open_toontown_panda3d/panda/src/putil/bamReader.h

256 lines
9.1 KiB
C++

// Filename: bamReader.h
// Created by: jason (12Jun00)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001 - 2004, Disney Enterprises, Inc. All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license. You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://etc.cmu.edu/panda3d/docs/license/ .
//
// To contact the maintainers of this program write to
// panda3d-general@lists.sourceforge.net .
//
////////////////////////////////////////////////////////////////////
#ifndef __BAM_READER_
#define __BAM_READER_
#include "pandabase.h"
#include "pnotify.h"
#include "typedWritable.h"
#include "datagramGenerator.h"
#include "datagramIterator.h"
#include "bamReaderParam.h"
#include "bamEndian.h"
#include "factory.h"
#include "vector_int.h"
#include "pset.h"
#include "pmap.h"
#include "dcast.h"
#include "pipelineCyclerBase.h"
#include <algorithm>
// A handy macro for reading PointerToArrays.
#define READ_PTA(Manager, source, Read_func, array) \
{ \
void *t; \
if ((t = Manager->get_pta(source)) == (void*)NULL) \
{ \
array = Read_func(Manager, source); \
Manager->register_pta(array.get_void_ptr()); \
} \
else \
{ \
array.set_void_ptr(t); \
} \
}
////////////////////////////////////////////////////////////////////
// Class : BamReader
// Description : This is the fundamental interface for extracting
// binary objects from a Bam file, as generated by a
// BamWriter.
//
// A Bam file can be thought of as a linear collection
// of objects. Each object is an instance of a class
// that inherits, directly or indirectly, from
// TypedWritable. The objects may include pointers to
// other objects within the Bam file; the BamReader
// automatically manages these (with help from code
// within each class) and restores the pointers
// correctly.
//
// This is the abstract interface and does not
// specifically deal with disk files, but rather with a
// DatagramGenerator of some kind, which is simply a
// linear source of Datagrams. It is probably from a
// disk file, but it might conceivably be streamed
// directly from a network or some such nonsense.
//
// Bam files are most often used to store scene graphs
// or subgraphs, and by convention they are given
// filenames ending in the extension ".bam" when they
// are used for this purpose. However, a Bam file may
// store any arbitrary list of TypedWritable objects;
// in this more general usage, they are given filenames
// ending in ".boo" to differentiate them from the more
// common scene graph files.
//
// See also BamFile, which defines a higher-level
// interface to read and write Bam files on disk.
////////////////////////////////////////////////////////////////////
class EXPCL_PANDA BamReader {
public:
typedef Factory<TypedWritable> WritableFactory;
static BamReader *const Null;
static WritableFactory *const NullFactory;
// The primary interface for a caller.
BamReader(DatagramGenerator *generator, const Filename &name = "");
~BamReader();
bool init();
void set_aux_data(const string &name, void *data);
void *get_aux_data(const string &name) const;
INLINE const Filename &get_filename() const;
TypedWritable *read_object();
INLINE bool is_eof() const;
bool resolve();
bool change_pointer(const TypedWritable *orig_pointer, const TypedWritable *new_pointer);
INLINE int get_file_major_ver() const;
INLINE int get_file_minor_ver() const;
INLINE BamEndian get_file_endian() const;
INLINE int get_current_major_ver() const;
INLINE int get_current_minor_ver() const;
// This special TypeHandle is written to the bam file to indicate an
// object id is no longer needed.
static TypeHandle _remove_flag;
public:
// Functions to support classes that read themselves from the Bam.
void read_pointer(DatagramIterator &scan);
void read_pointers(DatagramIterator &scan, int count);
void skip_pointer(DatagramIterator &scan);
void read_cdata(DatagramIterator &scan, PipelineCyclerBase &cycler);
void read_cdata(DatagramIterator &scan, PipelineCyclerBase &cycler,
void *extra_data);
void register_finalize(TypedWritable *whom);
typedef TypedWritable *(*ChangeThisFunc)(TypedWritable *object, BamReader *manager);
void register_change_this(ChangeThisFunc func, TypedWritable *whom);
void finalize_now(TypedWritable *whom);
void *get_pta(DatagramIterator &scan);
void register_pta(void *ptr);
TypeHandle read_handle(DatagramIterator &scan);
public:
INLINE static WritableFactory *get_factory();
private:
INLINE static void create_factory();
private:
void free_object_ids(DatagramIterator &scan);
int read_object_id(DatagramIterator &scan);
int read_pta_id(DatagramIterator &scan);
int p_read_object();
bool resolve_object_pointers(TypedWritable *object, const vector_int &pointer_ids);
bool resolve_cycler_pointers(PipelineCyclerBase *cycler, const vector_int &pointer_ids);
void finalize();
bool get_datagram(Datagram &datagram);
private:
static WritableFactory *_factory;
DatagramGenerator *_source;
bool _long_object_id;
bool _long_pta_id;
// This maps the type index numbers encountered within the Bam file
// to actual TypeHandles.
typedef phash_map<int, TypeHandle, int_hash> IndexMap;
IndexMap _index_map;
// This is the filename of the BAM, or null string if not in a file.
Filename _filename;
// This maps the object ID numbers encountered within the Bam file
// to the actual pointers of the corresponding generated objects.
class CreatedObj {
public:
TypedWritable *_ptr;
ChangeThisFunc _change_this;
};
typedef phash_map<int, CreatedObj, int_hash> CreatedObjs;
CreatedObjs _created_objs;
// This is the iterator into the above map for the object we are
// currently reading in p_read_object(). It is carefully maintained
// during recursion. We need this so we can associate
// read_pointer() calls with the proper objects.
CreatedObjs::iterator _now_creating;
// This is the pointer to the current PipelineCycler we are reading,
// if we are within a read_cdata() call.
PipelineCyclerBase *_reading_cycler;
// This is the reverse lookup into the above map.
typedef phash_map<const TypedWritable *, vector_int, pointer_hash> CreatedObjsByPointer;
CreatedObjsByPointer _created_objs_by_pointer;
// This records all the objects that still need their pointers
// completed, along with the object ID's of the pointers they need,
// in the order in which read_pointer() was called, so that we may
// call the appropriate complete_pointers() later.
typedef phash_map<int, vector_int, int_hash> ObjectPointers;
ObjectPointers _object_pointers;
// Ditto, for the PiplineCycler objects.
typedef phash_map<PipelineCyclerBase *, vector_int, pointer_hash> CyclerPointers;
CyclerPointers _cycler_pointers;
// This is the number of extra objects that must still be read (and
// saved in the _created_objs map) before returning from
// read_object().
int _num_extra_objects;
// This is the set of all objects that registered themselves for
// finalization.
typedef phash_set<TypedWritable *, pointer_hash> Finalize;
Finalize _finalize_list;
// These are used by get_pta() and register_pta() to unify multiple
// references to the same PointerToArray.
typedef phash_map<int, void *, int_hash> PTAMap;
PTAMap _pta_map;
int _pta_id;
// This is used internally to record all of the new types created
// on-the-fly to satisfy bam requirements. We keep track of this
// just so we can suppress warning messages from attempts to create
// objects of these types.
typedef phash_set<TypeHandle> NewTypes;
static NewTypes _new_types;
// This is used in support of set_aux_data() and get_aux_data().
typedef phash_map<string, void *, string_hash> AuxData;
AuxData _aux_data;
int _file_major, _file_minor;
BamEndian _file_endian;
static const int _cur_major;
static const int _cur_minor;
};
typedef BamReader::WritableFactory WritableFactory;
// Useful function for taking apart the Factory Params in the static
// functions that need to be defined in each writable class that will
// be generated by a factory. Sets the DatagramIterator and the
// BamReader pointers.
INLINE void
parse_params(const FactoryParams &params,
DatagramIterator &scan, BamReader *&manager);
#include "bamReader.I"
#endif