[ruby-core:51748] [ruby-trunk - Feature #7751] How to encapsulate File.delete and File.rename into one 'transaction'?

Issue #7751 has been updated by mghomn (Justin Peal).


What a great function! I've confirm it is true.

irb(main):001:0> File.write('src', '000')
=> 3
irb(main):002:0> File.write('dest', '1111')
=> 4
irb(main):003:0> File.rename('src', 'dest')
=> 0
irb(main):004:0> File.read('dest')
=> "000"

It is sorry that the doc of Ruby (Ruby19.chm) didn't describe it:

rename(old_name, new_name) 
Renames the given file to the new name. Raises a SystemCallError if the file cannot be renamed. 

   File.rename("afile", "afile.bak")   #=> 0

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Feature #7751: How to encapsulate File.delete and File.rename into one 'transaction'?
https://bugs.ruby-lang.org/issues/7751#change-35712

Author: mghomn (Justin Peal)
Status: Rejected
Priority: Normal
Assignee: 
Category: 
Target version: 


Following program has a line: File.delete(sql_file) and File.rename(tmp_file, sql_file)
It is not a 'transaction' which is I need. Has Ruby a feature to encapsulate File.delete and File.rename into one 'transaction'?
======
class String
  def camelize
    self.split('_').map {|w| w.capitalize }.join('_')
  end
end

class Busql
  WORD = /\A(\/\*.*?\*\/|'(?:[^']|'')*'|"(?:[^"]|"")*"|--.*?\n|\n|([$_]|\p{L})([$_]|\p{L}|\p{N})*|\p{M}+|\p{Z}+|\p{S}+|\p{N}+|\p{P}|\p{C}+)/m
  Oracle_Reserved_Words = /\A(ACCESS|ADD|ALL|ALTER|AND|ANY|ARRAYLEN|AS|ASC|AUDIT)\z/i
  Oracle_Keywords = /\A(ADMIN|AFTER|ALLOCATE|ANALYZE|ARCHIVE|ARCHIVELOG|AUTHORIZATION|AVG)\z/i
  PL_SQL_Reserved_Words = /\A(ABORT|ACCEPT|ACCESS|ADD|ALL|ALTER|AND|ANY|ARRAY|ARRAYLEN|AS|ASC|ASSERT|ASSIGN|AT|AUTHORIZATION|AVG)\z/i
  Data_Types = /\A(VARCHAR2|NVARCHAR2|NUMBER|FLOAT|LONG|DATE|BINARY_FLOAT|BINARY_DOUBLE|TIMESTAMP|INTERVAL|YEAR|DAY|RAW|ROWID|UROWID|CHAR|NCHAR|CLOB|NCLOB|BLOB|BFILE)\z/i
  Operators = /\A(PRIOR|CONNECT_BY_ROOT|UNION|ALL|INTERSECT|MINUS|MULTISET)\z/i
  Joins = /\A(NATURAL|LEFT|RIGHT|FULL|INNER|OUTER|CROSS|JOIN)\z/i
  SQL_Functions = /\A(ABS|ACOS|ADD_MONTHS|APPENDCHILDXML|ASCII|ASCIISTR|ASIN|ATAN|ATAN2|AVG)\z/i
  Pseudocolumns = /\A(CONNECT_BY_ISCYCLE|CONNECT_BY_ISLEAF|LEVEL|CURRVAL|NEXTVAL|VERSIONS_STARTSCN|VERSIONS_STARTTIME|VERSIONS_ENDSCN|VERSIONS_ENDTIME|VERSIONS_XID|VERSIONS_OPERATION|COLUMN_VALUE|OBJECT_ID|OBJECT_VALUE|ORA_ROWSCN|ROWID|ROWNUM|XMLDATA)\z/i
  NORMAL_WORDS = /\A([$_]|\p{L})/i

  def change_case text
    news = []
    shr_text = text.dup
    until shr_text.empty?
      case word = shr_text[WORD, 1]
          when Oracle_Reserved_Words, Oracle_Keywords, PL_SQL_Reserved_Words, Data_Types, Operators, Joins then word.upcase!()
          when SQL_Functions, Pseudocolumns then word = word.camelize()
          when NORMAL_WORDS then word.downcase!() if word.ascii_only?
      end
      news << word
      shr_text.slice!(0, word.size)
    end
    news.join
  end

  def change_sql sql_file
    text = File.read(sql_file, :mode => 'r:utf-8')
    new_text = change_case(text)
    if changed = (new_text != text)
      File.write(tmp_file = sql_file + '.t~m~p', new_text, :mode => 'wb')
      File.delete(sql_file) and File.rename(tmp_file, sql_file)
    end
    yield changed, text.size, new_text.size if block_given?
  end

  def beautify argv
    argv.each do |arg|
      Dir.glob(arg) do |sql_file|
        sql_file = sql_file.force_encoding(Encoding::GB18030).encode(Encoding::UTF_8)
        change_sql(sql_file) do |changed, old_len, new_len|
          yield sql_file, changed, old_len, new_len if block_given?
        end
      end
    end
  end
end

if $0 == __FILE__
  Busql.new.beautify(ARGV) do |sql_file, changed, old_len, new_len|
    str = changed ? " #{old_len} ==> #{new_len}" : ''
    print "#{sql_file}#{str}\n"
  end
end



-- 
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