Module: Amp::Repositories::Stores

Extended by:
Stores
Included in:
Stores
Defined in:
lib/amp/repository/store.rb

Defined Under Namespace

Modules: FilenameCache Classes: BasicStore, EncodedOpener, EncodedStore, FilenameCacheStore, StoreError

Constant Summary collapse

WINDOWS_RESERVED_FILENAMES =

can’t name a file one of these on windows, apparently

%w(con prn aux nul com1
com2 com3 com4 com5 com6 com7 com8 com8 lpt1 lpt2
lpt3 lpt4 lpt5 lpt6 lpt7 lpt8 lpt9)
MAX_PATH_LEN_IN_HGSTORE = 
120
DIR_PREFIX_LEN = 
8
MAX_SHORTENED_DIRS_LEN = 
8 * (DIR_PREFIX_LEN + 1) - 4

Instance Method Summary collapse

Instance Method Details

#auxilliary_encode(path) ⇒ Object

Copypasta



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# File 'lib/amp/repository/store.rb', line 413

def auxilliary_encode(path)
  res = []
  path.split('/').each do |n|
    if n.any?
      base = n.split('.')[0]
      if !(base.nil?) && base.any? && WINDOWS_RESERVED_FILENAMES.include?(base)
        ec = "~%02x" % n[2,1].ord
        n = n[0..1] + ec + n[3..-1]
      end
      if ['.',' '].include? n[-1,1]
        n = n[0..-2] + ("~%02x" % n[-1,1].ord)
      end
    end
    res << n
  end
  res.join("/")
end

#decode_filename(s) ⇒ Object

Decodes an encoding performed by encode_filename

Parameters:

  • s (String) —

    an encoded file path

  • the (String) —

    decoded file path



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# File 'lib/amp/repository/store.rb', line 385

def decode_filename(s)
  cmap = illegal_character_map true
  dmap = {}
  cmap.each do |k, v|
    dmap[v] = k
  end
  
  i = 0
  result = []
  while i < s.size
    1.upto(3) do |l|
      if dmap[s[i..(i+l-1)]]
        result << dmap[s[i..(i+l-1)]]
        i += l
        break
      end
    end
  end
  result.join
end

#encode_filename(s, underscore = true) ⇒ String

Reversible encoding of the filename

Parameters:

  • s (String) —

    a file’s path you wish to encode

  • underscore (Boolean) (defaults to: true) —

    should we insert underscores when downcasing letters? (e.g. if true, “A” => “_a”)

Returns:

  • (String) —

    an encoded file path



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# File 'lib/amp/repository/store.rb', line 375

def encode_filename(s, underscore=true)
  cmap = illegal_character_map underscore
  s.split("").map {|c| cmap[c]}.join
end

#hybrid_encode(path) ⇒ String

uber encoding that’s straight up crazy. Max length of 120 means we have a non-reversible encoding, but since the FilenameCache only cares about name lookups, one-way is really all that matters!

Parameters:

  • path (String) —

    the path to encode

Returns:

  • (String) —

    an encoded path, with a maximum length of 120.



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# File 'lib/amp/repository/store.rb', line 449

def hybrid_encode(path)
  return path unless path =~ /data\//
  ndpath = path["data/".size..-1]
  res = "data/" + auxilliary_encode(encode_filename(ndpath))
  if res.size > MAX_PATH_LEN_IN_HGSTORE
    digest = path.sha1.hexdigest
    aep = auxilliary_encode(lower_encode(ndpath))
    root, ext = File.amp_split_extension aep
    parts = aep.split('/')
    basename = File.basename aep
    sdirs = []
    parts[0..-2].each do |p|
      d = p[0..(DIR_PREFIX_LEN-1)]
      
      d = d[0..-2] + "_" if " .".include?(d[-1,1])
      
      t = sdirs.join("/") + "/" + d
      break if t.size > MAX_SHORTENED_DIRS_LEN
    
      sdirs << d
    end
    dirs = sdirs.join("/")
    dirs += "/" if dirs.size > 0
    
    res = "dh/" + dirs + digest + ext
    space_left = MAX_PATH_LEN_IN_HGSTORE - res.size
    if space_left > 0
      filler = basename[0..(space_left-1)]
      res = "dh/" + dirs + filler + digest + ext
    end
  end
  return res
      
end

#illegal_character_map(underscore = true) ⇒ Object

Gets the basic character map that maps disallowed letters to allowable substitutes.

Parameters:

  • underscore (Boolean) (defaults to: true) —

    Should underscores be inserted in front of capital letters before we downcase them? (e.g. if true, “A” => “_a”)



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# File 'lib/amp/repository/store.rb', line 353

def illegal_character_map(underscore=true)
  e = '_'
  win_reserved = "\\:*?\"<>|".split("").map {|x| x.ord}
  cmap = {}; 0.upto(126) {|x| cmap[x.chr] = x.chr}
  ((0..31).to_a + (126..255).to_a + win_reserved).each do |x|
    cmap[x.chr] = "~%02x" % x
  end
  ((("A".ord)..("Z".ord)).to_a + [e.ord]).each do |x|
    cmap[x.chr] = e + x.chr.downcase if underscore
    cmap[x.chr] = x.chr.downcase     unless underscore
  end
  cmap
end

#lower_encode(s) ⇒ Object

Normal encoding, but without extra underscores in the filenames.



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# File 'lib/amp/repository/store.rb', line 433

def lower_encode(s)
  encode_filename s, false
end

#pick(requirements, path, opener, pathjoiner = nil) ⇒ Object

Picks which store to use, given a list of requirements.



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# File 'lib/amp/repository/store.rb', line 7

def pick(requirements, path, opener, pathjoiner=nil)
  pathjoiner ||= proc {|*args| File.join(args) }
  if requirements.include? 'store'
    if requirements.include? 'fncache'
      return FilenameCacheStore.new(path, opener, pathjoiner)
    else
      return EncodedStore.new(path, EncodedOpener, pathjoiner)
    end
  else
    return BasicStore.new(path, opener, pathjoiner)
  end
end