src/parser.h

   1 ///
   2 /// \file       parser.h
   3 ///             Virtual parser wrapper
   4 ///
   5
   6 /*
   7     Copyright (C) 2005-2007, 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 <stdint.h>             // for uint32_t
  28
  29 // forward declarations
  30 namespace Barry { class Data; }
  31
  32 namespace Barry {
  33
  34 // also acts as a null parser
  35 //
  36 // Parser class
  37 //
  38 /// Base class for the parser hierarchy.  If in debug mode, this
  39 /// class can be used as a null parser.  Call Init() and the protocol
  40 /// will be dumped to stdout and no parsing will be done.
  41 ///
  42 /// This class provides the interface that the Controller class uses
  43 /// to pass raw data it reads from the device.  The Controller, along
  44 /// with the Packet class, calls each of the virtual functions below
  45 /// in the same order.
  46 ///
  47 class Parser
  48 {
  49 public:
  50         Parser() {}
  51         virtual ~Parser() {}
  52
  53         /// Reset and prepare for a new raw data packet
  54         virtual void Clear() {}
  55
  56         /// Stores the IDs
  57         virtual void SetIds(uint8_t RecType, uint32_t UniqueId) {}
  58
  59         /// Called to parse the header portion of the raw data packet.
  60         /// data contains the entire packet, and offset contains the
  61         /// location at which to start parsing.
  62         virtual void ParseHeader(const Data &data, size_t &offset) {}
  63
  64         /// Called to parse sub fields in the raw data packet.
  65         /// The same data is passed as was passed in ParseHeader,
  66         /// only the offset will be updated if it was advanced during
  67         /// the header parsing.
  68         virtual void ParseFields(const Data &data, size_t &offset) {}
  69
  70         /// Called at the very end of record parsing, and used to
  71         /// store the final packet somewhere, either in memory, disk, etc.
  72         virtual void Store() {}
  73 };
  74
  75
  76 //
  77 // RecordParser template class
  78 //
  79 /// Template class for easy creation of specific parser objects.  This template
  80 /// takes the following template arguments:
  81 ///
  82 ///     - Record: One of the record parser classes in record.h
  83 ///     - Storage: A custom storage functor class.  An object of this type
  84 ///             will be called as a function with parsed Record as an
  85 ///             argument.  This happens on the fly as the data is retrieved
  86 ///             from the device over USB, so it should not block forever.
  87 ///
  88 /// Example LoadDatabase() call:
  89 ///
  90 /// <pre>
  91 /// struct StoreContact
  92 /// {
  93 ///     std::vector<Contact> &amp;array;
  94 ///     StoreContact(std::vector<Contact> &amp;a) : array(a) {}
  95 ///     void operator() (const Contact &amp;c)
  96 ///     {
  97 ///         array.push_back(c);
  98 ///     }
  99 /// };
 100 ///
 101 /// Controller con(probeResult);
 102 /// con.OpenMode(Controller::Desktop);
 103 /// std::vector<Contact> contactList;
 104 /// StoreContact storage(contactList);
 105 /// RecordParser<Contact, StoreContact> parser(storage);
 106 /// con.LoadDatabase(con.GetDBID("Address Book"), parser);
 107 /// </pre>
 108 ///
 109 template <class Record, class Storage>
 110 class RecordParser : public Parser
 111 {
 112         Storage *m_store;
 113         bool m_owned;
 114         Record m_rec;
 115
 116 public:
 117         /// Constructor that references an externally managed storage object.
 118         RecordParser(Storage &storage)
 119                 : m_store(&storage), m_owned(false) {}
 120
 121         /// Constructor that references a locally managed storage object.
 122         /// The pointer passed in will be stored, and freed when this class
 123         /// is destroyed.  It is safe to call this constructor with
 124         /// a 'new'ly created storage object.
 125         RecordParser(Storage *storage)
 126                 : m_store(storage), m_owned(true) {}
 127
 128         ~RecordParser()
 129         {
 130                 if( this->m_owned )
 131                         delete m_store;
 132         }
 133
 134         virtual void Clear()
 135         {
 136                 m_rec = Record();
 137         }
 138
 139         virtual void SetIds(uint8_t RecType, uint32_t UniqueId)
 140         {
 141                 m_rec.SetIds(RecType, UniqueId);
 142         }
 143
 144         virtual void ParseHeader(const Data &data, size_t &offset)
 145         {
 146                 m_rec.ParseHeader(data, offset);
 147         }
 148
 149         virtual void ParseFields(const Data &data, size_t &offset)
 150         {
 151                 m_rec.ParseFields(data, offset);
 152         }
 153
 154         virtual void Store()
 155         {
 156                 (*m_store)(m_rec);
 157         }
 158 };
 159
 160 } // namespace Barry
 161
 162 #endif
 163