-/* $Id$
-
-This file is part of libmspdatafile
-Copyright © 2006 Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
#ifndef MSP_DATAFILE_COLLECTION_H_
#define MSP_DATAFILE_COLLECTION_H_
+#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 {
template<typename U>
static No f(...);
- enum { result=(sizeof(f<T>(0))==sizeof(Yes)) };
+ enum { value = (sizeof(f<T>(0))==sizeof(Yes)) };
};
-template<typename T>
-struct RemoveConst
-{ typedef T Type; };
+class CollectionItemTypeBase;
template<typename T>
-struct RemoveConst<const T>
-{ typedef T Type; };
+class CollectionItemType;
/**
A collection of objects that can be loaded from a datafile. Each object is
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
{
-public:
- class Loader;
-
-private:
- /* XXX I don't really like sticking all this stuff in here, but there's some
- complex inter-class relationships, especially between ItemKeyword and
- Collection::Loader. */
-
- struct ItemBase
- {
- virtual ~ItemBase() { }
- };
-
- template<typename T>
- struct Item: public ItemBase
- {
- T *data;
-
- Item(T *d): data(d) { }
- ~Item() { delete data; }
- };
-
- /**
- Used to store keywords for types that can be loaded.
- */
- struct ItemKeywordBase
- {
- virtual void add_to_loader(Loader &) const { };
- };
-
- template<typename T, typename S, bool need_coll=NeedsCollection<typename T::Loader>::result>
- struct ItemKeyword: public ItemKeywordBase
- {
- std::string keyword;
-
- ItemKeyword(const std::string &kw): keyword(kw) { }
-
- void add_to_loader(Loader &ldr) const
- { ldr.add(keyword, &Loader::item<T, S>); }
- };
-
- template<typename T, typename S>
- struct ItemKeyword<T, S, true>: public ItemKeywordBase
- {
- std::string keyword;
-
- ItemKeyword(const std::string &kw): keyword(kw) { }
-
- virtual void add_to_loader(Loader &ldr) const
- { ldr.add(keyword, &Loader::coll_item<T, S, typename T::Loader::Collection>); }
- };
-
- /**
- Used to store types that can be created automatically.
- */
- struct ItemCreatorBase
- {
- virtual ~ItemCreatorBase() { }
-
- template<typename S>
- S *create(Collection &coll, const std::string &name)
- {
- ItemCreatorBridge<S> *creator=dynamic_cast<ItemCreatorBridge<S> *>(this);
- if(creator)
- return creator->create(coll, name);
- return 0;
- }
- };
-
- template<typename S>
- struct ItemCreatorBridge: public ItemCreatorBase
- {
- virtual S *create(Collection &, const std::string &) const =0;
- };
-
- template<typename T, typename S, typename C>
- struct ItemCreator: public ItemCreatorBridge<S>
- {
- typedef T *(C::*fCreate)(const std::string &);
-
- fCreate create_func;
-
- ItemCreator(fCreate cf): create_func(cf) { }
- virtual S *create(Collection &coll, const std::string &name) const
- { return (dynamic_cast<C &>(coll).*create_func)(name); }
- };
-
public:
/**
- Loads objects into a Collection.
+ Loads objects into a Collection. Automatically picks up keywords from
+ defined item types.
*/
class Loader: public DataFile::Loader
{
+ template<typename T> friend class CollectionItemType;
+
private:
Collection &coll;
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);
+ RefPtr<T> it = new T;
+ ItemLoader<T> ldr(*it, coll);
+ load_sub_with(ldr);
coll.add<S>(n, it.get());
it.release();
}
-
- template<typename, typename, bool> friend class ItemKeyword;
};
+protected:
+ template<typename T, bool = NeedsCollection<typename T::Loader>::value>
+ class ItemLoader;
+
private:
- typedef std::map<std::string, ItemBase *> ItemMap;
- typedef std::list<ItemKeywordBase *> ItemKeywordSeq;
- typedef std::list<ItemCreatorBase *> ItemCreatorSeq;
+ typedef std::map<std::string, Variant> ItemMap;
+ typedef std::list<CollectionItemTypeBase *> TypeList;
+ typedef std::list<CollectionSource *> SourceList;
+ TypeList types;
ItemMap items;
- ItemKeywordSeq keywords;
- ItemCreatorSeq creators;
+ SourceList sources;
Collection(const Collection &);
Collection &operator=(const Collection &);
Collection() { }
virtual ~Collection();
- /**
- Adds an object into the collection. If a name collision occurs, an
- exception is thrown. The collection takes ownership of the object.
- */
+ /** Adds an object into the collection. The name must not pre-exist. The
+ collection takes ownership of the object. */
template<typename T>
- void add(const std::string &name, T *d)
+ void add(const std::string &name, T *item)
{
- if(items.count(name))
- throw KeyError("Duplicate key '"+name+"' in collection");
+ if(!item)
+ throw std::invalid_argument("Collection::add(item)");
- items[name]=new Item<typename RemoveConst<T>::Type>(d);
+ insert_unique(items, name, RefPtr<typename RemoveConst<T>::Type>(item));
}
- /**
- Gets an object of a specific type from the collection.
- */
+ /// 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));
+ }
- ItemMap::const_iterator i=items.find(name);
- if(i==items.end())
- throw KeyError("Item '"+name+"' not found in collection");
+ /** 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>()));
+ }
- const Item<NCT> *item=dynamic_cast<const Item<NCT> *>(i->second);
- if(!item)
- throw TypeError("Item '"+name+"' is not of correct type");
+private:
+ const Variant &get_var(const std::string &, const CollectionItemTypeBase *);
+
+ template<typename T>
+ T &extract(const Variant &var) const;
+
+ 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;
- return *item->data;
+ 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);
+ }
+ }
}
- /**
- Gets an object of a specific type from the collection. If the name is not
- found in the collection and there is a creator for the item type, it is
- invoked.
- */
+public:
+ /// Returns a list of the names of objects of one type in the collection.
template<typename T>
- T &get(const std::string &name)
+ std::list<std::string> get_names() const
+ {
+ std::list<std::string> result;
+ 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;
+ }
+
+ /// Returns a list of objects of one type in the collection.
+ template<typename T>
+ std::list<T *> get_list() const
{
- typedef typename RemoveConst<T>::Type NCT;
+ 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;
+ 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;
+ }
- ItemMap::const_iterator i=items.find(name);
+private:
+ template<typename T>
+ unsigned get_status(const std::string &name) const
+ {
+ ItemMap::const_iterator i = items.find(name);
if(i==items.end())
{
- for(ItemCreatorSeq::iterator j=creators.begin(); j!=creators.end(); ++j)
- if(NCT *d=(*j)->create<NCT>(*this, name))
- {
- // We already know that the item didn't exist yet
- items[name]=new Item<NCT>(d);
- return *d;
- }
- throw KeyError("Item '"+name+"' not found in collection");
+ 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;
}
- const Item<NCT> *item=dynamic_cast<const Item<NCT> *>(i->second);
- if(!item)
- throw TypeError("Item '"+name+"' is not of correct type");
+ typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+ if(!i->second.check_type<RPNCT>())
+ return 0;
- return *item->data;
+ return 1;
}
- /**
- Returns a list of the names of objects of a specific type in the collection.
- */
+public:
+ /// Checks whether a typed object exists in the collection.
template<typename T>
- std::list<std::string> get_names() const
+ 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
{
- std::list<std::string> result;
+ typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+
for(ItemMap::const_iterator i=items.begin(); i!=items.end(); ++i)
- if(dynamic_cast<const Item<T> *>(i->second))
- result.push_back(i->first);
- return result;
+ if(i->second.check_type<RPNCT>())
+ if(i->second.value<RPNCT>().get()==d)
+ return i->first;
+
+ // XXX Need better exception class
+ throw std::runtime_error("Item not found in collection");
}
- /**
- Checks whether a name exists in the collection. Does not care about the
- type of the object.
- */
- bool contains(const std::string &n) const;
+protected:
+ /** Adds a type to the collection. The returned descriptor object reference
+ 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;
+
+ /// Returns the descriptor for an item, or null if it's of an unknown type.
+ CollectionItemTypeBase *get_type_for_item(const Variant &) const;
+
+ void add_source(CollectionSource &);
+};
+
+template<typename T>
+class Collection::ItemLoader<T, false>: public T::Loader
+{
+public:
+ ItemLoader(T &o, Collection &):
+ T::Loader(o)
+ { }
+};
+
+template<typename T>
+class Collection::ItemLoader<T, true>: public T::Loader
+{
+public:
+ ItemLoader(T &o, Collection &c):
+ T::Loader(o, dynamic_cast<typename T::Loader::Collection &>(c))
+ { }
+};
+
+class CollectionItemTypeBase
+{
protected:
- /**
- Adds a type that can be loaded from datafiles.
- */
+ struct ExtractorBase
+ {
+ virtual ~ExtractorBase() { }
+ };
+
template<typename T>
- void add_keyword(const std::string &keyword)
- { add_keyword<T, T>(keyword); }
+ struct Extractor: ExtractorBase
+ {
+ virtual T &extract(const Variant &) const = 0;
+ };
- /**
- Adds a type that can be loaded from datafiles, with different storage type.
- */
- template<typename T, typename S>
- void add_keyword(const std::string &keyword)
- { keywords.push_back(new ItemKeyword<T, S>(keyword)); }
+ std::string kwd;
+ std::vector<std::string> suffixes;
+ std::vector<ExtractorBase *> extractors;
- /**
- Adds a type that can be created automatically.
- */
- template<typename T, typename C>
- void add_creator(T *(C::*func)(const std::string &))
- { add_creator<T, T, C>(func); }
+ CollectionItemTypeBase() { }
+public:
+ 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 bool check_item_type(const Variant &) const = 0;
+ 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 can_extract() const
+ {
+ for(std::vector<ExtractorBase *>::const_iterator i=extractors.begin(); i!=extractors.end(); ++i)
+ if(dynamic_cast<Extractor<T> *>(*i))
+ return true;
+ return false;
+ }
- template<typename T, typename S, typename C>
- void add_creator(T *(C::*func)(const std::string &))
- { creators.push_back(new ItemCreator<T, S, C>(func)); }
+ template<typename T>
+ T *extract(const Variant &var) const
+ {
+ for(std::vector<ExtractorBase *>::const_iterator i=extractors.begin(); i!=extractors.end(); ++i)
+ if(Extractor<T> *ex = dynamic_cast<Extractor<T> *>(*i))
+ return &ex->extract(var);
+ return 0;
+ }
};
+
+/**
+Describes a type of item that can be loaded by a Collection. These are created
+by Collection::add_type.
+*/
+template<typename T>
+class CollectionItemType: public CollectionItemTypeBase
+{
+private:
+ struct CreatorBase
+ {
+ virtual ~CreatorBase() { }
+
+ virtual T *create(Collection &, const std::string &) const = 0;
+ };
+
+ template<typename C>
+ struct Creator: CreatorBase
+ {
+ typedef T *(C::*FuncPtr)(const std::string &);
+
+ FuncPtr func;
+
+ Creator(FuncPtr f): func(f) { }
+
+ virtual T *create(Collection &coll, const std::string &name) const
+ { return (static_cast<C &>(coll).*func)(name); }
+ };
+
+ template<typename B>
+ struct Extractor: CollectionItemTypeBase::Extractor<B>
+ {
+ virtual B &extract(const Variant &var) const
+ { return *var.value<RefPtr<T> >(); }
+ };
+
+ CreatorBase *creat;
+
+public:
+ CollectionItemType():
+ creat(0)
+ { }
+
+ ~CollectionItemType()
+ {
+ delete creat;
+ }
+
+ /** Sets a datafile keyword for this item type. The Collection's loader
+ will accept a statement with this keyword and a single string argument - the
+ item's name. */
+ CollectionItemType &keyword(const std::string &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;
+ }
+
+ /** Attaches a creator function to this item type. If an item is not found
+ in the Collection, the creator function for its type is called to create it.
+ The function must be a member of the Collection subclass containing the
+ type. It must return the created object, or null if it could not be
+ created. It's also permissible to load the item via other means and then
+ return null. */
+ template<typename C>
+ CollectionItemType &creator(T *(C::*func)(const std::string &))
+ {
+ delete creat;
+ creat = new Creator<C>(func);
+ return *this;
+ }
+
+ /** Makes items of this type available through a base class. */
+ template<typename B>
+ CollectionItemType &base()
+ {
+ extractors.push_back(new Extractor<B>);
+ return *this;
+ }
+
+ virtual bool check_item_type(const Variant &var) const
+ { return var.check_type<RefPtr<T> >(); }
+
+ virtual void add_to_loader(Collection::Loader &loader) const
+ { loader.add(kwd, &Collection::Loader::item<T, T>); }
+
+ virtual bool can_create() const
+ { return creat!=0; }
+
+ virtual void create_item(Collection &coll, const std::string &name) const
+ {
+ if(!creat)
+ throw std::runtime_error("no creator");
+ T *obj = creat->create(coll, name);
+ if(obj)
+ coll.add(name, obj);
+ }
+
+ 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);
+ // Collection::add will delete the object if it fails
+ coll.add(name, obj.release());
+ }
+};
+
+
+template<typename T>
+T &Collection::extract(const Variant &var) const
+{
+ typedef RefPtr<typename RemoveConst<T>::Type> RPNCT;
+
+ if(!var.check_type<RPNCT>())
+ if(CollectionItemTypeBase *type = get_type_for_item(var))
+ if(T *item = type->extract<T>(var))
+ return *item;
+
+ return *var.value<RPNCT>();
+}
+
+template<typename T>
+CollectionItemType<T> &Collection::add_type()
+{
+ CollectionItemType<T> *type = new CollectionItemType<T>;
+ types.push_back(type);
+ return *type;
+}
+
+template<typename T>
+CollectionItemTypeBase *Collection::get_type() const
+{
+ for(TypeList::const_iterator j=types.begin(); j!=types.end(); ++j)
+ if(dynamic_cast<CollectionItemType<typename RemoveConst<T>::Type> *>(*j))
+ return *j;
+ for(TypeList::const_iterator j=types.begin(); j!=types.end(); ++j)
+ if((*j)->can_extract<T>())
+ return *j;
+ return 0;
+}
+
} // namespace DataFile
} // namespace Msp