Isis Developer Reference
Isis::Kernels Class Reference

Determine SPICE kernels defined in an ISIS file. More...

#include <Kernels.h>

Collaboration diagram for Isis::Kernels:
Collaboration graph

Public Member Functions

 Kernels ()
 Default Constructor.
 
 Kernels (const Kernels &kernels)
 Initialize new Kernels from state of existing one.
 
 Kernels (const QString &filename)
 Construct using an ISIS file name.
 
 Kernels (Cube &cube)
 Construct using an ISIS Cube object.
 
 Kernels (Pvl &pvl)
 Construct from an ISIS label.
 
virtual ~Kernels ()
 Destructor always unloads the kernels from the pool.
 
Kernelsoperator= (const Kernels &kernels)
 Copy constructor for existing Kernels objecr.
 
int size () const
 Returns the number of kernels found and/or loaded.
 
int Missing () const
 Return count of missing kernel files.
 
void Init (Pvl &pvl)
 Determine Spice kernels in an ISIS label.
 
bool Add (const QString &kfile)
 Add a new kernel to the list.
 
void Clear ()
 Remove all kernel files from internal list.
 
int Discover ()
 Determine which NAIF kernels are currently loaded in the pool.
 
void Manage ()
 Set each kernels management status to managed.
 
void UnManage ()
 Set each kernels' management state to unmanaged.
 
bool IsManaged () const
 Determine if all kernels are managed by this object.
 
void InitializeNaifKernelPool ()
 Initialize the NAIF kernel keeper pool.
 
int Load (const QString &ktype)
 Load all kernels with one more types.
 
int Load ()
 Load all kernels in list.
 
int UnLoad (const QString &ktype)
 Unloads all kernels of a specific type.
 
int UnLoad ()
 Unloads all kernels from the NAIF pool.
 
int UpdateLoadStatus ()
 Determine the load status of all kernels known to this object.
 
int Merge (const Kernels &other)
 Merge the contents of another Kernels object.
 
QStringList getKernelTypes () const
 Return list of types in kernel list.
 
QStringList getKernelList (const QString &ktype="") const
 Provide a list of all the kernels found.
 
QStringList getLoadedList (const QString &ktypes="") const
 Returns list of kernel currently loaded according to status.
 
QStringList getMissingList () const
 Returns list of kernels that were not found to exist.
 
int CameraVersion () const
 Returns the ISIS camera model version number.
 

Detailed Description

Determine SPICE kernels defined in an ISIS file.

This class determines all SPICE kernels associated with an ISIS cube file and optionally/selectively loads them using the NAIF toolkit. This creates the kernel pool as it was when spiceinit determined all the kernels and it initialized the file for geometric operations.

Note that because NAIF kernel management is global in nature, careful thought and planning should preceed use of this class. You can get yourself into trouble if you take over management of kernels and inadvertantly unload them without regard for use by other resources. Methods are provided in this implementation to help minimize problems related to management of this global resource.

Note that ISIS caches some of the voluminous NAIF kernels, extracting only what is required from the SPK and CK (generally) kernels for a given observation. After this occurs, these kernels are no longer loaded by the ISIS Spice class hierarchy. This class provides that environment so that further NAIF operations can occur, such as velocity vector and instrument timing manipulations.

This class can be used instead of instantiating an ISIS Spice object. The recommended usage is as follows:

Cube cube;
cube.Open("mycube.cub");
Kernels myKernels(cube);
myKernels.UpdateLoadStatus(); // Ensures loaded kernels stay loaded
myKernels.Load();
. . .
// After manipulating the CK Spice data...
myKernels.UnLoad();
IO Handler for Isis Cubes.
Definition Cube.h:168
Determine SPICE kernels defined in an ISIS file.
Definition Kernels.h:94

The implications of this code segment are: 1) All the kernels pertinent to an individual ISIS file are identified upon Kernels instantiation, 2) their load status is determined using the UpdateLoadStatus() method, 3) kernels already loaded are flagged as unmanaged, meaning they cannot be unloaded unless management is an explicit "hostile takeover" provided via the Manage() method (don't do it unless you absolutely have to), 4) after checking load status, and kernels you load are managed by your instantiation, and 5) when you UnLoad() or the object is destroyed, all managed kernels are unloaded - unmanaged kernels are not unloaded.

This class can be used in lieu of the Spice class with liberal use of the UpdateLoadStatus() and Discover() methods of this class.

It is possible to double load NAIF kernels, so be sure to maintain load status via UpdateLoadStatus() and proper usage techniques.

Author
2010-12-28 Kris Becker

Constructor & Destructor Documentation

◆ Kernels() [1/5]

Isis::Kernels::Kernels ( )

Default Constructor.

Default constructor simple initialization.

◆ Kernels() [2/5]

Isis::Kernels::Kernels ( const Kernels & kernels)

Initialize new Kernels from state of existing one.

Initialize new Kernels object from the state of an existing one while preserving the state of one copied. Each kernel file state is copied to this new one. It ensures that ones that are already opened are set to an unmanaged state from the source. It also checks the current open state and will set ones found to be open as unmanaged as well. All other kernels files can be managed by this new instance.

Author
kbecker (3/26/2011)
Parameters
kernelsSource kernels object

References UpdateLoadStatus().

◆ Kernels() [3/5]

Isis::Kernels::Kernels ( const QString & filename)

Construct using an ISIS file name.

Parameters
filenameName of ISIS cube file

References Init().

◆ Kernels() [4/5]

Isis::Kernels::Kernels ( Cube & cube)

Construct using an ISIS Cube object.

Parameters
cubeCube object of ISIS file

References Init(), and Isis::Cube::label().

◆ Kernels() [5/5]

Isis::Kernels::Kernels ( Pvl & pvl)

Construct from an ISIS label.

Parameters
pvlISIS label to get kernel information from

References Init().

◆ ~Kernels()

virtual Isis::Kernels::~Kernels ( )
inlinevirtual

Destructor always unloads the kernels from the pool.

References UnLoad().

Member Function Documentation

◆ Add()

bool Isis::Kernels::Add ( const QString & kfile)

Add a new kernel to the list.

This method is provided to add individual NAIF kernels directly. Files names must contain a path to the file. ISIS "shortcuts" as defined in the DataDirectory group in the IsisPreferences files (e.g., "$base/kernels/lsk/naif0009.tls") are supported as well.

Note that if the file already exists, it is not added. This situation is indicated with a return value of false.

Files added in this way are set to manageable status.

Parameters
kfileName of kernel file to add with valid directory path
Returns
bool True if the files was added to the list, false if it already exists

Referenced by Isis::PushFrameCameraCcdLayout::addKernel().

◆ CameraVersion()

int Isis::Kernels::CameraVersion ( ) const
inline

Returns the ISIS camera model version number.

◆ Clear()

void Isis::Kernels::Clear ( )

Remove all kernel files from internal list.

This method will clear out the kernel file list without any regard for its current state. This does not unload any kernels that are unloaded. One must Unload() prior to calling this method in order to gracefully close out the existing state of the kernel pool.

Referenced by operator=().

◆ Discover()

int Isis::Kernels::Discover ( )

Determine which NAIF kernels are currently loaded in the pool.

This method queries the NAIF KEEPER system/pool for all loaded kernels and adds them to the list in this object. It only knows about kernels that are loaded by the NAIF furnsh_c routine. If no kernels are loaded there will be no kernels discovered by this routine.

Upon entry into this method, the current list is discarded without unloading them. Hence, any kernels in this list are discard, whether they are loaded and managed by this class or not. If they are loaded according to the internal state as determined by previous activity in this class, and no additional NAIF activity has occured that unloads them, they should be found again by this method.

Note that ALL kernels discovered by this routine are marked as unmanaged, meaning you cannot unload the kernels without exerting management upon them via the Manage() method. See the Manage() documentation for more details and potential issues with this feature.

This method should not be used to update the load nature of an established kernel list. See the UpdateLoadStatus() method for this feature.

Here is a short coding example showing use of this method. It assumes there are some kernels already loaded (although it is entirely possible that no kernels are loaded). It will take over management of these kernels as well:

Kernels myKernels;
myKernels.Discover();
myKernels.Manage();
int Discover()
Determine which NAIF kernels are currently loaded in the pool.
Definition Kernels.cpp:235
Returns
int Number of kernels discovered

References Isis::NaifStatus::CheckErrors().

Referenced by Isis::LightTimeCorrectionState::checkSpkKernelsForAberrationCorrection().

◆ getKernelList()

QStringList Isis::Kernels::getKernelList ( const QString & ktypes = "") const

Provide a list of all the kernels found.

This method will return all the kernel file references as found in the ISIS label.

Parameters
ktypesOptional list of kernel types to return in the list. This can be any type found in the internal list as returned by getKernelTypes(). If empty, returns all kernels.
Returns
std::vector<QString> A vector of filenames of SPICE kernels

Referenced by Isis::LightTimeCorrectionState::checkSpkKernelsForAberrationCorrection().

◆ getKernelTypes()

QStringList Isis::Kernels::getKernelTypes ( ) const

Return list of types in kernel list.

This method determines what types of kernels are currently in the internal list and returns them in alphabetical order. An empty list is returned if there are no kernels. The list may contain "UNKNOWN" which is the default type assigned when the type of the kernel file cannot be determined. These kernels are excluded from any loading/unloading.

The list of known types are:

CK SPK DAF (synonymous for SPKs as well so load both) PCK EK META IK FK SCLK IAK (ISIS specific) DSK

Kernel types are determined by inspecting the first 8 characters of a kernel file and extracting the contents there. The actual type is the string value after the last '/' character. This is typically the value that is also returned by the NAIF kinfo_c utility.

Returns
std::vector<QString> Alphabetical list of kernel types

◆ getLoadedList()

QStringList Isis::Kernels::getLoadedList ( const QString & ktypes = "") const

Returns list of kernel currently loaded according to status.

This method returns a list of kernel filenames that are loaded according to internal status. If the load status is in question, used UpdateLoadStatus() prior to calling this method.

Users can restrict the list to loaded kernels of a specific type. For example, to get a list of all CKs and SPKs loaded, the following code can be used:

mykernels.getLoadedList("CK,SPK");
Parameters
ktypesOptional string containing comma separated list of types to return if loaded. If empty, returns all types of kernels that are deemed loaded.
Returns
std::vector<QString> List of kernel filenames that are currently loaded.

◆ getMissingList()

QStringList Isis::Kernels::getMissingList ( ) const

Returns list of kernels that were not found to exist.

This method can be used to identify which kernels do not exist when they were added to this object. If the Missing() method returns a number > 0, then this routine returns a list of files missing.

Returns
std::vector<QString> List of missing kernel files

◆ Init()

void Isis::Kernels::Init ( Pvl & pvl)

Determine Spice kernels in an ISIS label.

This method reads keywords in the Kernels group in the ISIS label hierarchy to find all the pertinent kernel files. They are found in the Kernels Group.

The order listed here is the same as the order specified in the ISIS Spice class at the time this class was written. When loading and unloading, the order is the same as is read in here.

Parameters
pvlAssumed to be a valid ISIS cube label containing the Kernels group

References UnLoad().

Referenced by Kernels(), Kernels(), and Kernels().

◆ InitializeNaifKernelPool()

void Isis::Kernels::InitializeNaifKernelPool ( )

Initialize the NAIF kernel keeper pool.

This method will thoroughly clear out the NAIF kernel keeper pool. This is done using the NAIF k_clear() utility. As the documentation states, it operates by side effects unloading all kernels and reinitializing the keeper pool.

This method has no regard at to whether any of the NAIF kernels are managed or not. It does update all kernels load status to unloaded.

NOTE: This method should be used with caution as it can have disasterous side effects for ISIS processing. Specifically, using this method arbitrarily will likely cause fatal exceptions particularly for Spice class instantiations.

References Isis::NaifStatus::CheckErrors().

◆ IsManaged()

bool Isis::Kernels::IsManaged ( ) const

Determine if all kernels are managed by this object.

This method will return true if all kernels listed in this object are marked as "managed". If any one of the kernels is found to have an unmanaged state, false will be returned by this routine.

Management/unmanagement is an all-or-nothing scheme.

Returns
bool True if all kernels are marked manageable, false if even one is not.

◆ Load() [1/2]

int Isis::Kernels::Load ( )

Load all kernels in list.

This method will iterate though all NAIF-type kernels and load them into the NAIF KEEPER system/pool using the NAIF furnsh_c utility. If they are already loaded, they are not loaded again. Status is set to show they are loaded.

This object cannot monitor the kernel pool unless explicit action is taken. See the CheckLoadStatus() method. It will update the load status of kernels in the current list.

NOTE: If individual kernel are not managed by this routine they are not loaded. Users must invoke the Manage() method to enable full kernel manipulation.

Returns
int Number of kernels loaded

References Load().

Referenced by Load(), and Load().

◆ Load() [2/2]

int Isis::Kernels::Load ( const QString & ktypes)

Load all kernels with one more types.

This method will find all kernels with a specific type and loads them into the NAIF KEEPER system/pool using the NAIF furnsh_c utility. If they are already loaded, they are not loaded again. Status is set to show they are loaded.

This object cannot monitor the kernel pool unless explicit action is taken. See the CheckLoadStatus() method. It will update the load status of kernels in the current list.

NOTE: If individual kernel are not managed by this routine they are not loaded. Users must invoke the Manage() method to enable full kernel manipulation.

Parameters
ktypesOne or more kernel types specified in a comma separated list
Returns
int Number of kernels loaded

References Load().

Referenced by Isis::PushFrameCameraCcdLayout::addKernel().

◆ Manage()

void Isis::Kernels::Manage ( )

Set each kernels management status to managed.

This method will change every kernels's management state to managed so that full manipulation of every kernel can be performed by this object.

If a kernel is managed, it will be allowed to UnLoad at will. This is typically the only restriction of an unmanaged kernel.

◆ Merge()

int Isis::Kernels::Merge ( const Kernels & other)

Merge the contents of another Kernels object.

This method mergest the contents of another Kernels object into this one. Kernels that exist in both instances of the object are handled special. The status of this object's version of the file is updated to reflect conditions of the other objects kernels.

When the file does not exist in this object, the kernel file structure is copied from the other Kernels object, its managed status is set to false (since it pre-exists in another object that must relinquish its management of it) and is added to this objects kernel list.

When the file does exist in this object, its load status is checked in the other Kernels object. If it is loaded according to the other object, it is marked as loaded in this object and its managed state is set to unmanaged (since it contained in another object, no assumptions can be made as to whom and how it came about to be loaded.

The following code fragment demonstrates how to ensure only one Kernels object retains complete control of the merged set of kernels:

Kernels master, other;
// ...
// Both objects are assumed to contain kenels and some state.
master.Merge(other);
other.UnManage();
master.Manage();
master.UpdateLoadStatus();
int Merge(const Kernels &other)
Merge the contents of another Kernels object.
Definition Kernels.cpp:599

The UpdateLoadStatus() ensures the state of the managed kernel list in master is completely up to date.

Parameters
otherOther Kenels object containing a separate list of NAIF kernels that will be merged with the contents of this object.
Returns
int Number of kernels added to this object. It does not include the count of kernels that are common to both and may have had its status modified.

◆ Missing()

int Isis::Kernels::Missing ( ) const

Return count of missing kernel files.

Returns
int Number of files that do not exist

◆ operator=()

Kernels & Isis::Kernels::operator= ( const Kernels & kernels)

Copy constructor for existing Kernels objecr.

This copy constructor ensures the kernel list copied from an existing object is set to proper conditions as to minimize interference of both object that existence.

Any current kernels that in this object are removed without regard for ther current state. The list of kernels in the source object are copied and their state is analyzed. Any opened kernels are set to unmanaged state.

Author
kbecker (3/26/2011)
Parameters
kernelsSource list from which the list is copied
Returns
Kernels& Returned Kernel instance

References Clear(), and UpdateLoadStatus().

◆ size()

int Isis::Kernels::size ( ) const
inline

Returns the number of kernels found and/or loaded.

◆ UnLoad() [1/2]

int Isis::Kernels::UnLoad ( )

Unloads all kernels from the NAIF pool.

This method will unload all kernels from the kernel pool. It will unload them one at a time, which is known to be inefficient. You could consider using the InitializeNaifKernelPool() method for a more thorough and efficient cleansing.

Returns
int Number of kernels unloaded

References UnLoad().

Referenced by Init(), UnLoad(), UnLoad(), and ~Kernels().

◆ UnLoad() [2/2]

int Isis::Kernels::UnLoad ( const QString & ktypes)

Unloads all kernels of a specific type.

This method will parse a string containing acronyms of NAIF kernels types and close only those found with the associated type. Types in the context of this class are loosely managed. They are typically types returned by the NAIF utilities, kinfo_c and kdata_c.

Only those files that match will be unloaded. There load states will be altered to reflect its load status.

Only files that are tagged as manageable but this object are closed. Unmanaged kernels are essentially ignored.

Parameters
ktypesComma delimited string specifying the type to unload. This string is of the form "LSK,FK,SPK".
Returns
int Number of kernels unloaded

References UnLoad().

◆ UnManage()

void Isis::Kernels::UnManage ( )

Set each kernels' management state to unmanaged.

This method changes the management state to unmanaged, thus restricting the ability of this method to unload loaded kernels.

When a kernel is marked as unmanaged, it will persist in its loaded state even after the destruction of this object (there is really no way to track how kernels get loaded reliably).

◆ UpdateLoadStatus()

int Isis::Kernels::UpdateLoadStatus ( )

Determine the load status of all kernels known to this object.

This method will reevaluate the load status of each NAIF kernel contained within this object. This method can be useful when there are more than one of these Kernels objects instantiated.

It will check to determine if each NAIF kernel is loaded using the NAIF kinfo_c utility. It will change loaded status to unloaded and unloaded status to loaded from results of the query. It does not consider the managed state of any kernel.

One can always choose to use the Load() and UnLoad() utilities for explicit handling of the kernel (type) states.

Returns
int Number of kernels whose states where changed/affected by this method

References Isis::NaifStatus::CheckErrors().

Referenced by Kernels(), and operator=().


The documentation for this class was generated from the following files: