GDAL
Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
GDALDriverManager Class Reference

Class for managing the registration of file format drivers. More...

#include <gdal_priv.h>

Inheritance diagram for GDALDriverManager:
GDALMajorObject

Public Member Functions

int GetDriverCount (void) const
 Fetch the number of registered drivers. More...
 
GDALDriverGetDriver (int)
 Fetch driver by index. More...
 
GDALDriverGetDriverByName (const char *)
 Fetch a driver based on the short name. More...
 
int RegisterDriver (GDALDriver *)
 Register a driver for use. More...
 
void DeregisterDriver (GDALDriver *)
 Deregister the passed driver. More...
 
void AutoLoadDrivers ()
 Auto-load GDAL drivers from shared libraries. More...
 
void AutoSkipDrivers ()
 This method unload undesirable drivers. More...
 
void ReorderDrivers ()
 Reorder drivers according to the order of the drivers.ini file. More...
 
int GetMOFlags () const
 Returns the GMO_ flags. More...
 
void SetMOFlags (int nFlagsIn)
 Assign GMO_flags. More...
 
virtual const char * GetDescription () const
 Fetch object description. More...
 
virtual void SetDescription (const char *)
 Set object description. More...
 
virtual char ** GetMetadataDomainList ()
 Fetch list of metadata domains. More...
 
virtual char ** GetMetadata (const char *pszDomain="")
 Fetch metadata. More...
 
virtual CPLErr SetMetadata (char **papszMetadata, const char *pszDomain="")
 Set metadata. More...
 
virtual const char * GetMetadataItem (const char *pszName, const char *pszDomain="")
 Fetch single metadata item. More...
 
virtual CPLErr SetMetadataItem (const char *pszName, const char *pszValue, const char *pszDomain="")
 Set single metadata item. More...
 

Static Public Member Functions

static void AutoLoadPythonDrivers ()
 Auto-load GDAL drivers from Python scripts. More...
 
static GDALMajorObjectH ToHandle (GDALMajorObject *poMajorObject)
 Convert a GDALMajorObject* to a GDALMajorObjectH. More...
 
static GDALMajorObjectFromHandle (GDALMajorObjectH hMajorObject)
 Convert a GDALMajorObjectH to a GDALMajorObject*. More...
 

Protected Member Functions

char ** BuildMetadataDomainList (char **papszList, int bCheckNonEmpty,...) CPL_NULL_TERMINATED
 Helper function for custom implementations of GetMetadataDomainList() More...
 

Detailed Description

Class for managing the registration of file format drivers.

Use GetGDALDriverManager() to fetch the global singleton instance of this class.

Member Function Documentation

◆ AutoLoadDrivers()

void GDALDriverManager::AutoLoadDrivers ( )

Auto-load GDAL drivers from shared libraries.

This function will automatically load drivers from shared libraries. It searches the "driver path" for .so (or .dll) files that start with the prefix "gdal_X.so". It then tries to load them and then tries to call a function within them called GDALRegister_X() where the 'X' is the same as the remainder of the shared library basename ('X' is case sensitive), or failing that to call GDALRegisterMe().

There are a few rules for the driver path. If the GDAL_DRIVER_PATH environment variable it set, it is taken to be a list of directories to search separated by colons on UNIX, or semi-colons on Windows. Otherwise the /usr/local/lib/gdalplugins directory, and (if known) the lib/gdalplugins subdirectory of the gdal home directory are searched on UNIX and \gdalplugins on Windows.

Auto loading can be completely disabled by setting the GDAL_DRIVER_PATH config option to "disable".

Starting with gdal 3.5, the default search path /lib/gdalplugins can be overridden at compile time by passing -DINSTALL_PLUGIN_DIR=/another/path to cmake.

◆ AutoLoadPythonDrivers()

void GDALDriverManager::AutoLoadPythonDrivers ( )
static

Auto-load GDAL drivers from Python scripts.

This function will automatically load drivers from Python scripts. It searches them first from the directory pointed by the GDAL_PYTHON_DRIVER_PATH configuration option. If not defined, it will use GDAL_DRIVER_PATH. If not defined, it will use the path for drivers hardcoded at build time. Scripts must begin with gdal_ or ogr_ and end up with .py

Since
GDAL 3.1

◆ AutoSkipDrivers()

void GDALDriverManager::AutoSkipDrivers ( )

This method unload undesirable drivers.

All drivers specified in the comma delimited list in the GDAL_SKIP environment variable) will be deregistered and destroyed. This method should normally be called after registration of standard drivers to allow the user a way of unloading undesired drivers. The GDALAllRegister() function already invokes AutoSkipDrivers() at the end, so if that functions is called, it should not be necessary to call this method from application code.

Note: space separator is also accepted for backward compatibility, but some vector formats have spaces in their names, so it is encouraged to use comma to avoid issues.

◆ BuildMetadataDomainList()

char ** GDALMajorObject::BuildMetadataDomainList ( char **  papszList,
int  bCheckNonEmpty,
  ... 
)
protectedinherited

Helper function for custom implementations of GetMetadataDomainList()

Parameters
papszListinitial list of domains. May be NULL. Will become invalid after function call (use return value)
bCheckNonEmptyif TRUE, each candidate domain will be tested to be non empty
...NULL terminated variadic list of candidate domains.
Returns
NULL or a string list. Must be freed with CSLDestroy()
Since
GDAL 1.11

◆ DeregisterDriver()

void GDALDriverManager::DeregisterDriver ( GDALDriver poDriver)

Deregister the passed driver.

If the driver isn't found no change is made.

The C analog is GDALDeregisterDriver().

Parameters
poDriverthe driver to deregister.

◆ FromHandle()

static GDALMajorObject * GDALMajorObject::FromHandle ( GDALMajorObjectH  hMajorObject)
inlinestaticinherited

Convert a GDALMajorObjectH to a GDALMajorObject*.

Since
GDAL 2.3

◆ GetDescription()

const char * GDALMajorObject::GetDescription ( ) const
virtualinherited

Fetch object description.

The semantics of the returned description are specific to the derived type. For GDALDatasets it is the dataset name. For GDALRasterBands it is actually a description (if supported) or "".

This method is the same as the C function GDALGetDescription().

Returns
non-null pointer to internal description string.

◆ GetDriver()

GDALDriver * GDALDriverManager::GetDriver ( int  iDriver)

Fetch driver by index.

This C analog to this is GDALGetDriver().

Parameters
iDriverthe driver index from 0 to GetDriverCount()-1.
Returns
the driver identified by the index or NULL if the index is invalid

◆ GetDriverByName()

GDALDriver * GDALDriverManager::GetDriverByName ( const char *  pszName)

Fetch a driver based on the short name.

The C analog is the GDALGetDriverByName() function.

Parameters
pszNamethe short name, such as GTiff, being searched for.
Returns
the identified driver, or NULL if no match is found.

◆ GetDriverCount()

int GDALDriverManager::GetDriverCount ( void  ) const

Fetch the number of registered drivers.

This C analog to this is GDALGetDriverCount().

Returns
the number of registered drivers.

◆ GetMetadata()

char ** GDALMajorObject::GetMetadata ( const char *  pszDomain = "")
virtualinherited

Fetch metadata.

The returned string list is owned by the object, and may change at any time. It is formatted as a "Name=value" list with the last pointer value being NULL. Use the CPL StringList functions such as CSLFetchNameValue() to manipulate it.

Note that relatively few formats return any metadata at this time.

This method does the same thing as the C function GDALGetMetadata().

Parameters
pszDomainthe domain of interest. Use "" or NULL for the default domain.
Returns
NULL or a string list.

Reimplemented in GDALPamDataset, and GDALDataset.

◆ GetMetadataDomainList()

char ** GDALMajorObject::GetMetadataDomainList ( )
virtualinherited

Fetch list of metadata domains.

The returned string list is the list of (non-empty) metadata domains.

This method does the same thing as the C function GDALGetMetadataDomainList().

Returns
NULL or a string list. Must be freed with CSLDestroy()
Since
GDAL 1.11

Reimplemented in GDALDataset.

◆ GetMetadataItem()

const char * GDALMajorObject::GetMetadataItem ( const char *  pszName,
const char *  pszDomain = "" 
)
virtualinherited

Fetch single metadata item.

The C function GDALGetMetadataItem() does the same thing as this method.

Parameters
pszNamethe key for the metadata item to fetch.
pszDomainthe domain to fetch for, use NULL for the default domain.
Returns
NULL on failure to find the key, or a pointer to an internal copy of the value string on success.

Reimplemented in GDALPamDataset.

◆ GetMOFlags()

int GDALMajorObject::GetMOFlags ( ) const
inherited

Returns the GMO_ flags.

Returns
flags

◆ RegisterDriver()

int GDALDriverManager::RegisterDriver ( GDALDriver poDriver)

Register a driver for use.

The C analog is GDALRegisterDriver().

Normally this method is used by format specific C callable registration entry points such as GDALRegister_GTiff() rather than being called directly by application level code.

If this driver (based on the object pointer, not short name) is already registered, then no change is made, and the index of the existing driver is returned. Otherwise the driver list is extended, and the new driver is added at the end.

Parameters
poDriverthe driver to register.
Returns
the index of the new installed driver.

◆ ReorderDrivers()

void GDALDriverManager::ReorderDrivers ( )

Reorder drivers according to the order of the drivers.ini file.

This function is called by GDALAllRegister(), at the end of driver loading, in particular after plugin loading. It will load the drivers.ini configuration file located next to plugins and will use it to reorder the registration order of drivers. This can be important in some situations where multiple drivers could open the same dataset.

◆ SetDescription()

void GDALMajorObject::SetDescription ( const char *  pszNewDesc)
virtualinherited

Set object description.

The semantics of the description are specific to the derived type. For GDALDatasets it is the dataset name. For GDALRasterBands it is actually a description (if supported) or "".

Normally application code should not set the "description" for GDALDatasets. It is handled internally.

This method is the same as the C function GDALSetDescription().

Reimplemented in GDALPamRasterBand.

◆ SetMetadata()

CPLErr GDALMajorObject::SetMetadata ( char **  papszMetadataIn,
const char *  pszDomain = "" 
)
virtualinherited

Set metadata.

The C function GDALSetMetadata() does the same thing as this method.

Parameters
papszMetadataInthe metadata in name=value string list format to apply.
pszDomainthe domain of interest. Use "" or NULL for the default domain.
Returns
CE_None on success, CE_Failure on failure and CE_Warning if the metadata has been accepted, but is likely not maintained persistently by the underlying object between sessions.

Reimplemented in GDALDataset, GDALRasterBand, GDALPamDataset, and GDALPamRasterBand.

◆ SetMetadataItem()

CPLErr GDALMajorObject::SetMetadataItem ( const char *  pszName,
const char *  pszValue,
const char *  pszDomain = "" 
)
virtualinherited

Set single metadata item.

The C function GDALSetMetadataItem() does the same thing as this method.

Parameters
pszNamethe key for the metadata item to fetch.
pszValuethe value to assign to the key.
pszDomainthe domain to set within, use NULL for the default domain.
Returns
CE_None on success, or an error code on failure.

Reimplemented in GDALDataset, GDALRasterBand, GDALPamDataset, GDALPamRasterBand, and GDALDriver.

◆ SetMOFlags()

void GDALMajorObject::SetMOFlags ( int  nNewFlags)
inherited

Assign GMO_flags.

Parameters
nNewFlagsnew flags.

◆ ToHandle()

static GDALMajorObjectH GDALMajorObject::ToHandle ( GDALMajorObject poMajorObject)
inlinestaticinherited

Convert a GDALMajorObject* to a GDALMajorObjectH.

Since
GDAL 2.3

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