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#import "CSMultiHandle.h"
NSString *CSSizeOfSegmentUnknownException=@"CSSizeOfSegmentUnknownException";
@implementation CSMultiHandle
+(CSMultiHandle *)multiHandleWithHandleArray:(NSArray *)handlearray
{
if(!handlearray) return nil;
int count=[handlearray count];
if(count==0) return nil;
else if(count==1) return [handlearray objectAtIndex:0];
else return [[[self alloc] initWithHandles:handlearray] autorelease];
}
+(CSMultiHandle *)multiHandleWithHandles:(CSHandle *)firsthandle,...
{
if(!firsthandle) return nil;
NSMutableArray *array=[NSMutableArray arrayWithObject:firsthandle];
CSHandle *handle;
va_list va;
va_start(va,firsthandle);
while((handle=va_arg(va,CSHandle *))) [array addObject:handle];
va_end(va);
return [self multiHandleWithHandleArray:array];
}
-(id)initWithHandles:(NSArray *)handlearray
{
if((self=[super initWithName:[NSString stringWithFormat:@"%@, and %d more combined",[[handlearray objectAtIndex:0] name],[handlearray count]-1]]))
{
handles=[handlearray copy];
currhandle=0;
}
return self;
}
-(id)initAsCopyOf:(CSMultiHandle *)other
{
if((self=[super initAsCopyOf:other]))
{
NSMutableArray *handlearray=[NSMutableArray arrayWithCapacity:[other->handles count]];
NSEnumerator *enumerator=[other->handles objectEnumerator];
CSHandle *handle;
while((handle=[enumerator nextObject])) [handlearray addObject:[[handle copy] autorelease]];
handles=[[NSArray arrayWithArray:handlearray] retain];
currhandle=other->currhandle;
}
return self;
}
-(void)dealloc
{
[handles release];
[super dealloc];
}
-(NSArray *)handles { return handles; }
-(CSHandle *)currentHandle { return [handles objectAtIndex:currhandle]; }
-(off_t)fileSize
{
off_t size=0;
int count=[handles count];
for(int i=0;i<count-1;i++)
{
off_t segsize=[(CSHandle *)[handles objectAtIndex:i] fileSize];
if(segsize==CSHandleMaxLength) [self _raiseSizeUnknownForSegment:i];
size+=segsize;
}
off_t segsize=[(CSHandle *)[handles lastObject] fileSize];
if(segsize==CSHandleMaxLength) return CSHandleMaxLength;
else return size+segsize;
}
-(off_t)offsetInFile
{
off_t offs=0;
for(int i=0;i<currhandle;i++)
{
off_t segsize=[(CSHandle *)[handles objectAtIndex:i] fileSize];
if(segsize==CSHandleMaxLength) [self _raiseSizeUnknownForSegment:i];
offs+=segsize;
}
return offs+[[handles objectAtIndex:currhandle] offsetInFile];
}
-(BOOL)atEndOfFile
{
return currhandle==[handles count]-1&&[[handles objectAtIndex:currhandle] atEndOfFile];
}
-(void)seekToFileOffset:(off_t)offs
{
int count=[handles count];
if(offs==0)
{
currhandle=0;
}
else
{
for(currhandle=0;currhandle<count-1;currhandle++)
{
off_t segsize=[(CSHandle *)[handles objectAtIndex:currhandle] fileSize];
if(segsize==CSHandleMaxLength) [self _raiseSizeUnknownForSegment:currhandle];
if(offs<segsize) break;
offs-=segsize;
}
}
[(CSHandle *)[handles objectAtIndex:currhandle] seekToFileOffset:offs];
}
-(void)seekToEndOfFile
{
currhandle=[handles count]-1;
[(CSHandle *)[handles objectAtIndex:currhandle] seekToEndOfFile];
}
-(int)readAtMost:(int)num toBuffer:(void *)buffer
{
off_t total=0;
for(;;)
{
off_t actual=[[handles objectAtIndex:currhandle] readAtMost:num-total toBuffer:((char *)buffer)+total];
total+=actual;
if(total==num||currhandle==[handles count]-1) return total;
currhandle++;
[(CSHandle *)[handles objectAtIndex:currhandle] seekToFileOffset:0];
}
}
-(void)_raiseSizeUnknownForSegment:(int)i
{
[NSException raise:CSSizeOfSegmentUnknownException
format:@"Size of CSMultiHandle segment %d (%@) unknown.",i,[handles objectAtIndex:i]];
}
@end
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