Class: Ferret::Index::FieldInfos

Inherits:
Object
  • Object
show all
Defined in:
lib/ferret/index/field_infos.rb

Overview

Access to the Field Info file that describes document fields and whether or not they are indexed. Each segment has a separate Field Info file. Objects of this class are thread-safe for multiple readers, but only one thread can be adding documents at a time, with no other reader or writer threads accessing this object.

Constant Summary collapse

NOT_A_FIELD =

-1 in java int

0xffffffff

Instance Method Summary collapse

Constructor Details

#initialize(dir = nil, name = nil) ⇒ FieldInfos

Construct a FieldInfos object using the directory and the name of the file InputStream

dir

The directory to open the InputStream from

name

The name of the file to open the InputStream from in the Directory



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# File 'lib/ferret/index/field_infos.rb', line 17

def initialize(dir = nil, name = nil)
  @fi_array = []
  @fi_hash = {}
  if dir and dir.exists?(name)
    input = dir.open_input(name)
    begin
      read(input)
    ensure
      input.close()
    end
  end
end

Instance Method Details

#[](index) ⇒ Object

Retrieve the field_info object by either field number or field name.



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# File 'lib/ferret/index/field_infos.rb', line 97

def [](index)
  if index.is_a? Integer
    if index == NOT_A_FIELD || index < 0 # < 0 is for C extensions
      return FieldInfo.new("", false, NOT_A_FIELD, false)
    end
    return @fi_array[index]
  else
    return @fi_hash[index]
  end
end

#add(name, indexed = true, store_term_vector = false, store_position = false, store_offset = false) ⇒ Object

If the field is not yet known, adds it. If it is known, checks to make sure that the indexed flag is the same as was given previously for this field. If not - marks it as being indexed. Same goes for the TermVector parameters.

name

The name of the field

indexed

true if the field is indexed

store_term_vector

true if the term vector should be stored

store_position

true if the positions should be stored

store_offset

true if the offsets should be stored



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# File 'lib/ferret/index/field_infos.rb', line 64

def add(name,
        indexed = true,
        store_term_vector = false,
        store_position = false,
        store_offset = false)
  fi = @fi_hash[name]
  if (fi == nil)
    fi = add_internal(name, indexed, store_term_vector, store_position, store_offset)
  else
    if (fi.indexed? != indexed)
      fi.indexed = true             # once indexed, always index
    end
    if (fi.store_term_vector? != store_term_vector)
      fi.store_term_vector = true   # once vector, always vector
    end
    if (fi.store_positions? != store_position)
      fi.store_position = true # once vector, always vector
    end
    if (fi.store_offsets? != store_offset)
      fi.store_offset = true   # once vector, always vector
    end
  end
  return fi
end

#add_doc_fields(doc) ⇒ Object Also known as: <<

Automatically adds all of the fields from the document if they haven’t been added already. Or it will update the values.



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# File 'lib/ferret/index/field_infos.rb', line 32

def add_doc_fields(doc)
  doc.all_fields.each do |field|
    add(field.name,
        field.indexed?,
        field.store_term_vector?,
        field.store_positions?,
        field.store_offsets?)
  end
end

#add_fields(names, indexed = true, store_term_vector = false, store_position = false, store_offset = false) ⇒ Object

Calls the 5 param add method to add all the names in the collection



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# File 'lib/ferret/index/field_infos.rb', line 44

def add_fields(names, 
              indexed = true,
              store_term_vector = false,
              store_position = false,
              store_offset = false)
  names.each do |name|
    add(name, indexed, store_term_vector, store_position, store_offset)
  end
end

#each ⇒ Object

Iterate through the field_info objects



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# File 'lib/ferret/index/field_infos.rb', line 116

def each()
  @fi_array.each() {|fi| yield(fi) }
end

#each_with_index ⇒ Object

Iterate through the field_info objects including the index



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# File 'lib/ferret/index/field_infos.rb', line 121

def each_with_index()
  @fi_array.each_with_index() {|fi, i| yield(fi, i) }
end

#field_number(name) ⇒ Object

Returns the number of the field that goes by the field name that is passed. If there is no field of this name then -1 is returned



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# File 'lib/ferret/index/field_infos.rb', line 91

def field_number(name)
  fi = @fi_hash[name]
  return fi ? fi.number : NOT_A_FIELD
end

#has_vectors? ⇒ Boolean

Return true if any of the fields have store_term_vector? set to true

Returns:

  • (Boolean) 


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# File 'lib/ferret/index/field_infos.rb', line 134

def has_vectors?()
  @fi_array.each() { |fi| return true if fi.store_term_vector? }
  return false
end

#name(index) ⇒ Object 



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# File 'lib/ferret/index/field_infos.rb', line 108

def name(index)
  if index == NOT_A_FIELD || index < 0 # < 0 is for C extensions
    return ""
  end
  return self[index].name
end

#size ⇒ Object

Get the number of field_infos in this object.

NOTE: There is a default empty field always added at the start. This may later be used to set the default values for a field.



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# File 'lib/ferret/index/field_infos.rb', line 129

def size()
  return @fi_array.size()
end

#write_to_dir(dir, name) ⇒ Object

Write the field_infos to a file specified by name in dir.

dir

the directory to write the fieldinfos to

name

the name of the file to write to.



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# File 'lib/ferret/index/field_infos.rb', line 143

def write_to_dir(dir, name)
  output = dir.create_output(name)
  begin
    write(output)
  ensure
    output.close()
  end
end