Class: FSDB::Format

Inherits:
Object
  • Object
show all
Defined in:
lib/fsdb/formats.rb

Overview

Formats are handled as instances rather than as subclasses so that they can be dynamically generated, serialized, etc. When defining a dump proc for a new format, be sure to perform the write with a single syswrite call to protect data consistency in case of exceptions.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Format

Returns a new instance of Format.



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# File 'lib/fsdb/formats.rb', line 9

def initialize(*args)
  @options = []; @patterns = []; @binary = false
  while arg = args.shift
    case arg
    when Symbol
      @options << arg
      eval "@#{arg} = true"  ## yech! use instance_variable_set in 1.8
    when Hash
      @name ||= arg[:name]
      @load ||= arg[:load]
      @dump ||= arg[:dump]
    else
      @patterns << arg
    end
  end
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/fsdb/formats.rb', line 8

def name
  @name
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/fsdb/formats.rb', line 8

def options
  @options
end

#patterns ⇒ Object

Returns the value of attribute patterns.



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# File 'lib/fsdb/formats.rb', line 8

def patterns
  @patterns
end

Instance Method Details

#===(path) ⇒ Object 



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# File 'lib/fsdb/formats.rb', line 37

def ===(path)
  @patterns.any? {|pat| pat === path}
end

#binary? ⇒ Boolean

Used only on Windows.

Returns:

  • (Boolean) 


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# File 'lib/fsdb/formats.rb', line 42

def binary?
  @binary
end

#dump(object, f, *opts) ⇒ Object 



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# File 'lib/fsdb/formats.rb', line 57

def dump(object, f, *opts)
  if @dump
    f.rewind; f.truncate(0)
    @dump[object, f]
    f.flush
  end
rescue StandardError => e
  raise e,
    "Format #{name} can't dump object at path #{f.path}: #{e.inspect}" +
    "\n\nObject is:\n#{object.inspect[0..1000]}\n\n"
end

#load(f) ⇒ Object 



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# File 'lib/fsdb/formats.rb', line 46

def load(f)
  @load[f] if @load
rescue Errno::EISDIR
  Formats::DIR_LOAD[f] ## any reason not to do this?
rescue Errno::ENOTDIR
  raise Database::NotDirError
rescue StandardError => e
  raise e,
    "Format #{name} can't load object at path #{f.path}: #{e.inspect}"
end

#when(*patterns) ⇒ Object

A convenient way to use a format for a different pattern. Duplicates the format and sets the patterns to the specified patterns.



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# File 'lib/fsdb/formats.rb', line 31

def when(*patterns)
  fmt = dup
  fmt.patterns = patterns
  fmt
end