@class NSString, NSMutableData; @interface SGChatLengthEstimator : NSObject { int _fd; NSMutableData *_backingData; unsigned short *_countPtr; char *_sketch; struct _opaque_pthread_mutex_t { long long __sig; char __opaque[56]; } _lock; } @property (readonly) NSString *path; @property (readonly) unsigned long long count; + (id)sharedInstance; + (void)setSharedInstance:(id)a0; - (id)initWithPath:(id)a0; - (id)init; - (void)dealloc; - (id)initInMemory; - (void).cxx_destruct; - (unsigned long long)estimateMessagesInChat:(id)a0; - (void)recordMessageInChat:(id)a0; @end