第六十三篇、runtime实现归解档

#import <objc/runtime.h>
#import <objc/message.h>

@implementation HDFArchiveModel

- (void)encodeWithCoder:(NSCoder *)aCoder {
  unsigned int outCount = 0;
  Ivar *ivars = class_copyIvarList([self class], &outCount);

  for (unsigned int i = 0; i < outCount; ++i) {
    Ivar ivar = ivars[i];

    // 获取成员变量名
    const void *name = ivar_getName(ivar);
    NSString *ivarName = [NSString stringWithUTF8String:name];
    // 去掉成员变量的下划线
    ivarName = [ivarName substringFromIndex:1];

    // 获取getter方法
    SEL getter = NSSelectorFromString(ivarName);
    if ([self respondsToSelector:getter]) {
      const void *typeEncoding = ivar_getTypeEncoding(ivar);
      NSString *type = [NSString stringWithUTF8String:typeEncoding];

      // const void *
      if ([type isEqualToString:@"r^v"]) {
        const char *value = ((const void *(*)(id, SEL))(void *)objc_msgSend)((id)self, getter);
        NSString *utf8Value = [NSString stringWithUTF8String:value];
        [aCoder encodeObject:utf8Value forKey:ivarName];
        continue;
      }
      // int
      else if ([type isEqualToString:@"i"]) {
        int value = ((int (*)(id, SEL))(void *)objc_msgSend)((id)self, getter);
        [aCoder encodeObject:@(value) forKey:ivarName];
        continue;
      }
      // float
      else if ([type isEqualToString:@"f"]) {
        float value = ((float (*)(id, SEL))(void *)objc_msgSend)((id)self, getter);
        [aCoder encodeObject:@(value) forKey:ivarName];
        continue;
      }

     id value = ((id (*)(id, SEL))(void *)objc_msgSend)((id)self, getter);
      if (value != nil && [value respondsToSelector:@selector(encodeWithCoder:)]) {
        [aCoder encodeObject:value forKey:ivarName];
      }
    }
  }

  free(ivars);
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
  if (self = [super init]) {
    unsigned int outCount = 0;
    Ivar *ivars = class_copyIvarList([self class], &outCount);

    for (unsigned int i = 0; i < outCount; ++i) {
      Ivar ivar = ivars[i];

      // 获取成员变量名
      const void *name = ivar_getName(ivar);
      NSString *ivarName = [NSString stringWithUTF8String:name];
      // 去掉成员变量的下划线
      ivarName = [ivarName substringFromIndex:1];
      // 生成setter格式
      NSString *setterName = ivarName;
      // 那么一定是字母开头
      if (![setterName hasPrefix:@"_"]) {
        NSString *firstLetter = [NSString stringWithFormat:@"%c", [setterName characterAtIndex:0]];
        setterName = [setterName substringFromIndex:1];
        setterName = [NSString stringWithFormat:@"%@%@", firstLetter.uppercaseString, setterName];
      }
     setterName = [NSString stringWithFormat:@"set%@:", setterName];
      // 获取getter方法
      SEL setter = NSSelectorFromString(setterName);
      if ([self respondsToSelector:setter]) {
        // 获取数据的类型
        const void *typeEncoding = ivar_getTypeEncoding(ivar);
        NSString *type = [NSString stringWithUTF8String:typeEncoding];
        NSLog(@"%@", type);

        // const void *
        if ([type isEqualToString:@"r^v"]) {
          NSString *value = [aDecoder decodeObjectForKey:ivarName];
          if (value) {
           ((void (*)(id, SEL, const void *))objc_msgSend)(self, setter, value.UTF8String);
          }

          continue;
        }
        // int
        else if ([type isEqualToString:@"i"]) {
          NSNumber *value = [aDecoder decodeObjectForKey:ivarName];
          if (value != nil) {
            ((void (*)(id, SEL, int))objc_msgSend)(self, setter, [value intValue]);
          }
          continue;
        } else if ([type isEqualToString:@"f"]) {
          NSNumber *value = [aDecoder decodeObjectForKey:ivarName];
          if (value != nil) {
            ((void (*)(id, SEL, float))objc_msgSend)(self, setter, [value floatValue]);
          }
          continue;
        }

        // object
        id value = [aDecoder decodeObjectForKey:ivarName];
        if (value != nil) {
          ((void (*)(id, SEL, id))objc_msgSend)(self, setter, value);
        }
      }
    }

    free(ivars);
  }

  return self;
}

+ (void)test {
  HDFArchiveModel *archiveModel = [[HDFArchiveModel alloc] init];
  archiveModel.archive = @"自动归档";
  archiveModel.session = "http://www.henishuo.com";
  archiveModel.totalCount = @(123);
  archiveModel.referenceCount = 10;
  archiveModel._floatValue = 10.0;

  NSString *path = NSHomeDirectory();
  path = [NSString stringWithFormat:@"%@/archive", path];
  [NSKeyedArchiver archiveRootObject:archiveModel
                              toFile:path];

  HDFArchiveModel *unarchiveModel = [NSKeyedUnarchiver unarchiveObjectWithFile:path];

}

@end