Class: Treet::Repo

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

Direct Known Subclasses

Gitrepo

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path, opts = {}) ⇒ Repo

Returns a new instance of Repo.

Raises:

  • (Errno::ENOENT) 


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# File 'lib/treet/repo.rb', line 6

def initialize(path, opts = {})
  raise Errno::ENOENT, "Missing or invalid source path #{path}" unless File.directory?(path)

  @root = path
end

Instance Attribute Details

#root ⇒ Object (readonly)

Returns the value of attribute root.



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# File 'lib/treet/repo.rb', line 4

def root
  @root
end

Class Method Details

.filefor(keyname) ⇒ Object

patch keys can look like

name.first
emails[]

(address syntax has been eliminated, we recognize array elements by matching the entire content)



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# File 'lib/treet/repo.rb', line 24

def self.filefor(keyname)
  if keyname =~ /\[/
    keyname = keyname.match(/^(.*)\[\]$/).captures.first
    [keyname, '', nil]
  elsif keyname =~ /\./
    # subelement
    # negative lookbehind; don't split on a dot at beginning of string
    filename,field = keyname.split(/(?<!^)\./)
    ['.', filename, field]
  else
    ['.', keyname]
  end
end

Instance Method Details

#compare(target) ⇒ Object 



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# File 'lib/treet/repo.rb', line 16

def compare(target)
  Treet::Hash.diff(to_hash, target.to_hash)
end

#patch(diffs) ⇒ Object

Patching a repo is not the same as patching a hash. Make the changes directly to the data files.



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# File 'lib/treet/repo.rb', line 40

def patch(diffs)
  @hash = nil # invalidate any cached image

  Dir.chdir(root) do
    diffs.each do |diff|
      flag, key, v1, _ = diff
      # if key =~ /\[/
      #   keyname = key.match(/^(.*)\[\]$/).captures
      # elsif key =~ /\./
      #   keyname, subkey = key.match(/^(.*)\.(.*)$/).captures
      # else
      #   keyname = key
      # end

      dirname, filename, fieldname = Treet::Repo.filefor(key)
      filepath = "#{dirname}/#{filename}"

      case flag
      when '~'
        # change a value in place
        # load the current data & overwrite with the new value
        # idempotent: this will overwrite the file with the same contents
        if fieldname
          # hash entry
          data = File.exists?(filepath) ? JSON.load(File.open(filepath)) : {}
          data[fieldname] = v1
          File.open(filepath, "w") {|f| f << JSON.pretty_generate(data)}
        else
          # string entry
          File.open(filepath, "w") {|f| f << v1}
        end

      when '+'
        # add something
        if fieldname
          # writing a value into a hash
          # idempotent: this will overwrite the file with the same contents
          data = File.exists?(filepath) ? JSON.load(File.open(filepath)) : {}
          data[fieldname] = v1
          Dir.mkdir(dirname) unless Dir.exists?(dirname)
          File.open(filepath, "w") {|f| f << JSON.pretty_generate(data)}
        else
          # writing an entire hash into an array entry
          # idempotent: this will overwrite the file with the same contents
          subfile = "#{dirname}/#{Treet::Hash.digestify(v1)}"
          Dir.mkdir(dirname) unless Dir.exists?(dirname)
          case v1
          when Hash
            # hash entry
            File.open(subfile, "w") {|f| f << JSON.pretty_generate(v1)}
          else
            # string entry - create empty file with this name
            FileUtils.touch(subfile)
          end
        end

      when '-'
        # remove something
        if fieldname
          # this is a key in a subhash
          if File.exists?(filepath)
            # if the subhash is missing, there's nothing to remove, so do nothing (for idempotence)
            data = JSON.load(File.open(filepath))
            data.delete(fieldname)
            if data.empty?
              # all keys have been removed, clean up the file
              File.delete(filename)
            else
              File.open(filepath, "w") {|f| f << JSON.pretty_generate(data)}
            end
          end
        elsif dirname == "."
          # this is a top-level string
          File.delete(filename) if File.exists?(filename) # need the existence check for idempotence
        else
          # this is an array, we look for a match on the entire contents via digest
          subfile = "#{dirname}/#{Treet::Hash.digestify(v1)}"
          File.delete(subfile) if File.exists?(subfile) # need the existence check for idempotence
          # TODO: if dirname is now empty, should it be removed? is that worthwhile?
        end
      end
    end
  end

  to_hash # ?? return the patched data? or no return value? true/false for success?
end

#to_hash ⇒ Object 



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# File 'lib/treet/repo.rb', line 12

def to_hash
  expand(root)
end