panda3d/direct/src/dcparser/dcPackerCatalog.cxx
2004-07-02 00:25:42 +00:00

356 lines
14 KiB
C++

// Filename: dcPackerCatalog.cxx
// Created by: drose (21Jun04)
//
////////////////////////////////////////////////////////////////////
//
// 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 .
//
////////////////////////////////////////////////////////////////////
#include "dcPackerCatalog.h"
#include "dcPackerInterface.h"
#include "dcPacker.h"
#include "dcSwitchParameter.h"
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::Constructor
// Access: Private
// Description: The catalog is created only by
// DCPackerInterface::get_catalog().
////////////////////////////////////////////////////////////////////
DCPackerCatalog::
DCPackerCatalog(const DCPackerInterface *root) : _root(root) {
_live_catalog = NULL;
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::Copy Constructor
// Access: Private
// Description: The copy constructor is used only internally, in
// update_switch_fields().
////////////////////////////////////////////////////////////////////
DCPackerCatalog::
DCPackerCatalog(const DCPackerCatalog &copy) :
_root(copy._root),
_entries(copy._entries),
_entries_by_name(copy._entries_by_name),
_entries_by_field(copy._entries_by_field)
{
_live_catalog = NULL;
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::Destructor
// Access: Private
// Description: The catalog is destroyed only by
// ~DCPackerInterface().
////////////////////////////////////////////////////////////////////
DCPackerCatalog::
~DCPackerCatalog() {
if (_live_catalog != (LiveCatalog *)NULL) {
delete _live_catalog;
}
SwitchCatalogs::iterator si;
for (si = _switch_catalogs.begin(); si != _switch_catalogs.end(); ++si) {
delete (*si).second;
}
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::find_entry_by_name
// Access: Public
// Description: Returns the index number of the entry with the
// indicated name, or -1 if no entry has the indicated
// name. The return value is suitable for passing to
// get_entry().
////////////////////////////////////////////////////////////////////
int DCPackerCatalog::
find_entry_by_name(const string &name) const {
EntriesByName::const_iterator ni;
ni = _entries_by_name.find(name);
if (ni != _entries_by_name.end()) {
return (*ni).second;
}
return -1;
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::find_entry_by_field
// Access: Public
// Description: Returns the index number of the entry with the
// indicated field, or -1 if no entry has the indicated
// field. The return value is suitable for passing to
// get_entry().
////////////////////////////////////////////////////////////////////
int DCPackerCatalog::
find_entry_by_field(const DCPackerInterface *field) const {
EntriesByField::const_iterator ni;
ni = _entries_by_field.find(field);
if (ni != _entries_by_field.end()) {
return (*ni).second;
}
return -1;
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::get_live_catalog
// Access: Public
// Description: Returns a LiveCatalog object indicating the positions
// within the indicated data record of each field within
// the catalog. If the catalog's fields are all
// fixed-width, this may return a statically-allocated
// LiveCatalog object that is the same for all data
// records; otherwise, it will allocate a new
// LiveCatalog object that must be freed with a later
// call to release_live_catalog().
////////////////////////////////////////////////////////////////////
const DCPackerCatalog::LiveCatalog *DCPackerCatalog::
get_live_catalog(const char *data, size_t length) const {
if (_live_catalog != (LiveCatalog *)NULL) {
// Return the previously-allocated live catalog; it will be the
// same as this one since it's based on a fixed-length field.
return _live_catalog;
}
LiveCatalog *live_catalog = new LiveCatalog;
live_catalog->_catalog = this;
live_catalog->_live_entries.reserve(_entries.size());
LiveCatalogEntry zero_entry;
zero_entry._begin = 0;
zero_entry._end = 0;
for (size_t i = 0; i < _entries.size(); i++) {
live_catalog->_live_entries.push_back(zero_entry);
}
DCPacker packer;
packer.set_unpack_data(data, length, false);
packer.begin_unpack(_root);
const DCSwitchParameter *last_switch = NULL;
r_fill_live_catalog(live_catalog, packer, last_switch);
bool okflag = packer.end_unpack();
if (!okflag) {
delete live_catalog;
return NULL;
}
if (_root->has_fixed_structure()) {
// If our root field has a fixed structure, then the live catalog
// will always be the same every time, so we might as well keep
// this one around as an optimization.
((DCPackerCatalog *)this)->_live_catalog = live_catalog;
}
return live_catalog;
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::release_live_catalog
// Access: Public
// Description: Releases the LiveCatalog object that was returned by
// an earlier call to get_live_catalog(). If this
// represents a newly-allocated live catalog, it will
// free it; otherwise, it will do nothing.
//
// It is therefore always correct (and necessary) to
// match a call to get_live_catalog() with a later call
// to release_live_catalog().
////////////////////////////////////////////////////////////////////
void DCPackerCatalog::
release_live_catalog(const DCPackerCatalog::LiveCatalog *live_catalog) const {
if (live_catalog != _live_catalog) {
delete (LiveCatalog *)live_catalog;
}
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::add_entry
// Access: Private
// Description: Called only by DCPackerInterface::r_fill_catalog(),
// this adds a new entry to the catalog.
////////////////////////////////////////////////////////////////////
void DCPackerCatalog::
add_entry(const string &name, const DCPackerInterface *field,
const DCPackerInterface *parent, int field_index) {
Entry entry;
entry._name = name;
entry._field = field;
entry._parent = parent;
entry._field_index = field_index;
int entry_index = (int)_entries.size();
_entries.push_back(entry);
_entries_by_name.insert(EntriesByName::value_type(name, entry_index));
_entries_by_field.insert(EntriesByField::value_type(field, entry_index));
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::r_fill_catalog
// Access: Private
// Description: Called by DCPackerInterface to recursively fill up a
// newly-allocated reference catalog. Also called by
// update_switch_fields to append fields to a catalog
// after a DCSwitch node is selected.
////////////////////////////////////////////////////////////////////
void DCPackerCatalog::
r_fill_catalog(const string &name_prefix, const DCPackerInterface *field,
const DCPackerInterface *parent, int field_index) {
string next_name_prefix = name_prefix;
if (parent != (const DCPackerInterface *)NULL && !field->get_name().empty()) {
// Record this entry in the catalog.
next_name_prefix += field->get_name();
add_entry(next_name_prefix, field, parent, field_index);
next_name_prefix += ".";
}
const DCSwitchParameter *switch_parameter = field->as_switch_parameter();
if (switch_parameter != (DCSwitchParameter *)NULL) {
// If we come upon a DCSwitch while building the catalog, save the
// name_prefix at this point so we'll have it again when we later
// encounter the switch while unpacking a live record (and so we
// can return to this point in the recursion from
// update_switch_fields).
_switch_prefixes[switch_parameter] = next_name_prefix;
}
// Add any children.
if (field->has_nested_fields()) {
int num_nested = field->get_num_nested_fields();
// It's ok if num_nested is -1.
for (int i = 0; i < num_nested; i++) {
DCPackerInterface *nested = field->get_nested_field(i);
if (nested != (DCPackerInterface *)NULL) {
r_fill_catalog(next_name_prefix, nested, field, i);
}
}
}
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::r_fill_live_catalog
// Access: Private
// Description: Recursively walks through all of the fields on the
// catalog and fills the live catalog with the
// appropriate offsets.
////////////////////////////////////////////////////////////////////
void DCPackerCatalog::
r_fill_live_catalog(LiveCatalog *live_catalog, DCPacker &packer,
const DCSwitchParameter *&last_switch) const {
const DCPackerInterface *current_field = packer.get_current_field();
int field_index = live_catalog->find_entry_by_field(current_field);
if (field_index >= 0) {
nassertv(field_index < (int)live_catalog->_live_entries.size());
live_catalog->_live_entries[field_index]._begin = packer.get_num_unpacked_bytes();
}
if (packer.has_nested_fields() &&
(packer.get_pack_type() != PT_string && packer.get_pack_type() != PT_blob)) {
packer.push();
while (packer.more_nested_fields()) {
r_fill_live_catalog(live_catalog, packer, last_switch);
}
packer.pop();
} else {
packer.unpack_skip();
}
if (field_index >= 0) {
live_catalog->_live_entries[field_index]._end = packer.get_num_unpacked_bytes();
}
if (last_switch != packer.get_last_switch()) {
// We've just invoked a new DCSwitch. That means we must add the
// new fields revealed by the switch to the reference catalog.
last_switch = packer.get_last_switch();
const DCPackerInterface *switch_case = packer.get_current_parent();
nassertv(switch_case != (DCPackerInterface *)NULL);
const DCPackerCatalog *switch_catalog =
live_catalog->_catalog->update_switch_fields(last_switch, switch_case);
nassertv(switch_catalog != (DCPackerCatalog *)NULL);
live_catalog->_catalog = switch_catalog;
// And we also have to expand the live catalog to hold the new
// entries.
LiveCatalogEntry zero_entry;
zero_entry._begin = 0;
zero_entry._end = 0;
for (size_t i = live_catalog->_live_entries.size();
i < switch_catalog->_entries.size();
i++) {
live_catalog->_live_entries.push_back(zero_entry);
}
}
}
////////////////////////////////////////////////////////////////////
// Function: DCPackerCatalog::update_switch_fields
// Access: Private
// Description: Returns a new DCPackerCatalog that includes all of
// the fields in this object, with the addition of the
// fields named by switch_case.
//
// This is used to implement switches, which change the
// set of fields they make available according to the
// data in the record, and therefore present a different
// catalog under different circumstances.
//
// This returned pointer is allocated one time for each
// different switch_case instance; if a given same
// switch_case is supplied twice, the same pointer is
// returned both times. The ownership of the returned
// pointer is kept by this object.
////////////////////////////////////////////////////////////////////
const DCPackerCatalog *DCPackerCatalog::
update_switch_fields(const DCSwitchParameter *switch_parameter,
const DCPackerInterface *switch_case) const {
SwitchCatalogs::const_iterator si = _switch_catalogs.find(switch_case);
if (si != _switch_catalogs.end()) {
return (*si).second;
}
// Look up the name_prefix will we use for all of the fields that
// descend from this switch. This should be stored in this record
// because we must have come across the DCSwitch when building the
// catalog the first time.
SwitchPrefixes::const_iterator pi = _switch_prefixes.find(switch_parameter);
nassertr(pi != _switch_prefixes.end(), NULL);
string name_prefix = (*pi).second;
// Start by creating a new DCPackerCatalog object that contains all
// of the fields that this one contains.
DCPackerCatalog *switch_catalog = new DCPackerCatalog(*this);
// Now record all of the fields of the switch case in the new
// catalog. We start with the second field of the switch case,
// since the first field will be the switch parameter itself, which
// we would have already recorded the first time around.
int num_nested = switch_case->get_num_nested_fields();
for (int i = 1; i < num_nested; i++) {
DCPackerInterface *nested = switch_case->get_nested_field(i);
if (nested != (DCPackerInterface *)NULL) {
switch_catalog->r_fill_catalog(name_prefix, nested, switch_case, i);
}
}
// Store the newly-generated switch catalog in the record so the
// same pointer can be returned in the future.
((DCPackerCatalog *)this)->_switch_catalogs[switch_case] = switch_catalog;
return switch_catalog;
}