collection.h

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#pragma once
 
#include "roo_logging.h"
#include "roo_prefs/store/preferences_store.h"
 
namespace roo_prefs {
 
class Transaction;
 
using Store = PreferencesStore;
 
/// Collection corresponds to a preferences namespace. Use it to group related
/// preferences.
class Collection {
 public:
  Collection(const char* name)
      : store_(), name_(name), refcount_(0), read_only_(true) {}
 
  bool inTransaction() const { return refcount_ > 0; }
 
 private:
  friend class Transaction;
 
  bool inc(bool read_only) {
    if (refcount_ == 0) {
      if (!store_.begin(name_, read_only)) {
        if (read_only) {
          LOG(WARNING) << "Failed to initialize preferences " << name_
                       << " for reading";
        } else {
          LOG(ERROR) << "Failed to initialize preferences " << name_
                     << " for writing";
        }
        return false;
      }
      read_only_ = read_only;
      ++refcount_;
      return true;
    }
    if (read_only_ && !read_only) return false;
    ++refcount_;
    return true;
  }
 
  void dec() {
    if (--refcount_ == 0) {
      store_.end();
    }
  }
 
  Store store_;
  const char* name_;
  int refcount_;
  bool read_only_;
};
 
}  // namespace roo_prefs