uuid.cpp

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/*
 * uuid.cpp
 *
 * Copyright (C) 2010  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THOMAS A. VAUGHAN BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 */

// includes --------------------------------------------------------------------
#include "uuid.h"               // always include our own header first!

#ifdef WIN32
#include "rpc.h"
#endif  // WIN32


////////////////////////////////////////////////////////////////////////////////
//
//      static helper methods
//
////////////////////////////////////////////////////////////////////////////////

#ifndef WIN32
static word_t
getr4
(
void
)
throw()
{
        static bool initRandom = false;
        if (!initRandom) {
                DPRINTF("TODO: link to proper UUID generation libraries!");
                srand(time(NULL) + 7 * getpid());
                initRandom = true;
        }

        // return 2-byte (4 hex character) random number
        return (rand() % 0x10000);
}
#endif  // WIN32


////////////////////////////////////////////////////////////////////////////////
//
//      public API
//
////////////////////////////////////////////////////////////////////////////////

const char *
generateUUID
(
OUT char * buffer
)
{
        ASSERT(buffer, "null");

#ifdef WIN32
        UUID uuid;
        UuidCreate(&uuid);
        unsigned char * rpcString = NULL;
        UuidToString(&uuid, &rpcString);
        ASSERT_THROW(rpcString, "windows returned null string for UUID");
        strcpy(buffer, (const char *) rpcString);
        RpcStringFree(&rpcString);
#else   // WIN32
        snprintf(buffer, eUUID_Length,
            "%04x%04x-%04x-%04x-%04x-%04x%08x",
            getr4(), getr4(), getr4(), getr4(), getr4(),
            (word_t) getpid(), (dword_t) time(NULL));
#endif  // WIN32
        DPRINTF("  uuid: '%s'", buffer);

        return buffer;
}