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Diffstat (limited to 'guides/source/caching_with_rails.md')
| -rw-r--r-- | guides/source/caching_with_rails.md | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/guides/source/caching_with_rails.md b/guides/source/caching_with_rails.md index f760f0a005..3f013fff3a 100644 --- a/guides/source/caching_with_rails.md +++ b/guides/source/caching_with_rails.md @@ -1,4 +1,4 @@ -**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON https://guides.rubyonrails.org.** Caching with Rails: An Overview =============================== @@ -51,10 +51,10 @@ For instance, it will not impact low-level caching, that we address ### Page Caching Page caching is a Rails mechanism which allows the request for a generated page -to be fulfilled by the webserver (i.e. Apache or NGINX) without having to go +to be fulfilled by the web server (i.e. Apache or NGINX) without having to go through the entire Rails stack. While this is super fast it can't be applied to every situation (such as pages that need authentication). Also, because the -webserver is serving a file directly from the filesystem you will need to +web server is serving a file directly from the filesystem you will need to implement cache expiration. INFO: Page Caching has been removed from Rails 4. See the [actionpack-page_caching gem](https://github.com/rails/actionpack-page_caching). @@ -63,7 +63,7 @@ INFO: Page Caching has been removed from Rails 4. See the [actionpack-page_cachi Page Caching cannot be used for actions that have before filters - for example, pages that require authentication. This is where Action Caching comes in. Action Caching works like Page Caching except the incoming web request hits the Rails stack so that before filters can be run on it before the cache is served. This allows authentication and other restrictions to be run while still serving the result of the output from a cached copy. -INFO: Action Caching has been removed from Rails 4. See the [actionpack-action_caching gem](https://github.com/rails/actionpack-action_caching). See [DHH's key-based cache expiration overview](http://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works) for the newly-preferred method. +INFO: Action Caching has been removed from Rails 4. See the [actionpack-action_caching gem](https://github.com/rails/actionpack-action_caching). See [DHH's key-based cache expiration overview](https://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works) for the newly-preferred method. ### Fragment Caching @@ -295,14 +295,14 @@ Consider the following example. An application has a `Product` model with an ins ```ruby class Product < ApplicationRecord def competing_price - Rails.cache.fetch("#{cache_key}/competing_price", expires_in: 12.hours) do + Rails.cache.fetch("#{cache_key_with_version}/competing_price", expires_in: 12.hours) do Competitor::API.find_price(id) end end end ``` -NOTE: Notice that in this example we used the `cache_key` method, so the resulting cache key will be something like `products/233-20140225082222765838000/competing_price`. `cache_key` generates a string based on the model's `id` and `updated_at` attributes. This is a common convention and has the benefit of invalidating the cache whenever the product is updated. In general, when you use low-level caching for instance level information, you need to generate a cache key. +NOTE: Notice that in this example we used the `cache_key_with_version` method, so the resulting cache key will be something like `products/233-20140225082222765838000/competing_price`. `cache_key_with_version` generates a string based on the model's class name, `id`, and `updated_at` attributes. This is a common convention and has the benefit of invalidating the cache whenever the product is updated. In general, when you use low-level caching for instance level information, you need to generate a cache key. ### SQL Caching @@ -362,7 +362,7 @@ This class provides the foundation for interacting with the cache in Rails. This The main methods to call are `read`, `write`, `delete`, `exist?`, and `fetch`. The fetch method takes a block and will either return an existing value from the cache, or evaluate the block and write the result to the cache if no value exists. -There are some common options used by all cache implementations. These can be passed to the constructor or the various methods to interact with entries. +There are some common options that can be used by all cache implementations. These can be passed to the constructor or the various methods to interact with entries. * `:namespace` - This option can be used to create a namespace within the cache store. It is especially useful if your application shares a cache with other applications. @@ -370,7 +370,7 @@ There are some common options used by all cache implementations. These can be pa * `:compress_threshold` - Defaults to 1kB. Cache entries larger than this threshold, specified in bytes, are compressed. -* `:expires_in` - This option sets an expiration time in seconds for the cache entry when it will be automatically removed from the cache. +* `:expires_in` - This option sets an expiration time in seconds for the cache entry, if the cache store supports it, when it will be automatically removed from the cache. * `:race_condition_ttl` - This option is used in conjunction with the `:expires_in` option. It will prevent race conditions when cache entries expire by preventing multiple processes from simultaneously regenerating the same entry (also known as the dog pile effect). This option sets the number of seconds that an expired entry can be reused while a new value is being regenerated. It's a good practice to set this value if you use the `:expires_in` option. @@ -563,7 +563,7 @@ class ProductsController < ApplicationController # If the request is stale according to the given timestamp and etag value # (i.e. it needs to be processed again) then execute this block - if stale?(last_modified: @product.updated_at.utc, etag: @product.cache_key) + if stale?(last_modified: @product.updated_at.utc, etag: @product.cache_key_with_version) respond_to do |wants| # ... normal response processing end @@ -577,7 +577,7 @@ class ProductsController < ApplicationController end ``` -Instead of an options hash, you can also simply pass in a model. Rails will use the `updated_at` and `cache_key` methods for setting `last_modified` and `etag`: +Instead of an options hash, you can also simply pass in a model. Rails will use the `updated_at` and `cache_key_with_version` methods for setting `last_modified` and `etag`: ```ruby class ProductsController < ApplicationController @@ -670,13 +670,13 @@ Caching in Development ---------------------- It's common to want to test the caching strategy of your application -in development mode. Rails provides the rake task `dev:cache` to +in development mode. Rails provides the rails command `dev:cache` to easily toggle caching on/off. ```bash -$ bin/rails dev:cache +$ rails dev:cache Development mode is now being cached. -$ bin/rails dev:cache +$ rails dev:cache Development mode is no longer being cached. ``` |