Class: Rcsv

Inherits:
Object
  • Object
show all
Defined in:
lib/rcsv.rb,
lib/rcsv/version.rb,
ext/rcsv/rcsv.c

Defined Under Namespace

Classes: ParseError

Constant Summary collapse

BOOLEAN_FALSE = 
[nil, false, 0, 'f', 'false']
VERSION = 
"0.3.1"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(write_options = {}) ⇒ Rcsv

Returns a new instance of Rcsv.



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

def initialize(write_options = {})
  @write_options = write_options
  @write_options[:column_separator] ||= ','
  @write_options[:newline_delimiter] ||= $INPUT_RECORD_SEPARATOR
  @write_options[:header] ||= false

  @quote = '"'
  @escaped_quote = @quote * 2
  @quotable_chars = Regexp.new('[%s%s%s]' % [
    Regexp.escape(@write_options[:column_separator]),
    Regexp.escape(@write_options[:newline_delimiter]),
    Regexp.escape(@quote)
  ])
end

Instance Attribute Details

#write_options ⇒ Object (readonly)

Returns the value of attribute write_options.



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# File 'lib/rcsv.rb', line 9

def write_options
  @write_options
end

Class Method Details

.parse(csv_data, options = {}, &block) ⇒ Object 



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# File 'lib/rcsv.rb', line 13

def self.parse(csv_data, options = {}, &block)
  #options = {
    #:column_separator => "\t",
    #:only_listed_columns => true,
    #:header => :use, # :skip, :none
    #:offset_rows => 10,
    #:columns => {
      #'a' => { # can be 0, 1, 2, ... -- column position
        #:alias => :a, # only for hashes
        #:type => :int,
        #:default => 100,
        #:match => '10'
      #},
      #...
    #}
  #}

  options[:header] ||= :use
  raw_options = {}

  raw_options[:col_sep] = options[:column_separator] && options[:column_separator][0] || ','
  raw_options[:quote_char] = options[:quote_char] && options[:quote_char][0] || '"'
  raw_options[:offset_rows] = options[:offset_rows] || 0
  raw_options[:nostrict] = options[:nostrict]
  raw_options[:parse_empty_fields_as] = options[:parse_empty_fields_as]
  raw_options[:buffer_size] = options[:buffer_size] || 1024 * 1024 # 1 MiB

  if csv_data.is_a?(String)
    csv_data = StringIO.new(csv_data)
  elsif !(csv_data.respond_to?(:each_line) && csv_data.respond_to?(:read))
    inspected_csv_data = csv_data.inspect
    raise ParseError.new("Supplied CSV object #{inspected_csv_data[0..127]}#{inspected_csv_data.size > 128 ? '...' : ''} is neither String nor looks like IO object.")
  end

  if csv_data.respond_to?(:external_encoding)
    raw_options[:output_encoding] = csv_data.external_encoding.to_s
  end

  initial_position = csv_data.pos

  case options[:header]
  when :use
    header = self.raw_parse(StringIO.new(csv_data.each_line.first), raw_options).first
    raw_options[:offset_rows] += 1
  when :skip
    header = (0..(csv_data.each_line.first.split(raw_options[:col_sep]).count)).to_a
    raw_options[:offset_rows] += 1
  when :none
    header = (0..(csv_data.each_line.first.split(raw_options[:col_sep]).count)).to_a
  end

  raw_options[:row_as_hash] = options[:row_as_hash] # Setting after header parsing

  if options[:columns]
    only_rows = []
    except_rows = []
    row_defaults = []
    column_names = []
    row_conversions = ''

    header.each do |column_header|
      column_options = options[:columns][column_header]
      if column_options
        if (options[:row_as_hash])
          column_names << (column_options[:alias] || column_header)
        end

        row_defaults << column_options[:default] || nil

        only_rows << case column_options[:match]
        when Array
          column_options[:match]
        when nil
          nil
        else
          [column_options[:match]]
        end

        except_rows << case column_options[:not_match]
        when Array
          column_options[:not_match]
        when nil
          nil
        else
          [column_options[:not_match]]
        end

        row_conversions << case column_options[:type]
        when :int
          'i'
        when :float
          'f'
        when :string
          's'
        when :bool
          'b'
        when nil
          's' # strings by default
        else
          fail "Unknown column type #{column_options[:type].inspect}."
        end
      elsif options[:only_listed_columns]
        column_names << nil
        row_defaults << nil
        only_rows << nil
        except_rows << nil
        row_conversions << ' '
      else
        column_names << column_header
        row_defaults << nil
        only_rows << nil
        except_rows << nil
        row_conversions << 's'
      end
    end

    raw_options[:column_names] = column_names if options[:row_as_hash]
    raw_options[:only_rows] = only_rows unless only_rows.compact.empty?
    raw_options[:except_rows] = except_rows unless except_rows.compact.empty?
    raw_options[:row_defaults] = row_defaults unless row_defaults.compact.empty?
    raw_options[:row_conversions] = row_conversions
  end

  csv_data.pos = initial_position
  return self.raw_parse(csv_data, raw_options, &block)
end

.raw_parse(*args) ⇒ Object

The main method that handles parsing



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# File 'ext/rcsv/rcsv.c', line 455

static VALUE rb_rcsv_raw_parse(int argc, VALUE * argv, VALUE self) {
  struct rcsv_metadata meta;
  VALUE csvio, options, option;
  VALUE ensure_container = rb_ary_new(); /* [] */

  struct csv_parser cp;
  unsigned char csv_options = CSV_STRICT_FINI | CSV_APPEND_NULL;

  /* Setting up some sane defaults */
  meta.row_as_hash = false;
  meta.empty_field_is_nil = false;
  meta.skip_current_row = false;
  meta.encoding_index = -1;
  meta.num_columns = 0;
  meta.current_col = 0;
  meta.current_row = 0;
  meta.offset_rows = 0;
  meta.num_only_rows = 0;
  meta.num_except_rows = 0;
  meta.num_row_defaults = 0;
  meta.num_row_conversions = 0;
  meta.only_rows = NULL;
  meta.except_rows = NULL;
  meta.row_defaults = NULL;
  meta.row_conversions = NULL;
  meta.column_names = NULL;
  meta.result = (VALUE[]){rb_ary_new()}; /* [] */

  /* csvio is required, options is optional (pun intended) */
  rb_scan_args(argc, argv, "11", &csvio, &options);

  /* options ||= {} */
  if (NIL_P(options)) {
    options = rb_hash_new();
  }

  /* First of all, we parse libcsv-related params so that it fails early if something is wrong with them */

  /* By default, parsing is strict */
  option = rb_hash_aref(options, ID2SYM(rb_intern("nostrict")));
  if (!option || (option == Qnil)) {
    csv_options |= CSV_STRICT;
  }

  /* By default, empty strings are treated as Nils and quoted empty strings are treated as empty Ruby strings */
  option = rb_hash_aref(options, ID2SYM(rb_intern("parse_empty_fields_as")));
  if ((option == Qnil) || (option == ID2SYM(rb_intern("nil_or_string")))) {
    csv_options |= CSV_EMPTY_IS_NULL;
  } else if (option == ID2SYM(rb_intern("nil"))) {
    meta.empty_field_is_nil = true;
  } else if (option == ID2SYM(rb_intern("string"))) {
    meta.empty_field_is_nil = false;
  } else {
    rb_raise(rcsv_parse_error, "The only valid options for :parse_empty_fields_as are :nil, :string and :nil_or_string, but %s was supplied.", RSTRING_PTR(rb_inspect(option)));
  }

  /* rb_ensure() only expects callback functions to accept and return VALUEs */
  /* This ugly hack converts C pointers into Ruby Fixnums in order to pass them in Array */
  rb_ary_push(ensure_container, options);               /* [options] */
  rb_ary_push(ensure_container, csvio);                 /* [options, csvio] */
  rb_ary_push(ensure_container, LONG2NUM((long)&meta)); /* [options, csvio, &meta] */
  rb_ary_push(ensure_container, LONG2NUM((long)&cp));   /* [options, csvio, &meta, &cp] */

  /* Try to initialize libcsv */
  if (csv_init(&cp, csv_options) == -1) {
    rb_raise(rcsv_parse_error, "Couldn't initialize libcsv");
  }

  /* From now on, cp handles allocated data and should be free'd on exit or exception */
  rb_ensure(rcsv_raw_parse, ensure_container, rcsv_free_memory, ensure_container);

  /* Remove the last row if it's empty. That happens if CSV file ends with a newline. */
  if (RARRAY_LEN(*(meta.result)) && /* meta.result.size != 0 */
      RARRAY_LEN(rb_ary_entry(*(meta.result), -1)) == 0) {
    rb_ary_pop(*(meta.result));
  }

  if (rb_block_given_p()) {
    return Qnil; /* STREAMING */
  } else {
    return *(meta.result); /* Return accumulated result */
  }
}

Instance Method Details

#generate_header ⇒ Object 



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# File 'lib/rcsv.rb', line 162

def generate_header
  return @write_options[:columns].map { |c|
    c[:name].to_s
  }.join(@write_options[:column_separator]) << @write_options[:newline_delimiter]
end

#generate_row(row) ⇒ Object 



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# File 'lib/rcsv.rb', line 168

def generate_row(row)
  column_separator = @write_options[:column_separator]
  csv_row = ''
  max_index = row.size - 1

  row.each_with_index do |field, index|
    unquoted_field = process(field, @write_options[:columns] && @write_options[:columns][index])
    csv_row << (unquoted_field.match(@quotable_chars) ? "\"#{unquoted_field.gsub(@quote, @escaped_quote)}\"" : unquoted_field)
    csv_row << column_separator unless index == max_index
  end

  return csv_row << @write_options[:newline_delimiter]
end

#write(io, &block) ⇒ Object 



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# File 'lib/rcsv.rb', line 155

def write(io, &block)
  io.write generate_header if @write_options[:header]
  while row = yield
    io.write generate_row(row)
  end
end