Class: Defog::File

Inherits:
File
  • Object
show all
Defined in:
lib/defog/file.rb

Overview

Create a Defog::File proxy instance via Defog::Proxy#file, such as

defog = Defog::Proxy.new(:provider => :AWS, :aws_access_key_id => access_key, ...)

defog.file("key/to/my/file", "w") do |file|
   # ... access the proxy file ...
end

or

file = defog.file("key/to/my/file", "w")
# ... access the proxy file ...
file.close

Defog::File inherits from ::File, so you can act on the proxy file using ordinary IO methods, such as

defog.file("key", "r") do |file|
   file.readlines
end

You can also access the proxy file via its path, allowing things such as

defog.file("image100x100.jpg", "w") do |file|
   system("convert souce.png -scale 100x100 #{file.path}")
end

(Note that the proxy file path has the same file extension as the cloud key string.)

Upon closing the proxy file, in normal use the cloud storage gets synchronized and the proxy deleted. See File#close for more details.

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}, &block) ⇒ File

:nodoc:



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# File 'lib/defog/file.rb', line 35

def initialize(opts={}, &block) #:nodoc:
  opts = opts.keyword_args(:handle => :required, :mode => :required, :persist => :optional)
  @handle = opts.handle
  @persist = opts.persist

  key = @handle.key
  proxy_path = @handle.proxy_path
  proxy_path.dirname.mkpath
  case opts.mode
  when "r"
    create_proxy
  when "w", "w+"
    @upload = true
  when "r+", "a", "a+"
    create_proxy
    @upload = true
  else
    raise ArgumentError, "Invalid mode #{opts.mode.inspect}"
  end

  super(proxy_path, opts.mode, &block)
end

Instance Method Details

#close(opts = {}) ⇒ Object

Closes the proxy file and synchronizes the cloud storage (if it was opened as writeable) then deletes the proxy file.

Synchronization can be suppressed by passing the option

:synchronize => false

Synchronization will also be implicitly suppressed if the proxy file was deleted before this call, e.g., via ::File.unlink(file.path).

Whether the proxy file gets deleted vs persisted after the close can be set by passing the option

:persist => true or false

(This will override the setting of :persist passed to Proxy#file)



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# File 'lib/defog/file.rb', line 82

def close(opts={})
  opts = opts.keyword_args(:persist => @persist, :synchronize => true)
  super()
  if @handle.proxy_path.exist?
    upload_proxy if @upload and opts.synchronize
    @handle.proxy_path.unlink unless opts.persist
  end
  @handle.proxy.close_proxy_file(@handle)
end

#create_proxy ⇒ Object 



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# File 'lib/defog/file.rb', line 58

def create_proxy
  @handle.proxy.open_proxy_file(@handle)
  @handle.proxy.fog_wrapper.get_file(@handle.key, @handle.proxy_path)
end

#upload_proxy ⇒ Object 



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# File 'lib/defog/file.rb', line 63

def upload_proxy
  @handle.proxy.fog_wrapper.put_file(@handle.key, @handle.proxy_path) 
end