Object
This class provides a complete interface to CSV files and data. It offers tools to enable you to read and write to and from Strings or IO objects, as needed.
FasterCSV.foreach("path/to/file.csv") do |row| # use row here... end
arr_of_arrs = FasterCSV.read("path/to/file.csv")
FasterCSV.parse("CSV,data,String") do |row| # use row here... end
arr_of_arrs = FasterCSV.parse("CSV,data,String")
FasterCSV.open("path/to/file.csv", "w") do |csv| csv << ["row", "of", "CSV", "data"] csv << ["another", "row"] # ... end
csv_string = FasterCSV.generate do |csv| csv << ["row", "of", "CSV", "data"] csv << ["another", "row"] # ... end
csv_string = ["CSV", "data"].to_csv # to CSV csv_array = "CSV,String".parse_csv # from CSV
FCSV { |csv_out| csv_out << %w{my data here} } # to $stdout FCSV(csv = "") { |csv_str| csv_str << %w{my data here} } # to a String FCSV($stderr) { |csv_err| csv_err << %w{my data here} } # to $stderr FCSV($stdin) { |csv_in| csv_in.each { |row| p row } } # from $stdin
csv = FCSV.new(io, options) # ... read (with gets() or each()) from and write (with <<) to csv here ...
The version of the installed library.
A FieldInfo Struct contains details about a field’s position in the data source it was read from. FasterCSV will pass this Struct to some blocks that make decisions based on field structure. See FasterCSV.convert_fields() for an example.
index | The zero-based index of the field in its row. |
line | The line of the data source this row is from. |
header | The header for the column, when available. |
A Regexp used to find and convert some common Date formats.
A Regexp used to find and convert some common DateTime formats.
This Hash holds the built-in converters of FasterCSV that can be accessed by name. You can select Converters with FasterCSV.convert() or through the options Hash passed to FasterCSV::new().
:integer | Converts any field Integer() accepts. |
:float | Converts any field Float() accepts. |
:numeric | A combination of :integer and :float. |
:date | Converts any field Date::parse() accepts. |
:date_time | Converts any field DateTime::parse() accepts. |
:all | All built-in converters. A combination of :date_time and :numeric. |
This Hash is intetionally left unfrozen and users should feel free to add values to it that can be accessed by all FasterCSV objects.
To add a combo field, the value should be an Array of names. Combo fields can be nested with other combo fields.
This Hash holds the built-in header converters of FasterCSV that can be accessed by name. You can select HeaderConverters with FasterCSV.header_convert() or through the options Hash passed to FasterCSV::new().
:downcase | Calls downcase() on the header String. |
:symbol | The header String is downcased, spaces are replaced with underscores, non-word characters are dropped, and finally to_sym() is called. |
This Hash is intetionally left unfrozen and users should feel free to add values to it that can be accessed by all FasterCSV objects.
To add a combo field, the value should be an Array of names. Combo fields can be nested with other combo fields.
The options used when no overrides are given by calling code. They are:
:col_sep | "," |
:row_sep | :auto |
:quote_char | '"' |
:converters | nil |
:unconverted_fields | nil |
:headers | false |
:return_headers | false |
:header_converters | nil |
:skip_blanks | false |
:force_quotes | false |
This method will build a drop-in replacement for many of the standard CSV methods. It allows you to write code like:
begin require "faster_csv" FasterCSV.build_csv_interface rescue LoadError require "csv" end # ... use CSV here ...
This is not a complete interface with completely identical behavior. However, it is intended to be close enough that you won’t notice the difference in most cases. CSV methods supported are:
foreach()
open()
parse()
readlines()
Be warned that this interface is slower than vanilla FasterCSV due to the extra layer of method calls. Depending on usage, this can slow it down to near CSV speeds.
# File lib/faster_csv.rb, line 874 874: def self.build_csv_interface 875: Object.const_set(:CSV, Class.new).class_eval do 876: def self.foreach(path, rs = :auto, &block) # :nodoc: 877: FasterCSV.foreach(path, :row_sep => rs, &block) 878: end 879: 880: def self.generate_line(row, fs = ",", rs = "") # :nodoc: 881: FasterCSV.generate_line(row, :col_sep => fs, :row_sep => rs) 882: end 883: 884: def self.open(path, mode, fs = ",", rs = :auto, &block) # :nodoc: 885: if block and mode.include? "r" 886: FasterCSV.open(path, mode, :col_sep => fs, :row_sep => rs) do |csv| 887: csv.each(&block) 888: end 889: else 890: FasterCSV.open(path, mode, :col_sep => fs, :row_sep => rs, &block) 891: end 892: end 893: 894: def self.parse(str_or_readable, fs = ",", rs = :auto, &block) # :nodoc: 895: FasterCSV.parse(str_or_readable, :col_sep => fs, :row_sep => rs, &block) 896: end 897: 898: def self.parse_line(src, fs = ",", rs = :auto) # :nodoc: 899: FasterCSV.parse_line(src, :col_sep => fs, :row_sep => rs) 900: end 901: 902: def self.readlines(path, rs = :auto) # :nodoc: 903: FasterCSV.readlines(path, :row_sep => rs) 904: end 905: end 906: end
# File lib/faster_csv.rb, line 12 12: def self.const_missing(*_) 13: raise NotImplementedError, "Please switch to Ruby 1.9's standard CSV " + 14: "library. It's FasterCSV plus support for " + 15: "Ruby 1.9's m17n encoding engine." 16: end
This method allows you to serialize an Array of Ruby objects to a String or File of CSV data. This is not as powerful as Marshal or YAML, but perhaps useful for spreadsheet and database interaction.
Out of the box, this method is intended to work with simple data objects or Structs. It will serialize a list of instance variables and/or Struct.members().
If you need need more complicated serialization, you can control the process by adding methods to the class to be serialized.
A class method csv_meta() is responsible for returning the first row of the document (as an Array). This row is considered to be a Hash of the form key_1,value_1,key_2,value_2,… FasterCSV::load() expects to find a class key with a value of the stringified class name and FasterCSV::dump() will create this, if you do not define this method. This method is only called on the first object of the Array.
The next method you can provide is an instance method called csv_headers(). This method is expected to return the second line of the document (again as an Array), which is to be used to give each column a header. By default, FasterCSV::load() will set an instance variable if the field header starts with an @ character or call send() passing the header as the method name and the field value as an argument. This method is only called on the first object of the Array.
Finally, you can provide an instance method called csv_dump(), which will be passed the headers. This should return an Array of fields that can be serialized for this object. This method is called once for every object in the Array.
The io parameter can be used to serialize to a File, and options can be anything FasterCSV::new() accepts.
# File lib/faster_csv.rb, line 943 943: def self.dump(ary_of_objs, io = "", options = Hash.new) 944: obj_template = ary_of_objs.first 945: 946: csv = FasterCSV.new(io, options) 947: 948: # write meta information 949: begin 950: csv << obj_template.class.csv_meta 951: rescue NoMethodError 952: csv << [:class, obj_template.class] 953: end 954: 955: # write headers 956: begin 957: headers = obj_template.csv_headers 958: rescue NoMethodError 959: headers = obj_template.instance_variables.sort 960: if obj_template.class.ancestors.find { |cls| cls.to_s =~ /\AStruct\b/ } 961: headers += obj_template.members.map { |mem| "#{mem}=" }.sort 962: end 963: end 964: csv << headers 965: 966: # serialize each object 967: ary_of_objs.each do |obj| 968: begin 969: csv << obj.csv_dump(headers) 970: rescue NoMethodError 971: csv << headers.map do |var| 972: if var[0] == @@ 973: obj.instance_variable_get(var) 974: else 975: obj[var[0..2]] 976: end 977: end 978: end 979: end 980: 981: if io.is_a? String 982: csv.string 983: else 984: csv.close 985: end 986: end
This method is a convenience for building Unix-like filters for CSV data. Each row is yielded to the provided block which can alter it as needed. After the block returns, the row is appended to output altered or not.
The input and output arguments can be anything FasterCSV::new() accepts (generally String or IO objects). If not given, they default to ARGF and $stdout.
The options parameter is also filtered down to FasterCSV::new() after some clever key parsing. Any key beginning with :in_ or :input_ will have that leading identifier stripped and will only be used in the options Hash for the input object. Keys starting with :out_ or :output_ affect only output. All other keys are assigned to both objects.
The :output_row_sep option defaults to $INPUT_RECORD_SEPARATOR ($/).
# File lib/faster_csv.rb, line 1012 1012: def self.filter(*args) 1013: # parse options for input, output, or both 1014: in_options, out_options = Hash.new, {:row_sep => $INPUT_RECORD_SEPARATOR} 1015: if args.last.is_a? Hash 1016: args.pop.each do |key, value| 1017: case key.to_s 1018: when /\Ain(?:put)?_(.+)\Z/ 1019: in_options[$1.to_sym] = value 1020: when /\Aout(?:put)?_(.+)\Z/ 1021: out_options[$1.to_sym] = value 1022: else 1023: in_options[key] = value 1024: out_options[key] = value 1025: end 1026: end 1027: end 1028: # build input and output wrappers 1029: input = FasterCSV.new(args.shift || ARGF, in_options) 1030: output = FasterCSV.new(args.shift || $stdout, out_options) 1031: 1032: # read, yield, write 1033: input.each do |row| 1034: yield row 1035: output << row 1036: end 1037: end
This method is intended as the primary interface for reading CSV files. You pass a path and any options you wish to set for the read. Each row of file will be passed to the provided block in turn.
The options parameter can be anything FasterCSV::new() understands.
# File lib/faster_csv.rb, line 1046 1046: def self.foreach(path, options = Hash.new, &block) 1047: open(path, "rb", options) do |csv| 1048: csv.each(&block) 1049: end 1050: end
This method wraps a String you provide, or an empty default String, in a FasterCSV object which is passed to the provided block. You can use the block to append CSV rows to the String and when the block exits, the final String will be returned.
Note that a passed String is modfied by this method. Call dup() before passing if you need a new String.
The options parameter can be anthing FasterCSV::new() understands.
# File lib/faster_csv.rb, line 1067 1067: def self.generate(*args) 1068: # add a default empty String, if none was given 1069: if args.first.is_a? String 1070: io = StringIO.new(args.shift) 1071: io.seek(0, IO::SEEK_END) 1072: args.unshift(io) 1073: else 1074: args.unshift("") 1075: end 1076: faster_csv = new(*args) # wrap 1077: yield faster_csv # yield for appending 1078: faster_csv.string # return final String 1079: end
This method is a shortcut for converting a single row (Array) into a CSV String.
The options parameter can be anthing FasterCSV::new() understands.
The :row_sep option defaults to $INPUT_RECORD_SEPARATOR ($/) when calling this method.
# File lib/faster_csv.rb, line 1090 1090: def self.generate_line(row, options = Hash.new) 1091: options = {:row_sep => $INPUT_RECORD_SEPARATOR}.merge(options) 1092: (new("", options) << row).string 1093: end
This method will return a FasterCSV instance, just like FasterCSV::new(), but the instance will be cached and returned for all future calls to this method for the same data object (tested by Object#object_id()) with the same options.
If a block is given, the instance is passed to the block and the return value becomes the return value of the block.
# File lib/faster_csv.rb, line 1104 1104: def self.instance(data = $stdout, options = Hash.new) 1105: # create a _signature_ for this method call, data object and options 1106: sig = [data.object_id] + 1107: options.values_at(*DEFAULT_OPTIONS.keys.sort_by { |sym| sym.to_s }) 1108: 1109: # fetch or create the instance for this signature 1110: @@instances ||= Hash.new 1111: instance = (@@instances[sig] ||= new(data, options)) 1112: 1113: if block_given? 1114: yield instance # run block, if given, returning result 1115: else 1116: instance # or return the instance 1117: end 1118: end
This method is the reading counterpart to FasterCSV::dump(). See that method for a detailed description of the process.
You can customize loading by adding a class method called csv_load() which will be passed a Hash of meta information, an Array of headers, and an Array of fields for the object the method is expected to return.
Remember that all fields will be Strings after this load. If you need something else, use options to setup converters or provide a custom csv_load() implementation.
# File lib/faster_csv.rb, line 1132 1132: def self.load(io_or_str, options = Hash.new) 1133: csv = FasterCSV.new(io_or_str, options) 1134: 1135: # load meta information 1136: meta = Hash[*csv.shift] 1137: cls = meta["class"].split("::").inject(Object) do |c, const| 1138: c.const_get(const) 1139: end 1140: 1141: # load headers 1142: headers = csv.shift 1143: 1144: # unserialize each object stored in the file 1145: results = csv.inject(Array.new) do |all, row| 1146: begin 1147: obj = cls.csv_load(meta, headers, row) 1148: rescue NoMethodError 1149: obj = cls.allocate 1150: headers.zip(row) do |name, value| 1151: if name[0] == @@ 1152: obj.instance_variable_set(name, value) 1153: else 1154: obj.send(name, value) 1155: end 1156: end 1157: end 1158: all << obj 1159: end 1160: 1161: csv.close unless io_or_str.is_a? String 1162: 1163: results 1164: end
# File lib/faster_csv.rb, line 18 18: def self.method_missing(*_) 19: const_missing 20: end
This constructor will wrap either a String or IO object passed in data for reading and/or writing. In addition to the FasterCSV instance methods, several IO methods are delegated. (See FasterCSV::open() for a complete list.) If you pass a String for data, you can later retrieve it (after writing to it, for example) with FasterCSV.string().
Note that a wrapped String will be positioned at the beginning (for reading). If you want it at the end (for writing), use FasterCSV::generate(). If you want any other positioning, pass a preset StringIO object instead.
You may set any reading and/or writing preferences in the options Hash. Available options are:
:col_sep | The String placed between each field. |
:row_sep | The String appended to the end of each row. This can be set to the special :auto setting, which requests that FasterCSV automatically discover this from the data. Auto-discovery reads ahead in the data looking for the next "r\n", "n", or "r" sequence. A sequence will be selected even if it occurs in a quoted field, assuming that you would have the same line endings there. If none of those sequences is found, or the stream is only available for output, the default $INPUT_RECORD_SEPARATOR ($/) is used. Obviously, discovery takes a little time. Set manually if speed is important. Also note that IO objects should be opened in binary mode on Windows if this feature will be used as the line-ending translation can cause problems with resetting the document position to where it was before the read ahead. |
:quote_char | The character used to quote fields. This has to be a single character String. This is useful for application that incorrectly use ' as the quote character instead of the correct ". FasterCSV will always consider a double sequence this character to be an escaped quote. |
:encoding | The encoding to use when parsing the file. Defaults to your $KCODE setting. Valid values: `n’ or `N’ for none, `e’ or `E’ for EUC, `s’ or `S’ for SJIS, and `u’ or `U’ for UTF-8 (see Regexp.new()). |
:field_size_limit | This is a maximum size FasterCSV will read ahead looking for the closing quote for a field. (In truth, it reads to the first line ending beyond this size.) If a quote cannot be found within the limit FasterCSV will raise a MalformedCSVError, assuming the data is faulty. You can use this limit to prevent what are effectively DoS attacks on the parser. However, this limit can cause a legitimate parse to fail and thus is set to nil, or off, by default. |
:converters | An Array of names from the Converters Hash and/or lambdas that handle custom conversion. A single converter doesn’t have to be in an Array. |
:unconverted_fields | If set to true, an unconverted_fields() method will be added to all returned rows (Array or FasterCSV::Row) that will return the fields as they were before convertion. Note that :headers supplied by Array or String were not fields of the document and thus will have an empty Array attached. |
:headers | If set to :first_row or true, the initial row of the CSV file will be treated as a row of headers. If set to an Array, the contents will be used as the headers. If set to a String, the String is run through a call of FasterCSV::parse_line() with the same :col_sep, :row_sep, and :quote_char as this instance to produce an Array of headers. This setting causes FasterCSV.shift() to return rows as FasterCSV::Row objects instead of Arrays and FasterCSV.read() to return FasterCSV::Table objects instead of an Array of Arrays. |
:return_headers | When false, header rows are silently swallowed. If set to true, header rows are returned in a FasterCSV::Row object with identical headers and fields (save that the fields do not go through the converters). |
:write_headers | When true and :headers is set, a header row will be added to the output. Note that if the table only contains header rows, :return_headers must also be set in order for a header row to be output. |
:header_converters | Identical in functionality to :converters save that the conversions are only made to header rows. |
:skip_blanks | When set to a true value, FasterCSV will skip over any rows with no content. |
:force_quotes | When set to a true value, FasterCSV will quote all CSV fields it creates. |
See FasterCSV::DEFAULT_OPTIONS for the default settings.
Options cannot be overriden in the instance methods for performance reasons, so be sure to set what you want here.
# File lib/faster_csv.rb, line 1423 1423: def initialize(data, options = Hash.new) 1424: # build the options for this read/write 1425: options = DEFAULT_OPTIONS.merge(options) 1426: 1427: # create the IO object we will read from 1428: @io = if data.is_a? String then StringIO.new(data) else data end 1429: 1430: init_separators(options) 1431: init_parsers(options) 1432: init_converters(options) 1433: init_headers(options) 1434: 1435: unless options.empty? 1436: raise ArgumentError, "Unknown options: #{options.keys.join(', ')}." 1437: end 1438: 1439: # track our own lineno since IO gets confused about line-ends is CSV fields 1440: @lineno = 0 1441: end
This method opens an IO object, and wraps that with FasterCSV. This is intended as the primary interface for writing a CSV file.
You may pass any args Ruby’s open() understands followed by an optional Hash containing any options FasterCSV::new() understands.
This method works like Ruby’s open() call, in that it will pass a FasterCSV object to a provided block and close it when the block termminates, or it will return the FasterCSV object when no block is provided. (Note: This is different from the standard CSV library which passes rows to the block. Use FasterCSV::foreach() for that behavior.)
An opened FasterCSV object will delegate to many IO methods, for convenience. You may call:
binmode()
close()
close_read()
close_write()
closed?()
eof()
eof?()
fcntl()
fileno()
flush()
fsync()
ioctl()
isatty()
pid()
pos()
reopen()
seek()
stat()
sync()
sync=()
tell()
to_i()
to_io()
tty?()
# File lib/faster_csv.rb, line 1211 1211: def self.open(*args) 1212: # find the +options+ Hash 1213: options = if args.last.is_a? Hash then args.pop else Hash.new end 1214: # default to a binary open mode 1215: args << "rb" if args.size == 1 1216: # wrap a File opened with the remaining +args+ 1217: csv = new(File.open(*args), options) 1218: 1219: # handle blocks like Ruby's open(), not like the CSV library 1220: if block_given? 1221: begin 1222: yield csv 1223: ensure 1224: csv.close 1225: end 1226: else 1227: csv 1228: end 1229: end
This method can be used to easily parse CSV out of a String. You may either provide a block which will be called with each row of the String in turn, or just use the returned Array of Arrays (when no block is given).
You pass your str to read from, and an optional options Hash containing anything FasterCSV::new() understands.
# File lib/faster_csv.rb, line 1243 1243: def self.parse(*args, &block) 1244: csv = new(*args) 1245: if block.nil? # slurp contents, if no block is given 1246: begin 1247: csv.read 1248: ensure 1249: csv.close 1250: end 1251: else # or pass each row to a provided block 1252: csv.each(&block) 1253: end 1254: end
This method is a shortcut for converting a single line of a CSV String into a into an Array. Note that if line contains multiple rows, anything beyond the first row is ignored.
The options parameter can be anything FasterCSV::new() understands.
# File lib/faster_csv.rb, line 1263 1263: def self.parse_line(line, options = Hash.new) 1264: new(line, options).shift 1265: end
Use to slurp a CSV file into an Array of Arrays. Pass the path to the file and any options FasterCSV::new() understands.
# File lib/faster_csv.rb, line 1271 1271: def self.read(path, options = Hash.new) 1272: open(path, "rb", options) { |csv| csv.read } 1273: end
Alias for FasterCSV::read().
# File lib/faster_csv.rb, line 1276 1276: def self.readlines(*args) 1277: read(*args) 1278: end
A shortcut for:
FasterCSV.read( path, { :headers => true, :converters => :numeric, :header_converters => :symbol }.merge(options) )
# File lib/faster_csv.rb, line 1287 1287: def self.table(path, options = Hash.new) 1288: read( path, { :headers => true, 1289: :converters => :numeric, 1290: :header_converters => :symbol }.merge(options) ) 1291: end
The primary write method for wrapped Strings and IOs, row (an Array or FasterCSV::Row) is converted to CSV and appended to the data source. When a FasterCSV::Row is passed, only the row’s fields() are appended to the output.
The data source must be open for writing.
# File lib/faster_csv.rb, line 1475 1475: def <<(row) 1476: # make sure headers have been assigned 1477: if header_row? and [Array, String].include? @use_headers.class 1478: parse_headers # won't read data for Array or String 1479: self << @headers if @write_headers 1480: end 1481: 1482: # Handle FasterCSV::Row objects and Hashes 1483: row = case row 1484: when self.class::Row then row.fields 1485: when Hash then @headers.map { |header| row[header] } 1486: else row 1487: end 1488: 1489: @headers = row if header_row? 1490: @lineno += 1 1491: 1492: @io << row.map(&@quote).join(@col_sep) + @row_sep # quote and separate 1493: 1494: self # for chaining 1495: end
You can use this method to install a FasterCSV::Converters built-in, or provide a block that handles a custom conversion.
If you provide a block that takes one argument, it will be passed the field and is expected to return the converted value or the field itself. If your block takes two arguments, it will also be passed a FieldInfo Struct, containing details about the field. Again, the block should return a converted field or the field itself.
# File lib/faster_csv.rb, line 1514 1514: def convert(name = nil, &converter) 1515: add_converter(:converters, self.class::Converters, name, &converter) 1516: end
Yields each row of the data source in turn.
Support for Enumerable.
The data source must be open for reading.
# File lib/faster_csv.rb, line 1545 1545: def each 1546: while row = shift 1547: yield row 1548: end 1549: end
Identical to FasterCSV.convert(), but for header rows.
Note that this method must be called before header rows are read to have any effect.
# File lib/faster_csv.rb, line 1529 1529: def header_convert(name = nil, &converter) 1530: add_converter( :header_converters, 1531: self.class::HeaderConverters, 1532: name, 1533: &converter ) 1534: end
Returns true if the next row read will be a header row.
# File lib/faster_csv.rb, line 1567 1567: def header_row? 1568: @use_headers and @headers.nil? 1569: end
Returns a simplified description of the key FasterCSV attributes.
# File lib/faster_csv.rb, line 1696 1696: def inspect 1697: str = "<##{self.class} io_type:" 1698: # show type of wrapped IO 1699: if @io == $stdout then str << "$stdout" 1700: elsif @io == $stdin then str << "$stdin" 1701: elsif @io == $stderr then str << "$stderr" 1702: else str << @io.class.to_s 1703: end 1704: # show IO.path(), if available 1705: if @io.respond_to?(:path) and (p = @io.path) 1706: str << " io_path:#{p.inspect}" 1707: end 1708: # show other attributes 1709: ] lineno col_sep row_sep 1710: quote_char skip_blanks encoding ].each do |attr_name| 1711: if a = instance_variable_get("@#{attr_name}") 1712: str << " #{attr_name}:#{a.inspect}" 1713: end 1714: end 1715: if @use_headers 1716: str << " headers:#{(@headers || true).inspect}" 1717: end 1718: str << ">" 1719: end
# File lib/faster_csv.rb, line 22 22: def method_missing(*_) 23: self.class.const_missing 24: end
Slurps the remaining rows and returns an Array of Arrays.
The data source must be open for reading.
# File lib/faster_csv.rb, line 1556 1556: def read 1557: rows = to_a 1558: if @use_headers 1559: Table.new(rows) 1560: else 1561: rows 1562: end 1563: end
Rewinds the underlying IO object and resets FasterCSV’s lineno() counter.
# File lib/faster_csv.rb, line 1458 1458: def rewind 1459: @headers = nil 1460: @lineno = 0 1461: 1462: @io.rewind 1463: end
The primary read method for wrapped Strings and IOs, a single row is pulled from the data source, parsed and returned as an Array of fields (if header rows are not used) or a FasterCSV::Row (when header rows are used).
The data source must be open for reading.
# File lib/faster_csv.rb, line 1578 1578: def shift 1579: ######################################################################### 1580: ### This method is purposefully kept a bit long as simple conditional ### 1581: ### checks are faster than numerous (expensive) method calls. ### 1582: ######################################################################### 1583: 1584: # handle headers not based on document content 1585: if header_row? and @return_headers and 1586: [Array, String].include? @use_headers.class 1587: if @unconverted_fields 1588: return add_unconverted_fields(parse_headers, Array.new) 1589: else 1590: return parse_headers 1591: end 1592: end 1593: 1594: # begin with a blank line, so we can always add to it 1595: line = String.new 1596: 1597: # 1598: # it can take multiple calls to <tt>@io.gets()</tt> to get a full line, 1599: # because of \r and/or \n characters embedded in quoted fields 1600: # 1601: loop do 1602: # add another read to the line 1603: if read_line = @io.gets(@row_sep) 1604: line += read_line 1605: else 1606: return nil 1607: end 1608: # copy the line so we can chop it up in parsing 1609: parse = line.dup 1610: parse.sub!(@parsers[:line_end], "") 1611: 1612: # 1613: # I believe a blank line should be an <tt>Array.new</tt>, not 1614: # CSV's <tt>[nil]</tt> 1615: # 1616: if parse.empty? 1617: @lineno += 1 1618: if @skip_blanks 1619: line = "" 1620: next 1621: elsif @unconverted_fields 1622: return add_unconverted_fields(Array.new, Array.new) 1623: elsif @use_headers 1624: return FasterCSV::Row.new(Array.new, Array.new) 1625: else 1626: return Array.new 1627: end 1628: end 1629: 1630: # parse the fields with a mix of String#split and regular expressions 1631: csv = Array.new 1632: current_field = String.new 1633: field_quotes = 0 1634: parse.split(@col_sep, 1).each do |match| 1635: if current_field.empty? && match.count(@quote_and_newlines).zero? 1636: csv << (match.empty? ? nil : match) 1637: elsif (current_field.empty? ? match[0] : current_field[0]) == 1638: @quote_char[0] 1639: current_field << match 1640: field_quotes += match.count(@quote_char) 1641: if field_quotes % 2 == 0 1642: in_quotes = current_field[@parsers[:quoted_field], 1] 1643: if !in_quotes || in_quotes[@parsers[:stray_quote]] 1644: raise MalformedCSVError, 1645: "Missing or stray quote in line #{lineno + 1}" 1646: end 1647: current_field = in_quotes 1648: current_field.gsub!(@quote_char * 2, @quote_char) # unescape contents 1649: csv << current_field 1650: current_field = String.new 1651: field_quotes = 0 1652: else # we found a quoted field that spans multiple lines 1653: current_field << @col_sep 1654: end 1655: elsif match.count("\r\n").zero? 1656: raise MalformedCSVError, "Illegal quoting in line #{lineno + 1}." 1657: else 1658: raise MalformedCSVError, "Unquoted fields do not allow " + 1659: "\\r or \\n (line #{lineno + 1})." 1660: end 1661: end 1662: 1663: # if parse is empty?(), we found all the fields on the line... 1664: if field_quotes % 2 == 0 1665: @lineno += 1 1666: 1667: # save fields unconverted fields, if needed... 1668: unconverted = csv.dup if @unconverted_fields 1669: 1670: # convert fields, if needed... 1671: csv = convert_fields(csv) unless @use_headers or @converters.empty? 1672: # parse out header rows and handle FasterCSV::Row conversions... 1673: csv = parse_headers(csv) if @use_headers 1674: 1675: # inject unconverted fields and accessor, if requested... 1676: if @unconverted_fields and not csv.respond_to? :unconverted_fields 1677: add_unconverted_fields(csv, unconverted) 1678: end 1679: 1680: # return the results 1681: break csv 1682: end 1683: # if we're not empty?() but at eof?(), a quoted field wasn't closed... 1684: if @io.eof? 1685: raise MalformedCSVError, "Unclosed quoted field on line #{lineno + 1}." 1686: elsif @field_size_limit and current_field.size >= @field_size_limit 1687: raise MalformedCSVError, "Field size exceeded on line #{lineno + 1}." 1688: end 1689: # otherwise, we need to loop and pull some more data to complete the row 1690: end 1691: end
The actual work method for adding converters, used by both FasterCSV.convert() and FasterCSV.header_convert().
This method requires the var_name of the instance variable to place the converters in, the const Hash to lookup named converters in, and the normal parameters of the FasterCSV.convert() and FasterCSV.header_convert() methods.
# File lib/faster_csv.rb, line 1905 1905: def add_converter(var_name, const, name = nil, &converter) 1906: if name.nil? # custom converter 1907: instance_variable_get("@#{var_name}") << converter 1908: else # named converter 1909: combo = const[name] 1910: case combo 1911: when Array # combo converter 1912: combo.each do |converter_name| 1913: add_converter(var_name, const, converter_name) 1914: end 1915: else # individual named converter 1916: instance_variable_get("@#{var_name}") << combo 1917: end 1918: end 1919: end
Thiw methods injects an instance variable unconverted_fields into row and an accessor method for it called unconverted_fields(). The variable is set to the contents of fields.
# File lib/faster_csv.rb, line 1990 1990: def add_unconverted_fields(row, fields) 1991: class << row 1992: attr_reader :unconverted_fields 1993: end
Processes fields with @converters, or @header_converters if headers is passed as true, returning the converted field set. Any converter that changes the field into something other than a String halts the pipeline of conversion for that field. This is primarily an efficiency shortcut.
# File lib/faster_csv.rb, line 1928 1928: def convert_fields(fields, headers = false) 1929: # see if we are converting headers or fields 1930: converters = headers ? @header_converters : @converters 1931: 1932: fields.enum_for(:each_with_index).map do |field, index| # map_with_index 1933: converters.each do |converter| 1934: field = if converter.arity == 1 # straight field converter 1935: converter[field] 1936: else # FieldInfo converter 1937: header = @use_headers && !headers ? @headers[index] : nil 1938: converter[field, FieldInfo.new(index, lineno, header)] 1939: end 1940: break unless field.is_a? String # short-curcuit pipeline for speed 1941: end 1942: field # return final state of each field, converted or original 1943: end 1944: end
Loads any converters requested during construction.
If field_name is set :converters (the default) field converters are set. When field_name is :header_converters header converters are added instead.
The :unconverted_fields option is also actived for :converters calls, if requested.
# File lib/faster_csv.rb, line 1855 1855: def init_converters(options, field_name = :converters) 1856: if field_name == :converters 1857: @unconverted_fields = options.delete(:unconverted_fields) 1858: end 1859: 1860: instance_variable_set("@#{field_name}", Array.new) 1861: 1862: # find the correct method to add the coverters 1863: convert = method(field_name.to_s.sub(/ers\Z/, "")) 1864: 1865: # load converters 1866: unless options[field_name].nil? 1867: # allow a single converter not wrapped in an Array 1868: unless options[field_name].is_a? Array 1869: options[field_name] = [options[field_name]] 1870: end 1871: # load each converter... 1872: options[field_name].each do |converter| 1873: if converter.is_a? Proc # custom code block 1874: convert.call(&converter) 1875: else # by name 1876: convert.call(converter) 1877: end 1878: end 1879: end 1880: 1881: options.delete(field_name) 1882: end
Stores header row settings and loads header converters, if needed.
# File lib/faster_csv.rb, line 1885 1885: def init_headers(options) 1886: @use_headers = options.delete(:headers) 1887: @return_headers = options.delete(:return_headers) 1888: @write_headers = options.delete(:write_headers) 1889: 1890: # headers must be delayed until shift(), in case they need a row of content 1891: @headers = nil 1892: 1893: init_converters(options, :header_converters) 1894: end
Pre-compiles parsers and stores them by name for access during reads.
# File lib/faster_csv.rb, line 1820 1820: def init_parsers(options) 1821: # store the parser behaviors 1822: @skip_blanks = options.delete(:skip_blanks) 1823: @encoding = options.delete(:encoding) # nil will use $KCODE 1824: @field_size_limit = options.delete(:field_size_limit) 1825: 1826: # prebuild Regexps for faster parsing 1827: esc_col_sep = Regexp.escape(@col_sep) 1828: esc_row_sep = Regexp.escape(@row_sep) 1829: esc_quote = Regexp.escape(@quote_char) 1830: @parsers = { 1831: :any_field => Regexp.new( "[^#{esc_col_sep}]+", 1832: Regexp::MULTILINE, 1833: @encoding ), 1834: :quoted_field => Regexp.new( "^#{esc_quote}(.*)#{esc_quote}$", 1835: Regexp::MULTILINE, 1836: @encoding ), 1837: :stray_quote => Regexp.new( "[^#{esc_quote}]#{esc_quote}[^#{esc_quote}]", 1838: Regexp::MULTILINE, 1839: @encoding ), 1840: # safer than chomp!() 1841: :line_end => Regexp.new("#{esc_row_sep}\\z", nil, @encoding) 1842: } 1843: end
Stores the indicated separators for later use.
If auto-discovery was requested for @row_sep, this method will read ahead in the @io and try to find one. ARGF, STDIN, STDOUT, STDERR and any stream open for output only with a default @row_sep of $INPUT_RECORD_SEPARATOR ($/).
This method also establishes the quoting rules used for CSV output.
# File lib/faster_csv.rb, line 1733 1733: def init_separators(options) 1734: # store the selected separators 1735: @col_sep = options.delete(:col_sep) 1736: @row_sep = options.delete(:row_sep) 1737: @quote_char = options.delete(:quote_char) 1738: @quote_and_newlines = "\r\n#{@quote_char}" 1739: 1740: if @quote_char.length != 1 1741: raise ArgumentError, ":quote_char has to be a single character String" 1742: end 1743: 1744: # automatically discover row separator when requested 1745: if @row_sep == :auto 1746: begin 1747: # 1748: # remember where we were (pos() will raise an axception if @io is pipe 1749: # or not opened for reading) 1750: # 1751: saved_pos = @io.pos 1752: while @row_sep == :auto 1753: # 1754: # if we run out of data, it's probably a single line 1755: # (ensure will set default value) 1756: # 1757: break if @io.eof? 1758: 1759: # read ahead a bit 1760: sample = @io.read(1024) 1761: sample += @io.read(1) if sample[1..1] == "\r" and not @io.eof? 1762: 1763: # try to find a standard separator 1764: if sample =~ /\r\n?|\n/ 1765: @row_sep = $& 1766: break 1767: end 1768: end 1769: 1770: # tricky seek() clone to work around GzipReader's lack of seek() 1771: @io.rewind 1772: # reset back to the remembered position 1773: while saved_pos > 1024 # avoid loading a lot of data into memory 1774: @io.read(1024) 1775: saved_pos -= 1024 1776: end 1777: @io.read(saved_pos) if saved_pos.nonzero? 1778: rescue IOError # not opened for reading 1779: # do nothing: ensure will set default 1780: rescue NoMethodError # Zlib::GzipWriter doesn't have eof? 1781: # do nothing: ensure will set default 1782: rescue SystemCallError # pipe 1783: # do nothing: ensure will set default 1784: ensure 1785: # 1786: # set default if we failed to detect 1787: # (stream not opened for reading, a pipe, or a single line of data) 1788: # 1789: @row_sep = $INPUT_RECORD_SEPARATOR if @row_sep == :auto 1790: end 1791: end 1792: 1793: # establish quoting rules 1794: do_quote = lambda do |field| 1795: @quote_char + 1796: String(field).gsub(@quote_char, @quote_char * 2) + 1797: @quote_char 1798: end 1799: @quote = if options.delete(:force_quotes) 1800: do_quote 1801: else 1802: lambda do |field| 1803: if field.nil? # represent +nil+ fields as empty unquoted fields 1804: "" 1805: else 1806: field = String(field) # Stringify fields 1807: # represent empty fields as empty quoted fields 1808: if field.empty? or 1809: field.count("\r\n#{@col_sep}#{@quote_char}").nonzero? 1810: do_quote.call(field) 1811: else 1812: field # unquoted field 1813: end 1814: end 1815: end 1816: end 1817: end
This methods is used to turn a finished row into a FasterCSV::Row. Header rows are also dealt with here, either by returning a FasterCSV::Row with identical headers and fields (save that the fields do not go through the converters) or by reading past them to return a field row. Headers are also saved in @headers for use in future rows.
When nil, row is assumed to be a header row not based on an actual row of the stream.
# File lib/faster_csv.rb, line 1956 1956: def parse_headers(row = nil) 1957: if @headers.nil? # header row 1958: @headers = case @use_headers # save headers 1959: # Array of headers 1960: when Array then @use_headers 1961: # CSV header String 1962: when String 1963: self.class.parse_line( @use_headers, 1964: :col_sep => @col_sep, 1965: :row_sep => @row_sep, 1966: :quote_char => @quote_char ) 1967: # first row is headers 1968: else row 1969: end 1970: 1971: # prepare converted and unconverted copies 1972: row = @headers if row.nil? 1973: @headers = convert_fields(@headers, true) 1974: 1975: if @return_headers # return headers 1976: return FasterCSV::Row.new(@headers, row, true) 1977: elsif not [Array, String].include? @use_headers.class # skip to field row 1978: return shift 1979: end 1980: end 1981: 1982: FasterCSV::Row.new(@headers, convert_fields(row)) # field row 1983: end
Disabled; run with --debug to generate this.
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