src/parser.h

   1 ///
   2 /// \file       parser.h
   3 ///             Virtual parser wrapper
   4 ///
   5
   6 /*
   7     Copyright (C) 2005-2010, 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 "dll.h"
  26 #include "data.h"
  27 #include "protocol.h"
  28 #include <stdint.h>             // for uint32_t
  29
  30 // forward declarations
  31 namespace Barry {
  32         class Data;
  33         class IConverter;
  34 }
  35
  36 namespace Barry {
  37
  38 //
  39 // Parser class
  40 //
  41 /// Base class for the parser hierarchy.
  42 ///
  43 /// This class provides the interface that the Controller class uses
  44 /// to pass raw data it reads from the device.  The Controller, along
  45 /// with the Packet class, calls each of the virtual functions below
  46 /// in the same order.
  47 ///
  48 /// This class is kept as a pure abstract class, in order to make sure
  49 /// that the compiler will catch any API changes, for code derived
  50 /// from it.
  51 ///
  52 class BXEXPORT Parser
  53 {
  54 public:
  55         Parser() {}
  56         virtual ~Parser() {}
  57
  58         /// Reset and prepare for a new raw data packet
  59         virtual void Clear() = 0;
  60
  61         /// Stores the IDs
  62         virtual void SetIds(uint8_t RecType, uint32_t UniqueId) = 0;
  63
  64         /// Called to parse the header portion of the raw data packet.
  65         /// data contains the entire packet, and offset contains the
  66         /// location at which to start parsing.
  67         virtual void ParseHeader(const Data &data, size_t &offset) = 0;
  68
  69         /// Called to parse sub fields in the raw data packet.
  70         /// The same data is passed as was passed in ParseHeader,
  71         /// only the offset will be updated if it was advanced during
  72         /// the header parsing.
  73         virtual void ParseFields(const Data &data, size_t &offset,
  74                 const IConverter *ic) = 0;
  75
  76         /// Called at the very end of record parsing, and used to
  77         /// store the final packet somewhere, either in memory, disk, etc.
  78         virtual void Store() = 0;
  79 };
  80
  81
  82 //
  83 // NullParser class
  84 //
  85 /// If in debug mode, this class can be used as a null parser.
  86 /// Call Init() and the protocol will be dumped to stdout and
  87 /// no parsing will be done.
  88 ///
  89 /// Do NOT derive your own personal parser classes from this,
  90 /// unless you are perfectly confident that you will catch
  91 /// future API changes on the devel tree without the compiler's
  92 /// help.
  93 ///
  94 class BXEXPORT NullParser : public Parser
  95 {
  96 public:
  97         NullParser() {}
  98         virtual ~NullParser() {}
  99
 100         /// Reset and prepare for a new raw data packet
 101         virtual void Clear() {}
 102
 103         /// Stores the IDs
 104         virtual void SetIds(uint8_t RecType, uint32_t UniqueId) {}
 105
 106         /// Called to parse the header portion of the raw data packet.
 107         /// data contains the entire packet, and offset contains the
 108         /// location at which to start parsing.
 109         virtual void ParseHeader(const Data &data, size_t &offset) {}
 110
 111         /// Called to parse sub fields in the raw data packet.
 112         /// The same data is passed as was passed in ParseHeader,
 113         /// only the offset will be updated if it was advanced during
 114         /// the header parsing.
 115         virtual void ParseFields(const Data &data, size_t &offset,
 116                 const IConverter *ic) {}
 117
 118         /// Called at the very end of record parsing, and used to
 119         /// store the final packet somewhere, either in memory, disk, etc.
 120         virtual void Store() {}
 121 };
 122
 123
 124 //
 125 // RecordParser template class
 126 //
 127 /// Template class for easy creation of specific parser objects.  This template
 128 /// takes the following template arguments:
 129 ///
 130 ///     - RecordT: One of the record parser classes in record.h
 131 ///     - StorageT: A custom storage functor class.  An object of this type
 132 ///             will be called as a function with parsed Record as an
 133 ///             argument.  This happens on the fly as the data is retrieved
 134 ///             from the device over USB, so it should not block forever.
 135 ///
 136 /// Example LoadDatabase() call:
 137 ///
 138 /// <pre>
 139 /// struct StoreContact
 140 /// {
 141 ///     std::vector<Contact> &amp;array;
 142 ///     StoreContact(std::vector<Contact> &amp;a) : array(a) {}
 143 ///     void operator() (const Contact &amp;c)
 144 ///     {
 145 ///         array.push_back(c);
 146 ///     }
 147 /// };
 148 ///
 149 /// Controller con(probeResult);
 150 /// con.OpenMode(Controller::Desktop);
 151 /// std::vector<Contact> contactList;
 152 /// StoreContact storage(contactList);
 153 /// RecordParser<Contact, StoreContact> parser(storage);
 154 /// con.LoadDatabase(con.GetDBID("Address Book"), parser);
 155 /// </pre>
 156 ///
 157 template <class RecordT, class StorageT>
 158 class RecordParser : public Parser
 159 {
 160         StorageT *m_store;
 161         bool m_owned;
 162         RecordT m_rec;
 163
 164 public:
 165         /// Constructor that references an externally managed storage object.
 166         RecordParser(StorageT &storage)
 167                 : m_store(&storage), m_owned(false) {}
 168
 169         /// Constructor that references a locally managed storage object.
 170         /// The pointer passed in will be stored, and freed when this class
 171         /// is destroyed.  It is safe to call this constructor with
 172         /// a 'new'ly created storage object.
 173         RecordParser(StorageT *storage)
 174                 : m_store(storage), m_owned(true) {}
 175
 176         ~RecordParser()
 177         {
 178                 if( this->m_owned )
 179                         delete m_store;
 180         }
 181
 182         virtual StorageT* GetStore()
 183         {
 184                 return m_store;
 185         }
 186
 187         virtual const StorageT* GetStore() const
 188         {
 189                 return m_store;
 190         }
 191
 192         virtual void Clear()
 193         {
 194                 m_rec = RecordT();
 195         }
 196
 197         virtual void SetIds(uint8_t RecType, uint32_t UniqueId)
 198         {
 199                 m_rec.SetIds(RecType, UniqueId);
 200         }
 201
 202         virtual void ParseHeader(const Data &data, size_t &offset)
 203         {
 204                 m_rec.ParseHeader(data, offset);
 205         }
 206
 207         virtual void ParseFields(const Data &data, size_t &offset,
 208                                  const IConverter *ic)
 209         {
 210                 m_rec.ParseFields(data, offset, ic);
 211         }
 212
 213         virtual void Store()
 214         {
 215                 (*m_store)(m_rec);
 216         }
 217 };
 218
 219 } // namespace Barry
 220
 221 #endif
 222