Class: Gemstar::Cache

Inherits:
Object
  • Object
show all
Defined in:
lib/gemstar/cache.rb

Constant Summary collapse

MAX_CACHE_AGE =

1 day

60 * 60 * 24
CACHE_DIR = 
File.join(Gemstar::Config.home_directory, "cache")
@@initialized = 
false

Class Method Summary collapse

Class Method Details

.fetch(key, force: false, &block) ⇒ Object 



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# File 'lib/gemstar/cache.rb', line 19

def self.fetch(key, force: false, &block)
  init

  path = path_for(key)

  if !force && fresh?(path)
    content = File.read(path)
    return nil if content == "__404__"
    return content
  end

  begin
    data = block.call
    File.write(path, data || "__404__")
    data
  rescue
    File.write(path, "__404__")
    nil
  end
end

.flush! ⇒ Object 



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# File 'lib/gemstar/cache.rb', line 62

def self.flush!
  init

  flush_directory(CACHE_DIR)
end

.flush_directory(directory) ⇒ Object 



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# File 'lib/gemstar/cache.rb', line 68

def self.flush_directory(directory)
  return 0 unless Dir.exist?(directory)

  entries = Dir.children(directory)
  entries.each do |entry|
    FileUtils.rm_rf(File.join(directory, entry))
  end

  entries.count
end

.fresh?(path) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/gemstar/cache.rb', line 56

def self.fresh?(path)
  return false unless File.exist?(path)

  (Time.now - File.mtime(path)) <= MAX_CACHE_AGE
end

.init ⇒ Object 



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# File 'lib/gemstar/cache.rb', line 12

def self.init
  return if @@initialized

  FileUtils.mkdir_p(CACHE_DIR)
  @@initialized = true
end

.path_for(key) ⇒ Object 



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# File 'lib/gemstar/cache.rb', line 52

def self.path_for(key)
  File.join(CACHE_DIR, Digest::SHA256.hexdigest(key))
end

.peek(key) ⇒ Object 



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# File 'lib/gemstar/cache.rb', line 40

def self.peek(key)
  init

  path = path_for(key)
  return nil unless fresh?(path)

  content = File.read(path)
  return nil if content == "__404__"

  content
end