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
|
#import "CSMemoryHandle.h"
@implementation CSMemoryHandle
+(CSMemoryHandle *)memoryHandleForReadingData:(NSData *)data
{
return [[[CSMemoryHandle alloc] initWithData:data] autorelease];
}
+(CSMemoryHandle *)memoryHandleForReadingBuffer:(const void *)buf length:(unsigned)len
{
return [[[CSMemoryHandle alloc] initWithData:[NSData dataWithBytesNoCopy:(void *)buf length:len freeWhenDone:NO]] autorelease];
}
+(CSMemoryHandle *)memoryHandleForReadingMappedFile:(NSString *)filename
{
return [[[CSMemoryHandle alloc] initWithData:[NSData dataWithContentsOfMappedFile:filename]] autorelease];
}
+(CSMemoryHandle *)memoryHandleForWriting
{
return [[[CSMemoryHandle alloc] initWithData:[NSMutableData data]] autorelease];
}
-(id)initWithData:(NSData *)data
{
if((self=[super initWithName:[NSString stringWithFormat:@"%@ at %p",[data class],data]]))
{
memorypos=0;
backingdata=[data retain];
}
return self;
}
-(id)initAsCopyOf:(CSMemoryHandle *)other
{
if((self=[super initAsCopyOf:other]))
{
memorypos=other->memorypos;
backingdata=[other->backingdata retain];
}
return self;
}
-(void)dealloc
{
[backingdata release];
[super dealloc];
}
-(NSData *)data { return backingdata; }
-(NSMutableData *)mutableData
{
if(![backingdata isKindOfClass:[NSMutableData class]]) [self _raiseNotSupported:_cmd];
return (NSMutableData *)backingdata;
}
-(off_t)fileSize { return [backingdata length]; }
-(off_t)offsetInFile { return memorypos; }
-(BOOL)atEndOfFile { return memorypos==[backingdata length]; }
-(void)seekToFileOffset:(off_t)offs
{
if(offs<0) [self _raiseNotSupported:_cmd];
if(offs>[backingdata length]) [self _raiseEOF];
memorypos=offs;
}
-(void)seekToEndOfFile { memorypos=[backingdata length]; }
//-(void)pushBackByte:(int)byte {}
-(int)readAtMost:(int)num toBuffer:(void *)buffer
{
if(!num) return 0;
unsigned int len=[backingdata length];
if(memorypos==len) return 0;
if(memorypos+num>len) num=len-memorypos;
memcpy(buffer,(uint8_t *)[backingdata bytes]+memorypos,num);
memorypos+=num;
return num;
}
-(void)writeBytes:(int)num fromBuffer:(const void *)buffer
{
if(![backingdata isKindOfClass:[NSMutableData class]]) [self _raiseNotSupported:_cmd];
NSMutableData *mbackingdata=(NSMutableData *)backingdata;
if(memorypos+num>[mbackingdata length]) [mbackingdata setLength:memorypos+num];
memcpy((uint8_t *)[mbackingdata mutableBytes]+memorypos,buffer,num);
memorypos+=num;
}
-(NSData *)fileContents { return backingdata; }
-(NSData *)remainingFileContents
{
if(memorypos==0) return backingdata;
else return [super remainingFileContents];
}
-(NSData *)readDataOfLength:(int)length
{
unsigned int totallen=[backingdata length];
if(memorypos+length>totallen) [self _raiseEOF];
NSData *subbackingdata=[backingdata subdataWithRange:NSMakeRange(memorypos,length)];
memorypos+=length;
return subbackingdata;
}
-(NSData *)readDataOfLengthAtMost:(int)length;
{
unsigned int totallen=[backingdata length];
if(memorypos+length>totallen) length=totallen-memorypos;
NSData *subbackingdata=[backingdata subdataWithRange:NSMakeRange(memorypos,length)];
memorypos+=length;
return subbackingdata;
}
-(NSData *)copyDataOfLength:(int)length { return [[self readDataOfLength:length] retain]; }
-(NSData *)copyDataOfLengthAtMost:(int)length { return [[self readDataOfLengthAtMost:length] retain]; }
@end
|
