]> git.tdb.fi Git - libs/datafile.git/blobdiff - source/collection.h
Move most of Collection::get implementation to collection.cpp
[libs/datafile.git] / source / collection.h
index d5e0806afeebad9fbfa2f043ef80d3ef9bc64878..be9ae88c491595f925db46e30aeff2daa67deb5f 100644 (file)
@@ -4,8 +4,12 @@
 #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 {
 
@@ -38,6 +42,9 @@ 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 can have sources for loading objects on demand.  Automatic loading
+only works on a non-const Collection.  See class CollectionSource for details.
 */
 class Collection
 {
@@ -51,40 +58,35 @@ public:
                template<typename T> friend class CollectionItemType;
 
        private:
-               template<typename T, typename S, bool = NeedsCollection<typename T::Loader>::value>
-               struct Add;
-
                Collection &coll;
 
        public:
                Loader(Collection &);
                Collection &get_object() const { return coll; }
        private:
-               template<typename T, typename S, typename C>
-               void coll_item(const std::string &n)
-               {
-                       RefPtr<T> it = new T;
-                       load_sub(*it, dynamic_cast<C &>(coll));
-                       coll.add<S>(n, it.get());
-                       it.release();
-               }
-
                template<typename T, typename S>
                void item(const std::string &n)
                {
                        RefPtr<T> it = new T;
-                       load_sub(*it);
+                       ItemLoader<T> ldr(*it, coll);
+                       load_sub_with(ldr);
                        coll.add<S>(n, it.get());
                        it.release();
                }
        };
 
+protected:
+       template<typename T, bool = NeedsCollection<typename T::Loader>::value>
+       class ItemLoader;
+
 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 &);
@@ -100,41 +102,78 @@ public:
                if(!item)
                        throw std::invalid_argument("Collection::add(item)");
 
-               RefPtr<typename RemoveConst<T>::Type> ptr(item);
-               try
-               {
-                       insert_unique(items, name, ptr);
-               }
-               catch(...)
-               {
-                       // Avoid deleting the object
-                       ptr.release();
-                       throw;
-               }
+               insert_unique(items, name, RefPtr<typename RemoveConst<T>::Type>(item));
        }
 
        /// Gets a typed object from the collection.
        template<typename T>
        T &get(const std::string &name) const
        {
-               typedef typename RemoveConst<T>::Type NCT;
+               return extract<T>(get_item(items, name));
+       }
 
-               return *get_item(items, name).value<RefPtr<NCT> >();
+       /** 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 &name)
+       {
+               return extract<T>(get_var(name, get_type<T>()));
        }
 
-       /** 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. */
+private:
+       const Variant &get_var(const std::string &, const CollectionItemTypeBase *);
+
        template<typename T>
-       T &get(const std::string &);
+       T &extract(const Variant &var) const
+       {
+               return *var.value<RefPtr<typename RemoveConst<T>::Type> >();
+       }
 
+       template<typename T>
+       void collect_items(std::list<T *> *objects, std::list<std::string> *names, std::list<std::string> *future_names) const
+       {
+               typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+
+               for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
+                       if(i->second.check_type<RPNCT>())
+                       {
+                               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)
+                               {
+                                       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);
+                               }
+                       }
+       }
+
+public:
        /// Returns a list of the names of objects of one type in the collection.
        template<typename T>
        std::list<std::string> get_names() const
        {
                std::list<std::string> result;
-               for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
-                       if(i->second.check_type<RefPtr<typename RemoveConst<T>::Type> >())
-                               result.push_back(i->first);
+               collect_items<T>(0, &result, 0);
+               return result;
+       }
+
+       /** 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()
+       {
+               std::list<std::string> result;
+               collect_items<T>(0, &result, &result);
                return result;
        }
 
@@ -142,26 +181,59 @@ public:
        template<typename T>
        std::list<T *> get_list() const
        {
-               typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+               std::list<T *> result;
+               collect_items<T>(&result, 0, 0);
+               return result;
+       }
 
+       /** Returns a list of objects of one type, loading them from sources if
+       necessary. */
+       template<typename T>
+       std::list<T *> get_list()
+       {
                std::list<T *> result;
-               for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
-                       if(i->second.check_type<RPNCT>())
-                               result.push_back(i->second.value<RPNCT>().get());
+               std::list<std::string> future;
+               collect_items<T>(&result, 0, &future);
+               for(std::list<std::string>::iterator i=future.begin(); i!=future.end(); ++i)
+                       result.push_back(&get<T>(*i));
                return result;
        }
 
-       /// Checks whether a typed object exists in the collection.
+private:
        template<typename T>
-       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;
+               {
+                       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;
+               }
 
-               return i->second.check_type<typename RemoveConst<T>::Type>();
+               typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+               if(!i->second.check_type<RPNCT>())
+                       return 0;
+
+               return 1;
        }
 
+public:
+       /// 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 or is loadable
+       from a source. */
+       template<typename T>
+       bool contains(const std::string &name)
+       { return get_status<T>(name)>0; }
+
        /// Returns the name of an item in the collection.
        template<typename T>
        const std::string &get_name(T *d) const
@@ -182,21 +254,30 @@ protected:
        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;
 
-template<typename T, typename S>
-struct Collection::Loader::Add<T, S, false>
+       void add_source(CollectionSource &);
+};
+
+template<typename T>
+class Collection::ItemLoader<T, false>: public T::Loader
 {
-       static void add(Loader &loader, const std::string &kwd)
-       { loader.add(kwd, &Loader::item<T, S>); }
+public:
+       ItemLoader(T &o, Collection &):
+               T::Loader(o)
+       { }
 };
 
-template<typename T, typename S>
-struct Collection::Loader::Add<T, S, true>
+template<typename T>
+class Collection::ItemLoader<T, true>: public T::Loader
 {
-       static void add(Loader &loader, const std::string &kwd)
-       { loader.add(kwd, &Loader::coll_item<T, S, typename T::Loader::Collection>); }
+public:
+       ItemLoader(T &o, Collection &c):
+               T::Loader(o, dynamic_cast<typename T::Loader::Collection &>(c))
+       { }
 };
 
 
@@ -213,22 +294,24 @@ protected:
 
        template<typename T>
        class Tag: public TagBase
-       {
-       public:
-               virtual ~Tag() { }
-       };
+       { };
 
        std::string kwd;
+       std::vector<std::string> suffixes;
        TagBase *tag;
 
-       CollectionItemTypeBase(): tag(0) { }
+       CollectionItemTypeBase();
 public:
-       virtual ~CollectionItemTypeBase()
-       { delete tag; }
+       virtual ~CollectionItemTypeBase();
 
+       void set_keyword(const std::string &);
+       const std::string &get_keyword() const { return kwd; }
+       void add_suffix(const std::string &);
+       bool match_name(const std::string &) const;
        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 void load_item(Collection &, Parser &, const std::string &) const = 0;
 
        template<typename T>
        bool check_type() const
@@ -290,7 +373,7 @@ private:
                { coll.add(name, static_cast<S *>(obj)); }
 
                virtual void add_to_loader(Collection::Loader &loader, const std::string &kwd)
-               { Collection::Loader::Add<T, S>::add(loader, kwd); }
+               { loader.add(kwd, &Collection::Loader::item<T, S>); }
        };
 
        CreatorBase *creat;
@@ -312,7 +395,17 @@ 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;
        }
 
@@ -356,23 +449,17 @@ public:
                if(obj)
                        store->store(coll, name, obj);
        }
-};
 
-
-template<typename T>
-T &Collection::get(const std::string &name)
-{
-       typedef typename RemoveConst<T>::Type NCT;
-
-       if(!items.count(name))
+       virtual void load_item(Collection &coll, Parser &parser, const std::string &name) const
        {
-               for(TypeList::iterator i=types.begin(); i!=types.end(); ++i)
-                       if((*i)->can_create() && (*i)->check_type<NCT>())
-                               (*i)->create_item(*this, name);
+               RefPtr<T> obj = new T;
+               Collection::ItemLoader<T> ldr(*obj, coll);
+               ldr.load(parser);
+               store->store(coll, name, obj.get());
+               obj.release();
        }
+};
 
-       return *get_item(items, name).value<RefPtr<NCT> >();
-}
 
 template<typename T>
 CollectionItemType<T> &Collection::add_type()
@@ -382,6 +469,15 @@ CollectionItemType<T> &Collection::add_type()
        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