YYCache前言以及简单使用

前言：首先缓存分为内存缓存跟硬盘缓存两种，而内存缓存的实现一般使用LRU算法来实现，硬盘缓存要么基于文件要么基于数据，要么结合文件缓存以及数据库缓存两种来实现。YYCache的内存缓存实现是基于双向链表来实现LRU算法，他的硬盘缓存是基于结合文件缓存以及数据库两者来实现的。

1.YYCache的使用场景:存服务器传过来的数据，以减少服务器的压力,避免每次都向服务器请求。 缓存的方式分为两种分别为内存缓存和磁盘缓存，内存缓存速度快容量小，磁盘缓存容量大速度慢可持久化存储。

2.YYCache相对与其他三方缓存策略的对比，参考官方的说明文档

3.YYCache的使用:

#import <Foundation/Foundation.h>

@interface Pet : NSObject<NSCoding>
@property (nonatomic, copy) NSArray *petName;
@property (nonatomic, copy) NSString *petSex;

@end

#import "Pet.h"
@implementation Pet
- (void)encodeWithCoder:(NSCoder *)aCoder
{
    [aCoder encodeObject:self.petName forKey:@"petName"];
    [aCoder encodeObject:self.petSex forKey:@"petSex"];
}

- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder
{
    self.petName = [aDecoder decodeObjectForKey:@"petName"];
    self.petSex = [aDecoder decodeObjectForKey:@"petSex"];
    return self;
}

#import <Foundation/Foundation.h>
#import "Pet.h"
@interface Person : NSObject<NSCoding>

@property (nonatomic, copy) NSString *name;
@property (nonatomic, copy) NSString *sex;
@property (nonatomic, copy) NSString *age;
@property (nonatomic, strong) Pet *pet;

@end

#import "Person.h"
@implementation Person
- (void)encodeWithCoder:(NSCoder *)aCoder
{
    [aCoder encodeObject:self.name forKey:@"name"];
    [aCoder encodeObject:self.age forKey:@"age"];
    [aCoder encodeObject:self.sex forKey:@"sex"];
    [aCoder encodeObject:self.pet forKey:@"pet"];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder{
   self.name = [aDecoder decodeObjectForKey:@"name"];
   self.age = [aDecoder decodeObjectForKey:@"age"];
   self.sex = [aDecoder decodeObjectForKey:@"sex"];
   self.pet = [aDecoder decodeObjectForKey:@"pet"];

    return self;
}
@end

开始使用YYCache缓存

#import "ViewController.h"
#import "YYCache.h"
#import "Person.h"
#import "Pet.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    YYCache *personCache = [YYCache cacheWithName:@"personCache"];
    
    Person *person = [[Person alloc] init];
    person.name = @"hxg";
    person.age = @"11";
    person.sex = @"女";
    
    Pet *pet = [[Pet alloc] init];
    pet.petName = @[@"111",@"222",@"33"];
    pet.petSex = @"男";
    person.pet = pet;
    
    [personCache setObject:person
                    forKey:@"personInfo"];

    NSLog(@"%@",[[(Person *)[personCache objectForKey:@"personInfo"] pet] petName]);
    
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *docDir = [paths objectAtIndex:0];
    NSLog(@"%@",docDir);
  
}

然后到打印的目录下去看生成的缓存文件如下：

屏幕快照 2017-11-02 上午1.09.16.png