Module: LineCache

Defined in:
lib/linecache.rb

Overview

module LineCache

A module to read and cache lines of a Ruby program.

Defined Under Namespace

Classes: LineCacheInfo

Constant Summary collapse

VERSION = 
'1.2'
@@file_cache =

The file cache. The key is a name as would be given by Ruby for __FILE__. The value is a LineCacheInfo object.

{}
@@script_cache = 
{}
@@ruby_highlighter =

Used for CodeRay syntax highlighting

nil
@@file2file_remap =

Maps a string filename (a String) to a key in @@file_cache (a String).

One important use of @@file2file_remap is mapping the a full path of a file into the name stored in @@file_cache or given by Ruby’s __FILE__. Applications such as those that get input from users, may want canonicalize a file name before looking it up. This map gives a way to do that.

Another related use is when a template system is used. Here we’ll probably want to remap not only the file name but also line ranges. Will probably use this for that, but I’m not sure.

{}
@@file2file_remap_lines = 
{}
@@script2file = 
{}

Class Method Summary collapse

Class Method Details

.cache(file_or_script, reload_on_change = false) ⇒ Object

Cache file name or script object if it’s not already cached. Return the expanded filename for it in the cache if a filename, or the script, or nil if we can’t find the file.



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# File 'lib/linecache.rb', line 193

def cache(file_or_script, reload_on_change=false)
  if file_or_script.kind_of?(String)
    cache_file(file_or_script, reload_on_change)
  else
    cache_script(file_or_script)
  end
end

.cache_file(filename, reload_on_change = false, opts = {}) ⇒ Object

Cache filename if it’s not already cached. Return the expanded filename for it in the cache or nil if we can’t find the file.



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# File 'lib/linecache.rb', line 204

def cache_file(filename, reload_on_change=false, opts={})
  if @@file_cache.member?(filename)
    checkcache(filename) if reload_on_change
  else
    opts[:use_script_lines] = true
    update_cache(filename, opts)
  end
  if @@file_cache.member?(filename)
    @@file_cache[filename].path
  else
    nil
  end
end

.cache_script(script, opts = {}) ⇒ Object

Cache script if it’s not already cached.



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# File 'lib/linecache.rb', line 183

def cache_script(script, opts={})
  if !@@script_cache.member?(script)
    update_script_cache(script, opts)
  end
  script
end

.cached?(file_or_script) ⇒ Boolean

Return true if file_or_script is cached

Returns:

  • (Boolean) 


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# File 'lib/linecache.rb', line 219

def cached?(file_or_script)
  if file_or_script.kind_of?(String) 
    @@file_cache.member?(map_file(file_or_script))
  else 
    cached_script?(file_or_script)
  end
end

.cached_files ⇒ Object

Return an array of cached file names



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# File 'lib/linecache.rb', line 140

def cached_files()
  @@file_cache.keys
end

.cached_script?(script) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/linecache.rb', line 227

def cached_script?(script)
    @@script_cache.member?(script)
end

.checkcache(filename = nil, opts = {}) ⇒ Object

Discard cache entries that are out of date. If filename is nil all entries in the file cache @@file_cache are checked. If we don’t have stat information about a file, which can happen if the file was read from __SCRIPT_LINES but no corresponding file is found, it will be kept. Return a list of invalidated filenames. nil is returned if a filename was given but not found cached.



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# File 'lib/linecache.rb', line 150

def checkcache(filename=nil, opts={})

  if !filename
    filenames = @@file_cache.keys()
  elsif @@file_cache.member?(filename)
    filenames = [filename]
  else
    return nil
  end

  result = []
  for filename in filenames
    next unless @@file_cache.member?(filename)
    path = @@file_cache[filename].path
    if File.exist?(path)
      cache_info = @@file_cache[filename].stat
      stat = File.stat(path)
      if cache_info
        if stat && 
            (cache_info.size != stat.size or cache_info.mtime != stat.mtime)
          result << filename
          update_cache(filename, opts)
        end
      else
        result << filename
        update_cache(filename, opts)
      end
    end
  end
  return result
end

.clear_file_cache(filename = nil) ⇒ Object

Clear the file cache entirely.



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# File 'lib/linecache.rb', line 109

def clear_file_cache(filename=nil)
  if filename 
    if @@file_cache[filename]
      @@file_cache.delete(filename)
    end
  else
    @@file_cache = {}
    @@file2file_remap = {}
    @@file2file_remap_lines = {}
  end
end

.clear_file_format_cache ⇒ Object

Remove syntax-formatted lines in the cache. Use this when you change the CodeRay syntax or Token formatting and want to redo how files may have previously been syntax marked.



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# File 'lib/linecache.rb', line 125

def clear_file_format_cache
  @@file_cache.each_pair do |fname, cache_info|
    cache_info.lines.each_pair do |format, lines|
      next if :plain == format
      @@file_cache[fname].lines[format] = nil
    end
  end
end

.clear_script_cache ⇒ Object

Clear the script cache entirely.



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# File 'lib/linecache.rb', line 135

def clear_script_cache()
  @@script_cache = {}
end

.compiled_method(filename) ⇒ Object

Return any compiled method saved for a filename.



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# File 'lib/linecache.rb', line 351

def compiled_method(filename)
  if (file = map_file(filename)) && @@file_cache[file]
    return @@file_cache[file].compiled_method 
  else
    return nil
  end
end

.empty?(filename) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/linecache.rb', line 231

def empty?(filename)
  filename=map_file(filename)
  !!@@file_cache[filename].lines[:plain]
end

.getline(file_or_script, line_number, opts = {}) ⇒ Object

Get line line_number from file named filename. Return nil if there was a problem. If a file named filename is not found, the function will look for it in the $: array.

Examples:

lines = LineCache::getline('/tmp/myfile.rb')
# Same as above
$: << '/tmp'
lines = LineCache.getlines('myfile.rb')



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# File 'lib/linecache.rb', line 247

def getline(file_or_script, line_number, opts={})
  lines = 
    if file_or_script.kind_of?(String)
      filename = map_file(file_or_script)
      filename, line_number = map_file_line(filename, line_number)
      getlines(filename, opts)
    else
      script_getlines(file_or_script)
    end
  if lines and (1..lines.size) === line_number
      return lines[line_number-1]
  else
      return nil
  end
end

.getlines(filename, opts = {}) ⇒ Object

Read lines of filename and cache the results. However filename was previously cached use the results from the cache. Return nil if we can’t get lines



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# File 'lib/linecache.rb', line 290

def getlines(filename, opts={})
  filename = map_file(filename)
  checkcache(filename) if opts[:reload_on_change]
  format = opts[:output] || :plain
  if @@file_cache.member?(filename)
    lines = @@file_cache[filename].lines
    if opts[:output] && !lines[format]
      lines[format] = 
        highlight_string(lines[:plain].join(''), format).split(/\n/)
    end
    return lines[format]
  else
    opts[:use_script_lines] = true
    update_cache(filename, opts)
    if @@file_cache.member?(filename)
      return @@file_cache[filename].lines[format]
    else
      return nil
    end
  end
end

.highlight_string(string, output_type) ⇒ Object 



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# File 'lib/linecache.rb', line 312

def highlight_string(string, output_type)
  require 'rubygems'
  begin
    require 'coderay'
    require 'term/ansicolor'
  rescue LoadError
    return string
  end
  @@ruby_highlighter ||= CodeRay::Duo[:ruby, output_type]
  @@ruby_highlighter.encode(string)
end

.map_file(file) ⇒ Object 



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# File 'lib/linecache.rb', line 409

def map_file(file)
  @@file2file_remap[file] ? @@file2file_remap[file] : file
end

.map_file_line(file, line) ⇒ Object 



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# File 'lib/linecache.rb', line 430

def map_file_line(file, line)
  if @@file2file_remap_lines[file]
    @@file2file_remap_lines[file].each do |from_file, range, start|
      if range === line
        from_file = from_file || file 
        return [from_file, start+line-range.begin] 
      end
    end
  end
  return [map_file(file), line]
end

.map_script(script) ⇒ Object 



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# File 'lib/linecache.rb', line 413

def map_script(script)
  if @@script2file[script] 
    @@script2file[script] 
  else 
    # Doc says there's new takes an optional string parameter
    # But it doesn't work for me
    sha1 = Digest::SHA1.new
    string = script.eval_source
    sha1 << script.eval_source
    tempfile = Tempfile.new(["eval-#{sha1.hexdigest[0...7]}-", '.rb'])
    tempfile.open.puts(string)
    tempfile.close
    @@script2file[script] = tempfile.path
    tempfile.path
  end
end

.path(filename) ⇒ Object

Return full filename path for filename



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# File 'lib/linecache.rb', line 325

def path(filename)
  return unless filename.kind_of?(String)
  filename = map_file(filename)
  return nil unless @@file_cache.member?(filename)
  @@file_cache[filename].path
end

.remap_file(from_file, to_file) ⇒ Object 



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# File 'lib/linecache.rb', line 332

def remap_file(from_file, to_file)
  @@file2file_remap[from_file] = to_file
  cache_file(to_file)
end

.remap_file_lines(from_file, to_file, range, start) ⇒ Object 



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# File 'lib/linecache.rb', line 337

def remap_file_lines(from_file, to_file, range, start)
  range = (range..range) if range.kind_of?(Fixnum)
  to_file = from_file unless to_file
  if @@file2file_remap_lines[to_file] 
    # FIXME: need to check for overwriting ranges: whether
    # they intersect or one encompasses another.
    @@file2file_remap_lines[to_file] << [from_file, range, start]
  else
    @@file2file_remap_lines[to_file]  = [[from_file, range, start]]
  end
end

.remove_script_temps ⇒ Object 



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# File 'lib/linecache.rb', line 100

def remove_script_temps
  @@script2file.values.each do |filename|
    File.unlink(filename) if File.exist?(filename)
  end
end

.script_getlines(script, opts = {}) ⇒ Object

Read lines of script and cache the results. However script was previously cached use the results from the cache. Return nil if we can’t get lines



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# File 'lib/linecache.rb', line 266

def script_getlines(script, opts={})
  format = opts[:output] || :plain
  line_formats = 
    if @@script_cache.member?(script)
      @@script_cache[script].lines
    else
      update_script_cache(script, opts)
      if @@script_cache.member?(script)
        @@script_cache[script].lines
      else
        nil
      end
    end
  return nil unless line_formats
  if format != :plain && !line_formats[format]
    highlight_string(line_formats[:plain].join('')).split(/\n/)
  else
    line_formats[format]
  end
end

.script_is_eval?(script) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/linecache.rb', line 442

def script_is_eval?(script)
  !!script.eval_source
end

.sha1(filename) ⇒ Object

Return SHA1 of filename.



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# File 'lib/linecache.rb', line 360

def sha1(filename)
  filename = map_file(filename)
  return nil unless @@file_cache.member?(filename)
  return @@file_cache[filename].sha1.hexdigest if 
    @@file_cache[filename].sha1
  sha1 = Digest::SHA1.new
  @@file_cache[filename].lines[:plain].each do |line|
    sha1 << line + "\n"
  end
  @@file_cache[filename].sha1 = sha1
  sha1.hexdigest
end

.size(file_or_script) ⇒ Object

Return the number of lines in filename



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# File 'lib/linecache.rb', line 374

def size(file_or_script)
  cache(file_or_script)
  if file_or_script.kind_of?(String)
    file_or_script = map_file(file_or_script)
    return nil unless @@file_cache.member?(file_or_script)
    @@file_cache[file_or_script].lines[:plain].length
  else
    return nil unless @@script_cache.member?(file_or_script)
    @@script_cache[file_or_script].lines[:plain].length
  end
end

.stat(filename) ⇒ Object

Return File.stat in the cache for filename.



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# File 'lib/linecache.rb', line 387

def stat(filename)
  return nil unless @@file_cache.member?(filename)
  @@file_cache[filename].stat
end

.trace_line_numbers(filename, reload_on_change = false) ⇒ Object

Return an Array of breakpoints in filename. The list will contain an entry for each distinct line event call so it is possible (and possibly useful) for a line number appear more than once.



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# File 'lib/linecache.rb', line 397

def trace_line_numbers(filename, reload_on_change=false)
  fullname = cache(filename, reload_on_change)
  return nil unless fullname
  e = @@file_cache[filename]
  unless e.line_numbers
    e.line_numbers = 
      TraceLineNumbers.lnums_for_str_array(e.lines[:plain])
    e.line_numbers = false unless e.line_numbers
  end
  e.line_numbers
end

.update_cache(filename, opts = {}) ⇒ Object

Update a cache entry. If something’s wrong, return nil. Return true if the cache was updated and false if not. If opts is true, use that as the source for the lines of the file



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# File 'lib/linecache.rb', line 464

def update_cache(filename, opts={})
  return nil unless filename

  @@file_cache.delete(filename)
  path = File.expand_path(filename)
  
  if File.exist?(path)
    stat = File.stat(path)
  elsif File.basename(filename) == filename
    # try looking through the search path.
    stat = nil
    for dirname in $:
      path = File.join(dirname, filename)
      if File.exist?(path)
          stat = File.stat(path)
          break
      end
    end
    return false unless stat
  end
  begin
    fp = File.open(path, 'r')
    raw_string = fp.read
    fp.rewind
    lines = {:plain => fp.readlines}
    fp.close()
    lines[opts[:output]] = 
      highlight_string(raw_string, opts[:output]).split(/\n/) if 
      opts[:output]
  rescue 
    ##  print '*** cannot open', path, ':', msg
    return nil
  end
  @@file_cache[filename] = 
    LineCacheInfo.new(File.stat(path), nil, lines, path, nil, 
                      opts[:compiled_method])
  @@file2file_remap[path] = filename
  return true
end

.update_script_cache(script, opts) ⇒ Object

Update a cache entry. If something is wrong, return nil. Return true if the cache was updated and false if not.



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# File 'lib/linecache.rb', line 448

def update_script_cache(script, opts)
  return false unless script_is_eval?(script)
  string = opts[:string] || script.eval_source
  lines = {:plain => string.split(/\n/)}
  lines[opts[:output]] = highlight_string(string, opts[:output]) if
    opts[:output]
  @@script_cache[script] = 
    LineCacheInfo.new(nil, nil, lines, nil, opts[:sha1], 
                      opts[:compiled_method])
  return true
end