Class: Bridgetown::Cache

Inherits:
Object
  • Object
show all
Defined in:
bridgetown-core/lib/bridgetown-core/cache.rb

Class Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Cache

Get an existing named cache, or create a new one if none exists

name - name of the cache

Returns nothing.



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 66

def initialize(name)
  @cache = Bridgetown::Cache.base_cache[name] ||= {}
  @name = name.gsub(%r![^\w\s-]!, "-")
end

Class Attribute Details

.base_cache ⇒ Object (readonly)

class-wide base cache reader



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 21

def base_cache
  @base_cache
end

.cache_dir ⇒ Object

class-wide cache location



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 15

def cache_dir
  @cache_dir
end

.disk_cache_enabled ⇒ Object (readonly)

class-wide directive to write cache to disk



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 18

def disk_cache_enabled
  @disk_cache_enabled
end

Class Method Details

.clear ⇒ Object

Clear all caches



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 29

def clear
  delete_cache_files
  base_cache.each_value(&:clear)
end

.clear_if_config_changed(config) ⇒ Object

Compare the current config to the cached config If they are different, clear all caches

Returns nothing.



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 38

def clear_if_config_changed(config)
  config = config.inspect
  cache = Bridgetown::Cache.new "Bridgetown::Cache"
  return if cache.key?("config") && cache["config"] == config

  clear
  cache = Bridgetown::Cache.new "Bridgetown::Cache"
  cache["config"] = config
  nil
end

.disable_disk_cache! ⇒ Object

Disable Marshaling cached items to disk



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 24

def disable_disk_cache!
  @disk_cache_enabled = false
end

Instance Method Details

#[](key) ⇒ Object

Retrieve a cached item Raises if key does not exist in cache

Returns cached value



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 81

def [](key)
  return @cache[key] if @cache.key?(key)

  path = path_to(hash(key))
  raise unless disk_cache_enabled? && File.file?(path) && File.readable?(path)

  @cache[key] = load(path)
end

#[]=(key, value) ⇒ Object

Add an item to cache

Returns nothing.



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 93

def []=(key, value)
  @cache[key] = value
  return unless disk_cache_enabled?

  path = path_to(hash(key))
  value = new Hash(value) if value.is_a?(Hash) && !value.default.nil?
  dump(path, value)
rescue TypeError
  Bridgetown.logger.debug "Cache:", "Cannot dump object #{key}"
end

#clear ⇒ Object

Clear this particular cache



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 72

def clear
  delete_cache_files
  @cache.clear
end

#delete(key) ⇒ Object

Remove one particular item from the cache

Returns nothing.



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 117

def delete(key)
  @cache.delete(key)
  File.delete(path_to(hash(key))) if disk_cache_enabled?
end

#disk_cache_enabled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 136

def disk_cache_enabled?
  !!Bridgetown::Cache.disk_cache_enabled
end

#getset(key) ⇒ Object

If an item already exists in the cache, retrieve it. Else execute code block, and add the result to the cache, and return that result.



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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 106

def getset(key)
  self[key]
rescue StandardError
  value = yield
  self[key] = value
  value
end

#key?(key) ⇒ Boolean

Check if key already exists in this cache

Returns true if key exists in the cache, false otherwise

Returns:

  • (Boolean) 


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# File 'bridgetown-core/lib/bridgetown-core/cache.rb', line 125

def key?(key)
  # First, check if item is already cached in memory
  return true if @cache.key?(key)
  # Otherwise, it might be cached on disk
  # but we should not consider the disk cache if it is disabled
  return false unless disk_cache_enabled?

  path = path_to(hash(key))
  File.file?(path) && File.readable?(path)
end