Method: PureCDB::Reader#initialize

Defined in:
lib/purecdb/reader.rb

#initialize(target, *options) ⇒ Reader

Open a CDB file for reading.

:call-seq:

r = PureCDB::Reader.new(file)
r = PureCDB::Reader.new(file, options)
PureCDB::Reader.new(file)  {|r| ... }
PureCDB::Reader.new(file, options) {|r| ... }

file can be a String or any object that meets the minimum requirements, which means having #sysseek, #sysopen to and #sysclose which does not arbitrarily sttop access ot it.

If Mmap is available, the code will attempt to use it if target is a filename



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# File 'lib/purecdb/reader.rb', line 29

def initialize target, *options
  if target.is_a?(String)
    @name = target
    @io = File.new(target,"rb")
    raise "Unable to open file #{target}" if !@io
  else
    set_stream(target)
  end
  
  @io.sysseek(-8,IO::SEEK_END)
  tail = @io.sysread(8)
  raise "Unable to read trailing 8 bytes for magic cookie" if tail.size != 8
  mode = tail == CDB64_MAGIC ? 64 : 32

  super *options
  if @mode == :detect
    set_mode(mode)
  elsif @mode != mode
    raise "#{mode}bit mode detected in file; options request #{@mode}bit mode"
  end

  @m = FFI::Mmap.new(target,"r", FFI::Mmap::MAP_SHARED) rescue nil
  read_hashes

  raise "Invalid File (Hashes are all empty)" if @hashes.uniq == [0]

  if block_given?
    yield(self)
    close
  else
  end
end