Rails缓存密钥生成为ActiveRecord :: Relation [英] Rails Cache Key generated as ActiveRecord::Relation
问题描述
我正在尝试生成片段缓存(使用Dalli/Memcached存储),但是该密钥是使用#"作为密钥的一部分来生成的,因此Rails似乎无法识别出存在缓存值并访问数据库.
I am attempting to generate a fragment cache (using a Dalli/Memcached store) however the key is being generated with "#" as part of the key, so Rails doesn't seem to be recognizing that there is a cache value and is hitting the database.
我在视图中的缓存键如下:
My cache key in the view looks like this:
cache([@jobs, "index"]) do
控制器具有:
@jobs = @current_tenant.active_jobs
使用像这样的实际Active Record查询:
With the actual Active Record query like this:
def active_jobs
self.jobs.where("published = ? and expiration_date >= ?", true, Date.today).order("(featured and created_at > now() - interval '" + self.pinned_time_limit.to_s + " days') desc nulls last, created_at desc")
end
看着rails服务器,我看到缓存已读取,但是SQL查询仍然运行:
Looking at the rails server, I see the cache read, but the SQL Query still runs:
Cache read: views/#<ActiveRecord::Relation:0x007fbabef9cd58>/1-index
Read fragment views/#<ActiveRecord::Relation:0x007fbabef9cd58>/1-index (1.0ms)
(0.6ms) SELECT COUNT(*) FROM "jobs" WHERE "jobs"."tenant_id" = 1 AND (published = 't' and expiration_date >= '2013-03-03')
Job Load (1.2ms) SELECT "jobs".* FROM "jobs" WHERE "jobs"."tenant_id" = 1 AND (published = 't' and expiration_date >= '2013-03-03') ORDER BY (featured and created_at > now() - interval '7 days') desc nulls last, created_at desc
关于我可能做错了什么的任何想法?我确定它必须与密钥生成和ActiveRecord :: Relation一起使用,但是我不确定该如何做.
Any ideas as to what I might be doing wrong? I'm sure it has to do w/ the key generation and ActiveRecord::Relation, but i'm not sure how.
推荐答案
我遇到了类似的问题,我无法成功将关系传递给缓存函数,并且您的@jobs变量是一个关系.
I have had similar problems, I have not been able to successfully pass relations to the cache function and your @jobs variable is a relation.
我为高速缓存密钥编写了一个解决方案,该解决方案可以解决这个问题以及其他一些问题.它基本上涉及通过迭代关系来生成缓存密钥.
I coded up a solution for cache keys that deals with this issue along with some others that I was having. It basically involves generating a cache key by iterating through the relation.
完整的文章在我的网站上.
A full write up is on my site here.
http://mark.stratmann.me/content_items/rails-caching-strategy-using-key-based-approach
总而言之,我向ActiveRecord :: Base添加了一个get_cache_keys函数
In summary I added a get_cache_keys function to ActiveRecord::Base
module CacheKeys
extend ActiveSupport::Concern
# Instance Methods
def get_cache_key(prefix=nil)
cache_key = []
cache_key << prefix if prefix
cache_key << self
self.class.get_cache_key_children.each do |child|
if child.macro == :has_many
self.send(child.name).all.each do |child_record|
cache_key << child_record.get_cache_key
end
end
if child.macro == :belongs_to
cache_key << self.send(child.name).get_cache_key
end
end
return cache_key.flatten
end
# Class Methods
module ClassMethods
def cache_key_children(*args)
@v_cache_key_children = []
# validate the children
args.each do |child|
#is it an association
association = reflect_on_association(child)
if association == nil
raise "#{child} is not an association!"
end
@v_cache_key_children << association
end
end
def get_cache_key_children
return @v_cache_key_children ||= []
end
end
end
# include the extension
ActiveRecord::Base.send(:include, CacheKeys)
我现在可以通过创建缓存片段
I can now create cache fragments by doing
cache(@model.get_cache_key(['textlabel'])) do
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