extensions/common/value_counter.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "extensions/common/value_counter.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/values.h"
  10
  11 namespace extensions {
  12
  13 ValueCounter::ValueCounter() {}
  14
  15 ValueCounter::~ValueCounter() {}
  16
  17 ValueCounter::Entry::Entry(const base::Value& value)
  18     : value_(value.DeepCopy()), count_(1) {}
  19
  20 ValueCounter::Entry::~Entry() {}
  21
  22 int ValueCounter::Entry::Increment() { return ++count_; }
  23
  24 int ValueCounter::Entry::Decrement() { return --count_; }
  25
  26 int ValueCounter::Add(const base::Value& value) { return AddImpl(value, true); }
  27
  28 int ValueCounter::Remove(const base::Value& value) {
  29   for (EntryList::iterator it = entries_.begin(); it != entries_.end(); it++) {
  30     (*it)->value()->GetType();
  31     if ((*it)->value()->Equals(&value)) {
  32       int remaining = (*it)->Decrement();
  33       if (remaining == 0) {
  34         std::swap(*it, entries_.back());
  35         entries_.pop_back();
  36       }
  37       return remaining;
  38     }
  39   }
  40   return 0;
  41 }
  42
  43 int ValueCounter::AddIfMissing(const base::Value& value) {
  44   return AddImpl(value, false);
  45 }
  46
  47 int ValueCounter::AddImpl(const base::Value& value, bool increment) {
  48   for (EntryList::iterator it = entries_.begin(); it != entries_.end(); it++) {
  49     if ((*it)->value()->Equals(&value))
  50       return increment ? (*it)->Increment() : (*it)->count();
  51   }
  52   entries_.push_back(linked_ptr<Entry>(new Entry(value)));
  53   return 1;
  54 }
  55
  56 }  // namespace extensions