summaryrefslogtreecommitdiffstats
path: root/base/property_bag.h
diff options
context:
space:
mode:
Diffstat (limited to 'base/property_bag.h')
-rw-r--r--base/property_bag.h179
1 files changed, 0 insertions, 179 deletions
diff --git a/base/property_bag.h b/base/property_bag.h
deleted file mode 100644
index 16c20fa..0000000
--- a/base/property_bag.h
+++ /dev/null
@@ -1,179 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_PROPERTY_BAG_H_
-#define BASE_PROPERTY_BAG_H_
-
-#include <map>
-
-#include "base/basictypes.h"
-#include "base/base_export.h"
-
-template <typename T> class linked_ptr;
-
-namespace base {
-
-class PropertyAccessorBase;
-
-// A property bag holds a generalized list of arbitrary metadata called
-// properties. Each property is a class type derived from PropertyBag::Prop
-// that can be set and retrieved.
-//
-// The property bag is not read or written directly. Instead, callers go
-// through a PropertyAccessor. The Accessor generates the unique IDs that
-// identify different properties. The Accessor is templatized to also provide
-// typesafety to the callers.
-//
-// Example:
-// // Note: you don't want to use Singleton for your Accessor if you're using
-// // a simple type like int or string as the data, since it will enforce that
-// // there is only one singleton for that type, which will conflict. If
-// // you're putting in some struct that's unique to you, go ahead.
-// PropertyAccessor<int>* my_accessor() const {
-// static PropertyAccessor<int>* accessor = NULL;
-// if (!accessor) accessor = new PropertyAccessor<int>;
-// return accessor;
-// }
-//
-// void doit(SomeObjectThatImplementsPropertyBag* object) {
-// PropertyAccessor<int>* accessor = my_accessor();
-// int* property = accessor->GetProperty(object);
-// if (property)
-// ... use property ...
-//
-// accessor->SetProperty(object, 22);
-// }
-class BASE_EXPORT PropertyBag {
- public:
- // The type that uniquely identifies a property type.
- typedef int PropID;
- enum { NULL_PROP_ID = -1 }; // Invalid property ID.
-
- // Properties are all derived from this class. They must be deletable and
- // copyable
- class Prop {
- public:
- virtual ~Prop() {}
-
- // Copies the property and returns a pointer to the new one. The caller is
- // responsible for managing the lifetime.
- virtual Prop* copy() = 0;
- };
-
- PropertyBag();
- PropertyBag(const PropertyBag& other);
- virtual ~PropertyBag();
-
- PropertyBag& operator=(const PropertyBag& other);
-
- private:
- friend class PropertyAccessorBase;
-
- typedef std::map<PropID, linked_ptr<Prop> > PropertyMap;
-
- // Used by the PropertyAccessor to set the property with the given ID.
- // Ownership of the given pointer will be transferred to us. Any existing
- // property matching the given ID will be deleted.
- void SetProperty(PropID id, Prop* prop);
-
- // Used by the PropertyAccessor to retrieve the property with the given ID.
- // The returned pointer will be NULL if there is no match. Ownership of the
- // pointer will stay with the property bag.
- Prop* GetProperty(PropID id);
- const Prop* GetProperty(PropID id) const;
-
- // Deletes the property with the given ID from the bag if it exists.
- void DeleteProperty(PropID id);
-
- PropertyMap props_;
-
- // Copy and assign is explicitly allowed for this class.
-};
-
-// PropertyAccessorBase -------------------------------------------------------
-
-// Manages getting the unique IDs to identify a property. Callers should use
-// PropertyAccessor below instead.
-class BASE_EXPORT PropertyAccessorBase {
- public:
- PropertyAccessorBase();
- virtual ~PropertyAccessorBase() {}
-
- // Removes our property, if any, from the given property bag.
- void DeleteProperty(PropertyBag* bag) {
- bag->DeleteProperty(prop_id_);
- }
-
- protected:
- void SetPropertyInternal(PropertyBag* bag, PropertyBag::Prop* prop) {
- bag->SetProperty(prop_id_, prop);
- }
- PropertyBag::Prop* GetPropertyInternal(PropertyBag* bag) {
- return bag->GetProperty(prop_id_);
- }
- const PropertyBag::Prop* GetPropertyInternal(const PropertyBag* bag) const {
- return bag->GetProperty(prop_id_);
- }
-
- private:
- // Identifier for this property.
- PropertyBag::PropID prop_id_;
-
- DISALLOW_COPY_AND_ASSIGN(PropertyAccessorBase);
-};
-
-// PropertyAccessor -----------------------------------------------------------
-
-// Provides typesafe accessor functions for a property bag, and manages the
-// unique identifiers for properties via the PropertyAccessorBase.
-template<class T>
-class PropertyAccessor : public PropertyAccessorBase {
- public:
- PropertyAccessor() : PropertyAccessorBase() {}
- virtual ~PropertyAccessor() {}
-
- // Makes a copy of the |prop| object for storage.
- void SetProperty(PropertyBag* bag, const T& prop) {
- SetPropertyInternal(bag, new Container(prop));
- }
-
- // Returns our property in the given bag or NULL if there is no match. The
- // returned pointer's ownership will stay with the property bag.
- T* GetProperty(PropertyBag* bag) {
- PropertyBag::Prop* prop = GetPropertyInternal(bag);
- if (!prop)
- return NULL;
- return static_cast<Container*>(prop)->get();
- }
- const T* GetProperty(const PropertyBag* bag) const {
- const PropertyBag::Prop* prop = GetPropertyInternal(bag);
- if (!prop)
- return NULL;
- return static_cast<const Container*>(prop)->get();
- }
-
- // See also DeleteProperty on thn PropertyAccessorBase.
-
- private:
- class Container : public PropertyBag::Prop {
- public:
- explicit Container(const T& data) : data_(data) {}
-
- T* get() { return &data_; }
- const T* get() const { return &data_; }
-
- private:
- virtual Prop* copy() {
- return new Container(data_);
- }
-
- T data_;
- };
-
- DISALLOW_COPY_AND_ASSIGN(PropertyAccessor);
-};
-
-} // namespace base
-
-#endif // BASE_PROPERTY_BAG_H_