source/binarywriter.cpp

   1 /* $Id$
   2
   3 This file is part of libmspdatafile
   4 Copyright © 2006  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #include "binarywriter.h"
   9 #include "statement.h"
  10
  11 using namespace std;
  12
  13 namespace Msp {
  14 namespace DataFile {
  15
  16 BinaryWriter::BinaryWriter(ostream &o):
  17         WriterMode(o),
  18         next_st_id(3),
  19         next_enum_id(1)
  20 {
  21         dict[DictEntry("__kw", "iss")]=1;
  22         dict[DictEntry("__enum", "is")]=1;
  23 }
  24
  25 void BinaryWriter::write(const Statement &st)
  26 {
  27         collect_keywords(st);
  28         write_(st);
  29 }
  30
  31 void BinaryWriter::write_(const Statement &st)
  32 {
  33         Dictionary::iterator i=dict.find(create_entry(st));
  34         if(i==dict.end())
  35                 throw InvalidParameterValue("Unknown statement");
  36
  37         write_int(i->second);
  38         for(ValueArray::const_iterator j=st.args.begin(); j!=st.args.end(); ++j)
  39                 switch(j->get_type())
  40                 {
  41                 case INTEGER: write_int   (j->get<long long>()); break;
  42                 case STRING:  write_string(j->get<const string &>()); break;
  43                 case BOOLEAN: write_int   (j->get<bool>()); break;
  44                 case FLOAT:   write_float (j->get<float>()); break;
  45                 case ENUM:    write_enum  (j->get_raw()); break;
  46                 }
  47
  48         write_int(st.sub.size());
  49         for(list<Statement>::const_iterator j=st.sub.begin(); j!=st.sub.end(); ++j)
  50                 write(*j);
  51 }
  52
  53 DictEntry BinaryWriter::create_entry(const Statement &st)
  54 {
  55         static const char types[]="ifsbe";
  56
  57         string args;
  58         for(ValueArray::const_iterator i=st.args.begin(); i!=st.args.end(); ++i)
  59         {
  60                 if(i->get_type()>=5)
  61                         throw InvalidParameterValue("Invalid argument type");
  62                 args+=types[i->get_type()];
  63         }
  64
  65         return DictEntry(st.keyword, args);
  66 }
  67
  68 void BinaryWriter::collect_keywords(const Statement &st)
  69 {
  70         DictEntry de=create_entry(st);
  71
  72         if(!dict.count(de))
  73         {
  74                 Statement kst;
  75                 kst.keyword="__kw";
  76                 kst.args.push_back(next_st_id);
  77                 kst.args.push_back(de.keyword);
  78                 kst.args.push_back(de.args);
  79                 write_(kst);
  80
  81                 dict.insert(Dictionary::value_type(de, next_st_id++)).first;
  82         }
  83
  84         for(ValueArray::const_iterator i=st.args.begin(); i!=st.args.end(); ++i)
  85                 if(i->get_type()==ENUM && !enums.count(i->get_raw()))
  86                 {
  87                         Statement est;
  88                         est.keyword="__enum";
  89                         est.args.push_back(next_enum_id);
  90                         est.args.push_back(i->get_raw());
  91                         write_(est);
  92
  93                         enums[i->get_raw()]=next_enum_id++;
  94                 }
  95
  96         for(list<Statement>::const_iterator i=st.sub.begin(); i!=st.sub.end(); ++i)
  97                 collect_keywords(*i);
  98 }
  99
 100 void BinaryWriter::write_int(long long n)
 101 {
 102         unsigned i=1;
 103         for(; n>>(i*7); ++i);
 104         for(; i--;)
 105                 out.put(n>>(i*7) & 0x7F | (i?0x80:0));
 106 }
 107
 108 void BinaryWriter::write_string(const string &s)
 109 {
 110         write_int(s.size());
 111         out.write(s.data(), s.size());
 112 }
 113
 114 void BinaryWriter::write_float(float f)
 115 {
 116         union
 117         {
 118                 float v;
 119                 char d[sizeof(float)];
 120         };
 121
 122         v=f;
 123 #if BYTE_ORDER == LITTLE_ENDIAN
 124         for(unsigned i=sizeof(float); i--;)
 125                 out.put(d[i]);
 126 #else
 127         for(unsigned i=0; i<sizeof(float); ++i)
 128                 out.put(d[i]);
 129 #endif
 130 }
 131
 132 void BinaryWriter::write_enum(const string &e)
 133 {
 134         EnumMap::const_iterator i=enums.find(e);
 135         if(i==enums.end())
 136                 throw InvalidParameterValue("Unknown enum");
 137         write_int(i->second);
 138 }
 139
 140 } // namespace DataFile
 141 } // namespace Msp