Source/core/platform/UUID.cpp

/*
* Copyright (C) 2010 Google Inc. All rights reserved.
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#include "config.h"
#include "core/platform/UUID.h"

#include "wtf/CryptographicallyRandomNumber.h"
#include "wtf/HexNumber.h"
#include "wtf/text/StringBuilder.h"

namespace WebCore {

String createCanonicalUUIDString()
{
    unsigned randomData[4];
    cryptographicallyRandomValues(reinterpret_cast<unsigned char*>(randomData), sizeof(randomData));

    // Format as Version 4 UUID.
    StringBuilder builder;
    builder.reserveCapacity(36);
    appendUnsignedAsHexFixedSize(randomData[0], builder, 8, Lowercase);
    builder.append("-");
    appendUnsignedAsHexFixedSize(randomData[1] >> 16, builder, 4, Lowercase);
    builder.append("-4");
    appendUnsignedAsHexFixedSize(randomData[1] & 0x00000fff, builder, 3, Lowercase);
    builder.append("-");
    appendUnsignedAsHexFixedSize((randomData[2] >> 30) | 0x8, builder, 1, Lowercase);
    appendUnsignedAsHexFixedSize((randomData[2] >> 16) & 0x00000fff, builder, 3, Lowercase);
    builder.append("-");
    appendUnsignedAsHexFixedSize(randomData[2] & 0x0000ffff, builder, 4, Lowercase);
    appendUnsignedAsHexFixedSize(randomData[3], builder, 8, Lowercase);
    return builder.toString();
}

}