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sql_type_int.h
/* Copyright (c) 2018, 2021, MariaDB 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; version 2 of the License. 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, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ #ifndef SQL_TYPE_INT_INCLUDED #define SQL_TYPE_INT_INCLUDED #include "my_bit.h" // my_count_bits() class Null_flag { protected: bool m_is_null; public: bool is_null() const { return m_is_null; } Null_flag(bool is_null) :m_is_null(is_null) { } }; class Longlong { protected: longlong m_value; public: longlong value() const { return m_value; } Longlong(longlong nr) :m_value(nr) { } ulonglong abs() { if (m_value == LONGLONG_MIN) // avoid undefined behavior return ((ulonglong) LONGLONG_MAX) + 1; return m_value < 0 ? -m_value : m_value; } }; class Longlong_null: public Longlong, public Null_flag { public: Longlong_null(longlong nr, bool is_null) :Longlong(nr), Null_flag(is_null) { } explicit Longlong_null() :Longlong(0), Null_flag(true) { } explicit Longlong_null(longlong nr) :Longlong(nr), Null_flag(false) { } Longlong_null operator|(const Longlong_null &other) const { if (is_null() || other.is_null()) return Longlong_null(); return Longlong_null(value() | other.value()); } Longlong_null operator&(const Longlong_null &other) const { if (is_null() || other.is_null()) return Longlong_null(); return Longlong_null(value() & other.value()); } Longlong_null operator^(const Longlong_null &other) const { if (is_null() || other.is_null()) return Longlong_null(); return Longlong_null((longlong) (value() ^ other.value())); } Longlong_null operator~() const { if (is_null()) return *this; return Longlong_null((longlong) ~ (ulonglong) value()); } Longlong_null operator<<(const Longlong_null &llshift) const { ulonglong res; uint shift; if (is_null() || llshift.is_null()) return Longlong_null(); shift= (uint) llshift.value(); res= 0; if (shift < sizeof(longlong) * 8) res= ((ulonglong) value()) << shift; return Longlong_null((longlong) res); } Longlong_null operator>>(const Longlong_null &llshift) const { ulonglong res; uint shift; if (is_null() || llshift.is_null()) return Longlong_null(); shift= (uint) llshift.value(); res= 0; if (shift < sizeof(longlong) * 8) res= ((ulonglong) value()) >> shift; return Longlong_null(res); } Longlong_null bit_count() const { if (is_null()) return *this; return Longlong_null((longlong) my_count_bits((ulonglong) value())); } }; class ULonglong { protected: ulonglong m_value; public: ulonglong value() const { return m_value; } explicit ULonglong(ulonglong nr) :m_value(nr) { } static bool test_if_sum_overflows_ull(ulonglong arg1, ulonglong arg2) { return ULONGLONG_MAX - arg1 < arg2; } Longlong_null operator-() const { if (m_value > (ulonglong) LONGLONG_MAX) // Avoid undefined behaviour { return m_value == (ulonglong) LONGLONG_MAX + 1 ? Longlong_null(LONGLONG_MIN, false) : Longlong_null(0, true); } return Longlong_null(-(longlong) m_value, false); } // Convert to Longlong_null with the range check Longlong_null to_longlong_null() const { if (m_value > (ulonglong) LONGLONG_MAX) return Longlong_null(0, true); return Longlong_null((longlong) m_value, false); } }; class ULonglong_null: public ULonglong, public Null_flag { public: ULonglong_null(ulonglong nr, bool is_null) :ULonglong(nr), Null_flag(is_null) { } /* Multiply two ulonglong values. Let a = a1 * 2^32 + a0 and b = b1 * 2^32 + b0. Then a * b = (a1 * 2^32 + a0) * (b1 * 2^32 + b0) = a1 * b1 * 2^64 + + (a1 * b0 + a0 * b1) * 2^32 + a0 * b0; We can determine if the above sum overflows the ulonglong range by sequentially checking the following conditions: 1. If both a1 and b1 are non-zero. 2. Otherwise, if (a1 * b0 + a0 * b1) is greater than ULONG_MAX. 3. Otherwise, if (a1 * b0 + a0 * b1) * 2^32 + a0 * b0 is greater than ULONGLONG_MAX. */ static ULonglong_null ullmul(ulonglong a, ulonglong b) { ulong a1= (ulong)(a >> 32); ulong b1= (ulong)(b >> 32); if (a1 && b1) return ULonglong_null(0, true); ulong a0= (ulong)(0xFFFFFFFFUL & a); ulong b0= (ulong)(0xFFFFFFFFUL & b); ulonglong res1= (ulonglong) a1 * b0 + (ulonglong) a0 * b1; if (res1 > 0xFFFFFFFFUL) return ULonglong_null(0, true); res1= res1 << 32; ulonglong res0= (ulonglong) a0 * b0; if (test_if_sum_overflows_ull(res1, res0)) return ULonglong_null(0, true); return ULonglong_null(res1 + res0, false); } }; // A longlong/ulonglong hybrid. Good to store results of val_int(). class Longlong_hybrid: public Longlong { protected: bool m_unsigned; int cmp_signed(const Longlong_hybrid& other) const { return m_value < other.m_value ? -1 : m_value == other.m_value ? 0 : 1; } int cmp_unsigned(const Longlong_hybrid& other) const { return (ulonglong) m_value < (ulonglong) other.m_value ? -1 : m_value == other.m_value ? 0 : 1; } public: Longlong_hybrid(longlong nr, bool unsigned_flag) :Longlong(nr), m_unsigned(unsigned_flag) { } bool is_unsigned() const { return m_unsigned; } bool is_unsigned_outside_of_signed_range() const { return m_unsigned && ((ulonglong) m_value) > (ulonglong) LONGLONG_MAX; } bool neg() const { return m_value < 0 && !m_unsigned; } ulonglong abs() const { if (m_unsigned) return (ulonglong) m_value; return Longlong(m_value).abs(); } /* Convert to an unsigned number: - Negative numbers are converted to 0. - Positive numbers bigger than upper_bound are converted to upper_bound. - Other numbers are returned as is. */ ulonglong to_ulonglong(ulonglong upper_bound) const { return neg() ? 0 : (ulonglong) m_value > upper_bound ? upper_bound : (ulonglong) m_value; } uint to_uint(uint upper_bound) const { return (uint) to_ulonglong(upper_bound); } Longlong_null val_int_signed() const { if (m_unsigned) return ULonglong((ulonglong) m_value).to_longlong_null(); return Longlong_null(m_value, false); } Longlong_null val_int_unsigned() const { if (!m_unsigned && m_value < 0) return Longlong_null(0, true); return Longlong_null(m_value, false); } /* Return in Item compatible val_int() format: - signed numbers as a straight longlong value - unsigned numbers as a ulonglong value reinterpreted to longlong */ Longlong_null val_int(bool want_unsigned_value) const { return want_unsigned_value ? val_int_unsigned() : val_int_signed(); } int cmp(const Longlong_hybrid& other) const { if (m_unsigned == other.m_unsigned) return m_unsigned ? cmp_unsigned(other) : cmp_signed(other); if (is_unsigned_outside_of_signed_range()) return 1; if (other.is_unsigned_outside_of_signed_range()) return -1; /* The unsigned argument is in the range 0..LONGLONG_MAX. The signed argument is in the range LONGLONG_MIN..LONGLONG_MAX. Safe to compare as signed. */ return cmp_signed(other); } bool operator==(const Longlong_hybrid &nr) const { return cmp(nr) == 0; } bool operator==(ulonglong nr) const { return cmp(Longlong_hybrid((longlong) nr, true)) == 0; } bool operator==(uint nr) const { return cmp(Longlong_hybrid((longlong) nr, true)) == 0; } bool operator==(longlong nr) const { return cmp(Longlong_hybrid(nr, false)) == 0; } bool operator==(int nr) const { return cmp(Longlong_hybrid(nr, false)) == 0; } }; class Longlong_hybrid_null: public Longlong_hybrid, public Null_flag { public: Longlong_hybrid_null(const Longlong_null &nr, bool unsigned_flag) :Longlong_hybrid(nr.value(), unsigned_flag), Null_flag(nr.is_null()) { } }; /* Stores the absolute value of a number, and the sign. Value range: -ULONGLONG_MAX .. +ULONGLONG_MAX. Provides a wider range for negative numbers than Longlong_hybrid does. Usefull to store intermediate results of an expression whose value is further needed to be negated. For example, these methods: - Item_func_mul::int_op() - Item_func_int_div::val_int() - Item_func_mod::int_op() calculate the result of absolute values of the arguments, then optionally negate the result. */ class ULonglong_hybrid: public ULonglong { bool m_neg; public: ULonglong_hybrid(ulonglong value, bool neg) :ULonglong(value), m_neg(neg) { if (m_neg && !m_value) m_neg= false; // convert -0 to +0 } Longlong_null val_int_unsigned() const { return m_neg ? Longlong_null(0, true) : Longlong_null((longlong) m_value, false); } Longlong_null val_int_signed() const { return m_neg ? -ULonglong(m_value) : ULonglong::to_longlong_null(); } /* Return in Item compatible val_int() format: - signed numbers as a straight longlong value - unsigned numbers as a ulonglong value reinterpreted to longlong */ Longlong_null val_int(bool want_unsigned_value) const { return want_unsigned_value ? val_int_unsigned() : val_int_signed(); } }; #endif // SQL_TYPE_INT_INCLUDED
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