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#ifndef _RTL_UUID_H_
#define _RTL_UUID_H_


#include <sal/types.h>
#include <rtl/string.h>

/**
   @HTML
   @file
   Specification (from draft-leach-uuids-guids-01.txt )

   <p>
   A UUID is an identifier that is unique across both space and time,
   with respect to the space of all UUIDs. To be precise, the UUID
   consists of a finite bit space. Thus, collision cannot be avoided in
   principle. A UUID can be used for multiple purposes, from tagging objects
   with an extremely short lifetime, to reliably identifying very persistent
   objects across a network.

   <p>
	The generation of UUIDs does not require that a registration
	authority be contacted for each identifier. Instead, Version 4 UUIDs are
    generated from (pseudo unique) sequences of (pseudo) random bits.
 */

#ifdef __cplusplus
extern "C" {
#endif	

/** Generates a new Version 4 (random number based) UUID (Universally Unique
    IDentifier).

	@param pTargetUUID          pointer to at least 16 bytes of memory. After the call it contains
	                            the newly generated uuid in network byte order.
	@param pPredecessorUUID     ignored (was used when this function returned
                                Version 1 instead of Version 4 UUIDs).
	@param bUseEthernetAddress  ignored (was used when this function returned
                                Version 1 instead of Version 4 UUIDs).
 */
void SAL_CALL rtl_createUuid( sal_uInt8 *pTargetUUID ,
							  const sal_uInt8 *pPredecessorUUID,
							  sal_Bool bUseEthernetAddress );

/** Compare two UUID's lexically

	<p>
	Note:   lexical ordering is not temporal ordering!
	<p>
	Note:   For equalnesschecking, a memcmp(pUUID1,pUUID2,16) is more efficient

	@return
	<ul>
	<li>-1   u1 is lexically before u2
	<li>0   u1 is equal to u2
	<li>1   u1 is lexically after u2
	</ul>

 */
sal_Int32 SAL_CALL rtl_compareUuid( const sal_uInt8 *pUUID1 , const sal_uInt8 *pUUID2 );

/** Creates named UUIDs.

	<p>
	The version 3 UUID is meant for generating UUIDs from <em>names</em> that
	are drawn from, and unique within, some <em>name space</em>. Some examples
	of names (and, implicitly, name spaces) might be DNS names, URLs, ISO
	Object IDs (OIDs), reserved words in a programming language, or X.500
	Distinguished Names (DNs); thus, the concept of name and name space
	should be broadly construed, and not limited to textual names. 

	<p>
	The requirements for such UUIDs are as follows:

	<ul>
	<li> The UUIDs generated at different times from the same name in the
         same namespace MUST be equal

	<li> The UUIDs generated from two different names in the same namespace
	     should be different (with very high probability)

	<li> The UUIDs generated from the same name in two different namespaces
	     should be different with (very high probability)

	<li> If two UUIDs that were generated from names are equal, then they
	     were generated from the same name in the same namespace (with very
	     high probability).
	</ul>

	@param pTargetUUID pointer to at least 16 bytes of memory. After the call
	                   it contains the newly generated uuid in network byte order.
	@param pNameSpaceUUID The namespace uuid. Below are some predefined ones,
	                      but any arbitray uuid can be used as namespace.

	@param pName the name
 */
void SAL_CALL rtl_createNamedUuid(
	sal_uInt8  *pTargetUUID,
	const sal_uInt8  *pNameSpaceUUID,
	const rtl_String *pName
	);



/*
	Predefined Namespaces
	(Use them the following way : sal_uInt8 aNsDNS[16])  = RTL_UUID_NAMESPACE_DNS;
 */
/** namesapce DNS

	<p>
	(Use them the following way : sal_uInt8 aNsDNS[16])  = RTL_UUID_NAMESPACE_DNS;
	<p>
   6ba7b810-9dad-11d1-80b4-00c04fd430c8 */
#define RTL_UUID_NAMESPACE_DNS {\
      0x6b,0xa7,0xb8,0x10,\
      0x9d,0xad,\
      0x11,0xd1,\
      0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8\
    }

/** namespace URL

   <p>
   6ba7b811-9dad-11d1-80b4-00c04fd430c8 */
#define RTL_UUID_NAMESPACE_URL { \
      0x6b, 0xa7, 0xb8, 0x11,\
      0x9d, 0xad,\
      0x11, 0xd1,\
      0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8\
    }

/** namespace oid

	<p>
	6ba7b812-9dad-11d1-80b4-00c04fd430c8 */
#define RTL_UUID_NAMESPACE_OID {\
      0x6b, 0xa7, 0xb8, 0x12,\
      0x9d, 0xad,\
      0x11, 0xd1,\
      0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8\
    }

/** namespace X500

	<p>
	6ba7b814-9dad-11d1-80b4-00c04fd430c8 */
#define RTL_UUID_NAMESPACE_X500 {\
      0x6b, 0xa7, 0xb8, 0x14,\
      0x9d, 0xad,\
      0x11, 0xd1,\
      0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8\
    }
	

/*
	This macro must have a value below the system time resolution of the
	system. The uuid routines use this value  as an upper limit for adding ticks to the
	the predecessor time value if system times are equal.
 */
#ifdef SAL_W32
#define UUID_SYSTEM_TIME_RESOLUTION_100NS_TICKS 1000
#elif defined SAL_OS2 // YD we use posix functions for time
#define UUID_SYSTEM_TIME_RESOLUTION_100NS_TICKS 10
#elif LINUX
#define UUID_SYSTEM_TIME_RESOLUTION_100NS_TICKS 10
#elif NETBSD
#define UUID_SYSTEM_TIME_RESOLUTION_100NS_TICKS 10
#elif FREEBSD
#define UUID_SYSTEM_TIME_RESOLUTION_100NS_TICKS 10
#elif SOLARIS
#define UUID_SYSTEM_TIME_RESOLUTION_100NS_TICKS 10
#elif MACOSX
#define UUID_SYSTEM_TIME_RESOLUTION_100NS_TICKS 100000
#else
#error "System time resolution must be calculated!"
#endif

#ifdef __cplusplus
}
#endif

#endif