-/* $Id$
-
-This file is part of libmspdatafile
-Copyright © 2006 Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
#ifndef MSP_DATAFILE_LOADER_H_
#define MSP_DATAFILE_LOADER_H_
-#include <fstream>
#include <map>
-#include "error.h"
+#include <msp/io/file.h>
+#include "loaderaction.h"
#include "parser.h"
#include "statement.h"
-#include "value.h"
namespace Msp {
namespace DataFile {
-class Loader;
-class Statement;
-
-/**
-Base class for loader actions.
-*/
-class LoaderAction
-{
-public:
- /**
- Called when a statement is to be loaded.
- */
- virtual void execute(Loader &, const Statement &) const=0;
- virtual ~LoaderAction() { }
-protected:
- LoaderAction() { }
-};
-
-
/**
-Loads a statement by calling a function that takes no arguments.
-*/
-template<typename L>
-class LoaderFunc0: public LoaderAction
-{
-public:
- typedef void (L::*FuncType)();
+Base class for data loaders. This class only provides core functionality.
+You'll almost certainly want to use one of the BasicLoader classes instead.
- LoaderFunc0(FuncType f): func(f) { }
- void execute(Loader &l, const Statement &st) const
- {
- if(st.args.size()!=0) throw TypeError(st.get_location()+": Wrong number of arguments");
- (dynamic_cast<L &>(l).*func)();
- };
-private:
- FuncType func;
-};
+Under normal circumstances, a class capable of being loaded should have a
+nested typed called Loader which resolves to a descendant of this class. If
+another structure is used, the loader object must be constructed manually.
+A loader class should execute one or more calls to the various add() functions
+to register actions with expected keywords. Currently possible actions are
+calling a function of the loader, storing values in member variables of an
+object and ignoring the statement. If a unexpected keyword is encountered, an
+exception is thrown and the loading is aborted.
-/**
-Loads a statement by calling a function that takes one argument.
-*/
-template<typename L, typename A0>
-class LoaderFunc1: public LoaderAction
-{
-public:
- typedef void (L::*FuncType)(A0);
-
- LoaderFunc1(FuncType f): func(f) { }
- void execute(Loader &l, const Statement &st) const
- {
- if(st.args.size()!=1) throw TypeError(st.get_location()+": Wrong number of arguments");
- (dynamic_cast<L &>(l).*func)(st.args[0].get<A0>());
- }
-private:
- FuncType func;
-};
+A sub-object can be loaded with one of the load_sub functions.
+When loading has finished successfully, the virtual function finish() is
+called. Any post-processing of the data should be placed here and not in the
+destructor.
-/**
-Loads a statement by calling a function that takes an array of values.
+See also classes ObjectLoader and CollectionObjectLoader in objectloader.h.
*/
-template<typename L, typename A0>
-class LoaderFunc1<L, const std::list<A0> &>: public LoaderAction
+class Loader
{
-public:
- typedef void (L::*FuncType)(const std::list<A0> &);
-
- LoaderFunc1(FuncType f): func(f) { }
- void execute(Loader &l, const Statement &st) const
- {
- std::vector<A0> values;
- values.reserve(st.args.size());
- for(ValueArray::iterator i=st.args.begin(); i!=st.args.end(); ++i)
- values.push_back(i->get<A0>());
- (dynamic_cast<L &>(l).*func)(values);
- }
private:
- FuncType func;
-};
-
-
-template<typename L, typename A0, typename A1>
-class LoaderFunc2: public LoaderAction
-{
-public:
- typedef void (L::*FuncType)(A0, A1);
-
- LoaderFunc2(FuncType f): func(f) { }
- void execute(Loader &l, const Statement &st) const
- {
- if(st.args.size()!=2) throw TypeError(st.get_location()+": Wrong number of arguments");
- (dynamic_cast<L &>(l).*func)(st.args[0].get<A0>(), st.args[1].get<A1>());
- }
-private:
- FuncType func;
-};
+ typedef std::map<StatementKey, LoaderAction *> ActionMap;
+ ActionMap actions;
+ Parser *cur_parser;
+ unsigned cur_level;
+ const Statement *cur_st;
+ bool sub_loaded;
+ bool direct;
+ std::list<Loader *> aux_loaders;
+protected:
+ bool check_sub_loads;
-template<typename L, typename A0, typename A1, typename A2>
-class LoaderFunc3: public LoaderAction
-{
+ Loader();
public:
- typedef void (L::*FuncType)(A0, A1, A2);
-
- LoaderFunc3(FuncType f): func(f) { }
- void execute(Loader &l, const Statement &st) const
- {
- if(st.args.size()!=3) throw TypeError(st.get_location()+": Wrong number of arguments");
- (dynamic_cast<L &>(l).*func)(st.args[0].get<A0>(), st.args[1].get<A1>(), st.args[2].get<A2>());
- }
-private:
- FuncType func;
-};
-
+ virtual ~Loader();
-template<typename L, typename A0, typename A1, typename A2, typename A3>
-class LoaderFunc4: public LoaderAction
-{
-public:
- typedef void (L::*FuncType)(A0, A1, A2, A3);
+ /** Loads statements from a parser. */
+ void load(Parser &p);
- LoaderFunc4(FuncType f): func(f) { }
- void execute(Loader &l, const Statement &st) const
- {
- if(st.args.size()!=4) throw TypeError(st.get_location()+": Wrong number of arguments");
- (dynamic_cast<L &>(l).*func)(st.args[0].get<A0>(), st.args[1].get<A1>(), st.args[2].get<A2>(), st.args[3].get<A3>());
- }
private:
- FuncType func;
-};
+ /** Loads data from a statement. */
+ void load(const Statement &st);
+ /** Loads statemsnts from a parser, feeding them directly to actions. */
+ void load_direct(Parser &, unsigned);
-template<typename L, typename T0>
-class LoadValue1: public LoaderAction
-{
-public:
- typedef T0 L::*Pointer0Type;
+ /** Processes a single statement */
+ void load_statement(const Statement &st);
- LoadValue1(Pointer0Type p0): ptr0(p0) { }
- void execute(Loader &l, const Statement &st) const
+protected:
+ /** Loads a sub-object from the statement being processed. The Loader class
+ of the sub-object is automatically used. */
+ template<typename S>
+ void load_sub(S &s)
{
- if(st.args.size()!=1) throw TypeError(st.get_location()+": Wrong number of arguments");
- dynamic_cast<typename L::Loader &>(l).get_object().*ptr0=st.args[0].get<T0>();
+ typename S::Loader ldr(s);
+ load_sub_with(ldr);
}
-private:
- Pointer0Type ptr0;
-};
-
-template<typename L, typename T0, typename T1>
-class LoadValue2: public LoaderAction
-{
-public:
- typedef T0 L::*Pointer0Type;
- typedef T1 L::*Pointer1Type;
-
- LoadValue2(Pointer0Type p0, Pointer1Type p1): ptr0(p0), ptr1(p1) { }
- void execute(Loader &l, const Statement &st) const
+ /** Loads a sub-object from the statement being processed with an extra
+ parameter for the Loader. The Loader class of the sub-object is
+ automatically used. */
+ template<typename S, typename T>
+ void load_sub(S &s, T &p)
{
- if(st.args.size()!=2) throw TypeError(st.get_location()+": Wrong number of arguments");
- dynamic_cast<typename L::Loader &>(l).get_object().*ptr0=st.args[0].get<T0>();
- dynamic_cast<typename L::Loader &>(l).get_object().*ptr1=st.args[1].get<T1>();
+ typename S::Loader ldr(s, p);
+ load_sub_with(ldr);
}
-private:
- Pointer0Type ptr0;
- Pointer1Type ptr1;
-};
-
-
-/**
-Base class for data loaders. To enable objects of a certain class to be loaded
-from datafiles, create a public Loader class in it, derived from this class.
-Typically the Loader class contains a reference to the object being loaded. If
-you want to load data members of the object directly, the Loader class must
-have a member function get_object() returning that reference.
-*/
-class Loader
-{
-public:
- /**
- Loads data from a statement. This is normally only used by the Loader class
- itself for loading sub-items, but needs to be public so it can be accessed
- in derived objects.
- */
- void load(const Statement &st);
- /**
- Loads statements from a parser.
- */
- void load(Parser &p);
-
- virtual ~Loader();
-protected:
- Loader(): cur_st(0) { }
+ /** Processes the current statement's substatements with another Loader. */
+ void load_sub_with(Loader &);
+ /** Adds a keyword that is loaded by calling a function. */
template<typename L>
void add(const std::string &k, void (L::*func)())
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc0<L>(func))); }
+ { add(k, new LoaderFunc0<L>(func)); }
template<typename L, typename A0>
void add(const std::string &k, void (L::*func)(A0))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc1<L, A0>(func))); }
+ { add(k, new LoaderFunc1<L, A0>(func)); }
template<typename L, typename A0, typename A1>
void add(const std::string &k, void (L::*func)(A0, A1))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc2<L, A0, A1>(func))); }
+ { add(k, new LoaderFunc2<L, A0, A1>(func)); }
template<typename L, typename A0, typename A1, typename A2>
void add(const std::string &k, void (L::*func)(A0, A1, A2))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc3<L, A0, A1, A2>(func))); }
+ { add(k, new LoaderFunc3<L, A0, A1, A2>(func)); }
template<typename L, typename A0, typename A1, typename A2, typename A3>
void add(const std::string &k, void (L::*func)(A0, A1, A2, A3))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc4<L, A0, A1, A2, A3>(func))); }
+ { add(k, new LoaderFunc4<L, A0, A1, A2, A3>(func)); }
+
+ template<typename L, typename A0, typename A1, typename A2, typename A3, typename A4>
+ void add(const std::string &k, void (L::*func)(A0, A1, A2, A3, A4))
+ { add(k, new LoaderFunc5<L, A0, A1, A2, A3, A4>(func)); }
+ /** Adds a keyword that is loaded into a member of the loaded object. */
template<typename L, typename T0>
void add(const std::string &k, T0 L::*p0)
- { actions.insert(typename ActionMap::value_type(k, new LoadValue1<L, T0>(p0))); }
+ { add(k, new LoadValue1<L, T0>(p0)); }
template<typename L, typename T0, typename T1>
void add(const std::string &k, T0 L::*p0, T1 L::*p1)
- { actions.insert(typename ActionMap::value_type(k, new LoadValue2<L, T0, T1>(p0, p1))); }
+ { add(k, new LoadValue2<L, T0, T1>(p0, p1)); }
+ /** Adds a keyword that is recognized but ignored. */
void add(const std::string &k)
- { actions.insert(ActionMap::value_type(k, 0)); }
+ { add(k, 0); }
- /**
- Loads a sub-object from the statement being currently processed. The Loader
- class of the sub-object is automatically used.
- */
- template<typename S>
- void load_sub(S &s)
- { load_sub<S, typename S::Loader>(s); }
+private:
+ void add(const std::string &, LoaderAction *);
- /**
- Loads a sub-object with a custom Loader class.
- */
- template<typename S, typename L>
- void load_sub(S &s)
- {
- if(!cur_st)
- throw InvalidState("load_sub called without current statement");
- L loader(s);
- loader.load(*cur_st);
- }
+protected:
+ void add_auxiliary_loader(Loader &);
- /**
- Loads a sub-object with a custom Loader class that takes one argument in
- addition to to object to be loaded.
- */
- template<typename S, typename L, typename T>
- void load_sub(S &s, T &p)
- {
- if(!cur_st)
- throw InvalidState("load_sub called without current statement");
- L loader(s, p);
- loader.load(*cur_st);
- }
private:
- typedef std::map<std::string, LoaderAction *> ActionMap;
+ bool has_action(const StatementKey &) const;
+ LoaderAction *find_action(const StatementKey &) const;
- ActionMap actions;
- const Statement *cur_st;
+protected:
+ /** Returns the source of the statement being processed. This can be used
+ to implement relative paths in include-like statements. Note that the
+ source may not necessarily be a file. */
+ const std::string &get_source() const;
- void load_statement(const Statement &st);
+ /** Returns the keyword of the statement being processed. Can be used to
+ implement dynamic keywords. */
+ const std::string &get_keyword() const;
+
+ virtual void finish() { }
};
+
/**
Loads an object from a file. The object must have a public Loader class.
*/
template<typename T>
void load(T &obj, const std::string &fn)
{
- std::ifstream in(fn.c_str());
- if(!in)
- throw Exception("Couldn't open "+fn);
+ IO::BufferedFile in(fn);
Parser parser(in, fn);
typename T::Loader loader(obj);
loader.load(parser);
}
+template<typename T, typename U>
+void load(T &obj, const std::string &fn, U &arg)
+{
+ IO::BufferedFile in(fn);
+
+ Parser parser(in, fn);
+ typename T::Loader loader(obj, arg);
+ loader.load(parser);
+}
+
} // namespace DataFile
} // namespace Msp
projects / libs / datafile.git / blobdiff