Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 486 insertions, 0 deletions

diff --git a/tools/source/generic/fract.cxx b/tools/source/generic/fract.cxx
new file mode 100644
index 000000000..7f2ffba10
--- /dev/null
+++ b/tools/source/generic/fract.cxx
@@ -0,0 +1,486 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <tools/fract.hxx>
+#include <tools/debug.hxx>
+#include <o3tl/hash_combine.hxx>
+#include <o3tl/safeint.hxx>
+#include <sal/log.hxx>
+#include <osl/diagnose.h>
+
+#include <algorithm>
+#include <cmath>
+#include <numeric>
+
+#include <boost/rational.hpp>
+
+#ifdef _MSC_VER
+#include <intrin.h>
+#endif
+
+static boost::rational<sal_Int32> rational_FromDouble(double dVal);
+static void rational_ReduceInaccurate(boost::rational<sal_Int32>& rRational, unsigned nSignificantBits);
+static int impl_NumberOfBits( sal_uInt32 nNum );
+
+static boost::rational<sal_Int32> toRational(sal_Int32 n, sal_Int32 d)
+{
+    // https://github.com/boostorg/boost/issues/335 when these are std::numeric_limits<sal_Int32>::min
+    if (n == d)
+        return 1;
+    // tdf#144319 avoid boost::bad_rational e.g. if numerator=-476741369, denominator=-2147483648
+    if (d < -std::numeric_limits<sal_Int32>::max())
+        return 0;
+    return boost::rational<sal_Int32>(n, d);
+}
+
+// Initialized by setting nNum as nominator and nDen as denominator
+// Negative values in the denominator are invalid and cause the
+// inversion of both nominator and denominator signs
+// in order to return the correct value.
+Fraction::Fraction( sal_Int64 nNum, sal_Int64 nDen ) : mnNumerator(nNum), mnDenominator(nDen)
+{
+    assert( nNum >= std::numeric_limits<sal_Int32>::min() );
+    assert( nNum <= std::numeric_limits<sal_Int32>::max( ));
+    assert( nDen >= std::numeric_limits<sal_Int32>::min() );
+    assert( nDen <= std::numeric_limits<sal_Int32>::max( ));
+    if ( nDen == 0 )
+    {
+        mbValid = false;
+        SAL_WARN( "tools.fraction", "'Fraction(" << nNum << ",0)' invalid fraction created" );
+        return;
+    }
+    if ((nDen == -1 && nNum == std::numeric_limits<sal_Int32>::min()) ||
+        (nNum == -1 && nDen == std::numeric_limits<sal_Int32>::min()))
+    {
+        mbValid = false;
+        SAL_WARN("tools.fraction", "'Fraction(" << nNum << "," << nDen << ")' invalid fraction created");
+        return;
+    }
+}
+
+/**
+ * only here to prevent passing of NaN
+ */
+Fraction::Fraction( double nNum, double nDen ) : mnNumerator(sal_Int64(nNum)), mnDenominator(sal_Int64(nDen))
+{
+    assert( !std::isnan(nNum) );
+    assert( !std::isnan(nDen) );
+    assert( nNum >= std::numeric_limits<sal_Int32>::min() );
+    assert( nNum <= std::numeric_limits<sal_Int32>::max( ));
+    assert( nDen >= std::numeric_limits<sal_Int32>::min() );
+    assert( nDen <= std::numeric_limits<sal_Int32>::max( ));
+    if ( nDen == 0 )
+    {
+        mbValid = false;
+        SAL_WARN( "tools.fraction", "'Fraction(" << nNum << ",0)' invalid fraction created" );
+        return;
+    }
+}
+
+Fraction::Fraction( double dVal )
+{
+    try
+    {
+        boost::rational<sal_Int32> v = rational_FromDouble( dVal );
+        mnNumerator = v.numerator();
+        mnDenominator = v.denominator();
+    }
+    catch (const boost::bad_rational&)
+    {
+        mbValid = false;
+        SAL_WARN( "tools.fraction", "'Fraction(" << dVal << ")' invalid fraction created" );
+    }
+}
+
+Fraction::operator double() const
+{
+    if (!mbValid)
+    {
+        SAL_WARN( "tools.fraction", "'double()' on invalid fraction" );
+        return 0.0;
+    }
+
+    return boost::rational_cast<double>(toRational(mnNumerator, mnDenominator));
+}
+
+// This methods first validates both values.
+// If one of the arguments is invalid, the whole operation is invalid.
+// After computation detect if result overflows a sal_Int32 value
+// which cause the operation to be marked as invalid
+Fraction& Fraction::operator += ( const Fraction& rVal )
+{
+    if ( !rVal.mbValid )
+        mbValid = false;
+
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator +=' with invalid fraction" );
+        return *this;
+    }
+
+    boost::rational<sal_Int32> a = toRational(mnNumerator, mnDenominator);
+    a += toRational(rVal.mnNumerator, rVal.mnDenominator);
+    mnNumerator = a.numerator();
+    mnDenominator = a.denominator();
+
+    return *this;
+}
+
+Fraction& Fraction::operator -= ( const Fraction& rVal )
+{
+    if ( !rVal.mbValid )
+        mbValid = false;
+
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator -=' with invalid fraction" );
+        return *this;
+    }
+
+    boost::rational<sal_Int32> a = toRational(mnNumerator, mnDenominator);
+    a -= toRational(rVal.mnNumerator, rVal.mnDenominator);
+    mnNumerator = a.numerator();
+    mnDenominator = a.denominator();
+
+    return *this;
+}
+
+namespace
+{
+    bool checked_multiply_by(boost::rational<sal_Int32>& i, const boost::rational<sal_Int32>& r)
+    {
+        // Protect against self-modification
+        sal_Int32 num = r.numerator();
+        sal_Int32 den = r.denominator();
+
+        // Fast-path if the number of bits in input is < the number of bits in the output, overflow cannot happen
+        // This is considerably faster than repeated std::gcd() operations
+        if ((impl_NumberOfBits(std::abs(i.numerator())) + impl_NumberOfBits(std::abs(r.numerator()))) < 32 &&
+            (impl_NumberOfBits(std::abs(i.denominator())) + impl_NumberOfBits(std::abs(r.denominator()))) < 32)
+        {
+            i *= r;
+            return false;
+        }
+
+        // Avoid overflow and preserve normalization
+        sal_Int32 gcd1 = std::gcd(i.numerator(), den);
+        sal_Int32 gcd2 = std::gcd(num, i.denominator());
+
+        if (!gcd1 || !gcd2)
+            return true;
+
+        bool fail = false;
+        fail |= o3tl::checked_multiply(i.numerator() / gcd1, num / gcd2, num);
+        fail |= o3tl::checked_multiply(i.denominator() / gcd2, den / gcd1, den);
+
+        if (!fail)
+            i.assign(num, den);
+
+        return fail;
+    }
+}
+
+Fraction& Fraction::operator *= ( const Fraction& rVal )
+{
+    if ( !rVal.mbValid )
+        mbValid = false;
+
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator *=' with invalid fraction" );
+        return *this;
+    }
+
+    boost::rational<sal_Int32> a = toRational(mnNumerator, mnDenominator);
+    boost::rational<sal_Int32> b = toRational(rVal.mnNumerator, rVal.mnDenominator);
+    bool bFail = checked_multiply_by(a, b);
+    mnNumerator = a.numerator();
+    mnDenominator = a.denominator();
+
+    if (bFail)
+    {
+        mbValid = false;
+    }
+
+    return *this;
+}
+
+Fraction& Fraction::operator /= ( const Fraction& rVal )
+{
+    if ( !rVal.mbValid )
+        mbValid = false;
+
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator /=' with invalid fraction" );
+        return *this;
+    }
+
+    boost::rational<sal_Int32> a = toRational(mnNumerator, mnDenominator);
+    a /= toRational(rVal.mnNumerator, rVal.mnDenominator);
+    mnNumerator = a.numerator();
+    mnDenominator = a.denominator();
+
+    return *this;
+}
+
+/** Inaccurate cancellation for a fraction.
+
+    Clip both nominator and denominator to said number of bits. If
+    either of those already have equal or less number of bits used,
+    this method does nothing.
+
+    @param nSignificantBits denotes, how many significant binary
+    digits to maintain, in both nominator and denominator.
+
+    @example ReduceInaccurate(8) has an error <1% [1/2^(8-1)] - the
+    largest error occurs with the following pair of values:
+
+    binary    1000000011111111111111111111111b/1000000000000000000000000000000b
+    =         1082130431/1073741824
+    = approx. 1.007812499
+
+    A ReduceInaccurate(8) yields 1/1.
+*/
+void Fraction::ReduceInaccurate( unsigned nSignificantBits )
+{
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'ReduceInaccurate' on invalid fraction" );
+        return;
+    }
+
+    if ( !mnNumerator )
+        return;
+
+    auto a = toRational(mnNumerator, mnDenominator);
+    rational_ReduceInaccurate(a, nSignificantBits);
+    mnNumerator = a.numerator();
+    mnDenominator = a.denominator();
+}
+
+sal_Int32 Fraction::GetNumerator() const
+{
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'GetNumerator()' on invalid fraction" );
+        return 0;
+    }
+    return mnNumerator;
+}
+
+sal_Int32 Fraction::GetDenominator() const
+{
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'GetDenominator()' on invalid fraction" );
+        return -1;
+    }
+    return mnDenominator;
+}
+
+Fraction::operator sal_Int32() const
+{
+    if ( !mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator sal_Int32()' on invalid fraction" );
+        return 0;
+    }
+    return boost::rational_cast<sal_Int32>(toRational(mnNumerator, mnDenominator));
+}
+
+Fraction operator+( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    Fraction aErg( rVal1 );
+    aErg += rVal2;
+    return aErg;
+}
+
+Fraction operator-( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    Fraction aErg( rVal1 );
+    aErg -= rVal2;
+    return aErg;
+}
+
+Fraction operator*( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    Fraction aErg( rVal1 );
+    aErg *= rVal2;
+    return aErg;
+}
+
+Fraction operator/( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    Fraction aErg( rVal1 );
+    aErg /= rVal2;
+    return aErg;
+}
+
+bool operator !=( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    return !(rVal1 == rVal2);
+}
+
+bool operator <=( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    return !(rVal1 > rVal2);
+}
+
+bool operator >=( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    return !(rVal1 < rVal2);
+}
+
+bool operator == ( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    if ( !rVal1.mbValid || !rVal2.mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator ==' with an invalid fraction" );
+        return false;
+    }
+
+    return toRational(rVal1.mnNumerator, rVal1.mnDenominator) == toRational(rVal2.mnNumerator, rVal2.mnDenominator);
+}
+
+bool operator < ( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    if ( !rVal1.mbValid || !rVal2.mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator <' with an invalid fraction" );
+        return false;
+    }
+
+    return toRational(rVal1.mnNumerator, rVal1.mnDenominator) < toRational(rVal2.mnNumerator, rVal2.mnDenominator);
+}
+
+bool operator > ( const Fraction& rVal1, const Fraction& rVal2 )
+{
+    if ( !rVal1.mbValid || !rVal2.mbValid )
+    {
+        SAL_WARN( "tools.fraction", "'operator >' with an invalid fraction" );
+        return false;
+    }
+
+    return toRational(rVal1.mnNumerator, rVal1.mnDenominator) > toRational(rVal2.mnNumerator, rVal2.mnDenominator);
+}
+
+// If dVal > LONG_MAX or dVal < LONG_MIN, the rational throws a boost::bad_rational.
+// Otherwise, dVal and denominator are multiplied by 10, until one of them
+// is larger than (LONG_MAX / 10).
+//
+// NOTE: here we use 'sal_Int32' due that only values in sal_Int32 range are valid.
+static boost::rational<sal_Int32> rational_FromDouble(double dVal)
+{
+    if ( dVal > std::numeric_limits<sal_Int32>::max() ||
+         dVal < std::numeric_limits<sal_Int32>::min() ||
+         std::isnan(dVal) )
+        throw boost::bad_rational();
+
+    const sal_Int32 nMAX = std::numeric_limits<sal_Int32>::max() / 10;
+    sal_Int32 nDen = 1;
+    while ( std::abs( dVal ) < nMAX && nDen < nMAX ) {
+        dVal *= 10;
+        nDen *= 10;
+    }
+    return boost::rational<sal_Int32>( sal_Int32(dVal), nDen );
+}
+
+/**
+ * Find the number of bits required to represent this number, using the CLZ intrinsic
+ */
+static int impl_NumberOfBits( sal_uInt32 nNum )
+{
+    if (nNum == 0)
+        return 0;
+#ifdef _MSC_VER
+    unsigned long r = 0;
+    _BitScanReverse(&r, nNum);
+    return r + 1;
+#else
+    return 32 - __builtin_clz(nNum);
+#endif
+}
+
+/** Inaccurate cancellation for a fraction.
+
+    Clip both nominator and denominator to said number of bits. If
+    either of those already have equal or less number of bits used,
+    this method does nothing.
+
+    @param nSignificantBits denotes, how many significant binary
+    digits to maintain, in both nominator and denominator.
+
+    @example ReduceInaccurate(8) has an error <1% [1/2^(8-1)] - the
+    largest error occurs with the following pair of values:
+
+    binary    1000000011111111111111111111111b/1000000000000000000000000000000b
+    =         1082130431/1073741824
+    = approx. 1.007812499
+
+    A ReduceInaccurate(8) yields 1/1.
+*/
+static void rational_ReduceInaccurate(boost::rational<sal_Int32>& rRational, unsigned nSignificantBits)
+{
+    if ( !rRational )
+        return;
+
+    // http://www.boost.org/doc/libs/release/libs/rational/rational.html#Internal%20representation
+    sal_Int32 nMul = rRational.numerator();
+    if (nMul == std::numeric_limits<sal_Int32>::min())
+    {
+        // ofz#32973 Integer-overflow
+        return;
+    }
+    const bool bNeg = nMul < 0;
+    if (bNeg)
+        nMul = -nMul;
+    sal_Int32 nDiv = rRational.denominator();
+
+    DBG_ASSERT(nSignificantBits<65, "More than 64 bit of significance is overkill!");
+
+    // How much bits can we lose?
+    const int nMulBitsToLose = std::max( ( impl_NumberOfBits( nMul ) - int( nSignificantBits ) ), 0 );
+    const int nDivBitsToLose = std::max( ( impl_NumberOfBits( nDiv ) - int( nSignificantBits ) ), 0 );
+
+    const int nToLose = std::min( nMulBitsToLose, nDivBitsToLose );
+
+    // Remove the bits
+    nMul >>= nToLose;
+    nDiv >>= nToLose;
+
+    if ( !nMul || !nDiv ) {
+        // Return without reduction
+        OSL_FAIL( "Oops, we reduced too much..." );
+        return;
+    }
+
+    rRational.assign( bNeg ? -nMul : nMul, nDiv );
+}
+
+size_t Fraction::GetHashValue() const
+{
+    size_t hash = 0;
+    o3tl::hash_combine( hash, mnNumerator );
+    o3tl::hash_combine( hash, mnDenominator );
+    o3tl::hash_combine( hash, mbValid );
+    return hash;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */