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// SDLProtocolHeader.m
//
#import "SDLProtocolHeader.h"
#import "SDLV1ProtocolHeader.h"
#import "SDLV2ProtocolHeader.h"
NS_ASSUME_NONNULL_BEGIN
@implementation SDLProtocolHeader
@synthesize version = _version;
@synthesize size = _size;
- (instancetype)init {
if (self = [super init]) {
_version = 0;
_size = 0;
}
return self;
}
- (id)copyWithZone:(nullable NSZone *)zone {
[self doesNotRecognizeSelector:_cmd];
return 0;
}
- (nullable NSData *)data {
[self doesNotRecognizeSelector:_cmd];
return nil;
}
- (void)parse:(NSData *)data {
[self doesNotRecognizeSelector:_cmd];
}
- (NSString *)description {
NSString *description = [NSString stringWithFormat:@"<%@: %p>", NSStringFromClass([self class]), self];
return description;
}
+ (__kindof SDLProtocolHeader *)headerForVersion:(UInt8)version {
// VERSION DEPENDENT CODE
switch (version) {
case 1: {
return [[SDLV1ProtocolHeader alloc] init];
} break;
case 2: // Fallthrough
case 3: // Fallthrough
case 4: // Fallthrough
case 5: {
return [[SDLV2ProtocolHeader alloc] initWithVersion:version];
} break;
default: {
// Assume V2 header for unknown header versions and hope it doesn't break
return [[SDLV2ProtocolHeader alloc] initWithVersion:version];
} break;
}
}
// For use in decoding a stream of bytes.
// Pass in bytes representing message (or beginning of message)
// Looks at and parses first byte to determine version.
+ (UInt8)determineVersion:(NSData *)data {
UInt8 firstByte = ((UInt8 *)data.bytes)[0];
UInt8 version = firstByte >> 4;
return version;
}
@end
NS_ASSUME_NONNULL_END
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