Class: ContentData::ContentData

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

Overview

Content Data(CD) object holds files information as contents and instances Files info retrieved from hardware: checksum, size, time modification, server, device and path Those attributes are divided into content and instance attributes:

unique checksum, size are content attributes
time modification, server, device and path are instance attributes

The relationship between content and instances is 1:many meaning that a content can have instances in many servers. content also has time attribute, which has the value of the time of the first instance. This can be changed by using unify_time method which sets all time attributes for a content and it’s instances to the min time off all. Different files(instances) with same content(checksum), are grouped together under that content. Interface methods include:

iterate over contents and instances info,
unify time, add/remove instance, queries, merge, remove directory and more.

Content info data structure:

@contents_info = { Checksum -> [size, *instances*, content_modification_time] }
  *instances* = {[server,path] -> instance_modification_time }

Notes:

1. content_modification_time is the instance_modification_time of the first
   instances which was added to @contents_info

Instance Method Summary collapse

Constructor Details

#initialize(other = nil) ⇒ ContentData

Returns a new instance of ContentData.



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# File 'lib/content_data/content_data.rb', line 32

def initialize(other = nil)
  if other.nil?
    @contents_info = {}  # Checksum --> [size, paths-->time(instance), time(content)]
    @instances_info = {}  # location --> checksum to optimize instances query
  else
    @contents_info = other.clone_contents_info
    @instances_info = other.clone_instances_info  # location --> checksum to optimize instances query
  end
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 203

def ==(other)
  return false if other.nil?
  return false if @contents_info.length != other.contents_size
  other.each_instance { |checksum, size, content_mod_time, instance_mod_time, server, path|
    return false if instance_exists(path, server) != other.instance_exists(path, server)
    local_content_info = @contents_info[checksum]
    return false if local_content_info.nil?
    return false if local_content_info[0] != size
    return false if local_content_info[2] != content_mod_time
    #check instances
    local_instances =  local_content_info[1]
    return false if other.checksum_instances_size(checksum) != local_instances.length
    location = [server, path]
    local_instance_mod_time = local_instances[location]
    return false if local_instance_mod_time.nil?
    return false if local_instance_mod_time != instance_mod_time
  }
  true
end

#add_instance(checksum, size, server, path, modification_time) ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 138

def add_instance(checksum, size, server, path, modification_time)
  location = [server, path]
  content_info = @contents_info[checksum]
  if content_info.nil?
    @contents_info[checksum] = [size,
                                {location => modification_time},
                                modification_time]
  else
    if size != content_info[0]
      Log.warning('File size different from content size while same checksum')
      Log.warning("instance location:server:'#{location[0]}'  path:'#{location[1]}'")
      Log.warning("instance mod time:'#{modification_time}'")
    end
    #override file if needed
    content_info[0] = size
    instances = content_info[1]
    instances[location] = modification_time
  end
  @instances_info[location] = checksum
end

#checksum_instances_size(checksum) ⇒ Object 



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

def checksum_instances_size(checksum)
  content_info = @contents_info[checksum]
  return 0 if content_info.nil?
  content_info[1].length
end

#clone_contents_info ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 55

def clone_contents_info
  @contents_info.keys.inject({}) { |clone_contents_info, checksum|
    instances = @contents_info[checksum]
    size = instances[0]
    content_time = instances[2]
    instances_db = instances[1]
    instances_db_cloned = {}
    instances_db.keys.each { |location|
      instance_mtime = instances_db[location]
      instances_db_cloned[[location[0].clone,location[1].clone]]=instance_mtime
    }
    clone_contents_info[checksum] = [size,
                          instances_db_cloned,
                          content_time]
    clone_contents_info
  }
end

#clone_instances_info ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 48

def clone_instances_info
  @instances_info.keys.inject({}) { |clone_instances_info, location|
    clone_instances_info[[location[0].clone, location[1].clone]] = @instances_info[location].clone
    clone_instances_info
  }
end

#content_each_instance(checksum, &block) ⇒ Object

iterator of instances over specific content block is provided with: checksum, size, content modification time,

instance modification time, server and file path



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# File 'lib/content_data/content_data.rb', line 102

def content_each_instance(checksum, &block)
  content_info = @contents_info[checksum]
  content_info[1].keys.each {|location|
    # provide the block with: checksum, size, content modification time,instance modification time,
    #   server and path.
    instance_modification_time = content_info[1][location]
    block.call(checksum,content_info[0], content_info[2], instance_modification_time,
               location[0], location[1])
  }
end

#content_exists(checksum) ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 163

def content_exists(checksum)
  @contents_info.has_key?(checksum)
end

#contents_size ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 113

def contents_size()
  @contents_info.length
end

#each_content(&block) ⇒ Object

iterator over @contents_info data structure (not including instances) block is provided with: checksum, size and content modification time



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# File 'lib/content_data/content_data.rb', line 75

def each_content(&block)
  @contents_info.keys.each { |checksum|
    content_val = @contents_info[checksum]
    # provide checksum, size and content modification time to the block
    block.call(checksum,content_val[0], content_val[2])
  }
end

#each_instance(&block) ⇒ Object

iterator over @contents_info data structure (including instances) block is provided with: checksum, size, content modification time,

instance modification time, server and file path



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# File 'lib/content_data/content_data.rb', line 86

def each_instance(&block)
  @contents_info.keys.each { |checksum|
    content_info = @contents_info[checksum]
    content_info[1].keys.each {|location|
      # provide the block with: checksum, size, content modification time,instance modification time,
      #   server and path.
      instance_modification_time = content_info[1][location]
      block.call(checksum,content_info[0], content_info[2], instance_modification_time,
                 location[0], location[1])
    }
  }
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/content_data/content_data.rb', line 159

def empty?
  @contents_info.empty?
end

#from_file(filename) ⇒ Object

TODO validation that file indeed contains ContentData missing



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

def from_file(filename)
  lines = IO.readlines(filename)
  number_of_contents = lines[0].to_i
  i = 1 + number_of_contents
  number_of_instances = lines[i].to_i
  i += 1
  number_of_instances.times {
    if lines[i].nil?
      Log.warning("line ##{i} is nil !!!, Backing filename: #{filename} to #{filename}.bad")
      FileUtils.cp(filename, "#{filename}.bad")
      Log.warning("Lines:\n#{lines[i].join("\n")}")
    else
      parameters = lines[i].split(',')
      # bugfix: if file name consist a comma then parsing based on comma separating fails
      if (parameters.size > 5)
        (4..parameters.size-2).each do |i|
          parameters[3] = [parameters[3], parameters[i]].join(",")
        end
        (4..parameters.size-2).each do |i|
          parameters.delete_at(4)
        end
      end

      add_instance(parameters[0],
                   parameters[1].to_i,
                   parameters[2],
                   parameters[3],
                   DateTime.parse(parameters[4]).to_time.to_i)
    end
    i += 1
  }
end

#get_instance_mod_time(checksum, location) ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 131

def get_instance_mod_time(checksum, location)
  content_info = @contents_info[checksum]
  return nil if content_info.nil?
  instances = content_info[1]
  instance_time = instances[location]
end

#get_query(variable, params) ⇒ Object

TODO simplify conditions This mehod is experimental and shouldn't be used nil is used to define +/- infinity for to/from method arguments from/to values are exlusive in condition’a calculations Need to take care about ‘==’ operation that is used for object’s comparison. In need of case user should define it’s own ‘==’ implemementation.



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# File 'lib/content_data/content_data.rb', line 454

def get_query(variable, params)
  raise RuntimeError.new 'This method is experimental and shouldn\'t be used'

  exact = params['exact'].nil? ? Array.new : params['exact']
  from = params['from']
  to = params ['to']
  is_inside = params['is_inside']

  unless ContentInstance.new.instance_variable_defined?("@#{attribute}")
    raise ArgumentError "#{variable} isn't a ContentInstance variable"
  end

  if (exact.nil? && from.nil? && to.nil?)
    raise ArgumentError 'At least one of the argiments {exact, from, to} must be defined'
  end

  if (!(from.nil? || to.nil?) && from.kind_of?(to.class))
    raise ArgumentError 'to and from arguments should be comparable one with another'
  end

  # FIXME add support for from/to for Strings
  if ((!from.nil? && !from.kind_of?(Numeric.new.class))\
        || (!to.nil? && to.kind_of?(Numeric.new.class)))
    raise ArgumentError 'from and to options supported only for numeric values'
  end

  if (!exact.empty? && (!from.nil? || !to.nil?))
    raise ArgumentError 'exact and from/to options are mutually exclusive'
  end

  result_index = ContentData.new
  instances.each_value do |instance|
    is_match = false
    var_value = instance.instance_variable_get("@#{variable}")

    if exact.include? var_value
      is_match = true
    elsif (from.nil? || var_value > from) && (to.nil? || var_value < to)
      is_match = true
    end

    if (is_match && is_inside) || (!is_match && !is_inside)
      checksum = instance.checksum
      result_index.add_content(contents[checksum]) unless result_index.content_exists(checksum)
      result_index.add_instance instance
    end
  end
  result_index
end

#instance_exists(path, server) ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 167

def instance_exists(path, server)
  @instances_info.has_key?([server, path])
end

#instances_size ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 117

def instances_size()
  counter=0
  @contents_info.values.each { |content_info|
    counter += content_info[1].length
  }
  counter
end

#remove_content(checksum) ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 223

def remove_content(checksum)
  content_info = @contents_info[checksum]
  if content_info
    content_info[1].each_key { |location|
      @instances_info.delete(location)
    }
    @contents_info.delete(checksum)
  end
end

#remove_directory(server, dir_to_remove) ⇒ Object

removes all instances records which are located under input param: dir_to_remove. found records are removed from both @instances_info and @instances_info. input params: server & dir_to_remove - are used to check each instance unique key (called location) removes also contents, if a contents becomes empty after removing instances



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# File 'lib/content_data/content_data.rb', line 189

def remove_directory(server, dir_to_remove)
  @contents_info.keys.each { |checksum|
    instances =  @contents_info[checksum][1]
    instances.each_key { |location|
      if location[0] == server and location[1].scan(dir_to_remove).size > 0
        instances.delete(location)
        @instances_info.delete(location)
      end
    }
    @contents_info.delete(checksum) if instances.empty?
  }
end

#remove_instance(server, path) ⇒ Object

removes an instance record both in @instances_info and @instances_info. input params: server & path - are the instance unique key (called location) removes also the content, if content becomes empty after removing the instance



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# File 'lib/content_data/content_data.rb', line 174

def remove_instance(server, path)
  location = [server, path]
  checksum = @instances_info[location]
  content_info = @contents_info[checksum]
  return nil if content_info.nil?
  instances = content_info[1]
  instances.delete(location)
  @contents_info.delete(checksum) if instances.empty?
  @instances_info.delete(location)
end

#to_file(filename) ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 250

def to_file(filename)
  content_data_dir = File.dirname(filename)
  FileUtils.makedirs(content_data_dir) unless File.directory?(content_data_dir)
  file = File.open(filename, 'w')
  file.write("#{@contents_info.length}\n")
  each_content { |checksum, size, content_mod_time|
    file.write("#{checksum},#{size},#{Time.at(content_mod_time)}\n")
  }
  file.write("#{@instances_info.length}\n")
  each_instance { |checksum, size, _, instance_mod_time, server, path|
    file.write("#{checksum},#{size},#{server},#{path},#{Time.at(instance_mod_time)}\n")
  }
  file.close
end

#to_s ⇒ Object 



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# File 'lib/content_data/content_data.rb', line 233

def to_s
  return_str = ""
  contents_str = ""
  instances_str = ""
  each_content { |checksum, size, content_mod_time|
    contents_str << "%s,%d,%d\n" % [checksum, size, content_mod_time]
  }
  each_instance { |checksum, size, content_mod_time, instance_mod_time, server, path|
    instances_str <<  "%s,%d,%s,%s,%d\n" % [checksum, size, server, path, instance_mod_time]
  }
  return_str << "%d\n" % [@contents_info.length]
  return_str << contents_str
  return_str << "%d\n" % [@instances_info.length]
  return_str << instances_str
  return_str
end

#unify_time ⇒ Object

for each content, all time fields (content and instances) are replaced with the min time found, while going through all time fields.



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# File 'lib/content_data/content_data.rb', line 301

def unify_time()
  @contents_info.keys.each { |checksum|
    content_info = @contents_info[checksum]
    min_time_per_checksum = content_info[2]
    instances = content_info[1]
    instances.keys.each { |location|
      instance_mod_time = instances[location]
      if instance_mod_time < min_time_per_checksum
        min_time_per_checksum = instance_mod_time
      end
    }
    # update all instances with min time
    instances.keys.each { |location|
      instances[location] = min_time_per_checksum
    }
    # update content time with min time
    content_info[2] = min_time_per_checksum
  }
end

#unique_id ⇒ ID

Content Data unique identification

Returns:

  • (ID) —

    hash identification



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

def unique_id
  @instances_info.hash
end

#validate(params = nil) ⇒ Boolean

Validates index against file system that all instances hold a correct data regarding files that they represents.

There are two levels of validation, controlled by instance_check_level system parameter:

  • shallow - quick, tests instance for file existence and attributes.

  • deep - can take more time, in addition to shallow recalculates hash sum.

Parameters:

  • params (Hash) (defaults to: nil) —

    hash of parameters of validation, can be used to return additional data.

    Supported key/value combinations:

    • key is :failed value is ContentData used to return failed instances

Returns:

  • (Boolean) —

    true when index is correct, false otherwise

Raises:

  • (ArgumentError) —

    when instance_check_level is incorrect



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# File 'lib/content_data/content_data.rb', line 333

def validate(params = nil)
  # used to answer whether specific param was set
  param_exists = Proc.new do |param|
    !(params.nil? || params[param].nil?)
  end

  # used to process method parameters centrally
  process_params = Proc.new do |values|
    if param_exists.call(:failed)
      info = values[:details]
      unless info.nil?
        checksum = info[0]
        content_mtime = info[1]
        size = info[2]
        inst_mtime = info[3]
        server = info[4]
        file_path = info[5]
        params[:failed].add_instance(checksum, size, server, file_path, inst_mtime)
      end
    end
  end

  is_valid = true
  @contents_info.keys.each { |checksum|
    instances = @contents_info[checksum]
    content_size = instances[0]
    content_mtime = instances[2]
    instances[1].keys.each { |unique_path|
      instance_mtime = instances[1][unique_path]
      instance_info = [checksum, content_mtime, content_size, instance_mtime]
      instance_info.concat(unique_path)
      unless check_instance(instance_info)
        is_valid = false

        unless params.nil? || params.empty?
          process_params.call({:details => instance_info})
        end
      end
    }
  }
  is_valid
end