diff options
Diffstat (limited to 'storage/ndb/src/old_files/rep/state/Interval.cpp')
-rw-r--r-- | storage/ndb/src/old_files/rep/state/Interval.cpp | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/storage/ndb/src/old_files/rep/state/Interval.cpp b/storage/ndb/src/old_files/rep/state/Interval.cpp new file mode 100644 index 00000000000..8266f19c58d --- /dev/null +++ b/storage/ndb/src/old_files/rep/state/Interval.cpp @@ -0,0 +1,171 @@ +/* Copyright (C) 2003 MySQL AB + + 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +#include "Interval.hpp" + +#undef min +#undef max +Uint32 max(Uint32 a, Uint32 b) { return a > b ? a : b; } +Uint32 min(Uint32 a, Uint32 b) { return a < b ? a : b; } + +Interval::Interval() +{ + set(1, 0); // EmptyInterval +} + +Interval::Interval(Uint32 f, Uint32 l) +{ + set(f, l); +} + +bool +Interval::isEmpty() const +{ + return (m_first > m_last) ? true : false; +} + +bool +Interval::isEqual(Uint32 a, Uint32 b) const +{ + return (a==m_first && b==m_last); +} + +bool +Interval::inInterval(Uint32 a) const +{ + return (m_first <= a && a <= m_last); +} + +void +Interval::set(Uint32 first, Uint32 last) +{ + m_first = first; + m_last = last; + normalize(); +} + +void +Interval::set(const Interval i) +{ + m_first = i.first(); + m_last = i.last(); + normalize(); +} + +void +Interval::setFirst(Uint32 first) +{ + m_first = first; +} + +void +Interval::setLast(Uint32 last) +{ + m_last = last; +} + +void +Interval::onlyLeft(Uint32 n) +{ + if (size() > n) m_last = m_first + n - 1; +} + +void +Interval::onlyUpToValue(Uint32 n) +{ + m_last = min(n, m_last); + normalize(); +} + +/*****************************************************************************/ + +void +Interval::normalize() +{ + if (isEmpty()) { + m_first = 1; + m_last = 0; + } +} + + +/*****************************************************************************/ + +bool +intervalAdd(const Interval a, const Interval b, Interval * r) +{ + /** + * Non-empty disjoint intervals + */ + if (!a.isEmpty() && + !b.isEmpty() && + (a.last() + 1 < b.first() || + b.last() + 1 < a.first()) ) { + return false; // Illegal add + } + + /** + * Interval A empty -> return B + */ + if (a.isEmpty()) { + r->set(b); + return true; + } + + /** + * Interval B empty -> return A + */ + if (b.isEmpty()) { + r->set(a); + return true; + } + + r->set(min(a.first(), b.first()), + max(a.last(), b.last())); + return true; +} + +/** + * Subtract the left part of interval 'a' up to last of 'b'. + * + * @note This is NOT ordinary arithmetic interval minus. + * In ordinary arithmetic, [11-25] - [12-15] would be undefined, + * but here it is [11-25] - [12-15] = [16-25]. + */ +void +intervalLeftMinus(const Interval a, const Interval b, Interval * r) +{ + if(b.last() != intervalMax) + r->set(max(a.first(), b.last()+1), a.last()); + else + r->set(max(a.first(), intervalMax), a.last()); +} + +void +intervalCut(const Interval a, const Interval b, Interval * r) +{ + r->set(max(a.first(), b.first()), min(a.last(), b.last())); + r->normalize(); +} + +bool +intervalDisjoint(const Interval a, const Interval b) +{ + return (a.isEmpty() || + b.isEmpty() || + a.last() < b.first() || + b.last() < a.first()); +} |