1 // This file is part of par2cmdline (a PAR 2.0 compatible file verification and
2 // repair tool). See http://parchive.sourceforge.net for details of PAR 2.0.
3 //
4 // Copyright (c) 2003 Peter Brian Clements
5 //
6 // par2cmdline is free software; you can redistribute it and/or modify
7 // it under the terms of the GNU General Public License as published by
8 // the Free Software Foundation; either version 2 of the License, or
9 // (at your option) any later version.
10 //
11 // par2cmdline is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 //
16 // You should have received a copy of the GNU General Public License
17 // along with this program; if not, write to the Free Software
18 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
19
20 #ifndef __CRITICALPACKET_H__
21 #define __CRITICALPACKET_H__
22
23 // Base class for main packet, file verification packet, file description packet
24 // and creator packet.
25
26 // These packets are all small and are held in memory in their entirity
27
28 class CriticalPacket
29 {
30 public:
31 CriticalPacket(void);
32 ~CriticalPacket(void);
33
34 public:
35 // Write a copy of the packet to the specified file at the specified offset
36 bool WritePacket(DiskFile &diskfile, u64 fileoffset) const;
37
38 // Obtain the lenght of the packet.
39 size_t PacketLength(void) const;
40
41 // Allocate some memory for the packet (plus some extra padding).
42 void* AllocatePacket(size_t length, size_t extra = 0);
43
44 // Finish a packet (by storing the set_id_hash and then computing the packet_hash).
45 void FinishPacket(const MD5Hash &set_id_hash);
46
47 protected:
48 u8 *packetdata;
49 size_t packetlength;
50 };
51
CriticalPacket(void)52 inline CriticalPacket::CriticalPacket(void)
53 {
54 // There is no data initially
55 packetdata = 0;
56 packetlength = 0;
57 }
58
~CriticalPacket(void)59 inline CriticalPacket::~CriticalPacket(void)
60 {
61 // Delete the data for the packet
62 delete [] packetdata;
63 }
64
PacketLength(void)65 inline size_t CriticalPacket::PacketLength(void) const
66 {
67 return packetlength;
68 }
69
AllocatePacket(size_t length,size_t extra)70 inline void* CriticalPacket::AllocatePacket(size_t length, size_t extra)
71 {
72 // Hey! We can't allocate the packet twice
73 assert(packetlength == 0 && packetdata == 0);
74
75 // Remember the requested packet length
76 packetlength = length;
77
78 // Allocate and clear the requested packet length plus the extra.
79 packetdata = new u8[length+extra];
80 memset(packetdata, 0, length+extra);
81
82 return packetdata;
83 }
84
85 // Class used to record the fact that a copy of a particular critical packet
86 // will be written to a particular file at a specific offset.
87
88 class CriticalPacketEntry
89 {
90 public:
CriticalPacketEntry(DiskFile * _diskfile,u64 _offset,const CriticalPacket * _packet)91 CriticalPacketEntry(DiskFile *_diskfile,
92 u64 _offset,
93 const CriticalPacket *_packet)
94 : diskfile(_diskfile)
95 , offset(_offset)
96 , packet(_packet)
97 {}
CriticalPacketEntry(void)98 CriticalPacketEntry(void)
99 : diskfile(0)
100 , offset(0)
101 , packet(0)
102 {}
CriticalPacketEntry(const CriticalPacketEntry & other)103 CriticalPacketEntry(const CriticalPacketEntry &other)
104 : diskfile(other.diskfile)
105 , offset(other.offset)
106 , packet(other.packet)
107 {}
108 CriticalPacketEntry& operator=(const CriticalPacketEntry &other)
109 {
110 diskfile = other.diskfile;
111 offset = other.offset;
112 packet = other.packet;
113 return *this;
114 }
115
116 public:
117 // Write the packet to disk.
118 bool WritePacket(void) const;
119
120 // Obtain the length of the packet.
121 u64 PacketLength(void) const;
122
123 protected:
124 DiskFile *diskfile;
125 u64 offset;
126 const CriticalPacket *packet;
127 };
128
WritePacket(void)129 inline bool CriticalPacketEntry::WritePacket(void) const
130 {
131 assert(packet != 0 && diskfile != 0);
132
133 // Tell the packet to write itself to disk
134 return packet->WritePacket(*diskfile, offset);
135 }
136
PacketLength(void)137 inline u64 CriticalPacketEntry::PacketLength(void) const
138 {
139 assert(packet != 0);
140
141 // Ask the packet how big it is.
142 return packet->PacketLength();
143 }
144
145 #endif // __CRITICALPACKET_H__
146