src/parser.h

   1 ///
   2 /// \file       parser.h
   3 ///             Virtual parser wrapper
   4 ///
   5
   6 /*
   7     Copyright (C) 2005-2006, Net Direct Inc. (http://www.netdirect.ca/)
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17
  18     See the GNU General Public License in the COPYING file at the
  19     root directory of this project for more details.
  20 */
  21
  22 #ifndef __BARRY_PARSER_H__
  23 #define __BARRY_PARSER_H__
  24
  25 #include "data.h"
  26 #include "protocol.h"
  27 #include "debug.h"
  28
  29 namespace Barry {
  30
  31 // also acts as a null parser
  32 //
  33 // Parser class
  34 //
  35 /// Base class for the parser functor hierarchy.  If in debug mode, this
  36 /// class can be used as a null parser.  Call Init() and the protocol
  37 /// will be dumped to stdout and no parsing will be done.
  38 ///
  39 class Parser
  40 {
  41 public:
  42         Parser() {}
  43         virtual ~Parser() {}
  44
  45         virtual bool operator()(const Data &data, size_t offset) { return true; }
  46
  47         virtual bool GetOperation(const Data &data, unsigned int &operation);
  48 };
  49
  50
  51 //
  52 // RecordParser template class
  53 //
  54 /// Template class for easy creation of specific parser objects.  This template
  55 /// takes the following template arguments:
  56 ///
  57 ///     - Record: One of the record parser classes in record.h
  58 ///     - Storage: A custom storage functor class.  An object of this type
  59 ///             will be called as a function with parsed Record as an
  60 ///             argument.  This happens on the fly as the data is retrieved
  61 ///             from the device over USB, so it should not block forever.
  62 ///
  63 /// Example LoadDatabase() call:
  64 ///
  65 /// <pre>
  66 /// struct StoreContact
  67 /// {
  68 ///     std::vector<Contact> &amp;array;
  69 ///     StoreContact(std::vector<Contact> &amp;a) : array(a) {}
  70 ///     void operator() (const Contact &amp;c)
  71 ///     {
  72 ///         array.push_back(c);
  73 ///     }
  74 /// };
  75 ///
  76 /// Controller con(probeResult);
  77 /// con.OpenMode(Controller::Desktop);
  78 /// std::vector<Contact> contactList;
  79 /// StoreContact storage(contactList);
  80 /// RecordParser<Contact, StoreContact> parser(storage);
  81 /// con.LoadDatabase(con.GetDBID("Address Book"), parser);
  82 /// </pre>
  83 ///
  84 template <class Record, class Storage>
  85 class RecordParser : public Parser
  86 {
  87         Storage *m_store;
  88         bool m_owned;
  89
  90 public:
  91         /// Constructor that references an externally managed storage object.
  92         RecordParser(Storage &storage)
  93                 : m_store(&storage), m_owned(false) {}
  94
  95         /// Constructor that references a locally managed storage object.
  96         /// The pointer passed in will be stored, and freed when this class
  97         /// is destroyed.  It is safe to call this constructor with
  98         /// a 'new'ly created storage object.
  99         RecordParser(Storage *storage)
 100                 : m_store(storage), m_owned(true) {}
 101
 102         ~RecordParser()
 103         {
 104                 if( this->m_owned )
 105                         delete m_store;
 106         }
 107
 108         virtual bool CheckHeaderSize(const Data &data, size_t offset, unsigned int operation)
 109         {
 110                 size_t recordsize;
 111                 switch( operation )
 112                 {
 113                 case SB_DBOP_GET_RECORDS:
 114                         // using the new protocol
 115                         recordsize = Record::GetProtocolRecordSize();
 116                         break;
 117
 118                 case SB_DBOP_OLD_GET_RECORDS_REPLY:
 119                         // using the old protocol
 120                         recordsize = Record::GetOldProtocolRecordSize();
 121                         break;
 122
 123                 default:
 124                         // unknown protocol
 125                         dout("Unknown protocol");
 126                         return false;
 127                 }
 128
 129                 // return true if header is ok
 130                 return data.GetSize() > (offset + recordsize);
 131         }
 132
 133         /// Functor member called by Controller::LoadDatabase() during
 134         /// processing.
 135         virtual bool operator()(const Data &data, size_t offset)
 136         {
 137                 unsigned int operation;
 138                 if( !GetOperation(data, operation) )
 139                         return false;
 140                 if( !CheckHeaderSize(data, offset, operation) )
 141                         return false;
 142
 143                 Record rec;
 144                 rec.Parse(data, offset, operation);
 145                 (*m_store)(rec);
 146                 return true;
 147         }
 148 };
 149
 150 } // namespace Barry
 151
 152 #endif
 153