kicad/common/kiid.cpp

319 lines
7.4 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2020 Ian McInerney <ian.s.mcinerney@ieee.org>
* Copyright (C) 2007-2014 Jean-Pierre Charras, jp.charras at wanadoo.fr
* Copyright (C) 1992-2021 KiCad Developers, see AUTHORS.TXT for contributors.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <kiid.h>
#include <boost/uuid/uuid_generators.hpp>
#include <boost/uuid/uuid_io.hpp>
#include <boost/functional/hash.hpp>
#if BOOST_VERSION >= 106700
#include <boost/uuid/entropy_error.hpp>
#endif
#include <mutex>
#include <wx/log.h>
// boost:mt19937 is not thread-safe
static std::mutex rng_mutex;
// Create only once, as seeding is *very* expensive
static boost::mt19937 rng;
static boost::uuids::basic_random_generator<boost::mt19937> randomGenerator( rng );
// These don't have the same performance penalty, but we might as well be consistent
static boost::uuids::string_generator stringGenerator;
static boost::uuids::nil_generator nilGenerator;
// Global nil reference
KIID niluuid( 0 );
// When true, always create nil uuids for performance, when valid ones aren't needed
static bool g_createNilUuids = false;
// For static initialization
KIID& NilUuid()
{
static KIID nil( 0 );
return nil;
}
KIID::KIID()
{
m_cached_timestamp = 0;
#if BOOST_VERSION >= 106700
try
{
#endif
if( g_createNilUuids )
{
m_uuid = nilGenerator();
}
else
{
std::lock_guard<std::mutex> lock( rng_mutex );
m_uuid = randomGenerator();
}
#if BOOST_VERSION >= 106700
}
catch( const boost::uuids::entropy_error& )
{
wxLogFatalError( "A Boost UUID entropy exception was thrown in %s:%s.",
__FILE__, __FUNCTION__ );
}
#endif
}
KIID::KIID( int null ) : m_uuid( nilGenerator() ), m_cached_timestamp( 0 )
{
wxASSERT( null == 0 );
}
KIID::KIID( const wxString& aString ) : m_uuid(), m_cached_timestamp( 0 )
{
if( aString.length() == 8 )
{
// A legacy-timestamp-based UUID has only the last 4 octets filled in.
// Convert them individually to avoid stepping in the little-endian/big-endian
// doo-doo.
for( int i = 0; i < 4; ++i )
{
wxString octet = aString.substr( i * 2, 2 );
m_uuid.data[i + 12] = strtol( octet.data(), nullptr, 16 );
}
m_cached_timestamp = strtol( aString.c_str(), nullptr, 16 );
}
else
{
try
{
m_uuid = stringGenerator( aString.wc_str() );
if( IsLegacyTimestamp() )
m_cached_timestamp = strtol( aString.substr( 28 ).c_str(), nullptr, 16 );
}
catch( ... )
{
// Failed to parse string representation; best we can do is assign a new
// random one.
#if BOOST_VERSION >= 106700
try
{
#endif
m_uuid = randomGenerator();
#if BOOST_VERSION >= 106700
}
catch( const boost::uuids::entropy_error& )
{
wxLogFatalError( "A Boost UUID entropy exception was thrown in %s:%s.",
__FILE__, __FUNCTION__ );
}
#endif
}
}
}
bool KIID::SniffTest( const wxString& aCandidate )
{
static wxString niluuidStr = niluuid.AsString();
if( aCandidate.Length() != niluuidStr.Length() )
return false;
for( wxChar c : aCandidate )
{
if( c >= '0' && c <= '9' )
continue;
if( c >= 'a' && c <= 'f' )
continue;
if( c >= 'A' && c <= 'F' )
continue;
if( c == '-' )
continue;
return false;
}
return true;
}
KIID::KIID( timestamp_t aTimestamp )
{
m_cached_timestamp = aTimestamp;
// A legacy-timestamp-based UUID has only the last 4 octets filled in.
// Convert them individually to avoid stepping in the little-endian/big-endian
// doo-doo.
wxString str = AsLegacyTimestampString();
for( int i = 0; i < 4; ++i )
{
wxString octet = str.substr( i * 2, 2 );
m_uuid.data[i + 12] = strtol( octet.data(), nullptr, 16 );
}
}
bool KIID::IsLegacyTimestamp() const
{
return !m_uuid.data[8] && !m_uuid.data[9] && !m_uuid.data[10] && !m_uuid.data[11];
}
timestamp_t KIID::AsLegacyTimestamp() const
{
return m_cached_timestamp;
}
size_t KIID::Hash() const
{
size_t hash = 0;
// Note: this is NOT little-endian/big-endian safe, but as long as it's just used
// at runtime it won't matter.
for( int i = 0; i < 4; ++i )
boost::hash_combine( hash, reinterpret_cast<const uint32_t*>( m_uuid.data )[i] );
return hash;
}
void KIID::Clone( const KIID& aUUID )
{
m_uuid = aUUID.m_uuid;
m_cached_timestamp = aUUID.m_cached_timestamp;
}
wxString KIID::AsString() const
{
return boost::uuids::to_string( m_uuid );
}
wxString KIID::AsLegacyTimestampString() const
{
return wxString::Format( "%8.8lX", (unsigned long) AsLegacyTimestamp() );
}
void KIID::ConvertTimestampToUuid()
{
if( !IsLegacyTimestamp() )
return;
m_cached_timestamp = 0;
m_uuid = randomGenerator();
}
void KIID::Increment()
{
// This obviously destroys uniform distribution, but it can be useful when a
// deterministic replacement for a duplicate ID is required.
for( int i = 15; i >= 0; --i )
{
m_uuid.data[i]++;
if( m_uuid.data[i] != 0 )
break;
}
}
void KIID::CreateNilUuids( bool aNil )
{
g_createNilUuids = aNil;
}
void KIID::SeedGenerator( unsigned int aSeed )
{
rng.seed( aSeed );
}
KIID_PATH::KIID_PATH( const wxString& aString )
{
for( const wxString& pathStep : wxSplit( aString, '/' ) )
{
if( !pathStep.empty() )
emplace_back( KIID( pathStep ) );
}
}
bool KIID_PATH::MakeRelativeTo( const KIID_PATH& aPath )
{
KIID_PATH copy = *this;
clear();
if( aPath.size() > copy.size() )
return false; // this path is not contained within aPath
for( size_t i = 0; i < aPath.size(); ++i )
{
if( copy.at( i ).AsString() != aPath.at( i ).AsString() )
return false; // this path is not contained within aPath
}
for( size_t i = aPath.size(); i < copy.size(); ++i )
push_back( copy.at( i ) );
return true;
}
wxString KIID_PATH::AsString() const
{
wxString path;
for( const KIID& pathStep : *this )
path += '/' + pathStep.AsString();
return path;
}