Class: Library::Ledger

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/library/ledger.rb

Overview

Ledger class track available libraries by library name. It is essentially a hash object, but with a special way of storing them to track versions. Each have key is the name of a library, as a String, and each value is either a Library object, if that particular version is active, or an Array of available versions of the library if inactive.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Ledger

Returns a new instance of Ledger.



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# File 'lib/library/ledger.rb', line 22

def initialize
  @table = Hash.new(){ |h,k| h[k] = [] }
end

Instance Method Details

#[](name) ⇒ Library, Array

Get library or library version set by name.

Parameters:

  • name (String) —

    Name of library.

Returns:

  • (Library, Array) —

    Library or lihbrary set referenced by name.



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# File 'lib/library/ledger.rb', line 97

def [](name)
  @table[name.to_s]
end

#[]=(name, library) ⇒ Object

Set ledger entry.

Parameters:

  • Name (String) —

    of library.

Raises:

  • (TypeError) —

    If library is not a Library object.



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# File 'lib/library/ledger.rb', line 108

def []=(name, library)
  raise TypeError unless Library === library

  @table[name.to_s] = library
end

#acivate_requirements(library, development = false, checklist = {}) ⇒ Object (private)

Activate library requirements.

@todo: checklist is used to prevent possible infinite recursion, but

it might be better to put a flag in Library instead.



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# File 'lib/library/ledger.rb', line 610

def acivate_requirements(library, development=false, checklist={})
  reqs = development ? library.requirements : library.runtime_requirements

  checklist[library] = true

  reqs.each do |req|
    name = req['name']
    vers = req['version']

    library = activate(name, vers)

    acivate_requirements(library, development, checklist) unless checklist[library]
  end
end

#activate(name, constraint = nil) ⇒ Library

TODO:

Should we also check $“? Eg. ‘return false if $”.include?(path)`.

Activate a library, retrieving a Library instance by name, or name and version, and ensuring only that instance will be returned for all subsequent requests. Libraries are singleton, so once activated the same object is always returned.

This method will raise a LoadError if the name is not found.

Note that activating all runtime requirements of a library being activated was considered, but decided against. There’s no reason to activatea library until it is actually needed. However this is not so when testing, or verifying available requirements, so other methods are provided such as ‘#activate_requirements`.

Parameters:

  • name (String) —

    Name of library.

  • constraint (String) (defaults to: nil) —

    Valid version constraint.

Returns:

  • (Library) —

    The activated Library object.

Raises:



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# File 'lib/library/ledger.rb', line 227

def activate(name, constraint=nil)
  raise LoadError, "no such library -- #{name}" unless key?(name)

  library = self[name]

  if Library === library
    if constraint
      unless library.version.satisfy?(constraint)
        raise Library::VersionConflict, library
      end
    end
  else # library is an array of versions
    if constraint
      verscon = Version::Constraint.parse(constraint)
      library = library.select{ |lib| verscon.compare(lib.version) }.max
    else
      library = library.max
    end
    unless library
      raise VersionError, "no library version -- #{name} #{constraint}"
    end

    self[name] = library #constrain(library)
  end

  library
end

#add(lib) ⇒ Library Also known as: <<

Add a library to the ledger.

Parameters:

  • A (String, Library) —

    path to a ruby library or a Library object.

Returns:

  • (Library) —

    Added library object.



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# File 'lib/library/ledger.rb', line 34

def add(lib)
  case lib
  when Library
    add_library(lib)
  else
    add_location(lib)
  end
end

#add_library(library) ⇒ Library

Add library to ledger given a Library object.

Returns:

  • (Library) —

    Added library object.

Raises:

  • (TypeError) 


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# File 'lib/library/ledger.rb', line 73

def add_library(library)
  #begin
    raise TypeError unless Library === library

    entry = @table[library.name]

    if Array === entry
      entry << library unless entry.include?(library)
    end
  #rescue Exception => error
  #  warn error.message if ENV['debug']
  #end

  library
end

#add_location(location) ⇒ Library

Add library to ledger given a location.

Returns:

  • (Library) —

    Added library object.



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# File 'lib/library/ledger.rb', line 50

def add_location(location)
  begin
    library = Library.new(location)

    entry = @table[library.name]

    if Array === entry
      entry << library unless entry.include?(library)
    else
      # todo: what to do here?
    end
  rescue Exception => error
    warn error.message if ENV['debug']
  end

  library
end

#constrain(name, contraint) ⇒ Array

Limit versions of a library to the given constraint. Unlike ‘#activate` this does not reduce the possible versions to a single library, but only reduces the number of possibilites.

Parameters:

  • name (String) —

    Name of library.

  • constraint (String) —

    Valid version constraint.

Returns:

  • (Array) —

    List of conforming versions.



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# File 'lib/library/ledger.rb', line 190

def constrain(name, contraint)
  libraries = self[name]

  return nil unless Array === libraries

  vers = libraries.select do |library|
    library.version.satisfy?(constraint)
  end

  self[name] = vers
end

#dotruby?(path) ⇒ Boolean (private)

Does the directory have a ‘.ruby` file?

Returns:

  • (Boolean) 


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# File 'lib/library/ledger.rb', line 628

def dotruby?(path)
  File.file?(File.join(path, '.ruby'))
end

#each(&block) ⇒ Object

Iterate over each ledger entry.



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# File 'lib/library/ledger.rb', line 127

def each(&block)
  @table.each(&block)
end

#expound_paths(*entries) ⇒ Object (private)

For flexible priming, this method can be used to recursively lookup library locations.

If a given path is a file, it will considered a lookup “roll”, such that each line entry in the file is considered another path to be expounded upon.

If a given path is a directory, it will be returned if it is a valid Ruby library location, otherwise each subdirectory will be checked to see if it is a valid Ruby library location, and returned if so.

If, on the other hand, a given path is a file glob pattern, the pattern will be expanded and those paths will expounded upon in turn.



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# File 'lib/library/ledger.rb', line 559

def expound_paths(*entries)
  paths = []

  entries.each do |entry|
    entry = entry.strip

    next if entry.empty?
    next if entry.start_with?('#')

    if File.directory?(entry)
      if library_path?(entry)
        paths << entry
      else
        subpaths = Dir.glob(File.join(entry, '*/'))
        subpaths.each do |subpath|
          paths << subpath if library_path?(subpath)
        end
      end
    elsif File.file?(entry)
      paths.concat(expound_paths(*File.readlines(entry)))
    else
      glob_paths = Dir.glob(entry)
      if glob_paths.first != entry
        paths.concat(expound_paths(*glob_paths))
      end
    end
  end

  paths
end

#find_any(path, options = {}) ⇒ Feature, Array

Brute force variation of ‘#find` looks through all libraries for a matching features. This serves as the fallback method if `#find` comes up empty.

Parameters:

  • path (String) —

    path name for which to search

  • options (Hash) (defaults to: {}) —

    Search options.

Options Hash (options):

  • :latest (Boolean) —

    Search only the active or most current version of any library.

  • :suffix (Boolean) —

    Automatically try standard extensions if pathname has none.

  • :legacy (Boolean) —

    Do not match within library’s name directory, eg. ‘lib/foo/*`.

Returns:

  • (Feature, Array) —

    Matching feature(s).



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# File 'lib/library/ledger.rb', line 360

def find_any(path, options={})
  options = options.merge(:main=>true)

  latest = options[:latest]

  # TODO: Perhaps the selected and unselected should be kept in separate lists?
  unselected, selected = *partition{ |name, libs| Array === libs }

  # broad search of pre-selected libraries
  selected.each do |(name, lib)|
    if ftr = lib.find(path, options)
      next if Library.load_stack.last == ftr
      return ftr
    end
  end

  # finally a broad search on unselected libraries
  unselected.each do |(name, libs)|
    libs = libs.sort
    libs = [libs.first] if latest
    libs.each do |lib|
      ftr = lib.find(path, options)
      return ftr if ftr
    end
  end

  nil
end

#find_feature(path, options = {}) ⇒ Object

Find matching library features. This is the “mac daddy” method used by the #require and #load methods to find the specified path among the various libraries and their load paths.



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# File 'lib/library/ledger.rb', line 260

def find_feature(path, options={})
  path   = path.to_s

  #suffix = options[:suffix]
  search = options[:search]
  local  = options[:local]
  from   = options[:from]

  $stderr.print path if monitor?  # debugging

  # absolute, home or current path
  #
  # NOTE: Ideally we would try to find a matching path among avaliable libraries
  # so that the library can be activated, however this would probably add a 
  # too much overhead and will by mostly a YAGNI, so we forgo any such
  # functionality, at least for now. 
  case path[0,1]
  when '/', '~', '.'
    $stderr.puts "  (absolute)" if monitor?  # debugging
    return nil
  end

  # from explicit library
  if from
    lib = library(from)
    ftr = lib.find(path, options)
    raise LoadError, "no such file to load -- #{path}" unless file
    $stderr.puts "  (direct)" if monitor?  # debugging
    return ftr
  end

  # check the load stack (TODO: just last or all?)
  if local
    if last = $LOAD_STACK.last
    #$LOAD_STACK.reverse_each do |feature|
      lib = last.library
      if ftr = lib.find(path, options)
        unless $LOAD_STACK.include?(ftr)  # prevent recursive loading
          $stderr.puts "  (2 stack)" if monitor?  # debugging
          return ftr
        end
      end
    end
  end

  name, fname = ::File.split_root(path)

  # if the head of the path is the library
  if fname
    lib = Library[name]
    if lib && ftr = lib.find(path, options) || lib.find(fname, options)
      $stderr.puts "  (3 indirect)" if monitor?  # debugging
      return ftr
    end
  end

  # plain library name?
  if !fname && lib = Library.instance(path)
    if ftr = lib.default  # default feature to load
      $stderr.puts "  (5 plain library name)" if monitor?  # debugging
      return ftr
    end
  end

  # fallback to brute force search
  #if search #or legacy
    #options[:legacy] = true
    if ftr = find_any(path, options)
      $stderr.puts "  (6 brute search)" if monitor?  # debugging
      return ftr
    end
  #end

  $stderr.puts "  (7 fallback)" if monitor?  # debugging

  nil
end

#gemspec?(path) ⇒ Boolean (private)

Does a path have a ‘.gemspec` file? This is fallback measure if a .ruby file is not found.

Returns:

  • (Boolean) 


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# File 'lib/library/ledger.rb', line 635

def gemspec?(path)
  glob = File.file?(File.join(path, '{,*}.gemspec'))
  Dir[glob].first
end

#glob(match, options = {}) ⇒ Array

TODO:

Should this return list of Feature objects instead of file paths?

Search for all matching library files that match the given pattern. This could be of useful for plugin loader.

Parameters:

  • options (Hash) (defaults to: {}) —

    Glob matching options.

Options Hash (options):

  • :latest (Boolean) —

    Search only activated libraries or the most recent version of a given library.

Returns:

  • (Array) —

    Matching file paths.



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# File 'lib/library/ledger.rb', line 456

def glob(match, options={})
  latest = options[:latest]

  matches = []

  each do |name, libs|
    case libs
    when Array
      libs = libs.sort
      libs = [libs.first] if latest
    else
      libs = [libs]
    end
      
    libs.each do |lib|
      lib.loadpath.each do |path|
        find = File.join(lib.location, path, match)
        list = Dir.glob(find)
        list = list.map{ |d| d.chomp('/') }
        matches.concat(list)
      end
    end
  end

  matches
end

#inspect ⇒ String

Inspection string.

Returns:

  • (String) —

    Inspection string.



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# File 'lib/library/ledger.rb', line 173

def inspect
  @table.inspect
end

#isolate(name, constraint = nil) ⇒ Ledger

Reduce the ledger to only those libraries the given library requires.

Parameters:

  • name (String) —

    The name of the primary library.

  • constraint (String) (defaults to: nil) —

    The version constraint string.

Returns:



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# File 'lib/library/ledger.rb', line 494

def isolate(name, constraint=nil)
  library = activate(name, constraint)

  # TODO: shouldn't this be done in #activate ?
  acivate_requirements(library)

  unused = []
  each do |name, libs|
    ununsed << name if Array === libs
  end
  unused.each{ |name| @table.delete(name) }

  self
end

#key?(name) ⇒ Boolean

Checks ledger for presents of library by name.

Returns:

  • (Boolean) 


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# File 'lib/library/ledger.rb', line 145

def key?(name)
  @table.key?(name.to_s)
end

#keys ⇒ Array<String>

Get a list of names of all libraries in the ledger.

Returns:

  • (Array<String>) —

    list of library names



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# File 'lib/library/ledger.rb', line 154

def keys
  @table.keys
end

#library_path?(path) ⇒ Boolean (private)

TODO:

Support gem home location.

Is a directory a Ruby library?

Returns:

  • (Boolean) 


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# File 'lib/library/ledger.rb', line 595

def library_path?(path)
  dotruby?(path) || (ENV['RUBYLIBS_GEMSPEC'] && gemspec?(path))
end

#monitor? ⇒ Boolean

State of monitoring setting. This is used for debugging.

Returns:

  • (Boolean) 


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# File 'lib/library/ledger.rb', line 17

def monitor?
  ENV['monitor'] || $MONITOR
end

#prime(*paths) ⇒ Ledger

Load up the ledger with a given set of paths and add an instance of the special ‘RubyLibrary` class after that.

Parameters:

  • paths (Array)

Options Hash (*paths):

Returns:

  • (Ledger) —

    The primed ledger.



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# File 'lib/library/ledger.rb', line 520

def prime(*paths)
  options = Hash === paths.last ? paths.pop : {}

  paths = expound_paths(*paths) if options[:expound]

  require 'library/rubylib'

  paths.each do |path|
    begin
      add_location(path) if library_path?(path)
    rescue => err
      $stderr.puts err.message if ENV['debug']
    end
  end

  add_library(RubyLibrary.new)

  self
end

#replace(table) ⇒ Object 



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# File 'lib/library/ledger.rb', line 117

def replace(table)
  initialize
  table.each do |name, value|
    @table[name.to_s] = value
  end
end

#search(path, options = {}) ⇒ Feature, Array

Brute force search looks through all libraries for matching features. This is the same as #find_any, but returns a list of matches rather then the first matching feature found.

Parameters:

  • path (String) —

    path name for which to search

  • options (Hash) (defaults to: {}) —

    Search options.

Options Hash (options):

  • :latest (Boolean) —

    Search only the active or most current version of any library.

  • :suffix (Boolean) —

    Automatically try standard extensions if pathname has none.

  • :legacy (Boolean) —

    Do not match within library’s name directory, eg. ‘lib/foo/*`.

Returns:

  • (Feature, Array) —

    Matching feature(s).



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# File 'lib/library/ledger.rb', line 411

def search(path, options={})
  options = options.merge(:main=>true)

  latest = options[:latest]

  matches = []

  # TODO: Perhaps the selected and unselected should be kept in separate lists?
  unselected, selected = *partition{ |name, libs| Array === libs }

  # broad search of pre-selected libraries
  selected.each do |(name, lib)|
    if ftr = lib.find(path, options)
      next if Library.load_stack.last == ftr
      matches << ftr
    end
  end

  # finally a broad search on unselected libraries
  unselected.each do |(name, libs)|
    libs = [libs.sort.first] if latest
    libs.each do |lib|
      ftr = lib.find(path, options)
      matches << ftr if ftr
    end
  end

  matches.uniq
end

#size ⇒ Fixnum

Size of the ledger is the number of libraries available.

Returns:

  • (Fixnum) —

    Size of the ledger.



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# File 'lib/library/ledger.rb', line 136

def size
  @table.size
end

#values ⇒ Array<Library,Array>

Get a list of libraries and library version sets in the ledger.

Returns:

  • (Array<Library,Array>) —

    List of libraries and library version sets.



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# File 'lib/library/ledger.rb', line 164

def values
  @table.values
end