1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
#import "XADLBRParser.h"
#import "XADSqueezeParser.h"
#import "XADSqueezeHandle.h"
#import "XADCrunchParser.h"
#import "XADCrunchHandles.h"
#import "XADCRCHandle.h"
#import "NSDateXAD.h"
@implementation XADLBRParser
+(int)requiredHeaderSize { return 128; }
+(BOOL)recognizeFileWithHandle:(CSHandle *)handle firstBytes:(NSData *)data name:(NSString *)name
{
const uint8_t *bytes=[data bytes];
int length=[data length];
if(length<128) return NO;
if(bytes[0]!=0) return NO;
for(int i=1;i<12;i++) if(bytes[i]!=' ') return NO;
if(bytes[12]!=0) return NO;
if(bytes[13]!=0) return NO;
for(int i=26;i<32;i++) if(bytes[i]!=0) return NO;
int sectors=CSUInt16LE(&bytes[14]);
if(sectors==0) return NO;
// Check CRC if it exists, and there is enough data to do so.
int correctcrc=CSUInt16LE(&bytes[16]);
int size=sectors*128;
if(correctcrc && size<=length)
{
int crc=0;
crc=XADCalculateCRC(crc,&bytes[0],16,XADCRCReverseTable_1021);
crc=XADCRC(crc,0,XADCRCReverseTable_1021);
crc=XADCRC(crc,0,XADCRCReverseTable_1021);
crc=XADCalculateCRC(crc,&bytes[18],size-18,XADCRCReverseTable_1021);
if(XADUnReverseCRC16(crc)!=correctcrc) return NO;
}
return YES;
}
-(void)parse
{
CSHandle *fh=[self handle];
[fh skipBytes:14];
int numsectors=[fh readUInt16LE];
int numentries=numsectors*4-1;
[fh skipBytes:16];
for(int i=0;i<numentries;i++)
{
int status=[fh readUInt8];
if(status!=0)
{
[fh skipBytes:31];
continue;
}
uint8_t namebuf[11];
[fh readBytes:11 toBuffer:namebuf];
NSMutableData *data=[NSMutableData data];
int namelength=8;
while(namelength>1 && namebuf[namelength-1]==' ') namelength--;
[data appendBytes:&namebuf[0] length:namelength];
[data appendBytes:(uint8_t []){'.'} length:1];
int extlength=3;
while(extlength>1 && namebuf[extlength+7]==' ') extlength--;
[data appendBytes:&namebuf[8] length:extlength];
BOOL lookslikesqueeze=(namebuf[9]=='q' || namebuf[9]=='Q');
BOOL lookslikecrunch=(namebuf[9]=='z' || namebuf[9]=='Z');
int index=[fh readUInt16LE];
int length=[fh readUInt16LE];
int crc=[fh readUInt16LE];
int creationdate=[fh readUInt16LE];
int modificationdate=[fh readUInt16LE];
int creationtime=[fh readUInt16LE];
int modificationtime=[fh readUInt16LE];
int padding=[fh readUInt8];
int filestart=index*128;
int filesize=length*128-padding;
if(!modificationdate)
{
modificationdate=creationdate;
modificationtime=creationtime;
}
[fh skipBytes:5];
off_t currpos=[fh offsetInFile];
NSMutableDictionary *dict=nil;
if(lookslikesqueeze)
{
[fh seekToFileOffset:filestart];
dict=[XADSqueezeParser parseWithHandle:fh endOffset:filestart+filesize parser:self];
if(dict)
{
[dict setObject:[NSNumber numberWithBool:YES] forKey:@"LBRIsSqueeze"];
[dict setObject:[NSNumber numberWithLongLong:length*128] forKey:XADCompressedSizeKey];
}
}
else if(lookslikecrunch)
{
[fh seekToFileOffset:filestart];
dict=[XADCrunchParser parseWithHandle:fh endOffset:filestart+filesize parser:self];
if(dict)
{
[dict setObject:[NSNumber numberWithBool:YES] forKey:@"LBRIsCrunch"];
[dict setObject:[NSNumber numberWithLongLong:length*128] forKey:XADCompressedSizeKey];
}
}
if(!dict)
{
dict=[NSMutableDictionary dictionaryWithObjectsAndKeys:
[self XADPathWithData:data separators:XADNoPathSeparator],XADFileNameKey,
[NSNumber numberWithLongLong:filesize],XADFileSizeKey,
[NSNumber numberWithLongLong:length*128],XADCompressedSizeKey,
[NSNumber numberWithLongLong:filesize],XADDataLengthKey,
[NSNumber numberWithLongLong:filestart],XADDataOffsetKey,
[NSNumber numberWithInt:crc],@"LBRCRC16",
nil];
}
if(creationdate)
[dict setObject:[NSDate XADDateWithCPMDate:creationdate
time:creationtime] forKey:XADCreationDateKey];
if(modificationdate)
[dict setObject:[NSDate XADDateWithCPMDate:modificationdate
time:modificationtime] forKey:XADLastModificationDateKey];
[self addEntryWithDictionary:dict];
[fh seekToFileOffset:currpos];
}
}
-(CSHandle *)handleForEntryWithDictionary:(NSDictionary *)dict wantChecksum:(BOOL)checksum
{
CSHandle *handle=[self handleAtDataOffsetForDictionary:dict];
NSNumber *squeezenum=[dict objectForKey:@"LBRIsSqueeze"];
NSNumber *crunchnum=[dict objectForKey:@"LBRIsCrunch"];
if(squeezenum && [squeezenum boolValue])
{
handle=[XADSqueezeParser handleForEntryWithDictionary:dict
wantChecksum:checksum handle:handle];
}
else if(crunchnum && [crunchnum boolValue])
{
handle=[XADCrunchParser handleForEntryWithDictionary:dict
wantChecksum:checksum handle:handle];
}
else
{
off_t length=[[dict objectForKey:XADDataLengthKey] intValue];
NSNumber *crc=[dict objectForKey:@"LBRCRC16"];
if(checksum&&crc) handle=[XADCRCHandle CCITTCRC16HandleWithHandle:handle
length:length correctCRC:[crc intValue] conditioned:NO];
}
return handle;
}
-(NSString *)formatName { return @"LBR"; }
@end
|
