Class: SpiceKernelHelper

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

Overview

The SpiceKernelHelper class is used to parse out mk files.

LROC mk files, as a whole, wayyy blow past the 1000 file handle limit.

This pares it down to only the kernels which we need.

This file is already 'required' when you run 'require "spice"'

Examples:

skh = SpiceKernelHelper.new

#Loop through an array of kernels, furnshing
#non-mk kernels directly

kernels.each do |kernel|
  if kernel =~ /mk$/
    skh.parse kernel
  else
    furnsh kernel
  end
end
furnsh *skh.base_kernels
furnsh *skh.detail_kernels(et2rb(start_et))

Instance Attribute Summary (collapse)

Instance Method Summary (collapse)

Constructor Details

- (SpiceKernelHelper) initialize

Returns a new instance of SpiceKernelHelper



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# File 'lib/spice_utils.rb', line 44

def initialize
  @base_kernels = []
  @detail_kernels = []
end

Instance Attribute Details

- (Object) base_kernels (readonly)

Returns the value of attribute base_kernels



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# File 'lib/spice_utils.rb', line 42

def base_kernels
  @base_kernels
end

Instance Method Details

- (Array<String>) detail_kernels(time)

Return kernels that cover a specified time

Parameters:

  • time (DateTime)

Returns:

  • (Array<String>) —

    An array of paths to kernels that cover the given time



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# File 'lib/spice_utils.rb', line 98

def detail_kernels time
  magic_sym = RUBY_VERSION =~ /^1\.8\./ ? :include? : :cover?
  @detail_kernels.find_all do |range, kernel|
    range.send(magic_sym, time) or range.send(magic_sym, time + 86400) or range.send(magic_sym, time - 86400)
  end.collect { |range, kernel| kernel }
end

- (Object) parse(file)

Parse an mk kernel and save kernel information that can be retrieved with #base_kernels or #detail_kernels

Parameters:

  • file (String) —

    Path to mk kernel



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# File 'lib/spice_utils.rb', line 54

def parse file
  mkdata = open(file).read.gsub(/\s+/, " ").strip

  mkdata =~ /PATH_VALUES\s*=\s*\(\s*([^)]+?)\s*\)/
  path_values = $1.split(/\s*,\s*/).collect {|v| v.gsub "'", ''}

  mkdata =~ /PATH_SYMBOLS\s*=\s*\(\s*([^)]+?)\s*\)/
  path_symbols = $1.split(/\s*,\s*/).collect {|v| v.gsub "'", ''}

  mkdata =~ /KERNELS_TO_LOAD\s*=\s*\(\s*([^)]+?)\s*\)/
  raw_kernels = $1

  path_symbols.zip(path_values).each do |key, value|
    raw_kernels.gsub!("$#{key}", value)
  end

  kernels = raw_kernels.split(/\s*,\s*/).collect {|v| v.gsub "'", ''}.collect

  kernels.each do |kernel|
    if kernel =~ /\w\w\w\w\w\w?_(\d\d\d\d\d\d\d)_(\d\d\d\d\d\d\d)_.*?.(bc|bsp)$/
      start_doy = $1
      stop_doy = $2

      if start_doy == stop_doy
        @base_kernels << kernel
      else
        start_time = Time.gm(start_doy[0..3].to_i, 1, 1, 0, 0, 0) + (start_doy[4..6].to_i-1)*24*60*60
        stop_time = Time.gm(stop_doy[0..3].to_i, 1, 1, 0, 0, 0) + (stop_doy[4..6].to_i-1)*24*60*60

        @detail_kernels << [start_time..stop_time, kernel]
      end
    else
      @base_kernels << kernel
    end
  end
end