx (const DasDesc *pThis, size_t uIdx)
	Get a property name by an index. More...

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

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

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

DAS_API const char *	DasDesc_getTypeByIdx3 (const DasDesc *pThis, size_t uIdx)
	Get a data type of a property by an index, das3 covention.

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

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

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

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

DAS_API size_t	DasDesc_getStrAry (DasDesc pThis, const char sName, char pBuf, size_t uBufSz, char *psVals, size_t uMaxVals)
	Get a multi-valued string property. More...

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

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

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

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

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

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

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

DAS_API DasErrCode	DasDesc_setDoubleArray (DasDesc pThis, const char sName, int nItems, double *pValues)
	Set the property of type double array.

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

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

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

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

DAS_API 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...

DAS_API DasErrCode	DasDesc_setFloatAry (DasDesc pThis, const char sName, int nItems, float *pValues)
	Set the property of type float array. More...

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

DAS_API DasErrCode	DasDesc_encode2 (DasDesc pThis, DasBuf pBuf, const char *sIndent)
	Encode a generic set of properties to a buffer. More...

Detailed Description

Base structure for Stream Header Items.

Descriptors have properties associated with them. Stream Descriptors, Packet Descriptors, and Plane Descriptors are all extensions of this object type, thus the functions for this structure may be used with any Descriptor structure in the library.

Note: Properties Cascade

Properties cascade in das streams. Thus if a particular descriptor does not have a particular property then the various getProperty() functions will search parent descriptors for requested property. The descriptor ownership hierarchy for das stream is:

StreamDesc's have 1-N ::FramePktDesc's
PktDesc's have 1-N PlaneDesc's
::

Todo:: Move child relationship into the descriptor base class, parent is there but the other direction is missing

Member Function Documentation

◆ DasDesc_equals()

DAS_API bool DasDesc_equals	(	const DasDesc *	pThis,
		const DasDesc *	pOther
	)

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

pThis	The first descriptor
pOther	The second descriptor

◆ DasDesc_parent()

DAS_API const DasDesc * DasDesc_parent ( DasDesc * pThis )

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)

◆ DasDesc_length()

DAS_API size_t DasDesc_length ( const DasDesc * pThis )

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.

◆ DasDesc_getPropByIdx()

DAS_API const DasProp * DasDesc_getPropByIdx	(	const DasDesc *	pThis,
		size_t	uIdx
	)

Get a property name by an index.

This is useful when iterating over all properties in a Descriptor. Only valid 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_length(). For efficient storage properties that have been erased or over-written are left in place internally and just marked as invalid.

Returns: A pointer the requested property, or NULL if the property is not valid. A NULL return does not mean than the next higher index has an invalid property

◆ DasDesc_getNameByIdx()

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

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_length()

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

◆ DasDesc_getValByIdx()

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

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_length()

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

◆ DasDesc_has()

DAS_API bool DasDesc_has	(	const DasDesc *	pThis,
		const char *	sName
	)

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

Parameters

pThis	the descriptor object to query
sName	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.

◆ DasDesc_set()

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

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. This value is passed down to DasProp_init2(), see that function for a list of known values.
sName	The property name. For das2 & das3 this can't 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.

◆ DasDesc_remove()

DAS_API bool DasDesc_remove	(	DasDesc *	pThis,
		const char *	sName
	)

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

◆ DasDesc_getStrAry()

DAS_API size_t DasDesc_getStrAry	(	DasDesc *	pThis,
		const char *	sName,
		char *	pBuf,
		size_t	uBufSz,
		char **	psVals,
		size_t	uMaxVals
	)

Get a multi-valued string property.

Some properties, especially those from DSDF files, contain multiple string values in a single field separated by pipe "|" characters. For example:

data_01 = 'efield | Electric field intensity | V m**-1'

This function breaks these values into multiple strings without requiring heap memory.

Output bytes are copied into the given val_buf. Then null values are then written over all leading and trailing whitespace for each element as well as the pipe characters.

Finally a pointer to each starting string is copied into ptr_buf. If an element contains not data, for example:

coord_01 = 'frequency | | Hz'

then the corresponding character pointer will be NULL, but the number of character pointers is unchanged.

Parameters

[in]	pThis	the descriptor to query
[in]	name	the name of the property to retrieve
[out]	val_buf	will hold the full output property data
[in]	val_buf_sz	the maximum number of bytes to copy out including the terminating null character.
[out]	ptr_buf	will hold pointers to the start of each property value. If a value is empty, the corresponding pointer is null.
[in]	ptr_buf_sz	the maximum number of string pointers write to ptr_buf.

Returns: The number of string values for this property, which is zero if a property with the given name is not present.

See also: DasDesc_getStr to retrieve the original property value in a single buffer unaltered.

◆ DasDesc_setStr()

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

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.

◆ DasDesc_getDouble()

DAS_API double DasDesc_getDouble	(	const DasDesc *	pThis,
		const char *	sName
	)

Read the property of type double named sName.

The property value is parsed using sscanf.

◆ DasDesc_setDouble()

DAS_API DasErrCode DasDesc_setDouble	(	DasDesc *	pThis,
		const char *	sName,
		double	value
	)

Set property of type double.

◆ DasDesc_getDatum()

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

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.
sName	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.

◆ DasDesc_setDatum()

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

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

◆ DasDesc_getDoubleAry()

DAS_API double * DasDesc_getDoubleAry	(	DasDesc *	pThis,
		const char *	sName,
		int *	pNumItems
	)

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]	sName	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: DasDesc_has()

◆ DasDesc_getInt()

DAS_API int DasDesc_getInt	(	const DasDesc *	pThis,
		const char *	sName
	)

Get a property integer value.

Parameters

pThis	the descriptor object to query
sName	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: DasDesc_has()

◆ DasDesc_getBool()

DAS_API bool DasDesc_getBool	(	DasDesc *	pThis,
		const char *	sName
	)

Get a property boolean value.

Parameters

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

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

◆ DasDesc_getStrRng()

DAS_API 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.

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.

◆ DasDesc_setFloatAry()

DAS_API DasErrCode DasDesc_setFloatAry	(	DasDesc *	pThis,
		const char *	sName,
		int	nItems,
		float *	pValues
	)

Set the property of type float array.

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

◆ DasDesc_copyIn()

DAS_API void DasDesc_copyIn	(	DasDesc *	pThis,
		const DasDesc *	pOther
	)

Deepcopy properties into a descriptor.

Parameters

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

◆ DasDesc_encode2()

DAS_API DasErrCode DasDesc_encode2	(	DasDesc *	pThis,
		DasBuf *	pBuf,
		const char *	sIndent
	)

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.

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

das2/descriptor.h

Public Member Functions

Detailed Description

Member Function Documentation

◆ DasDesc_equals()

◆ DasDesc_parent()

◆ DasDesc_length()

◆ DasDesc_getPropByIdx()

◆ DasDesc_getNameByIdx()

◆ DasDesc_getValByIdx()

◆ DasDesc_has()

◆ DasDesc_set()

◆ DasDesc_remove()

◆ DasDesc_getStrAry()

◆ DasDesc_setStr()

◆ DasDesc_getDouble()

◆ DasDesc_setDouble()

◆ DasDesc_getDatum()

◆ DasDesc_setDatum()

◆ DasDesc_getDoubleAry()

◆ DasDesc_getInt()

◆ DasDesc_getBool()

◆ DasDesc_getStrRng()

◆ DasDesc_setFloatAry()

◆ DasDesc_copyIn()

◆ DasDesc_encode2()