類別 CSV::Parser::InputsScanner
CSV::InputsScanner 接收 IO
輸入、編碼和區塊大小。它也使用其方法 keep_start
、keep_end
、keep_back
、keep_drop
控制物件的生命週期。
CSV::InputsScanner.scan() 會嘗試與當前位置的樣式相符。如果相符,掃描器會前進「掃描指標」,並傳回相符的字串。否則,掃描器會傳回 nil。
CSV::InputsScanner.rest() 會傳回字串的「剩餘部分」(即掃描指標之後的所有內容)。如果沒有更多資料(eos? = true),它會傳回「」。
公開類別方法
new(inputs, encoding, row_separator, chunk_size: 8192) 按一下以切換來源
# File lib/csv/parser.rb, line 87 def initialize(inputs, encoding, row_separator, chunk_size: 8192) @inputs = inputs.dup @encoding = encoding @row_separator = row_separator @chunk_size = chunk_size @last_scanner = @inputs.empty? @keeps = [] read_chunk end
公開實例方法
check(pattern) 按一下以切換來源
# File lib/csv/parser.rb, line 248 def check(pattern) @scanner.check(pattern) end
each_line(row_separator) { |buffer| ... } 按一下以切換來源
# File lib/csv/parser.rb, line 97 def each_line(row_separator) return enum_for(__method__, row_separator) unless block_given? buffer = nil input = @scanner.rest position = @scanner.pos offset = 0 n_row_separator_chars = row_separator.size # trace(__method__, :start, input) while true input.each_line(row_separator) do |line| @scanner.pos += line.bytesize if buffer if n_row_separator_chars == 2 and buffer.end_with?(row_separator[0]) and line.start_with?(row_separator[1]) buffer << line[0] line = line[1..-1] position += buffer.bytesize + offset @scanner.pos = position offset = 0 yield(buffer) buffer = nil next if line.empty? else buffer << line line = buffer buffer = nil end end if line.end_with?(row_separator) position += line.bytesize + offset @scanner.pos = position offset = 0 yield(line) else buffer = line end end break unless read_chunk input = @scanner.rest position = @scanner.pos offset = -buffer.bytesize if buffer end yield(buffer) if buffer end
eos?() 按一下以切換來源
# File lib/csv/parser.rb, line 170 def eos? @scanner.eos? end
keep_back() 按一下以切換來源
# File lib/csv/parser.rb, line 197 def keep_back # trace(__method__, :start) scanner, start, buffer = @keeps.pop if buffer # trace(__method__, :rescan, start, buffer) string = @scanner.string if scanner == @scanner keep = string.byteslice(start, string.bytesize - @scanner.pos - start) else keep = string end if keep and not keep.empty? @inputs.unshift(StringIO.new(keep)) @last_scanner = false end @scanner = StringScanner.new(buffer) else if @scanner != scanner message = "scanners are different but no buffer: " message += "#{@scanner.inspect}(#{@scanner.object_id}): " message += "#{scanner.inspect}(#{scanner.object_id})" raise UnexpectedError, message end # trace(__method__, :repos, start, buffer) @scanner.pos = start end read_chunk if @scanner.eos? end
keep_drop() 按一下以切換來源
# File lib/csv/parser.rb, line 227 def keep_drop _, _, buffer = @keeps.pop # trace(__method__, :done, :empty) unless buffer return unless buffer last_keep = @keeps.last # trace(__method__, :done, :no_last_keep) unless last_keep return unless last_keep if last_keep[2] last_keep[2] << buffer else last_keep[2] = buffer end # trace(__method__, :done) end
keep_end() 按一下以切換來源
# File lib/csv/parser.rb, line 181 def keep_end # trace(__method__, :start) scanner, start, buffer = @keeps.pop if scanner == @scanner keep = @scanner.string.byteslice(start, @scanner.pos - start) else keep = @scanner.string.byteslice(0, @scanner.pos) end if buffer buffer << keep keep = buffer end # trace(__method__, :done, keep) keep end
keep_start() 按一下以切換來源
# File lib/csv/parser.rb, line 174 def keep_start # trace(__method__, :start) adjust_last_keep @keeps.push([@scanner, @scanner.pos, nil]) # trace(__method__, :done) end
rest() 按一下以切換來源
# File lib/csv/parser.rb, line 244 def rest @scanner.rest end
scan(pattern) 按一下以切換來源
# File lib/csv/parser.rb, line 143 def scan(pattern) # trace(__method__, pattern, :start) value = @scanner.scan(pattern) # trace(__method__, pattern, :done, :last, value) if @last_scanner return value if @last_scanner read_chunk if value and @scanner.eos? # trace(__method__, pattern, :done, value) value end
scan_all(pattern) 按一下以切換來源
# File lib/csv/parser.rb, line 154 def scan_all(pattern) # trace(__method__, pattern, :start) value = @scanner.scan(pattern) # trace(__method__, pattern, :done, :last, value) if @last_scanner return value if @last_scanner # trace(__method__, pattern, :done, :nil) if value.nil? return nil if value.nil? while @scanner.eos? and read_chunk and (sub_value = @scanner.scan(pattern)) # trace(__method__, pattern, :sub, sub_value) value << sub_value end # trace(__method__, pattern, :done, value) value end
私人實例方法
adjust_last_keep() 按一下以切換來源
# File lib/csv/parser.rb, line 257 def adjust_last_keep # trace(__method__, :start) keep = @keeps.last # trace(__method__, :done, :empty) if keep.nil? return if keep.nil? scanner, start, buffer = keep string = @scanner.string if @scanner != scanner start = 0 end if start == 0 and @scanner.eos? keep_data = string else keep_data = string.byteslice(start, @scanner.pos - start) end if keep_data if buffer buffer << keep_data else keep[2] = keep_data.dup end end # trace(__method__, :done) end
read_chunk() 按一下以切換來源
# File lib/csv/parser.rb, line 285 def read_chunk return false if @last_scanner adjust_last_keep input = @inputs.first case input when StringIO string = input.read raise InvalidEncoding unless string.valid_encoding? # trace(__method__, :stringio, string) @scanner = StringScanner.new(string) @inputs.shift @last_scanner = @inputs.empty? true else chunk = input.gets(@row_separator, @chunk_size) if chunk raise InvalidEncoding unless chunk.valid_encoding? # trace(__method__, :chunk, chunk) @scanner = StringScanner.new(chunk) if input.respond_to?(:eof?) and input.eof? @inputs.shift @last_scanner = @inputs.empty? end true else # trace(__method__, :no_chunk) @scanner = StringScanner.new("".encode(@encoding)) @inputs.shift @last_scanner = @inputs.empty? if @last_scanner false else read_chunk end end end end
trace(*args) 按一下以切換來源
# File lib/csv/parser.rb, line 253 def trace(*args) pp([*args, @scanner, @scanner&.string, @scanner&.pos, @keeps]) end