Feature #15151: String#slice!(0,..) creates a duplicate of original string

• Status: Open
• Assignee: -
• Target version: -

[chopraanmol1 (Anmol Chopra)]

String#slice! when used at beginning of string (e.g. slice!(0,10)) calls rb_str_drop_bytes which creates shared string for non embedded string. str_modify_keep_cr clears the flag of shared string which is called before rb_str_drop_bytes. Due to which while calling slice! multiple time on same string creates multiple duplicate string.

Patch:

https://github.com/ruby/ruby/pull/1961

Comparison:
trunk:

Total allocated: 141116188 bytes (11250 objects)

  0.048000   0.000000   0.048000 (  0.045974)

patch:

Total allocated: 300080 bytes (7502 objects)

  0.016000   0.004000   0.020000 (  0.017376)

[chopraanmol1 (Anmol Chopra)]

• Description updated (diff)

[chopraanmol1 (Anmol Chopra)]

• Description updated (diff)

[chopraanmol1 (Anmol Chopra)]

• File bench_slice_bang.rb bench_slice_bang.rb added
• File deleted (bench_slice_bang.rb)

[chopraanmol1 (Anmol Chopra)]

@nobu (Nobuyoshi Nakada) can you look into this? Thank you.

[chopraanmol1 (Anmol Chopra)]

ping @nobu (Nobuyoshi Nakada)

[jeremyevans0 (Jeremy Evans)]

• Tracker changed from Bug to Feature
• ruby -v deleted (ruby 2.6.0dev (2018-09-23 trunk 64815) [x86_64-linux])
• Backport deleted (2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN)