CFUUID Reference

Overview

CFUUID objects are used by plug-ins to uniquely identify types, interfaces, and factories. When creating a new type, host developers must generate UUIDs to identify the type as well as its interfaces and factories.

UUIDs (Universally Unique Identifiers), also known as GUIDs (Globally Unique Identifiers) or IIDs (Interface Identifiers), are 128-bit values guaranteed to be unique. A UUID is made unique over both space and time by combining a value unique to the computer on which it was generated—usually the Ethernet hardware address—and a value representing the number of 100-nanosecond intervals since October 15, 1582 at 00:00:00.

The standard format for UUIDs represented in ASCII is a string punctuated by hyphens, for example 68753A44-4D6F-1226-9C60-0050E4C00067. The hex representation looks, as you might expect, like a list of numerical values preceded by 0x. For example, 0xD7, 0x36, 0x95, 0x0A, 0x4D, 0x6E, 0x12, 0x26, 0x80, 0x3A, 0x00, 0x50, 0xE4, 0xC0, 0x00, 0x67 . To use a UUID, you simply create it and then copy the resulting strings into your header and C language source files. Because a UUID is expressed simply as an array of bytes, there are no endianness considerations for different platforms.

You can create a CFUUID object, and thereby generate a UUID, using any one of the CFUUIDCreate... functions. Use the CFUUIDGetConstantUUIDWithBytes function if you want to declare a UUID constant in a #define statement. You can get the raw bytes of an existing CFUUID object using the CFUUIDGetUUIDBytes function.

Functions by Task

Creating CFUUID Objects

• CFUUIDCreate
• CFUUIDCreateFromString
• CFUUIDCreateFromUUIDBytes
• CFUUIDCreateWithBytes

Getting Information About CFUUID Objects

• CFUUIDCreateString
• CFUUIDGetConstantUUIDWithBytes
• CFUUIDGetUUIDBytes

Getting the CFUUID Type Identifier

• CFUUIDGetTypeID

Functions

CFUUIDCreate

Creates a Universally Unique Identifier (UUID) object.

CFUUIDRef CFUUIDCreate (
   CFAllocatorRef alloc
);

CFUUIDCreateFromString

Creates a CFUUID object for a specified string.

CFUUIDRef CFUUIDCreateFromString (
   CFAllocatorRef alloc,
   CFStringRef uuidStr
);

CFUUIDCreateFromUUIDBytes

Creates a CFUUID object from raw UUID bytes.

CFUUIDRef CFUUIDCreateFromUUIDBytes (
   CFAllocatorRef alloc,
   CFUUIDBytes bytes
);

CFUUIDCreateString

Returns the string representation of a specified CFUUID object.

CFStringRef CFUUIDCreateString (
   CFAllocatorRef alloc,
   CFUUIDRef uuid
);

CFUUIDCreateWithBytes

Creates a CFUUID object from raw UUID bytes.

CFUUIDRef CFUUIDCreateWithBytes (
   CFAllocatorRef alloc,
   UInt8 byte0,
   UInt8 byte1,
   UInt8 byte2,
   UInt8 byte3,
   UInt8 byte4,
   UInt8 byte5,
   UInt8 byte6,
   UInt8 byte7,
   UInt8 byte8,
   UInt8 byte9,
   UInt8 byte10,
   UInt8 byte11,
   UInt8 byte12,
   UInt8 byte13,
   UInt8 byte14,
   UInt8 byte15
);

CFUUIDGetConstantUUIDWithBytes

Returns a CFUUID object from raw UUID bytes.

CFUUIDRef CFUUIDGetConstantUUIDWithBytes (
   CFAllocatorRef alloc,
   UInt8 byte0,
   UInt8 byte1,
   UInt8 byte2,
   UInt8 byte3,
   UInt8 byte4,
   UInt8 byte5,
   UInt8 byte6,
   UInt8 byte7,
   UInt8 byte8,
   UInt8 byte9,
   UInt8 byte10,
   UInt8 byte11,
   UInt8 byte12,
   UInt8 byte13,
   UInt8 byte14,
   UInt8 byte15
);

CFUUIDGetTypeID

Returns the type identifier for all CFUUID objects.

CFTypeID CFUUIDGetTypeID (
   void
);

CFUUIDGetUUIDBytes

Returns the value of a UUID object as raw bytes.

CFUUIDBytes CFUUIDGetUUIDBytes (
   CFUUIDRef uuid
);

Data Types

CFUUIDBytes

A 128-bit struct that represents a UUID as raw bytes.

typedef struct {
   UInt8 byte0;
   UInt8 byte1;
   UInt8 byte2;
   UInt8 byte3;
   UInt8 byte4;
   UInt8 byte5;
   UInt8 byte6;
   UInt8 byte7;
   UInt8 byte8;
   UInt8 byte9;
   UInt8 byte10;
   UInt8 byte11;
   UInt8 byte12;
   UInt8 byte13;
   UInt8 byte14;
   UInt8 byte15;
} CFUUIDBytes;

Fields

byte0

The first byte.

byte1

The second byte.

byte2

The third byte.

byte3

The fourth byte.

byte4

The fifth byte.

byte5

The sixth byte.

byte6

The seventh byte.

byte7

The eighth byte.

byte8

The ninth byte.

byte9

The tenth byte.

byte10

The eleventh byte.

byte11

The twelfth byte.

byte12

The thirteenth byte.

byte13

The fourteenth byte.

byte14

The fifteenth byte.

byte15

The sixteenth byte.

CFUUIDRef

A reference to a CFUUID object.

typedef const struct __CFUUID *CFUUIDRef;