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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 length 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 // Sort critical packets by type and FileId
48 static bool CompareLess(const CriticalPacket* const &left, const CriticalPacket* const &right);
49
50 protected:
51 u8 *packetdata;
52 size_t packetlength;
53 };
54
CriticalPacket(void)55 inline CriticalPacket::CriticalPacket(void)
56 {
57 // There is no data initially
58 packetdata = 0;
59 packetlength = 0;
60 }
61
~CriticalPacket(void)62 inline CriticalPacket::~CriticalPacket(void)
63 {
64 // Delete the data for the packet
65 delete [] packetdata;
66 }
67
PacketLength(void)68 inline size_t CriticalPacket::PacketLength(void) const
69 {
70 return packetlength;
71 }
72
AllocatePacket(size_t length,size_t extra)73 inline void* CriticalPacket::AllocatePacket(size_t length, size_t extra)
74 {
75 // Hey! We can't allocate the packet twice
76 assert(packetlength == 0 && packetdata == 0);
77
78 // Remember the requested packet length
79 packetlength = length;
80
81 // Allocate and clear the requested packet length plus the extra.
82 packetdata = new u8[length+extra];
83 memset(packetdata, 0, length+extra);
84
85 return packetdata;
86 }
87
88 // Class used to record the fact that a copy of a particular critical packet
89 // will be written to a particular file at a specific offset.
90
91 class CriticalPacketEntry
92 {
93 public:
CriticalPacketEntry(DiskFile * _diskfile,u64 _offset,const CriticalPacket * _packet)94 CriticalPacketEntry(DiskFile *_diskfile,
95 u64 _offset,
96 const CriticalPacket *_packet)
97 : diskfile(_diskfile)
98 , offset(_offset)
99 , packet(_packet)
100 {}
CriticalPacketEntry(void)101 CriticalPacketEntry(void)
102 : diskfile(0)
103 , offset(0)
104 , packet(0)
105 {}
CriticalPacketEntry(const CriticalPacketEntry & other)106 CriticalPacketEntry(const CriticalPacketEntry &other)
107 : diskfile(other.diskfile)
108 , offset(other.offset)
109 , packet(other.packet)
110 {}
111 CriticalPacketEntry& operator=(const CriticalPacketEntry &other)
112 {
113 diskfile = other.diskfile;
114 offset = other.offset;
115 packet = other.packet;
116 return *this;
117 }
118
119 public:
120 // Write the packet to disk.
121 bool WritePacket(void) const;
122
123 // Obtain the length of the packet.
124 u64 PacketLength(void) const;
125
126 protected:
127 DiskFile *diskfile;
128 u64 offset;
129 const CriticalPacket *packet;
130 };
131
WritePacket(void)132 inline bool CriticalPacketEntry::WritePacket(void) const
133 {
134 assert(packet != 0 && diskfile != 0);
135
136 // Tell the packet to write itself to disk
137 return packet->WritePacket(*diskfile, offset);
138 }
139
PacketLength(void)140 inline u64 CriticalPacketEntry::PacketLength(void) const
141 {
142 assert(packet != 0);
143
144 // Ask the packet how big it is.
145 return packet->PacketLength();
146 }
147
148 #endif // __CRITICALPACKET_H__
149