text: /*
   * Copyright (C) 2011, 2014 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
   */
  
  #ifndef Spectrum_h
  #define Spectrum_h
  
  #include <wtf/HashMap.h>
  #include <wtf/Vector.h>
  #include <algorithm>
  
  namespace WTF {
  
  template<typename T, typename CounterType = unsigned>
  class Spectrum {
  public:
      typedef typename HashMap<T, CounterType>::iterator iterator;
      typedef typename HashMap<T, CounterType>::const_iterator const_iterator;
      
      Spectrum() { }
      
      void add(const T& key, CounterType count = 1)
      {
          if (!count)
              return;
          typename HashMap<T, CounterType>::AddResult result = m_map.add(key, count);
          if (!result.isNewEntry)
              result.iterator->value += count;
      }
      
      template<typename U>
      void addAll(const Spectrum<T, U>& otherSpectrum)
      {
          for (auto& entry : otherSpectrum)
              add(entry.key, entry.count);
      }
      
      CounterType get(const T& key) const
      {
          const_iterator iter = m_map.find(key);
          if (iter == m_map.end())
              return 0;
          return iter->value;
      }
      
      size_t size() const { return m_map.size(); }
      
      iterator begin() { return m_map.begin(); }
      iterator end() { return m_map.end(); }
      const_iterator begin() const { return m_map.begin(); }
      const_iterator end() const { return m_map.end(); }
      
      struct KeyAndCount {
          KeyAndCount() { }
          
          KeyAndCount(const T& key, CounterType count)
              : key(key)
              , count(count)
          {
          }
          
          bool operator<(const KeyAndCount& other) const
          {
              if (count != other.count)
                  return count < other.count;
              // This causes lower-ordered keys being returned first; this is really just
              // here to make sure that the order is somewhat deterministic rather than being
              // determined by hashing.
              return key > other.key;
          }
  
          T key;
          CounterType count;
      };
      
      // Returns a list ordered from lowest-count to highest-count.
      Vector<KeyAndCount> buildList() const
      {
          Vector<KeyAndCount> list;
          for (const_iterator iter = begin(); iter != end(); ++iter)
              list.append(KeyAndCount(iter->key, iter->value));
          
          std::sort(list.begin(), list.end());
          return list;
      }
      
      void clear() { m_map.clear(); }
      
      template<typename Functor>
      void removeIf(const Functor& functor)
      {
          m_map.removeIf([&functor] (typename HashMap<T, CounterType>::KeyValuePairType& pair) {
                  return functor(KeyAndCount(pair.key, pair.value));
              });
      }
      
  private:
      HashMap<T, CounterType> m_map;
  };
  
  } // namespace WTF
  
  using WTF::Spectrum;
  
  #endif // Spectrum_h
  