YYModel底层解析- Runtime

/**
 Instance variable information.
 */
@interfaceYYClassIvarInfo : NSObject
@property (nonatomic, assign, readonly) Ivar ivar;              ///< ivar opaque struct
@property (nonatomic, strong, readonly) NSString *name;         ///< Ivar's name
@property (nonatomic, assign, readonly) ptrdiff_t offset;       ///< Ivar's offset
@property (nonatomic, strong, readonly) NSString *typeEncoding; ///< Ivar's type encoding
@property (nonatomic, assign, readonly) YYEncodingType type;    ///< Ivar's type

/**
 Creates and returns an ivar info object.
 @param ivar ivar opaque struct
 @return A new object, or nil if an error occurs.
 */
-(instancetype)initWithIvar:(Ivar)ivar;
@end

structobjc_ivar{
char*_Nullableivar_nameOBJC2_UNAVAILABLE;//变量名称
char*_Nullableivar_typeOBJC2_UNAVAILABLE;//变量类型
intivar_offsetOBJC2_UNAVAILABLE;//变量偏移量
#ifdef__LP64__//如果已定义__LP64__则表示正在构建64位目标
intspaceOBJC2_UNAVAILABLE;//变量空间
#endif
}

@interfaceYYClassMethodInfo : NSObject
@property (nonatomic, assign, readonly) Method method; ///< 方法
@property (nonatomic, strong, readonly) NSString *name; ///< 方法名称
@property (nonatomic, assign, readonly) SEL sel; ///< 方法选择器
@property (nonatomic, assign, readonly) IMP imp; ///< 方法实现，指向实现方法函数的函数指针
@property (nonatomic, strong, readonly) NSString *typeEncoding; ///< 方法参数和返回类型编码
@property (nonatomic, strong, readonly) NSString *returnTypeEncoding; ///< 返回值类型编码
@property (nullable, nonatomic, strong, readonly) NSArray<nsstring *>*argumentTypeEncodings; ///< 参数类型编码数组
 
-(instancetype)initWithMethod:(Method)method;
@end

structobjc_method {
    SEL _Nonnull method_name OBJC2_UNAVAILABLE; //方法名称
    char * _Nullable method_types OBJC2_UNAVAILABLE; //方法类型
    IMP _Nonnull method_imp OBJC2_UNAVAILABLE; //方法实现（函数指针）
}

@interfaceYYClassPropertyInfo : NSObject
@property (nonatomic, assign, readonly) objc_property_t property; ///< 属性
@property (nonatomic, strong, readonly) NSString *name; ///< 属性名称
@property (nonatomic, assign, readonly) YYEncodingType type; ///< 属性类型
@property (nonatomic, strong, readonly) NSString *typeEncoding; ///< 属性类型编码
@property (nonatomic, strong, readonly) NSString *ivarName; ///< 变量名称
@property (nullable, nonatomic, assign, readonly) Class cls; ///< 类型
@property (nullable, nonatomic, strong, readonly) NSArray<nsstring *>*protocols; ///< 属性相关协议
@property (nonatomic, assign, readonly) SEL getter; ///< getter 方法选择器
@property (nonatomic, assign, readonly) SEL setter; ///< setter 方法选择器
 
-(instancetype)initWithProperty:(objc_property_t)property;
@end</nsstring *>

structproperty_t {
    const char *name; //名称
    const char *attributes; //修饰
};

@interfaceYYClassInfo : NSObject
@property (nonatomic, assign, readonly) Class cls; ///< 类
@property (nullable, nonatomic, assign, readonly) Class superCls; ///< 超类
@property (nullable, nonatomic, assign, readonly) Class metaCls;  ///< 元类
@property (nonatomic, readonly) BOOL isMeta; ///< 元类标识，自身是否为元类
@property (nonatomic, strong, readonly) NSString *name; ///< 类名称
@property (nullable, nonatomic, strong, readonly) YYClassInfo *superClassInfo; ///< 父类（超类）信息
@property (nullable, nonatomic, strong, readonly) NSDictionary<nsstring *, yyclassivarinfo *>*ivarInfos; ///< 变量信息
@property (nullable, nonatomic, strong, readonly) NSDictionary<nsstring *, yyclassmethodinfo *>*methodInfos; ///< 方法信息
@property (nullable, nonatomic, strong, readonly) NSDictionary<nsstring *, yyclasspropertyinfo *>*propertyInfos; ///< 属性信息
 
- (void)setNeedUpdate;
-(BOOL)needUpdate;
+(nullable instancetype)classInfoWithClass:(Class)cls;
+ (nullable instancetype)classInfoWithClassName:(NSString *)className;
@end

//objc.h
typedef struct objc_class *Class;
//runtime.h
structobjc_class {
    Class _Nonnull isa OBJC_ISA_AVAILABILITY; //isa 指针
#if !__OBJC2__
    Class _Nullable super_class OBJC2_UNAVAILABLE; //父类（超类）指针
    const char * _Nonnull name OBJC2_UNAVAILABLE; //类名
    long version OBJC2_UNAVAILABLE; //版本
    long info OBJC2_UNAVAILABLE; //信息
    long instance_size OBJC2_UNAVAILABLE; //初始尺寸
    struct objc_ivar_list * _Nullable ivars OBJC2_UNAVAILABLE; //变量列表
    struct objc_method_list * _Nullable * _Nullable methodLists OBJC2_UNAVAILABLE; //方法列表
    struct objc_cache * _Nonnull cache OBJC2_UNAVAILABLE; //缓存
    struct objc_protocol_list * _Nullable protocols OBJC2_UNAVAILABLE; //协议列表
#endif
} OBJC2_UNAVAILABLE;

+(instancetype)classInfoWithClass:(Class)cls {
    //判空入参
    if (!cls) returnnil;
    //单例缓存 classCache 与 metaCache，对应缓存类和元类
    staticCFMutableDictionaryRef classCache;
    staticCFMutableDictionaryRef metaCache;
    staticdispatch_once_t onceToken;
    static dispatch_semaphore_t lock;
    dispatch_once(&onceToken, ^{
        classCache = CFDictionaryCreateMutable(CFAllocatorGetDefault(), 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
        metaCache = CFDictionaryCreateMutable(CFAllocatorGetDefault(), 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
        //这里把 dispatch_semaphore 当做锁来使用（当信号量只有 1 时）
        lock = dispatch_semaphore_create(1);
    });
    //初始化之前，首先会根据当前 YYClassInfo 是否为元类去对应的单例缓存中查找
    //这里使用了上面的 dispatch_semaphore 加锁，保证单例缓存的线程安全 
    dispatch_semaphore_wait(lock, DISPATCH_TIME_FOREVER);
    YYClassInfo *info = CFDictionaryGetValue(class_isMetaClass(cls) ? metaCache : classCache, (__bridge const void *)(cls));
    //如果找到了，且找到的信息需要更新的话则执行更新操作
    if (info && info->_needUpdate) {
        [info _update];
    }
    dispatch_semaphore_signal(lock);
    //如果没找到，才会去老实初始化
    if (!info) {
        info =[[YYClassInfo alloc] initWithClass:cls];
        if (info) { //初始化成功
            //线程安全
            dispatch_semaphore_wait(lock, DISPATCH_TIME_FOREVER);
            //根据初始化信息选择向对应的类/元类缓存注入信息，key = cls，value = info
            CFDictionarySetValue(info.isMeta ? metaCache : classCache, (__bridge const void *)(cls), (__bridge const void *)(info));
            dispatch_semaphore_signal(lock);
        }
    }
    returninfo;
}

@interface_YYModelPropertyMeta : NSObject {
    @package
    NSString *_name;             ///< 属性名称
YYEncodingType _type;        ///< 属性类型
YYEncodingNSType _nsType;    ///< 属性在 Foundation 框架中的类型
BOOL _isCNumber;             ///< 是否为 CNumber
Class _cls;                  ///< 属性类
Class _genericCls;           ///< 属性包含的泛型类型，没有则为 nil
SEL _getter;                 ///< getter
SEL _setter;                 ///< setter
BOOL _isKVCCompatible;       ///< 如果可以使用 KVC 则返回 YES
BOOL _isStructAvailableForKeyedArchiver; ///< 如果可以使用 archiver/unarchiver 归/解档则返回 YES
BOOL _hasCustomClassFromDictionary; ///< 类/泛型自定义类型，例如需要在数组中实现不同类型的转换需要用到
     
    /*
     property->key:       _mappedToKey:key     _mappedToKeyPath:nil            _mappedToKeyArray:nil
     property->keyPath:   _mappedToKey:keyPath _mappedToKeyPath:keyPath(array) _mappedToKeyArray:nil
     property->keys:      _mappedToKey:keys[0] _mappedToKeyPath:nil/keyPath    _mappedToKeyArray:keys(array)
     */
    NSString *_mappedToKey;      ///< 映射 key
NSArray *_mappedToKeyPath;   ///< 映射 keyPath，如果没有映射到 keyPath 则返回 nil
NSArray *_mappedToKeyArray;  ///< key 或者 keyPath 的数组，如果没有映射多个键的话则返回 nil
YYClassPropertyInfo *_info;  ///< 属性信息，详见上文 YYClassPropertyInfo && property_t 章节
_YYModelPropertyMeta *_next; ///< 如果有多个属性映射到同一个 key 则指向下一个模型属性元
}
@end

@interface_YYModelMeta : NSObject {
    @package
    YYClassInfo *_classInfo;
    ///Key:被映射的 key 与 keyPath, Value:_YYModelPropertyMeta.
    NSDictionary *_mapper;
    ///Array<_YYModelPropertyMeta>, 当前模型的所有 _YYModelPropertyMeta 数组
    NSArray *_allPropertyMetas;
    ///Array<_YYModelPropertyMeta>, 被映射到 keyPath 的 _YYModelPropertyMeta 数组
    NSArray *_keyPathPropertyMetas;
    ///Array<_YYModelPropertyMeta>, 被映射到多个 key 的 _YYModelPropertyMeta 数组
    NSArray *_multiKeysPropertyMetas;
    ///映射 key 与 keyPath 的数量，等同于 _mapper.count
NSUInteger _keyMappedCount;
    ///模型 class 类型
YYEncodingNSType _nsType;
    //忽略
...
}
@end

#import <Foundation/Foundation.h>
//"time":"2018-07-04 12:13:52",
//"ftime":"2018-07-04 12:13:52",
//"context":"快件已签收 签收人: 他人代收 感谢使用圆通速递，期待再次为您服
@interfaceIOALogisticsDetailModel : NSObject
@property(nonatomic,copy)NSString   *time;
@property(nonatomic,copy)NSString   *ftime;
@property(nonatomic,copy)NSString   *context;
@end
#import "IOALogisticsDetailModel.h"
@implementationIOALogisticsDetailModel
@end

- (NSArray <IOALogisticsDetailModel *>*)setupOrderWithArray:(NSArray <NSDictionary *>*)array{
    NSMutableArray <IOALogisticsDetailModel *>*modelArray =[NSMutableArray arrayWithCapacity:array.count];
    for(NSDictionary *dic inarray){
IOALogisticsDetailModel *model = [IOALogisticsDetailModel yy_modelWithDictionary:dic];
        if (!model) continue;
        [modelArray addObject:model];
    }
    returnmodelArray;
}

#import <Foundation/Foundation.h>
@interfaceIOAOrderAftersaleRequestModel : NSObject
@property(nonatomic,copy)NSString *order_sn;
@property(nonatomic,copy)NSString *rec_id;
@property(nonatomic,copy)NSString  *is_type;
@property(nonatomic,assign)NSInteger refund_count;
@property(nonatomic,copy)NSString *content;
@property(nonatomic,copy)NSString *return_attachs;
@property(nonatomic,copy)NSString *shop_id;
@property(nonatomic,copy)NSString *reason;
@property(nonatomic,assign)floattotal;
@end
#import "IOAOrderAftersaleRequestModel.h"
@implementationIOAOrderAftersaleRequestModel
@end

//提交退货商品
@interfaceIOAOrderAftersaleRequest:IOARequest
@property (nonatomic,strong)IOAOrderAftersaleRequestModel *requestModel;
@end
//提交退货商品
@implementationIOAOrderAftersaleRequest
- (id)requestArgument{
    NSMutableDictionary *dic = [IOAApiManager getParametersWithService:@"App.Order.SetOrderAftersaleGoodsrefundsList"];
NSDictionary *temDic =[self.requestModel yy_modelToJSONObject];
    [dic addEntriesFromDictionary:temDic];
    returndic;
}

//JSON:
{
    "n":"Harry Pottery",
    "p": 256,
    "ext": {
        "desc" : "A book written by J.K.Rowing."
    },
    "ID" : 100010
}
//Model:
@interfaceBook : NSObject
@property NSString *name;
@property NSInteger page;
@property NSString *desc;
@property NSString *bookID;
@end
@implementationBook
//返回一个 Dict，将 Model 属性名对映射到 JSON 的 Key。
+ (NSDictionary *)modelCustomPropertyMapper {
    return @{@"name" : @"n",
             @"page" : @"p",
             @"desc" : @"ext.desc",
             @"bookID" : @[@"id",@"ID",@"book_id"]};
}

//JSON
{
    "author":{
        "name":"J.K.Rowling",
        "birthday":"1965-07-31T00:00:00+0000"
    },
    "name":"Harry Potter",
    "pages":256
}
//Model: 什么都不用做，转换会自动完成
@interfaceAuthor : NSObject
@property NSString *name;
@property NSDate *birthday;
@end
@implementationAuthor
@end
@interfaceBook : NSObject
@property NSString *name;
@property NSUInteger pages;
@property Author *author; //Book 包含 Author 属性
@end
@implementationBook
@end

@interfaceUser
@property NSString *name;
@property NSUInteger age;
@end
@implementationAttributes
//如果实现了该方法，则处理过程中会忽略该列表内的所有属性
+ (NSArray *)modelPropertyBlacklist {
    return @[@"test1", @"test2"];
}
//如果实现了该方法，则处理过程中不会处理该列表外的属性。
+ (NSArray *)modelPropertyWhitelist {
    return @[@"name"];
}
@end