#include <msp/core/maputils.h>
#include <msp/core/meta.h>
#include <msp/core/refptr.h>
+#include "collectionsource.h"
#include "loader.h"
+/* XXX This file is a big mess with too many things in it. However, the
+dependencies between those things make it difficult to split up. */
+
namespace Msp {
namespace DataFile {
loading requires that a subclass defines the supported types. See the add_type
method for details.
-Collections also support a notion of "future objects". These are objects which
-are known to be possible to load, but loading them is deferred to the first
-time they are requested.
-
-Other classes are available to provide refined ways of loading objects from
-files. See DirectoryCollection and PackCollection.
+Collections can have sources for loading objects on demand. Automatic loading
+only works on a non-const Collection. See class CollectionSource for details.
*/
class Collection
{
private:
typedef std::map<std::string, Variant> ItemMap;
typedef std::list<CollectionItemTypeBase *> TypeList;
+ typedef std::list<CollectionSource *> SourceList;
TypeList types;
ItemMap items;
+ SourceList sources;
Collection(const Collection &);
Collection &operator=(const Collection &);
if(!item)
throw std::invalid_argument("Collection::add(item)");
- typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
-
- ItemMap::iterator i = items.find(name);
- if(i!=items.end())
- {
- if(i->second.check_type<RPNCT>())
- {
- // Replace a future object placeholder
- RPNCT &ptr = i->second.value<RPNCT>();
- if(!ptr)
- {
- ptr = item;
- return;
- }
- }
-
- throw key_error(typeid(ItemMap));
- }
-
- items.insert(ItemMap::value_type(name, RPNCT(item)));
- }
-
-protected:
- /** Adds the name of a future object to the collection. The object itself
- will be loaded on first access. The calling subclass should be prepared to
- create the object on request. */
- template<typename T>
- void add_future(const std::string &name)
- {
- RefPtr<typename RemoveConst<T>::Type> ptr(0);
- insert_unique(items, name, ptr);
+ insert_unique(items, name, RefPtr<typename RemoveConst<T>::Type>(item));
}
- /** Adds the name of a future object, guessing its type. If a type matching
- the name can't be found, nothing is done. */
- void add_future(const std::string &name);
-
- /** Adds the name of a future object, using a keyword to determine its type.
- The keyword must be known to the collection. */
- void add_future_with_keyword(const std::string &name, const std::string &);
-
-public:
/// Gets a typed object from the collection.
template<typename T>
T &get(const std::string &name) const
{
- typedef typename RemoveConst<T>::Type NCT;
-
- T *ptr = get_item(items, name).value<RefPtr<NCT> >().get();
- if(!ptr)
- throw key_error(typeid(ItemMap));
- return *ptr;
+ return *get_item(items, name).value<RefPtr<typename RemoveConst<T>::Type> >();
}
- /** Gets a typed object from the collection. If the name is not found in
- and a creator for the item type is defined, it is invoked. */
+ /** Gets a typed object from the collection. If the name is not found,
+ automatic creation with the type's creator function (if defined) or from
+ sources (if present) is attempted. */
template<typename T>
T &get(const std::string &);
for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
if(i->second.check_type<RPNCT>())
{
- T *ptr = i->second.value<RPNCT>().get();
- if(ptr)
+ if(objects)
+ objects->push_back(i->second.value<RPNCT>().get());
+ if(names)
+ names->push_back(i->first);
+ }
+
+ if(future_names)
+ if(CollectionItemTypeBase *type = get_type<T>())
+ {
+ for(SourceList::const_iterator i=sources.begin(); i!=sources.end(); ++i)
{
- if(objects)
- objects->push_back(ptr);
- if(names)
- names->push_back(i->first);
+ std::list<std::string> available_names = (*i)->get_names(*type);
+ for(std::list<std::string>::iterator j=available_names.begin(); j!=available_names.end(); ++j)
+ if(!items.count(*j))
+ future_names->push_back(*j);
}
- else if(future_names)
- future_names->push_back(i->first);
}
}
public:
- /** Returns a list of the names of loaded objects of one type in the
- collection. */
+ /// Returns a list of the names of objects of one type in the collection.
template<typename T>
std::list<std::string> get_names() const
{
return result;
}
- /** Returns a list of the names of objects of one type in the collection,
- including any future objects. */
+ /** Returns a list of the names of objects of one type in the collection or
+ available from sources. */
template<typename T>
std::list<std::string> get_names()
{
return result;
}
- /// Returns a list of loaded objects of one type in the collection.
+ /// Returns a list of objects of one type in the collection.
template<typename T>
std::list<T *> get_list() const
{
return result;
}
- /** Returns a list of objects of one type in the collection. Any future
- objects of that type are loaded and returned in the list. */
+ /** Returns a list of objects of one type, loading them from sources if
+ necessary. */
template<typename T>
std::list<T *> get_list()
{
{
ItemMap::const_iterator i = items.find(name);
if(i==items.end())
- return false;
+ {
+ if(CollectionItemTypeBase *type = get_type<T>())
+ {
+ for(SourceList::const_iterator j=sources.begin(); j!=sources.end(); ++j)
+ if((*j)->is_loadable(*type, name))
+ return 2;
+ }
+ return 0;
+ }
typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
if(!i->second.check_type<RPNCT>())
- return false;
+ return 0;
- T *ptr = i->second.value<RPNCT>().get();
- return ptr ? 1 : 2;
+ return 1;
}
public:
- /// Checks whether a typed object exists and is loaded in the collection.
+ /// Checks whether a typed object exists in the collection.
template<typename T>
bool contains(const std::string &name) const
{ return get_status<T>(name)==1; }
- /** Checks whether a typed object exists in the collection, as either a
- loaded or future object. */
+ /** Checks whether a typed object exists in the collection or is loadable
+ from a source. */
template<typename T>
bool contains(const std::string &name)
{ return get_status<T>(name)>0; }
can be used to define how objects of that type can be loaded. */
template<typename T>
CollectionItemType<T> &add_type();
+
+ /** Returns the descriptor for a type, or null if one isn't defined. */
+ template<typename T>
+ CollectionItemTypeBase *get_type() const;
+
+ void add_source(CollectionSource &);
};
template<typename T>
virtual void add_to_loader(Collection::Loader &) const = 0;
virtual bool can_create() const = 0;
virtual void create_item(Collection &, const std::string &) const = 0;
- virtual Variant create_future() const = 0;
+ virtual void load_item(Collection &, Parser &, const std::string &) const = 0;
template<typename T>
bool check_type() const
virtual ~StoreBase() { }
virtual void store(Collection &, const std::string &, T *) = 0;
- virtual Variant create_future() const = 0;
virtual void add_to_loader(Collection::Loader &, const std::string &) = 0;
};
virtual void store(Collection &coll, const std::string &name, T *obj)
{ coll.add(name, static_cast<S *>(obj)); }
- virtual Variant create_future() const
- { return RefPtr<S>(0); }
-
virtual void add_to_loader(Collection::Loader &loader, const std::string &kwd)
{ loader.add(kwd, &Collection::Loader::item<T, S>); }
};
store->store(coll, name, obj);
}
- virtual Variant create_future() const
- { return store->create_future(); }
+ virtual void load_item(Collection &coll, Parser &parser, const std::string &name) const
+ {
+ RefPtr<T> obj = new T;
+ Collection::ItemLoader<T> ldr(*obj, coll);
+ ldr.load(parser);
+ store->store(coll, name, obj.get());
+ obj.release();
+ }
};
template<typename T>
T &Collection::get(const std::string &name)
{
- typedef typename RemoveConst<T>::Type NCT;
+ typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
ItemMap::iterator i = items.find(name);
if(i!=items.end())
+ return *i->second.value<RPNCT>();
+
+ if(CollectionItemTypeBase *type = get_type<T>())
{
- NCT *ptr = i->second.value<RefPtr<NCT> >().get();
- if(ptr)
- return *ptr;
+ bool loaded = false;
+ if(type->can_create())
+ {
+ type->create_item(*this, name);
+ loaded = items.count(name);
+ }
+ for(SourceList::iterator j=sources.begin(); (!loaded && j!=sources.end()); ++j)
+ {
+ (*j)->load(*this, *type, name);
+ loaded = items.count(name);
+ }
}
- for(TypeList::iterator j=types.begin(); j!=types.end(); ++j)
- if((*j)->can_create() && (*j)->check_type<NCT>())
- (*j)->create_item(*this, name);
-
- NCT *ptr = get_item(items, name).value<RefPtr<NCT> >().get();
- if(!ptr)
- throw key_error(typeid(ItemMap));
- return *ptr;
+ return *get_item(items, name).value<RPNCT>();
}
template<typename T>
return *type;
}
+template<typename T>
+CollectionItemTypeBase *Collection::get_type() const
+{
+ for(TypeList::const_iterator j=types.begin(); j!=types.end(); ++j)
+ if((*j)->check_type<typename RemoveConst<T>::Type>())
+ return *j;
+ return 0;
+}
+
} // namespace DataFile
} // namespace Msp
projects / libs / datafile.git / blobdiff