Class: CTioga2::Data::DataStack

Inherits:
Object
  • Object
show all
Includes:
Log
Defined in:
lib/ctioga2/data/stack.rb

Overview

This is the central class for acquisition and handling of Dataset objects, retrieved from from a Backends::BackendFactory.

TODO: provide real stack manipulation functions such as

  • interpolation: pops the last object from the stack and add its interpolated values on the element before.

  • mathematical functions on each column (DataColumn)

  • other stack-based operations.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Log

debug, error, fatal, #format_exception, #identify, info, init_logger, logger, set_level, #spawn, warn

Constructor Details

#initialize ⇒ DataStack

Creates a new DataStack object.



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# File 'lib/ctioga2/data/stack.rb', line 68

def initialize
  @stack = Array.new

  @named_datasets = Hash.new

  # Defaults to the 'text' backend
  @backend_factory = Data::Backends::BackendFactory.new('text')
end

Instance Attribute Details

#backend_factory ⇒ Object

The BackendFactory used for retrieving data from named sets.



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# File 'lib/ctioga2/data/stack.rb', line 50

def backend_factory
  @backend_factory
end

#dataset_hook ⇒ Object

A hook executed every time a dataset is pushed unto the stack using #add_dataset.

TODO: this string is parsed for each call to #add_dataset. Perhaps it would be good to provide a way to record a Command call, without parsing it from scratch ???

Although, with variables, that could be interesting to reparse everytime, since any change in the variables would be taken into account.



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# File 'lib/ctioga2/data/stack.rb', line 65

def dataset_hook
  @dataset_hook
end

#named_datasets ⇒ Object

Named datasets



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# File 'lib/ctioga2/data/stack.rb', line 53

def named_datasets
  @named_datasets
end

#stack ⇒ Object

The array containing all the Dataset used so far.



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# File 'lib/ctioga2/data/stack.rb', line 47

def stack
  @stack
end

Instance Method Details

#add_dataset(dataset, ignore_hooks = false) ⇒ Object

Adds a Dataset object onto the stack, running hooks if necessary.

Makes use of Plotmaker.plotmaker



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# File 'lib/ctioga2/data/stack.rb', line 142

def add_dataset(dataset, ignore_hooks = false)
  @stack << dataset
  if @dataset_hook && (! ignore_hooks)
    # TODO: error handling
    begin
      PlotMaker.plotmaker.interpreter.run_commands(@dataset_hook)
    rescue Exception => e
      error "There was a problem running the dataset hook '#{@dataset_hook}', disabling it"
      @dataset_hook = nil
      info "-> '#{format_exception e}'"
    end
  end
end

#add_to_dataset_hook(commands) ⇒ Object

Appends a set of commands to the dataset hook



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# File 'lib/ctioga2/data/stack.rb', line 157

def add_to_dataset_hook(commands)
  if @dataset_hook
    @dataset_hook << "\n#{commands}"
  else
    @dataset_hook = commands
  end
end

#concatenate_datasets(n = 2) ⇒ Object

Pops the last n datasets off the stack



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# File 'lib/ctioga2/data/stack.rb', line 176

def concatenate_datasets(n = 2)
  ds = @stack.pop
  raise "Nothing on the stack" unless ds
  (n-1).times do
    ds2 = @stack.pop
    raise "Not enough datasets on the stack" unless ds2
    ds << ds2
  end
  @stack.push(ds)
end

#get_datasets(set, options = {}) ⇒ Object

Performs expansion on the given set with the current backend, retrieves corresponding Dataset objects, pushes them onto the stack and returns them.

options is a Hash that can contain the options available to the ‘load’ command:

  • ‘name’ to name each element added to the stack. A %d will be replaced by the number of the dataset within the ones just added.

Additional members of the Hash are simply ignored.



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# File 'lib/ctioga2/data/stack.rb', line 89

def get_datasets(set, options = {})
  backend = @backend_factory.current
  retval = []
  i = 0
  for s in backend.expand_sets(set)
    ds = backend.dataset(s)
    add_dataset(ds, options['ignore_hooks'])

    # Selection
    if options['where']
      ds.select_formula!(options['where'])
    end

    retval << ds
    if options['name']
      @named_datasets[options['name'] % [i]] = ds
    end
    i += 1
  end
  return retval
end

#last ⇒ Object

Returns the last Dataset pushed onto the stack.



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# File 'lib/ctioga2/data/stack.rb', line 188

def last
  return @stack.last
end

#print_dataset(dataset, io) ⇒ Object

Writes the contents of the the given dataset (a DataSet object) to the given io stream.



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# File 'lib/ctioga2/data/stack.rb', line 167

def print_dataset(dataset, io)
  io.puts "# #{dataset.name}"
  io.puts "# #{dataset.column_names.join("\t")}"
  dataset.each_values do |i, *vals|
    io.puts vals.join("\t")
  end
end

#specified_dataset(options) ⇒ Object

Gets a dataset from the given options hash. If a ‘which’ key is present, it is used as an argument for #stored_dataset; else, -1 is used.



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# File 'lib/ctioga2/data/stack.rb', line 129

def specified_dataset(options)
  spec = if options && options['which']
           options['which']
         else
           -1
         end
  return stored_dataset(spec)
end

#stored_dataset(spec) ⇒ Object

Returns the stored dataset, either using its index in the stack, or its name in the dataset.



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# File 'lib/ctioga2/data/stack.rb', line 113

def stored_dataset(spec)
  if spec.is_a? Numeric or spec =~ /^\s*-?\d+\s*$/
    spec = spec.to_i
    return @stack[spec]
  else
    if @named_datasets.key? spec
      return @named_datasets[spec]
    else
      raise "Unkown named dataset from the stack: '#{spec}'"
    end
  end
end