LineIterator re-uses memory buffer
Moderators:
kris
Posted: 10/17/07 17:51:37
I noticed with LineIterator? that if you save copies of the lines they get corrupted while iterating through a stream. I don't know exactly where the problem is, but it seems to occur with large files. For example:
import tango.io.FileConduit; import tango.text.stream.LineIterator; import tango.io.Stdout; int main(char[][] args) { FileConduit fc = new FileConduit(args[1]); char[][] lines; foreach(line; new LineIterator!(char)(fc)) { lines ~= line; } foreach(char[] line; lines) { Stdout(line).newline; } return 0; }and if I use a large file with lots of lines, on my linux system, I'm using /lib/modules/<kernelversion>/modules.alias, the output is not the same as the input file. I'm not sure what size is the critical mass.
To "fix" this, you can use the .dup property like so:
lines ~= line.dup;So either this is by design, in which case there should be a documentation to this effect (i.e. "do not store the elements or slices of elements returned by the line iterator outside the foreach loop"), or this is a bug.
-Steve
