Compounds | |||
![]() | ![]() | struct | UDataInfo |
Typedefs | |||
![]() | ![]() | typedef struct UDataMemory | UDataMemory |
![]() | ![]() | Forward declaration of the data memory type. | |
![]() | ![]() | typedef bool_t | UDataMemoryIsAcceptable (void *context, const char *type, const char *name, UDataInfo *pInfo) |
![]() | ![]() | Callback function for udata_openChoice(). More... | |
Functions | |||
![]() | ![]() | U_CAPI UDataMemory* U_EXPORT2 | udata_open (const char *path, const char *type, const char *name, UErrorCode *pErrorCode) |
![]() | ![]() | Convenience function. More... | |
![]() | ![]() | U_CAPI UDataMemory* U_EXPORT2 | udata_openChoice (const char *path, const char *type, const char *name, UDataMemoryIsAcceptable *isAcceptable, void *context, UErrorCode *pErrorCode) |
![]() | ![]() | Data loading function. More... | |
![]() | ![]() | U_CAPI void U_EXPORT2 | udata_close (UDataMemory *pData) |
![]() | ![]() | Close the data memory. More... | |
![]() | ![]() | U_CAPI const void* U_EXPORT2 | udata_getMemory (UDataMemory *pData) |
![]() | ![]() | Get the pointer to the actual data inside the data memory. More... | |
![]() | ![]() | U_CAPI void U_EXPORT2 | udata_getInfo (UDataMemory *pData, UDataInfo *pInfo) |
![]() | ![]() | Get the information from the data memory header. More... |
typedef struct UDataMemory UDataMemory |
Forward declaration of the data memory type.
typedef bool_t UDataMemoryIsAcceptable(void *context, const char *type, const char *name, UDataInfo *pInfo) |
Callback function for udata_openChoice().
context |
parameter passed into udata_openChoice() . |
type |
The type of the data as passed into udata_openChoice() . It may be NULL . |
name |
The name of the data as passed into udata_openChoice() . |
pInfo |
A pointer to the UDataInfo structure of data that has been loaded and will be returned by udata_openChoice() if this function returns TRUE . |
U_CAPI UDataMemory *U_EXPORT2 udata_open (const char * path, const char * type, const char * name, UErrorCode * pErrorCode) |
Convenience function.
This function works the same as udata_openChoice
except that any data that matches the type and name is assumed to be acceptable.
U_CAPI UDataMemory *U_EXPORT2 udata_openChoice (const char * path, const char * type, const char * name, UDataMemoryIsAcceptable * isAcceptable, void * context, UErrorCode * pErrorCode) |
Data loading function.
This function is used to find and load efficiently data for ICU and applications using ICU. It provides an abstract interface that allows to specify a data type and name to find and load the data.
The implementation depends on platform properties and user preferences and may involve loading shared libraries (DLLs), mapping files into memory, or fopen()/fread() files. It may also involve using static memory or database queries etc. Several or all data items may be combined into one entity (DLL, memory-mappable file).
The data is always preceded by a header that includes a UDataInfo
structure. The caller's isAcceptable()
function is called to make sure that the data is useful. It may be called several times if it rejects the data and there is more than one location with data matching the type and name.
If path==NULL
, then ICU data is loaded. Otherwise, it is separated into a basename and a basename-less path string. If the path string is empty, then u_getDataDirectory()
is set in its place. When data is loaded from files or DLLs (shared libraries) and may be stored in common files, then the data finding is roughly as follows:
path |
Specifies an absolute path and/or a basename for the finding of the data in the file system. NULL for ICU data. |
type |
A string that specifies the type of data to be loaded. For example, resource bundles are loaded with type "res", conversion tables with type "cnv". This may be NULL or empty. |
name | A string that specifies the name of the data. |
isAcceptable |
This function is called to verify that loaded data is useful for the client code. If it returns FALSE for all data items, then udata_openChoice() will return with an error. |
context | Arbitrary parameter to be passed into isAcceptable. |
pErrorCode |
An ICU UErrorCode parameter. It must not be NULL . |
NULL
if an error occurs. Call udata_getMemory()
to get a pointer to the actual data. U_CAPI void U_EXPORT2 udata_close (UDataMemory * pData) |
Close the data memory.
This function must be called to allow the system to release resources associated with this data memory.
U_CAPI const void *U_EXPORT2 udata_getMemory (UDataMemory * pData) |
Get the pointer to the actual data inside the data memory.
The data is read-only.
U_CAPI void U_EXPORT2 udata_getInfo (UDataMemory * pData, UDataInfo * pInfo) |
Get the information from the data memory header.
This allows to get access to the header containing platform data properties etc. which is not part of the data itself and can therefore not be accessed via the pointer that udata_getMemory()
returns.
pData | pointer to the data memory object |
pInfo |
pointer to a UDataInfo object; its size field must be set correctly, typically to sizeof(UDataInfo) .
|
*pInfo
will be filled with the UDataInfo structure in the data memory object. If this structure is smaller than pInfo->size
, then the size
will be adjusted and only part of the structure will be filled.