Class: HTTPDisk::Cache

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

Overview

Disk cache for cache_keys => response. Files are compressed.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Cache

Returns a new instance of Cache.



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# File 'lib/httpdisk/cache.rb', line 8

def initialize(options)
  @options = options

  # heavy sanity checking on arguments here
  if !dir.is_a?(String)
    raise ArgumentError, "expected :dir to be a string, not #{dir.inspect}"
  end
  if expires_in && !expires_in.is_a?(Integer)
    raise ArgumentError, "expected :expires_in to be an integer, not #{expires_in.inspect}"
  end

  %i[force force_errors].each do
    value = send(_1)
    if ![nil, true, false].include?(value)
      raise ArgumentError, "expected #{_1} to be a boolean, not #{value.inspect}"
    end
  end
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/httpdisk/cache.rb', line 6

def options
  @options
end

Instance Method Details

#diskpath(cache_key) ⇒ Object

Relative path for this cache_key based on the cache key



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# File 'lib/httpdisk/cache.rb', line 57

def diskpath(cache_key)
  File.join(dir, cache_key.diskpath)
end

#read(cache_key) ⇒ Object

Get cached response. If there is a cached error it will be raised.



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# File 'lib/httpdisk/cache.rb', line 36

def read(cache_key)
  payload_or_status = read0(cache_key)
  payload_or_status.is_a?(Symbol) ? nil : payload_or_status
end

#status(cache_key) ⇒ Object

Cache status for a cache_key, %i[error force hit miss stale]



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# File 'lib/httpdisk/cache.rb', line 42

def status(cache_key)
  payload_or_status = read0(cache_key, peek: true)
  return payload_or_status if payload_or_status.is_a?(Symbol)

  payload_or_status.error_999? ? :error : :hit
end

#write(cache_key, payload) ⇒ Object

Write response to the disk cache



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# File 'lib/httpdisk/cache.rb', line 50

def write(cache_key, payload)
  path = diskpath(cache_key)
  FileUtils.mkdir_p(File.dirname(path))
  Zlib::GzipWriter.open(path) { payload.write(_1) }
end