src/builder.h

   1 ///
   2 /// \file       builder.h
   3 ///             Virtual protocol packet builder 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_BUILDER_H__
  23 #define __BARRY_BUILDER_H__
  24
  25 //#include "data.h"
  26 //#include "protocol.h"
  27 //#include "debug.h"
  28
  29 namespace Barry {
  30
  31 //
  32 // Builder class
  33 //
  34 /// Base class for the builder functor hierarchy.
  35 ///
  36 class Builder
  37 {
  38 public:
  39         Builder() {}
  40         virtual ~Builder() {}
  41
  42         virtual bool operator()(Data &data, size_t offset, unsigned int databaseId) = 0;
  43 };
  44
  45
  46 //
  47 // RecordBuilder template class
  48 //
  49 /// Template class for easy creation of specific protocol packet builder
  50 /// objects.  This template takes the following template arguments:
  51 ///
  52 ///     - Record: One of the record classes in record.h
  53 ///     - Storage: A custom storage functor class.  An object of this type
  54 ///             will be called as a function with empty Record as an
  55 ///             argument.  The storage class is expected to fill the
  56 ///             record object in preparation for building the packet
  57 ///             out of that data.  These calls happen on the fly as the data
  58 ///             is sent to the device over USB, so it should not block forever.
  59 ///
  60 /// Example SaveDatabase() call:
  61 ///
  62 /// <pre>
  63 /// FIXME
  64 /// </pre>
  65 ///
  66 template <class Record, class Storage>
  67 class RecordBuilder : public Builder
  68 {
  69         Storage *m_storage;
  70         bool m_owned;
  71
  72 public:
  73         /// Constructor that references an externally managed storage object.
  74         RecordBuilder(Storage &storage)
  75                 : m_storage(&storage), m_owned(false) {}
  76
  77         /// Constructor that references a locally managed storage object.
  78         /// The pointer passed in will be stored, and freed when this class
  79         /// is destroyed.  It is safe to call this constructor with
  80         /// a 'new'ly created storage object.
  81         RecordBuilder(Storage *storage)
  82                 : m_storage(storage), m_owned(true) {}
  83
  84         ~RecordBuilder()
  85         {
  86                 if( this->m_owned )
  87                         delete m_storage;
  88         }
  89
  90         /// Functor member called by Controller::SaveDatabase() during
  91         /// processing.
  92         virtual bool operator()(Data &data, size_t offset, unsigned int databaseId)
  93         {
  94                 Record rec;
  95                 if( !(*m_storage)(rec, databaseId) )
  96                         return false;
  97                 rec.Build(data, offset);
  98                 return true;
  99         }
 100 };
 101
 102 } // namespace Barry
 103
 104 #endif
 105