ICU 59.1  59.1
Data Fields
UDataInfo Struct Reference

UDataInfo contains the properties about the requested data. More...

#include <udata.h>

Data Fields

uint16_t size
 sizeof(UDataInfo) More...
 
uint16_t reservedWord
 unused, set to 0 More...
 
uint8_t isBigEndian
 0 for little-endian machine, 1 for big-endian More...
 
uint8_t charsetFamily
 see U_CHARSET_FAMILY values in utypes.h More...
 
uint8_t sizeofUChar
 sizeof(UChar), one of { 1, 2, 4 } More...
 
uint8_t reservedByte
 unused, set to 0 More...
 
uint8_t dataFormat [4]
 data format identifier More...
 
uint8_t formatVersion [4]
 versions: [0] major [1] minor [2] milli [3] micro More...
 
uint8_t dataVersion [4]
 versions: [0] major [1] minor [2] milli [3] micro More...
 

Detailed Description

UDataInfo contains the properties about the requested data.

This is meta data.

This structure may grow in the future, indicated by the size field.

ICU data must be at least 8-aligned, and should be 16-aligned. The UDataInfo struct begins 4 bytes after the start of the data item, so it is 4-aligned.

The platform data property fields help determine if a data file can be efficiently used on a given machine. The particular fields are of importance only if the data is affected by the properties - if there is integer data with word sizes > 1 byte, char* text, or UChar* text.

The implementation for the udata_open[Choice]() functions may reject data based on the value in isBigEndian. No other field is used by the udata API implementation.

The dataFormat may be used to identify the kind of data, e.g. a converter table.

The formatVersion field should be used to make sure that the format can be interpreted. It may be a good idea to check only for the one or two highest of the version elements to allow the data memory to get more or somewhat rearranged contents, for as long as the using code can still interpret the older contents.

The dataVersion field is intended to be a common place to store the source version of the data; for data from the Unicode character database, this could reflect the Unicode version.

Stable:
ICU 2.0

Definition at line 113 of file udata.h.

Field Documentation

§ charsetFamily

uint8_t UDataInfo::charsetFamily

see U_CHARSET_FAMILY values in utypes.h

Stable:
ICU 2.0

Definition at line 129 of file udata.h.

§ dataFormat

uint8_t UDataInfo::dataFormat[4]

data format identifier

Stable:
ICU 2.0

Definition at line 141 of file udata.h.

§ dataVersion

uint8_t UDataInfo::dataVersion[4]

versions: [0] major [1] minor [2] milli [3] micro

Stable:
ICU 2.0

Definition at line 149 of file udata.h.

§ formatVersion

uint8_t UDataInfo::formatVersion[4]

versions: [0] major [1] minor [2] milli [3] micro

Stable:
ICU 2.0

Definition at line 145 of file udata.h.

§ isBigEndian

uint8_t UDataInfo::isBigEndian

0 for little-endian machine, 1 for big-endian

Stable:
ICU 2.0

Definition at line 125 of file udata.h.

§ reservedByte

uint8_t UDataInfo::reservedByte

unused, set to 0

Stable:
ICU 2.0

Definition at line 137 of file udata.h.

§ reservedWord

uint16_t UDataInfo::reservedWord

unused, set to 0

Stable:
ICU 2.0

Definition at line 120 of file udata.h.

§ size

uint16_t UDataInfo::size

sizeof(UDataInfo)

Stable:
ICU 2.0

Definition at line 116 of file udata.h.

§ sizeofUChar

uint8_t UDataInfo::sizeofUChar

sizeof(UChar), one of { 1, 2, 4 }

Stable:
ICU 2.0

Definition at line 133 of file udata.h.


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