Class: Madeleine::ZMarshal

Inherits:
Object
  • Object
show all
Defined in:
lib/madeleine/zmarshal.rb

Overview

Snapshot marshaller for compressed snapshots.

Compresses the snapshots created by another marshaller. Uses either Marshal (the default) or another supplied marshaller.

Uses zlib to do on-the-fly compression/decompression.

ZMarshal works with Ruby’s own Marshal and YAML, but not with SOAP marshalling.

Usage:

require 'madeleine'
require 'madeleine/zmarshal'

marshaller = Madeleine::ZMarshal.new(YAML)
madeleine = SnapshotMadeleine.new("my_example_storage", marshaller) {
  SomeExampleApplication.new()
}

Instance Method Summary collapse

Constructor Details

#initialize(marshaller = Marshal) ⇒ ZMarshal

Returns a new instance of ZMarshal.



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# File 'lib/madeleine/zmarshal.rb', line 32

def initialize(marshaller=Marshal)
  @marshaller = marshaller
end

Instance Method Details

#dump(system, stream) ⇒ Object 



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# File 'lib/madeleine/zmarshal.rb', line 50

def dump(system, stream)
  zstream = Zlib::GzipWriter.new(stream)
  begin
    @marshaller.dump(system, zstream)
  ensure
    zstream.finish
  end
  nil
end

#load(stream) ⇒ Object 



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# File 'lib/madeleine/zmarshal.rb', line 36

def load(stream)
  zstream = Zlib::GzipReader.new(stream)
  begin
    # Buffer into a string first, since GzipReader can't handle
    # Marshal's 0-sized reads and SOAP can't handle streams at all.
    # In a bright future we can revert to reading directly from the
    # stream again.
    buffer = zstream.read
    return @marshaller.load(buffer)
  ensure
    zstream.finish
  end
end