CFHostSample/QCFHostResolver.h

/*
    File:       QCFHostResolver.h
 
    Contains:   A Cocoa-style wrapper around CFHost.
 
    Written by: DTS
 
    Copyright:  Copyright (c) 2012 Apple Inc. All Rights Reserved.
 
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*/
 
#import <Foundation/Foundation.h>
 
/*
    You can use the object to map from a DNS name to a set of addresses or from a 
    address to a set of DNS names.  To do this:
    
    1. create the QCFHostResolver object with the info you have
    
    2. set a delegate
    
    3. call -start
    
    4. wait for -hostResolverDidFinish: to be called
    
    5. extract the information you need from the resolvedXxx properties
*/
 
@protocol QCFHostResolverDelegate;
 
@interface QCFHostResolver : NSObject
 
- (id)initWithName:(NSString *)name;
    // Initialise the object for name-to-address translation.
    
- (id)initWithAddress:(NSData *)address;
    // Initialise the object for address-to-name translation based on a (struct sockaddr) 
    // embedded in an NSData object.
 
- (id)initWithAddressString:(NSString *)addressString;
    // Initialise the object for address-to-name translation based on an address string.
 
// properties set up by the various -init routines
 
@property (nonatomic, copy,   readonly ) NSString *     name;
@property (nonatomic, copy,   readonly ) NSData *       address;
@property (nonatomic, copy,   readonly ) NSString *     addressString;
 
// properties you can set at any time
 
@property (nonatomic, weak,   readwrite) id<QCFHostResolverDelegate> delegate;
 
- (void)start;
    // Starts the resolution process.
    // 
    // It's not safe to call this is if the resolve is running.
 
- (void)cancel;
    // Cancels a resolve.  It's safe to call this redundantly.
 
// properties that are set when resolution completes
 
@property (nonatomic, copy,   readonly ) NSError *      error;
@property (nonatomic, copy,   readonly ) NSArray *      resolvedAddresses;          // of NSData, each containing a (struct sockaddr)
@property (nonatomic, copy,   readonly ) NSArray *      resolvedAddressStrings;     // of NSString
@property (nonatomic, copy,   readonly ) NSArray *      resolvedNames;              // of NSString
 
@end
 
@protocol QCFHostResolverDelegate <NSObject>
 
@optional
 
- (void)hostResolverDidFinish:(QCFHostResolver *)resolver;
    // Called when resolution completes succesfully.  Either the resolvedAddress[es|Strings] 
    // or the resolvedNames properties will contain meaningful results depending on whether 
    // the object was initialised for name-to-address or address-to-name translation.
    
- (void)hostResolver:(QCFHostResolver *)resolver didFailWithError:(NSError *)error;
    // Called when resolution fails.  The error parameter reflects the value in the error 
    // property
 
@end