libzypp  17.23.8
SetTracker.h
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11 #ifndef ZYPP_BASE_SETTRACKER_H
12 #define ZYPP_BASE_SETTRACKER_H
13 
14 #include <iosfwd>
15 #include <utility>
16 #include <algorithm>
17 
19 namespace zypp
20 {
22  namespace base
23  {
36  template <class TSet>
37  struct SetTracker
38  {
39  typedef TSet set_type;
40  typedef typename TSet::key_type key_type;
41  typedef typename TSet::value_type value_type;
42 
45  {}
46 
48  SetTracker( set_type initial_r )
49  : _current( std::move(initial_r) )
50  {}
51 
53 
54 
57  bool setInitial()
58  { _added.clear(); _removed.clear(); return false; }
59 
63  bool setInitial( set_type new_r )
64  {
65  setInitial();
66  bool changed = ( new_r != _current );
67  if ( changed )
68  {
69  _current = std::move(new_r);
70  }
71  return changed;
72  }
73 
74 
78  bool set( set_type new_r )
79  {
80  bool changed = ( new_r != _current );
81  if ( changed )
82  {
83  // build the initial (cur-add+rem) set in _current
85  _current.swap( _removed );
86  _added.clear();
87  _removed.clear();
88 
89  const set_type & initial( _current );
90  setDifference( initial, new_r, _removed );
91  setDifference( new_r, initial, _added );
92  _current.swap( new_r );
93  }
94  return changed;
95  }
96 
100  bool add( const value_type & val_r )
101  {
102  bool done = _current.insert( val_r ).second;
103  if ( done )
104  {
105  if ( ! _removed.erase( val_r ) )
106  _added.insert( val_r );
107  }
108  return done;
109  }
110 
114  bool remove( const value_type & val_r )
115  {
116  bool done = _current.erase( val_r );
117  if ( done )
118  {
119  if ( ! _added.erase( val_r ) )
120  _removed.insert( val_r );
121  }
122  return done;
123  }
125 
127 
128 
129  bool contains( const key_type & key_r ) const { return find( _current, key_r ); }
130 
132  bool wasAdded( const key_type & key_r ) const { return find( _added, key_r ); }
133 
135  bool wasRemoved( const key_type & key_r ) const { return find( _removed, key_r ); }
136 
137 
139  const set_type & current() const { return _current; }
140 
142  const set_type & added() const { return _added; }
143 
145  const set_type & removed() const { return _removed; }
147 
149 
150 
151  set_type & current() { return _current; }
152 
154  set_type & added() { return _added; }
155 
157  set_type & removed() { return _removed; }
159 
160  private:
161 
162  static bool find( const set_type & set_r, const key_type & key_r )
163  { return set_r.find( key_r ) != set_r.end(); }
164 
165  template <class TORDERED_SET, typename enable_if = typename TORDERED_SET::key_compare>
166  static void setDifference( const TORDERED_SET & lhs, const TORDERED_SET & rhs, TORDERED_SET & result_r )
167  {
168  // std::set_difference requires ordered sets!
169  std::set_difference( lhs.begin(), lhs.end(), rhs.begin(), rhs.end(),
170  std::inserter( result_r, result_r.end() ),
171  typename TORDERED_SET::key_compare() );
172  }
173 
174  template <class TUNORDERED_SET, typename enable_if = typename TUNORDERED_SET::hasher, typename = void>
175  static void setDifference( const TUNORDERED_SET & lhs, const TUNORDERED_SET & rhs, TUNORDERED_SET & result_r )
176  {
177  // std::set_difference requires ordered sets!
178  for ( const auto & l : lhs )
179  { if ( rhs.find( l ) == rhs.end() ) result_r.insert( l ); }
180  }
181 
182  private:
186  };
187 
189  template <class TSet>
190  std::ostream & operator<<( std::ostream & str, const SetTracker<TSet> & obj )
191  { return str << "set(" << obj.current().size() << "|+" << obj.added().size() << "|-" << obj.removed().size() << ')'; }
192 
193  } // namespace base
195 } // namespace zypp
197 #endif // ZYPP_BASE_SETTRACKER_H
zypp::base::SetTracker::set_type
TSet set_type
Definition: SetTracker.h:39
zypp::base::SetTracker::wasRemoved
bool wasRemoved(const key_type &key_r) const
Whether val_r is tracked as removed.
Definition: SetTracker.h:135
zypp::base::SetTracker::SetTracker
SetTracker(set_type initial_r)
Ctor taking an initial set.
Definition: SetTracker.h:48
zypp::base::SetTracker::key_type
TSet::key_type key_type
Definition: SetTracker.h:40
zypp::base::SetTracker::setInitial
bool setInitial(set_type new_r)
Start tracking a new set (discards previously tracked changes).
Definition: SetTracker.h:63
zypp::base::SetTracker::remove
bool remove(const value_type &val_r)
Remove an element from the set and track changes.
Definition: SetTracker.h:114
zypp::base::SetTracker::value_type
TSet::value_type value_type
Definition: SetTracker.h:41
zypp::base::SetTracker::added
set_type & added()
Return the set of added items.
Definition: SetTracker.h:154
zypp::base::SetTracker::added
const set_type & added() const
Return the set of added items.
Definition: SetTracker.h:142
zypp::base::SetTracker::current
const set_type & current() const
Return the current set.
Definition: SetTracker.h:139
zypp::base::SetTracker::add
bool add(const value_type &val_r)
Add an element to the set and track changes.
Definition: SetTracker.h:100
zypp::base::SetTracker::contains
bool contains(const key_type &key_r) const
Whether val_r is in the set.
Definition: SetTracker.h:129
zypp::base::SetTracker::find
static bool find(const set_type &set_r, const key_type &key_r)
Definition: SetTracker.h:162
zypp::base::SetTracker::wasAdded
bool wasAdded(const key_type &key_r) const
Whether val_r is tracked as added.
Definition: SetTracker.h:132
zypp::base::SetTracker::SetTracker
SetTracker()
Default Ctor: empty set.
Definition: SetTracker.h:44
zypp::base::SetTracker::setInitial
bool setInitial()
(Re-)Start tracking the current set (discards previously tracked changes).
Definition: SetTracker.h:57
zypp::base::SetTracker::current
set_type & current()
Return the current set.
Definition: SetTracker.h:151
zypp::base::SetTracker::_removed
set_type _removed
Definition: SetTracker.h:185
zypp::base::SetTracker::_current
set_type _current
Definition: SetTracker.h:183
zypp::base::SetTracker::_added
set_type _added
Definition: SetTracker.h:184
zypp::base::SetTracker::removed
set_type & removed()
Return the set of removed items.
Definition: SetTracker.h:157
zypp
Easy-to use interface to the ZYPP dependency resolver.
Definition: CodePitfalls.doc:1
zypp::base::SetTracker::operator<<
std::ostream & operator<<(std::ostream &str, const SetTracker< TSet > &obj)
Definition: SetTracker.h:190
std
Definition: Arch.h:347
zypp::base::SetTracker::setDifference
static void setDifference(const TUNORDERED_SET &lhs, const TUNORDERED_SET &rhs, TUNORDERED_SET &result_r)
Definition: SetTracker.h:175
str
String related utilities and Regular expression matching.
zypp::base::SetTracker::set
bool set(set_type new_r)
Set a new_r set and track changes.
Definition: SetTracker.h:78
zypp::base::SetTracker::setDifference
static void setDifference(const TORDERED_SET &lhs, const TORDERED_SET &rhs, TORDERED_SET &result_r)
Definition: SetTracker.h:166
zypp::base::SetTracker::removed
const set_type & removed() const
Return the set of removed items.
Definition: SetTracker.h:145
zypp::base::SetTracker
Track added/removed set items based on an initial set.
Definition: SetTracker.h:37