# Marshal.dump() taking a long time **URL:** \ **Category:** ruby-talk\ **Created:** [12 March 2003 12:28 UTC](https://rubytalk.org/t/marshal-dump-taking-a-long-time/5125 "2003-03-12T12:28:04Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Philip\_Mak1](https://avatars.discourse-cdn.com/v4/letter/p/3ab097/32.png) [@Philip\_Mak1](https://rubytalk.org/u/Philip_Mak1)\ **Post date:** [12 March 2003 12:28 UTC](https://rubytalk.org/t/marshal-dump-taking-a-long-time/5125/1 "2003-03-12T12:28:04Z")
I have a program that parses a text file into a list of objects, then tries to write it out using Marshal.dump(). But, it’s taking a ridiculous amount of time. This is how I’m using Marshal.dump: STDERR.puts "Successfully parsed #{line\_num} entries. Saving…" print Marshal.dump(dict) STDERR.puts “Saved.” And this is what happens: $ ./edict.rb \< edict \> edict.dat Parsing dictionary entries… Successfully parsed 103527 entries. Saving… (it just sits here forever) The text file itself consists of 103527 lines, and it took less than 10 seconds before it said “Successfully parsed”. But I waited several minutes, and the Marshal.dump() still didn’t complete. The object being dumped is a list of 103527 objects, each containing two strings, and a short list of strings. This object is generated from a 5 MB data file. It runs fine if I feed it only a 1000-line sample of the actual data file. Does anyone have suggestions on how to make Marshal.dump() work faster? I wanted to be able to load the parsed representation of the file quickly whenever the program starts, rather than having to parse a text file every time… ---
**Author:** ![NAKAMURA\_Hiroshi1](https://avatars.discourse-cdn.com/v4/letter/n/fbc32d/32.png) [@NAKAMURA\_Hiroshi1](https://rubytalk.org/u/NAKAMURA_Hiroshi1)\ **Post date:** [12 March 2003 12:33 UTC](https://rubytalk.org/t/marshal-dump-taking-a-long-time/5125/2 "2003-03-12T12:33:34Z")
Hi, Philip, > From: Philip Mak [[mailto:pmak@aaanime.net](mailto:pmak@aaanime.net)] > Sent: Wednesday, March 12, 2003 9:28 PM > STDERR.puts “Successfully parsed #{line\_num} entries. Saving…” > print Marshal.dump(dict) Try anIO = STDOUT Marshal.dump(dict, anIO) > STDERR.puts “Saved.” String concatination while serialization might be the bottleneck. Regards, // NaHi ---
**Author:** ![Philip\_Mak1](https://avatars.discourse-cdn.com/v4/letter/p/3ab097/32.png) [@Philip\_Mak1](https://rubytalk.org/u/Philip_Mak1)\ **Post date:** [12 March 2003 13:06 UTC](https://rubytalk.org/t/marshal-dump-taking-a-long-time/5125/3 "2003-03-12T13:06:29Z")
Thanks for the suggestion! I changed: ``` print Marshal.dump(dict) ``` to: ``` Marshal.dump(dict, STDOUT) ``` and it runs fine now. Interesting thing I noticed before when I was doing it the slow way - 1000 entries took 1 second, but 2000 entries took 7.7 seconds. So the time required seemed to scale up exponentially. ---
**Author:** ![Matt\_Armstrong](https://avatars.discourse-cdn.com/v4/letter/m/41988e/32.png) [@Matt\_Armstrong](https://rubytalk.org/u/Matt_Armstrong)\ **Post date:** [12 March 2003 15:44 UTC](https://rubytalk.org/t/marshal-dump-taking-a-long-time/5125/4 "2003-03-12T15:44:40Z")
Philip Mak [pmak@aaanime.net](mailto:pmak@aaanime.net) writes: > Thanks for the suggestion! I changed: > > print Marshal.dump(dict) > > to: > > Marshal.dump(dict, STDOUT) > > and it runs fine now. > > Interesting thing I noticed before when I was doing it the slow way - > 1000 entries took 1 second, but 2000 entries took 7.7 seconds. So the > time required seemed to scale up exponentially. What version of ruby are you using? String concatenation is much faster under ruby 1.8. > **···** > > – > matt