Class: EveOnline::Api::FileCache

Inherits:
Object
  • Object
show all
Defined in:
lib/eve_online/api/file_cache.rb

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ FileCache

Returns a new instance of FileCache.



13
14
15
16
17
 
# File 'lib/eve_online/api/file_cache.rb', line 13

def initialize options = {}
  self.directory = options[:directory] || Dir.tmpdir
  self.logger = options[:logger] || NullLogger.instance
  self.boundary = options[:boundary] || '_FILE_CACHE_'
end

Instance Method Details

#expiration_date(file_path) ⇒ Object 



66
67
68
69
70
71
72
73
74
75
 
# File 'lib/eve_online/api/file_cache.rb', line 66

def expiration_date file_path
  logger.debug "Finding expiration date from #{file_path}"
  file_name = File.basename file_path
  logger.debug "File name = #{file_name}"
  timestamp, _ = file_name.split %r{#{boundary}}, 2
  logger.debug "Timestamp = #{timestamp}"
  time = Time.at timestamp.to_i
  logger.debug "Time = #{time}"
  time
end

#file_for(key) ⇒ Object 



41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
 
# File 'lib/eve_online/api/file_cache.rb', line 41

def file_for key
  logger.debug "Finding cache instances for #{key}"
  hex = Digest::SHA1.hexdigest key.to_s
  pattern = File.join directory, "*#{boundary}#{hex}"
  logger.debug "Glob for #{pattern} on disk"
  files = Dir.glob pattern
  logger.debug "Found #{files.size} cache instances"
  return unless files.any?
  request_time = Time.now
  logger.debug "Excluding expired instanced"
  live = files.select { |file_name|
    expiration_date = expiration_date file_name
    expiration_date > request_time
  }
  logger.debug "Found #{live.size} live cache instances"
  return unless live.any?
  logger.debug "Selecting most recent live instance"
  instance = live.sort_by { |file_name|
    expiration_date file_name
  }[-1]
  expiration_date = expiration_date instance
  logger.debug "Instance is #{instance}, expires = #{expiration_date}"
  instance
end

#get(key) ⇒ Object 



19
20
21
22
23
24
25
 
# File 'lib/eve_online/api/file_cache.rb', line 19

def get key
  logger.debug "Cache asked for #{key}"
  file = file_for key
  return unless file
  logger.debug "Reading from cache at #{file}"
  File.read file
end

#set(key, data, expiration_date) ⇒ Object 



27
28
29
30
31
32
33
34
35
36
37
38
39
 
# File 'lib/eve_online/api/file_cache.rb', line 27

def set key, data, expiration_date
  logger.debug "Asked to cache #{key} until #{expiration_date}"
  request_time = Time.now
  return unless expiration_date > request_time
  hex = Digest::SHA1.hexdigest key.to_s
  file_name = "#{expiration_date.to_i}#{boundary}#{hex}"
  file_path = File.join directory, file_name
  logger.debug "Realising cache instance as #{file_path}"
  File.open file_path, 'w' do |file|
    file.print data
  end
  logger.debug "Cached #{key} in #{file_path}"
end