X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fcollection.h;h=3d5b7f0a6abce95bc8aa5d6ec05749be3ec6f8b2;hb=8955db30f9cd1c1566b349da29e669f065f84e36;hp=d5e0806afeebad9fbfa2f043ef80d3ef9bc64878;hpb=e249d648f6393fbb4b74e76c2a7b9eee9f1187f1;p=libs%2Fdatafile.git diff --git a/source/collection.h b/source/collection.h index d5e0806..3d5b7f0 100644 --- a/source/collection.h +++ b/source/collection.h @@ -38,6 +38,10 @@ identified by a name, which must be unique across the entire collection. While this class can be instantiated by itself and used for storing objects, 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. */ class Collection { @@ -51,34 +55,27 @@ public: template friend class CollectionItemType; private: - template::value> - struct Add; - Collection &coll; public: Loader(Collection &); Collection &get_object() const { return coll; } private: - template - void coll_item(const std::string &n) - { - RefPtr it = new T; - load_sub(*it, dynamic_cast(coll)); - coll.add(n, it.get()); - it.release(); - } - template void item(const std::string &n) { RefPtr it = new T; - load_sub(*it); + ItemLoader ldr(*it, coll); + load_sub_with(ldr); coll.add(n, it.get()); it.release(); } }; +protected: + template::value> + class ItemLoader; + private: typedef std::map ItemMap; typedef std::list TypeList; @@ -100,26 +97,52 @@ public: if(!item) throw std::invalid_argument("Collection::add(item)"); - RefPtr::Type> ptr(item); - try - { - insert_unique(items, name, ptr); - } - catch(...) + typedef RefPtr::Type> RPNCT; + + ItemMap::iterator i = items.find(name); + if(i!=items.end()) { - // Avoid deleting the object - ptr.release(); - throw; + if(i->second.check_type()) + { + // Replace a future object placeholder + RPNCT &ptr = i->second.value(); + 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 + void add_future(const std::string &name) + { + RefPtr::Type> ptr(0); + insert_unique(items, name, ptr); + } + + void add_future(const std::string &name); + +public: /// Gets a typed object from the collection. template T &get(const std::string &name) const { typedef typename RemoveConst::Type NCT; - return *get_item(items, name).value >(); + T *ptr = get_item(items, name).value >().get(); + if(!ptr) + throw key_error(typeid(ItemMap)); + return *ptr; } /** Gets a typed object from the collection. If the name is not found in @@ -127,41 +150,99 @@ public: template T &get(const std::string &); - /// Returns a list of the names of objects of one type in the collection. +private: + template + void collect_items(std::list *objects, std::list *names, std::list *future_names) const + { + typedef RefPtr::Type> RPNCT; + + for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i) + if(i->second.check_type()) + { + T *ptr = i->second.value().get(); + if(ptr) + { + if(objects) + objects->push_back(ptr); + if(names) + names->push_back(i->first); + } + 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. */ template std::list get_names() const { std::list result; - for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i) - if(i->second.check_type::Type> >()) - result.push_back(i->first); + collect_items(0, &result, 0); + return result; + } + + /** Returns a list of the names of objects of one type in the collection, + including any future objects. */ + template + std::list get_names() + { + std::list result; + collect_items(0, &result, &result); return result; } - /// Returns a list of objects of one type in the collection. + /// Returns a list of loaded objects of one type in the collection. template std::list get_list() const { - typedef RefPtr::Type> RPNCT; + std::list result; + collect_items(&result, 0, 0); + 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. */ + template + std::list get_list() + { std::list result; - for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i) - if(i->second.check_type()) - result.push_back(i->second.value().get()); + std::list future; + collect_items(&result, 0, &future); + for(std::list::iterator i=future.begin(); i!=future.end(); ++i) + result.push_back(&get(*i)); return result; } - /// Checks whether a typed object exists in the collection. +private: template - bool contains(const std::string &name) const + unsigned get_status(const std::string &name) const { ItemMap::const_iterator i = items.find(name); if(i==items.end()) return false; - return i->second.check_type::Type>(); + typedef RefPtr::Type> RPNCT; + if(!i->second.check_type()) + return false; + + T *ptr = i->second.value().get(); + return ptr ? 1 : 2; } +public: + /// Checks whether a typed object exists and is loaded in the collection. + template + bool contains(const std::string &name) const + { return get_status(name)==1; } + + /** Checks whether a typed object exists in the collection, as either a + loaded or future object. */ + template + bool contains(const std::string &name) + { return get_status(name)>0; } + /// Returns the name of an item in the collection. template const std::string &get_name(T *d) const @@ -184,19 +265,22 @@ protected: CollectionItemType &add_type(); }; - -template -struct Collection::Loader::Add +template +class Collection::ItemLoader: public T::Loader { - static void add(Loader &loader, const std::string &kwd) - { loader.add(kwd, &Loader::item); } +public: + ItemLoader(T &o, Collection &): + T::Loader(o) + { } }; -template -struct Collection::Loader::Add +template +class Collection::ItemLoader: public T::Loader { - static void add(Loader &loader, const std::string &kwd) - { loader.add(kwd, &Loader::coll_item); } +public: + ItemLoader(T &o, Collection &c): + T::Loader(o, dynamic_cast(c)) + { } }; @@ -213,22 +297,23 @@ protected: template class Tag: public TagBase - { - public: - virtual ~Tag() { } - }; + { }; std::string kwd; + std::vector suffixes; TagBase *tag; - CollectionItemTypeBase(): tag(0) { } + CollectionItemTypeBase(); public: - virtual ~CollectionItemTypeBase() - { delete tag; } + virtual ~CollectionItemTypeBase(); + void set_keyword(const std::string &); + void add_suffix(const std::string &); 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; + bool match_name(const std::string &) const; + virtual Variant create_future() const = 0; template bool check_type() const @@ -278,6 +363,7 @@ private: 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; }; @@ -289,8 +375,11 @@ private: virtual void store(Collection &coll, const std::string &name, T *obj) { coll.add(name, static_cast(obj)); } + virtual Variant create_future() const + { return RefPtr(0); } + virtual void add_to_loader(Collection::Loader &loader, const std::string &kwd) - { Collection::Loader::Add::add(loader, kwd); } + { loader.add(kwd, &Collection::Loader::item); } }; CreatorBase *creat; @@ -312,7 +401,17 @@ public: item's name. */ CollectionItemType &keyword(const std::string &k) { - kwd = k; + set_keyword(k); + return *this; + } + + /** Adds a suffix that is used to match names when looking for future + objects. There is no implied separator; a name matches if it ends with the + suffix. If a keyword is defined before any suffixes, then "."+keyword is + added as a suffix. */ + CollectionItemType &suffix(const std::string &s) + { + add_suffix(s); return *this; } @@ -356,6 +455,9 @@ public: if(obj) store->store(coll, name, obj); } + + virtual Variant create_future() const + { return store->create_future(); } }; @@ -364,13 +466,18 @@ T &Collection::get(const std::string &name) { typedef typename RemoveConst::Type NCT; - if(!items.count(name)) + ItemMap::iterator i = items.find(name); + if(i!=items.end()) { - for(TypeList::iterator i=types.begin(); i!=types.end(); ++i) - if((*i)->can_create() && (*i)->check_type()) - (*i)->create_item(*this, name); + NCT *ptr = i->second.value >().get(); + if(ptr) + return *ptr; } + for(TypeList::iterator j=types.begin(); j!=types.end(); ++j) + if((*j)->can_create() && (*j)->check_type()) + (*j)->create_item(*this, name); + return *get_item(items, name).value >(); }